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  • CLASSES

    Thiazolidinediones/Glitazone and Other Oral Antidiabetic Combinations

    DEA CLASS

    Rx

    DESCRIPTION

    Oral combination of metformin, a biguanide, and pioglitazone, a thiazolidinedione, for type 2 DM; rare but serious risk of lactic acidosis.

    COMMON BRAND NAMES

    Actoplus Met, Actoplus Met XR

    HOW SUPPLIED

    Actoplus Met XR Oral Tab ER: 15-1000mg, 30-1000mg
    Actoplus Met/Pioglitazone Hydrochloride, Metformin Hydrochloride/Pioglitazone, Metformin Hydrochloride Oral Tab: 15-500mg, 15-850mg

    DOSAGE & INDICATIONS

    For the treatment of type 2 diabetes mellitus in combination with diet and exercise and when treatment with both metformin and pioglitazone is appropriate.
    NOTE: Metformin; pioglitazone is not for use in patients with type 1 diabetes or diabetic ketoacidosis.
    NOTE: When metformin; pioglitazone is used in combination with insulin or an insulin secretagogue, a lower dose of the insulin or insulin secretagogue may be needed in order to reduce the risk of hypoglycemia. In patients taking insulin and metformin; pioglitazone who experience hypoglycemia, reduce the dose of insulin by 10 to 25%. Individualize any further adjustments based on glycemic response.
    NOTE: When adding pioglitazone to metformin in patients with or without symptomatic heart disease and diabetes, monitor closely for signs of weight gain, peripheral edema, or congestive heart failure. In general, pioglitazone should be initiated at the lowest dose and increased gradually after at least three months of therapy. The risk of these symptoms is increased when higher doses of pioglitazone are used in combination with insulin in patients at risk of congestive heart failure. Pioglitazone should not be used in patients with New York Heart Association Class III or IV heart failure; metformin should not be used in patients with congestive heart failure requiring pharmacological therapy. Metformin; pioglitazone should be discontinued if any deterioration in cardiac status occurs during therapy.
    NOTE: Liver function tests (serum alanine and aspartate aminotransferases, alkaline phosphatase, and total bilirubin) should be obtained prior to initiating metformin; pioglitazone (see Contraindications/Precautions).
    For use when initial treatment with metformin alone or pioglitazone alone does not result in adequate glycemic control.
    Oral dosage (regular-release tablets)
    Adults

    The usual starting dose is 15 mg pioglitazone/ 500 mg metformin twice daily or 15 mg pioglitazone/ 850 mg metformin once daily with meals; gradually titrate after assessing adequacy of therapeutic response. The maximum recommended dose for pioglitazone is 45 mg/day and for metformin is 2550 mg/day (i.e., 3 tablets per day of Actoplus Met in any combination). Metformin doses greater than 2000 mg may be better tolerated given 3 times per day.

    Geriatric, or malnourished or debilitated Adults

    See adult dose. Avoid if greater than or equal to 80 years unless normal renal function is documented. In general, do not titrate to the maximum dose.

    Oral dosage (extended-release tablets)
    Adults

    The usual starting dose is 15 mg pioglitazone/ 1000 mg metformin or 30 mg pioglitazone/ 1000 mg metformin once daily with an evening meal; gradually titrate after assessing adequacy of therapeutic response. Unless there is a deterioration in glycemic control as indicated by the fasting plasma glucose, ideally, dose increases should occur only after time to evaluate a change in HbA1c has passed (i.e., every 8 to 12 weeks). The maximum recommended dose for pioglitazone is 45 mg/day and for metformin is 2000 mg/day.

    Geriatric, or malnourished or debilitated Adults

    See adult dose. Avoid if greater than or equal to 80 years unless normal renal function is documented. In general, do not titrate to the maximum dose.

    For use when switching from pioglitazone plus metformin as separate tablets to the single, combination tablet.
    Oral dosage(regular-release tablets)
    Adults

    The usual starting dose of Actoplus Met is the dose of pioglitazone and metformin already being taken. Gradually titrate after assessing adequacy of therapeutic response. The maximum recommended dose for pioglitazone is 45 mg/day and for metformin is 2550 mg/day (i.e., 3 tablets/day of Actoplus Met in any combination). Metformin doses greater than 2000 mg may be better tolerated given 3 times per day.

    Geriatric, or malnourished or debilitated Adults

    See adult dose. Avoid if greater than or equal to 80 years unless normal renal function is documented. In general, do not titrate to the maximum dose.

    Oral dosage (extended-release tablets)
    Adults

    The usual starting dose of Actoplus Met XR is the dose of pioglitazone and metformin already being taken. Gradually titrate after assessing adequacy of therapeutic response. The maximum recommended dose for pioglitazone is 45 mg/day and for metformin is 2000 mg/day.

    Geriatric, or malnourished or debilitated Adults

    See adult dose. Avoid if greater than or equal to 80 years unless normal renal function is documented. In general, do not titrate to the maximum dose.

    MAXIMUM DOSAGE

    Adults

    45 mg/day PO pioglitazone and 2550 mg/day PO metformin for regular-release tablets; 45 mg/day PO pioglitazone and 2000 mg/day PO metformin for extended-release tablets.

    Elderly

    In general do not titrate to the adult maximum dosage.

    Adolescents

    Safe and effective use has not been established.

    Children

    Safe and effective use has not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Metformin; pioglitazone should be avoided in patients with clinical or laboratory evidence of hepatic impairment. Hepatic impairment increases the risk of metformin-associated lactic acidosis.

    Renal Impairment

    eGFR more than 45 mL/minute/1.73 m2: No dosage adjustment needed. Obtain an eGFR at least annually in all patients taking metformin.
    eGFR 30 to 45 mL/minute/1.73 m2: Initiation of pioglitazone; metformin is not recommended. Obtain an eGFR at least annually in all patients taking pioglitazone; metformin. In patients whose eGFR is initially greater than 45 mL/minute/1.73 m2, and then later falls below 45 mL/minute/1.73 m2, assess the benefits and risks of continuing treatment. Discontinue pioglitazone; metformin if the patient’s eGFR later falls below 30 mL/minute/1.73 m2. The ADA and others suggest it is reasonable to decrease the dose by 50% (or use one-half the maximum recommended dose) and monitor renal function every 3 months in those with an eGFR less than 45 mL/minute/1.73 m2. Do not initiate the drug in patients at this stage. Additional caution is required in patients with anticipated significant fluctuations in renal status or those at risk for abrupt deterioration in kidney function, based on previous history, other comorbidities, albuminuria, and medication regimen (e.g., potent diuretics or nephrotoxic agents).
    eGFR less than 30 mL/minute/1.73 m2: Use is contraindicated.
     
    Intermittent hemodialysis
    Pioglitazone; metformin use is contraindicated. Metformin is dialyzable; hemodialysis will efficiently remove accumulated metformin in the case of drug-induced lactic acidosis, provided metformin administration is halted.

    ADMINISTRATION

    Oral Administration
    Oral Solid Formulations

    Regular-release tablets: Administer orally with meals.
    Extended-release tablets: Usually administered once-daily with the evening meal. Do not crush or chew; swallow whole. The inactive ingredients may occasionally be eliminated in the feces as a soft mass that may resemble the original tablet.

    STORAGE

    Actoplus Met:
    - Avoid excessive humidity
    - Protect from moisture
    - Store between 68 to 77 degrees F, excursions permitted 59 to 86 degrees F
    Actoplus Met XR :
    - Avoid excessive heat (above 104 degrees F)
    - Avoid excessive humidity
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    This monograph discusses the use of metformin; pioglitazone for the management of type 2 diabetes. Clinicians may wish to consult the individual drug monographs for more information.
     
    Do not use metformin; pioglitazone in patients who have a known metformin or pioglitazone hypersensitivity, or a known or suspected allergy to any of the inactive ingredients.

    Diabetic ketoacidosis, type 1 diabetes mellitus

    Metformin; pioglitazone use is contraindicated in patients with diabetic ketoacidosis (DKA), with or without coma; DKA should be treated with insulin. This combination is not intended for the treatment of type 1 diabetes mellitus. No efficacy or safety studies have been performed specifically with Actoplus Met for the treatment of type 2 diabetes mellitus. The combination of metformin and pioglitazone has been previously approved based on clinical trials in people with type 2 diabetes inadequately controlled on metformin alone. Patients undergoing changes in diabetic therapy should be monitored for fluctuations in glycemic control.

    Acidemia, acute myocardial infarction, cardiogenic shock, dehydration, hypoxemia, lactic acidosis, metabolic acidosis, sepsis

    Metformin; pioglitazone is contraindicated in patients with metabolic acidosis. Metformin is associated with an increased risk for lactic acidosis. Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia). Lactic acidosis is a rare, but serious complication that can occur due to metformin accumulation and is fatal in approximately 50% of cases. Lactic acidosis may also occur in association with a number of pathophysiologic conditions, including diabetes mellitus, and whenever there is significant tissue hypoperfusion and hypoxemia or significant renal dysfunction. Certain medications that are eliminated via the kidney when used concomitantly with metformin may also increase the risk of lactic acidosis. Acute congestive cardiac failure, cardiogenic shock, or acute myocardial infarction and other conditions characterized by acute hypoxia have been associated with the development of lactic acidosis and may cause prerenal azotemia. To reduce the risk of lactic acidosis, metformin; pioglitazone should be promptly withheld in the presence of any condition associated with hypoxemia, dehydration, or sepsis. Lactic acidosis is characterized by elevated blood lactate levels, acidemia, electrolyte disturbances, an increased anion gap, and an increased lactate/pyruvate ratio. When metformin is implicated as the cause of lactic acidosis, metformin plasma levels more than 5 mcg/mL are generally noted. The reported incidence of lactic acidosis in patients receiving metformin is very low (approximately 0.03 cases/1,000 patient-years). A nested case-control study of 50,048 patients with type 2 diabetes mellitus demonstrated that during concurrent use of oral diabetes drugs, there were 6 identified cases of lactic acidosis. The crude incidence rate was 3.3 cases per 100,000 person-years in patients treated with metformin; it should be noted that all of the subjects had relevant comorbidities known to be risk factors for lactic acidosis. The onset of lactic acidosis often is subtle, and accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, increasing somnolence, and nonspecific abdominal distress. There may be associated hypothermia, hypotension, and resistant bradycardia with more marked acidemia. The patient and the prescriber must be aware of such symptoms and the patient should be instructed to notify the physician immediately if they occur. Metformin should be withdrawn until the situation is clarified. Serum electrolytes, ketones, blood glucose, and, if indicated, blood pH, lactate levels, and even blood metformin levels may be useful.

    Diarrhea, vomiting

    Gastrointestinal side effects are common during metformin; pioglitazone initiation. However, once a patient is stabilized on any dose of metformin; pioglitazone, GI symptoms are unlikely to be drug related. Later occurrence of GI symptoms may be due to a change in clinical status and may increase the risk of lactic acidosis or may be due to lactic acidosis (from the metformin component), hepatic dysfunction (from the pioglitazone component), or other serious disease. Patients stable on metformin; pioglitazone therapy who complain of an increase in GI symptoms should undergo laboratory investigation to determine the etiology of the GI symptoms. These include, but are not limited to, diarrhea and nausea/vomiting. Furthermore, withholding metformin; pioglitazone therapy until the cause of the GI symptoms is known may be necessary. Finally, diarrhea and nausea/vomiting may alter gastric emptying and caloric intake, which could all affect blood glucose control, especially increasing the risk of low blood glucose. Patients should be advised to contact their prescriber if an increase in gastrointestinal symptoms occurs while taking metformin; pioglitazone; patients should also be advised to monitor their blood glucose concentrations more frequently.

    Renal disease, renal failure, renal impairment

    Pioglitazone; metformin is contraindicated for use in patients with renal failure or severe renal impairment, defined as estimated glomerular filtration rate (eGFR) below 30 mL/minute/1.73 m2. Metformin is substantially eliminated by the kidney and the risk of lactic acidosis increases with the degree of intrinsic renal disease or impairment. Initiating pioglitazone; metformin in patients with an eGFR between 30 to 45 mL/minute/1.73 m2 is not recommended. Before initiation of treatment and at least annually thereafter, obtain an eGFR to assess renal function. In those patients at increased risk for the development of renal impairment, such as the elderly, renal function should be assessed more frequently. In patients taking pioglitazone; metformin whose eGFR later falls below 45 mL/minute/1.73 m2, assess the benefits and risks of continuing treatment. Discontinue pioglitazone; metformin if the patient’s eGFR later falls below 30 mL/minute/1.73 m2. Based on the results of a comprehensive FDA safety review, the FDA concluded that metformin can be used safely in patients with mild renal impairment, and in some patients with moderate renal impairment. The measure of kidney function used to determine whether a patient can receive metformin has been changed from serum creatinine to the eGFR; this is because in addition to serum creatinine concentration, the eGFR takes into account additional parameters that are important, such as the patient’s age, gender, race and/or weight.

    Acute heart failure, cardiac disease, edema, heart failure, peripheral edema, pulmonary edema

    Metformin; pioglitazone is contraindicated in patients with pre-existing New York Heart Association (NYHA) Class III or IV heart failure and should be used with caution in any patient with cardiac disease. Acute decompensation in cardiac status (e.g., acute heart failure, cardiogenic shock, or acute myocardial infarction) characterized by hypoxia has been associated with the development of lactic acidosis in patients taking metformin. Thiazolidinediones (TZDs), including pioglitazone, when used alone or in combination with other antidiabetic agents, can cause or exacerbate congestive heart failure. Patients should be carefully observed for signs and symptoms of heart failure including excessive, rapid weight gain, dyspnea, and/or edema (peripheral edema, pulmonary edema) after drug initiation and changes in dose. If these signs and symptoms develop, the heart failure should be managed according to current standards of care, and clinicians must consider reducing the dose or discontinuing metformin; pioglitazone. Therapy should be discontinued if deterioration in cardiac status occurs. The incidence of heart failure associated with pioglitazone use is higher in those patients receiving concomitant insulin therapy, older adult patients (65 years of age and older), those receiving higher doses of pioglitazone, and those with risk factors for congestive heart failure. In addition, in postmarketing experience with pioglitazone, cases of congestive heart failure have been reported in patients both with and without previously known cardiac disease. When compared with glyburide during a postmarketing safety study, pioglitazone was associated with a higher incidence of overnight hospitalization for congestive heart failure (9.9% for pioglitazone vs. 4.7% for glyburide). Dose-related edema and weight gain have been reported in patients treated with pioglitazone therapy; caution is advised in patients with preexisting edema. An association between pioglitazone and myocardial infarction has not been demonstrated. In a study of patients with type 2 diabetes, the addition of pioglitazone to existing diabetes therapy did not result in increased all-cause mortality or total macrovascular events such as non-fatal myocardial infarction, stroke, acute coronary syndrome, cardiac intervention, major leg amputation, or leg revascularization (HR 0.90, 95% CI 0.80 to 1.02, p = 0.1). Dose-related edema and weight-gain has been reported in patients treated with pioglitazone therapy.

    Alcoholism, ethanol ingestion, ethanol intoxication, hepatic disease

    Metformin administration increases the risk for lactic acidosis. Since the liver is important for clearing accumulated lactic acid, metformin is not recommended in patients with clinical or laboratory evidence of hepatic disease as the risk of lactic acidosis may be increased. Hepatic disease also causes altered gluconeogenesis, which may affect glycemic control. Alcohol is known to potentiate the effect of metformin on lactate metabolism. Patients should be warned against excessive ethanol ingestion (ethanol intoxication) while taking pioglitazone; metformin due to the increased risk for lactic acidosis. Those with ethanol intoxication are also particularly susceptible to hypoglycemic effects of oral antidiabetic agents. Pioglitazone; metformin use should be avoided by those patients with alcoholism. Cautious use of pioglitazone is also needed for patients with hepatic disease. In all patients, obtain a liver test panel and assess the patient before pioglitazone initiation. Patients with type 2 diabetes may have fatty liver disease or cardiac disease with episodic congestive heart failure, both of which may cause liver test abnormalities, and they may also have other forms of liver disease, many of which can be treated or managed. Clinical trials with pioglitazone have generally excluded patients with serum ALT more than 2.5 times the upper limit of normal (ULN). Initiate therapy with caution in patients with abnormal liver function tests (LFTs). Measure liver tests promptly in patients who report symptoms that may indicate liver injury, including fatigue, anorexia, right upper abdominal discomfort, dark urine or jaundice. If the patient is found to have abnormal LFTs (i.e., ALT more than 3 times the ULN), interrupt treatment with pioglitazone and investigate the probable cause. Pioglitazone should not be restarted in these patients without another explanation for the liver test abnormalities. Do not restart pioglitazone in patients who have serum ALT more than 3 times the ULN with serum total bilirubin more than 2 times the ULN and do not have alternative etiologies. Pioglitazone may be used with caution in patients with lesser elevations of serum ALT or bilirubin and who have an alternate probable cause. There have been postmarketing reports of fatal and non-fatal hepatic failure in patients taking pioglitazone, although the reports contain insufficient information necessary to establish the probable cause. There has been no evidence of drug-induced hepatotoxicity in the pioglitazone controlled clinical trial database to date.

    Radiographic contrast administration

    Discontinue pioglitazone; metformin at the time of or before radiographic contrast administration in patients with an estimated glomerular filtration rate (eGFR) between 30 and 60 mL/minute/1.73 m2; in patients with a history of hepatic disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate the eGFR 48 hours after the imaging procedure; restart metformin if renal function is stable.

    Burns, fever, infection, surgery, trauma

    Metformin; pioglitazone therapy should be temporarily suspended for any surgery, except for minor procedures where intake of fluids and food is not restricted. Do not restart this drug until oral intake is resumed and renal function has been evaluated as normal. Temporary use of insulin in place of oral antidiabetic agents may be necessary during periods of physiologic stress (i.e., burns, systemic infection, trauma, surgery, or fever). Any change in clinical status, including substantial loss of fluids may also increase the risk of lactic acidosis and may require laboratory evaluation in patients on metformin; pioglitazone; the drug may need to be withheld. Prior to initiation or dose escalation of metformin; pioglitazone, secondary causes of poor glycemic control (i.e., infection) should be evaluated and treated.

    Adrenal insufficiency, gastroparesis, GI obstruction, hypercortisolism, hyperglycemia, hyperthyroidism, hypoglycemia, hypothyroidism, ileus, malnutrition, pituitary insufficiency

    Delayed stomach emptying may alter blood glucose control; carefully monitor patients taking metformin; pioglitazone who have diarrhea, gastroparesis, GI obstruction, ileus, or vomiting. Conditions that predispose patients to developing hypoglycemia or hyperglycemia may also alter antidiabetic agent efficacy. Conditions associated with hypoglycemia include insufficient caloric intake, strenuous exercise, debilitated physical condition, drug interactions (additional hypoglycemic agents), malnutrition, uncontrolled adrenal insufficiency, pituitary insufficiency, or hypothyroidism. Hypoglycemia may be difficult to recognize in geriatric patients and those taking beta-blockers. In addition, if hypoglycemia occurs when metformin; pioglitazone is used in combination with insulin or an insulin secretagogue (e.g., sulfonylurea), the dose of insulin or the insulin secretagogue should be reduced. Individualize any further adjustments based on glycemic response. Hyperglycemia-related conditions include drug interactions, female hormonal changes, elevated temperature, severe psychological stress, and uncontrolled hypercortisolism or hyperthyroidism. More frequent blood glucose monitoring may be necessary in patients with these conditions.

    Anemia, pernicious anemia

    Pioglitazone can cause about a 2% to 4% decrease in hemoglobin during the first 4 to 12 weeks of therapy; the drops in hemoglobin are rarely associated with significant clinical effects; however, this reduction may be significant in patients with pre-existing anemia. In addition, metformin may result in suboptimal vitamin B12 absorption, possibly due to interference with the B12-intrinsic factor complex. The interaction very rarely results in a pernicious anemia that appears reversible with discontinuation of metformin or with cyanocobalamin supplementation. Certain individuals may be predisposed to this type of anemia; a nested case-control study of 465 patients taking metformin (155 with vitamin B12 deficiency and 310 without) demonstrated that dose and duration of metformin use may be associated with an increased odds of vitamin B12 deficiency. Each 1 gram/day increment in dose significantly increased the odds of vitamin B12 deficiency (OR 2.88, 95% CI 2.15 to 3.87) as did taking metformin for 3 years or more (OR 2.39, 95% CI 1.46 to 3.91). Regular measurement of hematologic parameters are recommended in all patients on metformin; pioglitazone treatment.

    Bone fractures, osteoporosis

    Use pioglitazone; metformin with caution in female patients with osteoporosis or risk factors for osteopenia. In a randomized trial (PROactive) in patients with type 2 diabetes, an increased incidence of bone fractures was noted in female patients taking pioglitazone. During a mean follow-up of 34.5 months, the incidence of bone fracture in females was 5.1% for pioglitazone versus 2.5% for placebo. This difference was noted after the first year of treatment and remained during the course of the study. The majority of fractures observed in female patients were nonvertebral fractures including lower limb and distal upper limb. These sites of fracture are different from those usually associated with postmenopausal osteoporosis (e.g., hip or spine). No increase in fracture rates was observed in men treated with pioglitazone 1.7% vs. placebo 2.1%. The risk of fracture should be considered in the care of patients treated with metformin; pioglitazone, especially female patients, and attention given to assessing and maintaining bone health according to current standards of care.

    Contraception requirements, menstrual irregularity, polycystic ovary syndrome, pregnancy

    Premenopausal anovulatory females with insulin resistance, such as those with polycystic ovary syndrome (PCOS), may resume ovulation as a result of metformin; pioglitazone therapy; patients may be at risk of conception if adequate contraception is not used in those not desiring to become pregnant. Adequate contraception requirements have been recommended during pioglitazone therapy for women of childbearing potential. If unexpected menstrual irregularity occurs, the benefits of continued metformin; pioglitazone therapy should be reviewed. There is a lack of data describing the use of pioglitazone during human pregnancy. Limited data with metformin; pioglitazone in pregnant women are not sufficient to determine a drug-associated risk for major birth defects or miscarriage. Animal data suggest no teratogenic effects; however, embryotoxicities (increased post implantation losses, delayed development, reduced fetal weights, and delayed parturition) have been observed in rats receiving 10-times or above the maximum recommended human dose (MRHD) and rabbits receiving 40-times the MRHD of pioglitazone. There are data describing metformin for gestational diabetes as a single agent; however, published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk. Based on the results of a small study, it appears that metformin does pass through the placenta and the fetus is exposed to therapeutic concentrations of metformin. A study of 109 women with PCOS who were treated with metformin 1.5 to 2.55 grams/day at the time of conception and continued treatment throughout pregnancy found no difference in the development of preeclampsia and a lower rate of gestational diabetes when compared to a control group of pregnant women without PCOS. Among the 126 infants born to the women with PCOS, 2 birth defects occurred: one sacrococcygeal teratoma and one tethered spinal cord. Follow up to 18 months of age found no differences in height or weight in infants exposed to metformin compared to controls and no abnormalities in motor or social development. Other epidemiologic data suggest no increase in the rates of expected birth defects in women taking metformin who become pregnant. Metformin has been studied during the second and third trimesters of pregnancy; the neonatal mortality rate appeared lower in patients receiving metformin than in mildly diabetic controls, but slightly higher incidences of polycythemia and necrotizing enterocolitis were noted in the metformin group and the most frequently encountered infant problems were jaundice, polycythemia, and hypoglycemia. The American College of Obstetrician and Gynecologists recommends insulin as the therapy of choice to maintain blood glucose as close to normal as possible during pregnancy in patients with type 1 or 2 diabetes mellitus, and, if diet therapy alone is not successful, for those patients with gestational diabetes. More recent studies comparing metformin to insulin in the treatment of gestational diabetes found no significant differences in glycemic control or pregnancy outcomes. One study comparing metformin (n = 100) to insulin (n = 100) for the treatment of gestational diabetes found significantly lower weight gain during pregnancy and improved neonatal morbidity with respect to prematurity, neonatal jaundice, and admission to the neonatal unit in the metformin group.

    Breast-feeding

    The effects of metformin; pioglitazone on the nursing infant are unknown and therefore, the developmental and health benefits of breast-feeding should be considered along with the mother’s clinical need for metformin; pioglitazone and any potential adverse effects on the nursing infant from metformin; pioglitazone or from the underlying maternal condition. Animal data suggest that pioglitazone may be excreted in milk, however, it is unknown if pioglitazone or its metabolites are excreted in human milk. Animal data show that metformin is excreted into breast milk and reaches levels similar to those in plasma. Small studies indicate that metformin is excreted in human breast milk. However, adverse effects on infant plasma glucose have not been reported in human studies. Furthermore, the use of metformin 2,550 mg/day by mothers breast-feeding their infants for 6 months does not affect growth, motor, or social development; the effects beyond 6 months are not known. In all of these studies, the estimated weight-adjusted infant exposure to metformin ranged from 0.11% to 1.08% of the mother's dose. If blood glucose is not controlled on diet and exercise alone, insulin therapy should be considered; insulin is considered by experts to be compatible with breast-feeding. Other oral hypoglycemics may also be considered as possible alternatives in some patients. Because acarbose has limited systemic absorption, which results in minimal maternal plasma concentrations, clinically significant exposure via breast milk is not expected. Metformin monotherapy can also be a consideration. Tolbutamide is usually considered compatible with breast-feeding. Glyburide may be a suitable alternative since it was not detected in the breast milk of lactating women who received single and multiple doses of glyburide. If any oral hypoglycemics are used during breast-feeding, the nursing infant should be monitored for signs of hypoglycemia, such as increased fussiness or somnolence.

    Bladder cancer, secondary malignancy

    Metformin; pioglitazone should not be used in patients with active bladder cancer. In patients with a prior history of bladder cancer, the benefits of blood sugar control should be weighed against the unknown risks for cancer recurrence. In December 2016, the FDA concluded that use of pioglitazone may be linked to an increased risk of bladder cancer; this was based on an extensive evidence review. Patients currently taking metformin; pioglitazone are encouraged to report any symptoms of bladder cancer to their health care provider. Symptoms of bladder cancer include blood or red-colored urine (hematuria), new or worsening urge to urinate, and pain when urinating. Both patients and health care providers should report metformin; pioglitazone related adverse events to the FDA's MedWatch Safety Information and Adverse Events Reporting Program. In September 2010 and June 2011, the FDA warned about the possible risk of secondary malignancy, specifically bladder cancer, with pioglitazone based on interim results from a 10-year U.S. epidemiologic study and a French epidemiological study. Based on the results of the French study, France has suspended the use of pioglitazone and Germany has recommended not to start pioglitazone in new patients. The FDA has reviewed additional published studies evaluating the risk of bladder cancer in patients treated with pioglitazone, including the final 10-year results of the U.S. epidemiologic study. The results did not show an increased risk for bladder cancer in patients who used pioglitazone at some point (ever users) compared to patients who never used pioglitazone (never users), with a fully adjusted HR of 1.06 (95% CI 0.89 to 1.26). The investigators identified 1,075 newly diagnosed cases of bladder cancer in never users (n = 158,918) and 186 cases in ever users (n = 34,181). The study also suggested a modest trend towards higher risk with increasing duration of use, but this trend was not statistically significant; it could have been due to chance. Compared to the interim 5-year results, these final 10-year results found weaker associations that were not statistically significant. However, the directions of the associations remained unchanged. In addition, during the 3 year PROactive Study (PROspective pioglitAzone Clinical Trial In macroVascular Events), 14 patients out of 2,605 (0.54%) randomized to pioglitazone and 5 out of 2,633 (0.19%) randomized to placebo were diagnosed with bladder cancer. After excluding patients in whom exposure to study drug was less than 1 year at the time of diagnosis of bladder cancer, there were 6 (0.23%) cases receiving pioglitazone and 2 (0.08%) cases receiving placebo. In a 10-year observational follow-up of the PROactive Study, researchers investigated the occurrence of cardiovascular outcomes and malignancies after the PROactive clinical trial period ended. Among patients who entered the follow-up study, the median total follow-up (clinical trial and observational periods) was 12.8 years. Results revealed the imbalance in the number of bladder cancer cases observed in patients using pioglitazone during the clinical trial period (RR 2.83; 95% CI 1.02 to 7.85) did not persist during the combined 12.8-year period (HR 1; 95% CI 0.59 to 1.72). In contrast, in a retrospective cohort study that assessed the association between pioglitazone use and bladder cancer, statistically significant trends in the risk of bladder cancer were observed with increasing cumulative duration of use and cumulative dose of pioglitazone. The investigators used the United Kingdom Clinical Practice Research Datalink (CPRD) to identify a cohort of 145,806 patients newly treated with antidiabetic drugs (n = 10,951 initiators of pioglitazone) with a mean follow-up of 4.7 years, during which 622 patients received a diagnosis of bladder cancer. Of these, 54 developed bladder cancer after pioglitazone exposure. The fully adjusted HR for bladder cancer with pioglitazone use compared with no thiazolidinedione use was 1.63 (95% CI 1.22 to 2.19).

    Geriatric

    Use metformin; pioglitazone with caution in the geriatric patient, especially those patients with pre-existing cardiac or kidney disease, due to a risk for heart failure or lactic acidosis. Metformin is substantially excreted by the kidney and the risk of adverse reactions (including lactic acidosis) is greater in patients with reduced renal function. Because aging is associated with renal function decline, care should be taken with dose selection and titration. Obtain an estimated glomerular filtration rate (eGFR) at least annually in all patients taking pioglitazone; metformin. In patients at increased risk for the development of renal impairment such as geriatric patients, renal function should be assessed more frequently. Unless estimated renal function via the eGFR is determined to be normal, generally do not initiate metformin in geriatric patients 80 years of age and older. Generally, elderly or debilitated patients should not be titrated up to maximum metformin dosages. Geriatric, debilitated, or malnourished patients are also particularly susceptible to hypoglycemic effects of antidiabetic agents; monitor blood glucose frequently. Pioglitazone use is not recommended in geriatric patients with symptomatic or acute heart failure, and initiation in patients with established New York Heart Association (NYHA) Class III or IV heart failure is contraindicated. Observe geriatric patients receiving metformin; pioglitazone for signs and symptoms of heart failure, and if heart failure or other deterioration in cardiac status develops, discontinue the drug and monitor for diabetic control. The incidence of heart failure associated with pioglitazone use is higher in those patients receiving concomitant insulin therapy, older adult patients (65 years of age and older), those receiving higher doses of pioglitazone, and those with risk factors for congestive heart failure. In a nested case-control analysis of more than 150,000 geriatric adults with diabetes and receiving at least 1 oral hypoglycemic drug, the use of a thiazolidinedione (TZD) as monotherapy or in combination with other antidiabetic agents was associated with an increased rate of heart failure, myocardial infarction, and death; when analyzed separately, the authors found the risks for all 3 endpoints to be significantly increased for rosiglitazone and NOT pioglitazone, although there may have not been enough power to detect a difference in patients receiving pioglitazone. The median duration of follow-up was 3.8 years. Patients treated with TZD monotherapy were more likely to have a history of renal or cardiovascular disease at baseline. Similarly, in an observational study of 28,361 geriatric patients (65 years and older) with diabetes who initiated treatment with rosiglitazone or pioglitazone, the use of rosiglitazone was associated with a 15% greater mortality (95% CI 5% to 26%) and a 13% greater risk of congestive heart failure (95% CI 1% to 26%) compared with pioglitazone; there were no differences, however, in the rates of MI or stroke between the two drugs.] According to the Beers Criteria, pioglitazone is considered a potentially inappropriate medication (PIM) for use in geriatric patients with heart failure and should be avoided in this patient population due to the potential for fluid retention and exacerbation of the condition. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). According to OBRA, the use of antidiabetic medications should include monitoring (e.g., periodic blood glucose) for effectiveness based on desired goals for that individual and to identify complications of treatment such as hypoglycemia or impaired renal function. Pioglitazone has been associated with edema and weight gain and use should be avoided in LTCF residents with NYHA Stage III or Stage IV heart failure. Metformin has been associated with lactic acidosis, which is more likely to occur under the following conditions: serum creatinine of 1.5 mg/dL or higher in males or 1.4 mg/dL or higher in females, abnormal creatinine clearance from any cause, age of 80 years or older unless measurement of creatinine clearance verifies normal renal function, radiologic studies in which intravascular iodinated contrast materials are given, congestive heart failure requiring pharmacologic management, or acute/chronic metabolic acidosis with or without coma (including diabetic ketoacidosis).

    Children

    No data are available on the use of metformin; pioglitazone in children and adolescents under 18 years of age. Use of metformin; pioglitazone is not recommended in pediatric patients.

    ADVERSE REACTIONS

    Severe

    heart failure / Delayed / 1.1-5.7
    bone fractures / Delayed / 5.1-5.1
    megaloblastic anemia / Delayed / 0-1.0
    lactic acidosis / Delayed / 0-0.1
    hepatic encephalopathy / Delayed / Incidence not known
    hepatic failure / Delayed / Incidence not known
    visual impairment / Early / Incidence not known
    macular edema / Delayed / Incidence not known
    rhabdomyolysis / Delayed / Incidence not known

    Moderate

    peripheral edema / Delayed / 1.6-26.7
    hypoglycemia / Early / 0-8.5
    vitamin B12 deficiency / Delayed / 7.0-7.0
    edema / Delayed / 3.0-6.0
    fluid retention / Delayed / 3.0-6.0
    anemia / Delayed / 0-2.0
    elevated hepatic enzymes / Delayed / 0.3-0.3
    metabolic acidosis / Delayed / 0-0.1
    dyspnea / Early / Incidence not known
    jaundice / Delayed / Incidence not known
    cholestasis / Delayed / Incidence not known
    hepatitis / Delayed / Incidence not known
    hyperbilirubinemia / Delayed / Incidence not known
    blurred vision / Early / Incidence not known
    osteopenia / Delayed / Incidence not known
    secondary malignancy / Delayed / Incidence not known

    Mild

    infection / Delayed / 4.4-16.0
    weight gain / Delayed / 2.7-13.9
    metallic taste / Early / 1.0-10.0
    dysgeusia / Early / 1.0-10.0
    anorexia / Delayed / 1.0-10.0
    abdominal pain / Early / 1.0-10.0
    flatulence / Early / 1.0-10.0
    dyspepsia / Early / 1.0-10.0
    headache / Early / 4.6-6.0
    nausea / Early / 3.6-5.8
    diarrhea / Early / 4.8-5.8
    myalgia / Early / 1.0-5.4
    dizziness / Early / 4.8-5.4
    pharyngitis / Delayed / 5.1-5.1
    malaise / Early / 1.0-5.0
    sinusitis / Delayed / 4.4-5.0
    menstrual irregularity / Delayed / 0-0.4

    DRUG INTERACTIONS

    Abacavir; Dolutegravir; Lamivudine: (Major) Avoid concurrent use of dolutegravir with pioglitazone, as coadministration may result in decreased dolutegravir plasma concentrations. Pioglitazone is a weak inducer of CYP3A, dolutegravir is partially metabolized by this isoenzyme. (Major) Caution is advised when administering dolutegravir with metformin, as coadministration may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. If these drugs are used in combination, the total daily dose of metformin must not exceed 1000 mg/day. Close monitoring of blood glucose and patient clinical status is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin was administered at a dose of 500 mg PO twice daily. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]). (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abacavir; Lamivudine, 3TC: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abiraterone: (Moderate) Use abiraterone, a strong CYP2C8 inhibitor, and pioglitazone, a CYP2C8 substrate, together cautiously, as levels of pioglitazone may be increased. Monitor closely for signs of pioglitazone toxicity such as weight gain, edema, hypoglycemia, and signs of liver dysfunction. If a stong CYP2C8 inhibitor, such as abiraterone, is started or stopped during pioglitazone therapy, changes in diabetes treatment may be warranted based on clinical response.
    Acebutolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Acetaminophen; Dichloralphenazone; Isometheptene: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Acetaminophen; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Acetaminophen; Propoxyphene: (Moderate) Propoxyphene may enhance the hypoglycemic action of antidiabetic agents. Patients should be closely monitored for changes in glycemic control while receiving propoxyphene in combination with antidiabetic agents.
    Acetaminophen; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Acetazolamide: (Moderate) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction. Carbonic anhydrase inhibitors frequently decrease serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Use these drugs with caution in patients treated with metformin, as the risk of lactic acidosis may increase. Monitor electrolytes and renal function. (Minor) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Acrivastine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Adefovir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion (e.g., adefovir) may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Aliskiren; Amlodipine: (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Aliskiren; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Amlodipine: (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Amlodipine; Atorvastatin: (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased. (Minor) Concentrations of atorvastatin may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of atorvastatin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with atorvastatin 80 mg daily for 7 days resulted in a 14% and 23% reduction in atorvastatin AUC and Cmax, respectively. In addition, coadministration resulted in a 24% and 31% reduction in pioglitazone AUC and Cmax, respectively. Patients should be evaluated more frequently with respect to glycemic control and lipid therapy.
    Amlodipine; Benazepril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Amlodipine; Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Amlodipine; Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Amlodipine; Olmesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Amlodipine; Telmisartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Amlodipine; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Amoxicillin; Clarithromycin; Lansoprazole: (Major) Clarithromycin may enhance the hypoglycemic effects of antidiabetic agents. With certain agents, such as pioglitazone and rosiglitazone, inhibition of the CYP3A4 enzyme by clarithromycin may be involved. (Moderate) Clarithromycin may enhance the hypoglycemic effects of antidiabetic agents.
    Amoxicillin; Clarithromycin; Omeprazole: (Major) Clarithromycin may enhance the hypoglycemic effects of antidiabetic agents. With certain agents, such as pioglitazone and rosiglitazone, inhibition of the CYP3A4 enzyme by clarithromycin may be involved. (Moderate) Clarithromycin may enhance the hypoglycemic effects of antidiabetic agents.
    Amphetamine; Dextroamphetamine Salts: (Moderate) Amphetamines may potentiate the actions of some antidiabetic agents. As long as blood glucose is carefully monitored to avoid hypoglycemia, it appears that amphetamines can be used concurrently. (Moderate) Amphetamines may potentiate the actions of some antidiabetic agents. As long as blood glucose is carefully monitored to avoid hypoglycemia, it appears that amphetamines can be used concurrently.
    Amprenavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Androgens: (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Angiotensin II receptor antagonists: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Angiotensin-converting enzyme inhibitors: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Aprepitant, Fosaprepitant: (Moderate) Use caution if pioglitazone and aprepitant, fosaprepitant are used concurrently and monitor for a possible decrease in the efficacy of aprepitant as well as an increase in pioglitazone-related adverse effects for several days after administration of a multi-day aprepitant regimen. Pioglitazone is a CYP3A4 substrate. Aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor and inducer and may increase plasma concentrations of pioglitazone. For example, a 5-day oral aprepitant regimen increased the AUC of another CYP3A4 substrate, midazolam (single dose), by 2.3-fold on day 1 and by 3.3-fold on day 5. After a 3-day oral aprepitant regimen, the AUC of midazolam (given on days 1, 4, 8, and 15) increased by 25% on day 4, and then decreased by 19% and 4% on days 8 and 15, respectively. As a single 125 mg or 40 mg oral dose, the inhibitory effect of aprepitant on CYP3A4 is weak, with the AUC of midazolam increased by 1.5-fold and 1.2-fold, respectively. After administration, fosaprepitant is rapidly converted to aprepitant and shares many of the same drug interactions. However, as a single 150 mg intravenous dose, fosaprepitant only weakly inhibits CYP3A4 for a duration of 2 days; there is no evidence of CYP3A4 induction. Fosaprepitant 150 mg IV as a single dose increased the AUC of midazolam (given on days 1 and 4) by approximately 1.8-fold on day 1; there was no effect on day 4. Less than a 2-fold increase in the midazolam AUC is not considered clinically important. Additionally, pioglitazone is a weak CYP3A4 inducer and aprepitant is a CYP3A4 substrate. When a single dose of aprepitant (375 mg, or 3 times the maximum recommended dose) was administered on day 9 of a 14-day rifampin regimen (a strong CYP3A4 inducer), the AUC of aprepitant decreased approximately 11-fold and the mean terminal half-life decreased by 3-fold. The manufacturer of aprepitant recommends avoidance of administration with strong CYP3A4 inducers, but does not provide guidance for weak-to-moderate inducers.
    Aripiprazole: (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when any of these antipsychotics is instituted. Atypical antipsychotics have been associated with causing hyperglycemia, even diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported. In addition, because aripiprazole is metabolized by CYP3A4, concurrent use of CYP3A4 inducers such as pioglitazone may result in decreased plasma concentrations of aripiprazole. If these agents are used in combination, the patient should be carefully monitored for a decrease in aripiprazole efficacy. An increase in oral aripiprazole dosage may be clinically warranted in some patients. Avoid concurrent use of Abilify Maintena with a CYP3A4 inducer when the combined treatment period exceeds 14 days because aripiprazole blood concentrations decline and may become suboptimal. There are no dosing recommendations for Aristada during use of a mild to moderate CYP3A4 inducer.
    Articaine; Epinephrine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Asenapine: (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when asenapine is instituted. Atypical antipsychotics have been associated with hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma in some instances. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Atazanavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Atazanavir; Cobicistat: (Major) Coadministration of cobicistat with pioglitazone is not recommended as there is a potential for elevated pioglitazone concentrations and decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 substrate/inducer. Cobicistat is an inhibitor/substrate of CYP3A4. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Atenolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Atenolol; Chlorthalidone: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Atorvastatin: (Minor) Concentrations of atorvastatin may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of atorvastatin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with atorvastatin 80 mg daily for 7 days resulted in a 14% and 23% reduction in atorvastatin AUC and Cmax, respectively. In addition, coadministration resulted in a 24% and 31% reduction in pioglitazone AUC and Cmax, respectively. Patients should be evaluated more frequently with respect to glycemic control and lipid therapy.
    Atorvastatin; Ezetimibe: (Minor) Concentrations of atorvastatin may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of atorvastatin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with atorvastatin 80 mg daily for 7 days resulted in a 14% and 23% reduction in atorvastatin AUC and Cmax, respectively. In addition, coadministration resulted in a 24% and 31% reduction in pioglitazone AUC and Cmax, respectively. Patients should be evaluated more frequently with respect to glycemic control and lipid therapy.
    Atropine; Hyoscyamine; Phenobarbital; Scopolamine: (Minor) It is possible that a decrease in exposure of pioglitazone will occur when coadministered with drugs that induce CYP2C8 including phenobarbital. Patients receiving phenobarbital in combination with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    atypical antipsychotic: (Moderate) Patients taking metformin should be closely monitored for worsening glycemic control when an atypical antipsychotic is instituted. The atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. Temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Axitinib: (Moderate) Use caution if coadministration of axitinib with pioglitazone is necessary, due to the risk of decreased efficacy of axitinib. Axitinib is a CYP3A4 substrate and pioglitazone is a weak CYP3A4 inducer. Pioglitazone decreased the AUC and Cmax of midazolam, another CYP3A4 substrate, by 26%. Coadministration with a strong CYP3A4/5 inducer, rifampin, significantly decreased the plasma exposure of axitinib in healthy volunteers.
    Azelaic Acid; Copper; Folic Acid; Nicotinamide; Pyridoxine; Zinc: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia. When used at daily doses of 750 to 2000 mg, niacin significantly lowers LDL cholesterol and triglycerides while increasing HDL cholesterol. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients on antidiabetic therapy for blood glucose control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia; monitor patients on antidiabetic agents for loss of blood glucose control if niacin therapy is added. (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together.
    Azelastine; Fluticasone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Azilsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Azilsartan; Chlorthalidone: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Baclofen: (Minor) Because baclofen can increase blood glucose, doses of antidiabetic agents may need adjustment in patients receiving these drugs concomitantly. (Minor) Coadministration of metformin and baclofen may result in increases in blood glucose concentrations, thereby decreasing the hypoglycemic effect of metformin. Baclofen can increase blood glucose. Patients receiving metformin should be closely monitored for signs indicating loss of diabetic control when therapy with baclofen is instituted. Doses of metformin may need adjustment in patients receiving these drugs concomitantly.
    Beclomethasone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Minor) It is possible that a decrease in exposure of pioglitazone will occur when coadministered with drugs that induce CYP2C8 including phenobarbital. Patients receiving phenobarbital in combination with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Benazepril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Bendroflumethiazide; Nadolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Benzphetamine: (Moderate) Benzphetamine may potentiate the actions of some antidiabetic agents. As long as blood glucose is carefully monitored to avoid hypoglycemia, it appears that benzphetamine can be used concurrently. (Moderate) Benzphetamine may potentiate the actions of some antidiabetic agents. As long as blood glucose is carefully monitored to avoid hypoglycemia, it appears that benzphetamine can be used concurrently.
    Beta-blockers: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response. (Moderate) Beta-blockers exert complex actions on the body's ability to regulate blood glucose. Because of this, beta-blockers may cause a pharmacodynamic interaction with antidiabetic agents. Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis (secondary to blocking the compensatory actions of epinephrine) or can promote hyperglycemia (by inhibiting insulin secretion and decreasing tissue sensitivity to insulin). Furthermore, a prospective trial in non-diabetic patients with hypertension indicated that treatment with beta-blockers increased the risk of the development of diabetes by 28% at six years. In addition, beta-blockers may mask the signs and symptoms of hypoglycemia, specifically the tachycardic response, and exaggerate the hypertensive response to hypoglycemia. Although no significant pharmacokinetic interactions between beta-blockers and antidiabetic agents have been observed, patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response. Selective beta-blockers, such as acebutolol, atenolol, or metoprolol, can cause fewer problems with blood glucose regulation, although these agents can still mask the symptoms of hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes. Furthermore, their use should not be avoided in patients with compelling indications for beta-blocker therapy (i.e., post-MI, heart failure, etc.) when no other contraindications are present. Decreased mortality has been shown in the post-MI and heart failure populations when beta-blockers are used, especially in patients with coexisting diabetes mellitus.
    Betamethasone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Betaxolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Bexarotene: (Moderate) Systemic bexarotene may enhance the action of thiazolidinediones resulting in hypoglycemia. Patients should be closely monitored while receiving bexarotene capsules in combination with these agents; monitor for hypoglycemia and the need for diabetic therapy adjustments.
    Bisoprolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Boceprevir: (Moderate) Close clinical monitoring is advised when administering pioglitazone with boceprevir due to an increased potential for pioglitazone-related adverse events and the potential for boceprevir treatment failure. If pioglitazone dose adjustments are made, re-adjust the dose upon completion of boceprevir treatment. Although this interaction has not been studied, predictions about the interaction can be made based on the metabolic pathways of pioglitazone and boceprevir. Pioglitazone is a substrate and inducer of the hepatic isoenzyme CYP3A4; boceprevir is a substrate and an inhibitor of this isoenzyme. When used in combination, the plasma concentrations of pioglitazone may increase and the plasma concentrations of boceprevir may decrease.
    Bortezomib: (Moderate) Coadministration of metformin and bortezomib may require close blood glucose monitoring and dosage adjustment. During clinical trials of bortezomib, hypoglycemia and hyperglycemia were reported in diabetic patients receiving antidiabetic agents, including metformin. (Minor) During clinical trials of bortezomib, hypoglycemia and hyperglycemia were reported in diabetic patients receiving antidiabetic agents. Patients on oral antidiabetic agents receiving bortezomib treatment may require close monitoring of their blood glucose levels and dosage adjustment of their medication.
    Bosentan: (Major) Bosentan is a significant inducer of CYP3A4 and CYP2C9 hepatic enzymes. Theoretically, bosentan can increase the hepatic clearance of pioglitazone, a CYP3A4 substrate.
    Brexpiprazole: (Moderate) Patients taking medications for diabetes should be closely monitored for worsening glycemic control when brexpiprazole therapy is instituted. Atypical antipsychotics have been associated with metabolic changes including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported. In addition, brexpiprazole is a CYP3A4 substrate and pioglitazone and troglitazone (off-market) are CYP3A4 inducers. Theoretically, there might be a decrease in brexpiprazole concentrations. A dosage adjustment of brexpiprazole may be necessary if these thiazolidinediones are used.concomitantly. Monitor for signs and symptoms of decreased antipsychotic efficacy.
    Brimonidine; Timolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Brompheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Brompheniramine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Budesonide: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Budesonide; Formoterol: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Bumetanide: (Minor) Bumetanide has been associated with hyperglycemia, possibly due to potassium depletion, and, glycosuria has been reported. Because of this, a potential pharmacodynamic interaction exists between bumetanide and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Bupivacaine; Lidocaine: (Moderate) Concomitant use of systemic lidocaine and pioglitazone may decrease lidocaine plasma concentrations. Higher lidocaine doses may be required; titrate to effect. Lidocaine is a CYP3A4 and CYP1A2 substrate; pioglitazone induces CYP3A4.
    Candesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Captopril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Captopril; Hydrochlorothiazide, HCTZ: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Carbetapentane; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Carbetapentane; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Carbetapentane; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Carbinoxamine; Hydrocodone; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Carbinoxamine; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Carbinoxamine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Cariprazine: (Moderate) If cariprazine is used along with pioglitazone, montitor the patient for signs or symptoms of reduced antipsychotic efficacy and adjust therapy as clinically indicated. Cariprazine and its active metabolites are extensively metabolized by CYP3A4. Concurrent use of cariprazine with CYP3A4 inducers, such as pioglitazone, has not been evaluated and is not recommended because the net effect on active drug and metabolites is unclear. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Carteolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Carvedilol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Cephalexin: (Moderate) In healthy subjects given single 500 mg doses of cephalexin and metformin, plasma metformin Cmax and AUC increased by an average of 34% and 24%, respectively; metformin renal clearance decreased by an average of 14%. No information is available about the interaction of cephalexin and metformin following multiple dose administration.
    Cetirizine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Chlophedianol; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Chloroquine: (Major) Careful monitoring of blood glucose is recommended when chloroquine and antidiabetic agents, including metformin, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with chloroquine and an antidiabetic agent. (Major) Careful monitoring of blood glucose is recommended when chloroquine and antidiabetic agents, including the thiazolidinediones, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with chloroquine and an antidiabetic agent.
    Chlorothiazide: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Chlorpheniramine; Dihydrocodeine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Chlorpheniramine; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Chlorpheniramine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Chlorthalidone: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Chlorthalidone; Clonidine: (Moderate) Clonidine may potentiate or weaken the hypoglycemic effects of antidiabetic agents and may mask the signs and symptoms of hypoglycemia. (Moderate) Clonidine may potentiate or weaken the hypoglycemic effects of antidiabetic agents and may mask the signs and symptoms of hypoglycemia. Patients receiving clonidine concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Chromium: (Moderate) Chromium dietary supplements may lower blood glucose. As part of the glucose tolerance factor molecule, chromium appears to facilitate the binding of insulin to insulin receptors in tissues and to aid in glucose metabolism. Because blood glucose may be lowered by the use of chromium, patients who are on antidiabetic agents may need dose adjustments. Close monitoring of blood glucose is recommended.
    Ciclesonide: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Cimetidine: (Moderate) Caution is advised when administering cimetidine with metformin. Cimetidine inhibits renal elimination of metformin. Increased metformin exposure may lead to hypoglycemia, gastrointestinal complaints, and an increased risk for lactic acidosis. Consider alternatives to cimetidine. If medically necessary to use cimetidine, carefully monitor. Metformin dose reduction may be needed. An interaction between metformin and oral cimetidine has been observed in normal healthy volunteers in both single- and multiple-dose, metformin-cimetidine drug interaction studies, with a 60% increase in peak metformin plasma and whole blood concentrations and a 40% increase in plasma and whole blood metformin AUC. There was no change in elimination half-life in the single-dose study. Cimetidine inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Ciprofloxacin: (Moderate) Careful monitoring of blood glucose is recommended when quinolones and antidiabetic agents, including metformin, are coadministered. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. (Moderate) Careful monitoring of blood glucose is recommended when quinolones and antidiabetic agents, including the thiazolidinediones (e.g., rosiglitazone, pioglitazone), are coadministered. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent.
    Cisapride: (Moderate) Because cisapride can enhance gastric emptying in patients with diabetes, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. The dosing of antidiabetic agents may require adjustment.
    Clarithromycin: (Major) Clarithromycin may enhance the hypoglycemic effects of antidiabetic agents. With certain agents, such as pioglitazone and rosiglitazone, inhibition of the CYP3A4 enzyme by clarithromycin may be involved. (Moderate) Clarithromycin may enhance the hypoglycemic effects of antidiabetic agents.
    Clofarabine: (Moderate) Concomitant use of clofarabine and metformin may result in altered clofarabine levels because both agents are a substrate of OCT1. Therefore, monitor for signs of clofarabine toxicity such as gastrointestinal toxicity (e.g., nausea, vomiting, diarrhea, mucosal inflammation), hematologic toxicity, and skin toxicity (e.g. hand and foot syndrome, rash, pruritus) in patients also receiving OCT1 substrates.
    Clonidine: (Moderate) Clonidine may potentiate or weaken the hypoglycemic effects of antidiabetic agents and may mask the signs and symptoms of hypoglycemia. (Moderate) Clonidine may potentiate or weaken the hypoglycemic effects of antidiabetic agents and may mask the signs and symptoms of hypoglycemia. Patients receiving clonidine concomitantly with antidiabetic agents should be monitored for changes in glycemic control.
    Clopidogrel: (Major) Do not exceed 15 mg/day of pioglitazone if coadministered with clopidogrel. Coadministration may result in increased concentrations of pioglitazone. Pioglitazone is a CYP2C8 substrate and clopidogrel is a strong inhibitor of CYP2C8. When coadministered with gemfibrozil, another strong CYP2C8 inhibitor, the exposure to pioglitazone was increased by 226%.
    Clozapine: (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when clozapine is instituted. Atypical antipsychotics have been associated with causing metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Cobicistat: (Major) Coadministration of cobicistat with pioglitazone is not recommended as there is a potential for elevated pioglitazone concentrations and decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 substrate/inducer. Cobicistat is an inhibitor/substrate of CYP3A4. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Cobicistat; Elvitegravir; Emtricitabine; Tenofovir Alafenamide: (Major) Coadministration of cobicistat with pioglitazone is not recommended as there is a potential for elevated pioglitazone concentrations and decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 substrate/inducer. Cobicistat is an inhibitor/substrate of CYP3A4. (Major) Coadministration of elvitegravir with pioglitazone is not recommended as there is a potential for decreased elvitegravir concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 inducer, while elvitegravir is a substrate of CYP3A4. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Cobicistat; Elvitegravir; Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) Coadministration of cobicistat with pioglitazone is not recommended as there is a potential for elevated pioglitazone concentrations and decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 substrate/inducer. Cobicistat is an inhibitor/substrate of CYP3A4. (Major) Coadministration of elvitegravir with pioglitazone is not recommended as there is a potential for decreased elvitegravir concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 inducer, while elvitegravir is a substrate of CYP3A4. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Cobimetinib: (Moderate) If concurrent use of cobimetinib and pioglitazone is necessary, use caution and monitor for decreased efficacy of cobimetinib. Cobimetinib is a CYP3A substrate in vitro, and pioglitazone is a weak inducer of CYP3A. The manufacturer of cobimetinib recommends avoiding coadministration of cobimetinib with moderate or strong CYP3A inducers based on simulations demonstrating that cobimetinib exposure would decrease by 73% or 83% when coadministered with a moderate or strong CYP3A inducer, respectively. Guidance is not available regarding concomitant use of cobimetinib with weak CYP3A inducers.
    Codeine; Phenylephrine; Promethazine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Minor) Promethazine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Phenothiazines have been reported to increase blood glucose concentrations. (Minor) The phenothiazines such as promethazine may increase blood sugar. Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when a phenothiazine is instituted.
    Codeine; Promethazine: (Minor) Promethazine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Phenothiazines have been reported to increase blood glucose concentrations. (Minor) The phenothiazines such as promethazine may increase blood sugar. Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when a phenothiazine is instituted.
    Colesevelam: (Moderate) Colesevelam increases the Cmax and AUC of extended-release metformin (metformin ER) by approximately 8% and 44%, respectively. According to the manufacturer of colesevelam, the clinical response to metformin ER should be monitored in patients receiving concomitant therapy. Colesevelam has no significant effect on the bioavailability of immediate-release metformin.
    Conjugated Estrogens: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Conjugated Estrogens; Bazedoxifene: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Conjugated Estrogens; Medroxyprogesterone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Corticosteroids: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent. (Moderate) Endogenous counter-regulatory hormones such as glucocorticoids are released in response to hypoglycemia. When released, blood glucose concentrations rise. When corticosteroids are administered exogenously, increases in blood glucose concentrations would be expected thereby decreasing the hypoglycemic effect of antidiabetic agents. In addition, blood lactate concentrations and the lactate to pyruvate ratio increase when metformin is coadministered with corticosteroids (e.g., hydrocortisone). Elevated lactic acid concentrations are associated with increased morbidity rates. Patients receiving antidiabetic agents should be closely monitored for signs indicating loss of diabetic control when corticosteroids are instituted.
    Corticotropin, ACTH: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Cortisone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Crizotinib: (Moderate) Monitor for an increase in metformin-related adverse reactions and toxicities (e.g., lactic acidosis) if coadministration with crizotinib is necessary; consider the risks and benefits of coadministration. Metformin is a substrate of the renal uptake transporter, OCT2. Crizotinib inhibits OCT2 at clinically relevant concentrations, and has the potential to increase plasma concentrations of drugs that are substrates of OCT2. Coadministration with another OCT2 inhibitor increased the Cmax and AUC of metformin by 60% and 40%, respectively; there was no change in the elimination half-life of metformin.
    Cyanocobalamin, Vitamin B12: (Minor) Metformin may result in suboptimal oral vitamin B12 absorption by competitively blocking the calcium-dependent binding of the intrinsic factor-vitamin B12 complex to its receptor. Regular measurement of hematologic parameters is recommended in all patients on chronic metformin treatment; abnormalities should be investigated.
    Cyclosporine: (Moderate) Cyclosporine has been reported to cause hyperglycemia; this effect appears to be dose-related and caused by direct beta-cell toxicity. Therefore, a pharmacodynamic interaction is possible with all antidiabetic agents and cyclosporine. Patients should be monitored for worsening glycemic control if therapy with cyclosporine is initiated in patients receiving antidiabetic agents. (Moderate) Cyclosporine has been reported to cause hyperglycemia; this effect appears to be dose-related and caused by direct beta-cell toxicity. Therefore, a pharmacodynamic interaction is possible with all antidiabetic agents and cyclosporine. Patients should be monitored for worsening glycemic control if therapy with cyclosporine is initiated in patients receiving antidiabetic agents.
    Dabrafenib: (Major) The concomitant use of dabrafenib and pioglitazone may lead to decreased pioglitazone exposure and loss of efficacy. Use of an alternative agent is recommended. If concomitant use is unavoidable, monitor patients for loss of pioglitazone efficacy. A change in diabetes treatment may be needed based upon clinical response if dabrafenib is started or stopped during treatment with pioglitazone; do not exceed the maximum recommended dose of 45 mg/day. In vitro, dabrafenib is an inducer of CYP2C isoenzymes via activation of the pregnane X receptor and constitutive androstane receptor nuclear receptors. Pioglitazone is a moderately sensitive CYP2C8 substrate. Administration of Rifampin 600 mg/day for 5 days with a single 30 mg dose of pioglitazone decreased the AUC of pioglitazone by 54% in a drug interaction study (n = 10).
    Danazol: (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Dapsone: (Minor) The metabolism of dapsone may be accelerated when administered concurrently with pioglitazone, a known inducer of CYP3A4. Coadministration is expected to decrease the plasma concentration of dapsone and increase the formation of dapsone hydroxylamine (a metabolite associated with hemolysis). If these drugs must be administered together, closely monitor for a reduction in dapsone efficacy and signs of hemolytic anemia.
    Darunavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Darunavir; Cobicistat: (Major) Coadministration of cobicistat with pioglitazone is not recommended as there is a potential for elevated pioglitazone concentrations and decreased cobicistat concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 substrate/inducer. Cobicistat is an inhibitor/substrate of CYP3A4. (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Major) Concurrent administration of pioglitazone with dasabuvir; ombitasvir; paritaprevir; ritonavir may result in elevated pioglitazone plasma concentrations and decreased concentrations of dasabuvir, paritaprevir, and ritonavir. Pioglitazone is an inducer of the hepatic isoenzyme CYP3A4; ritonavir, paritaprevir, and dasabuvir (minor) are CYP3A4 substrates. In addition, pioglitazone is metabolized by CYP3A4; ritonavir is a potent inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are administered together. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Deflazacort: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Desiccated Thyroid: (Minor) Addition of thyroid hormones to metformin may result in increased dosage requirements of metformin. Monitor blood sugars carefully when thyroid therapy is added, discontinued or doses changed.
    Desloratadine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Dexamethasone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Dexmethylphenidate: (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta-2 receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with a sympathomimetic agent, such as dexmethylphenidate, is instituted.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Dextromethorphan; Promethazine: (Minor) Promethazine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Phenothiazines have been reported to increase blood glucose concentrations. (Minor) The phenothiazines such as promethazine may increase blood sugar. Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when a phenothiazine is instituted.
    Diazoxide: (Minor) Because diazoxide increases blood glucose, a pharmacodynamic interaction exists between this drug and all other antidiabetic agents, including metformin. (Minor) Diazoxide inhibits the release of insulin from pancreatic islet cells. Because diazoxide increases blood glucose, a pharmacodynamic interaction exists between this drug and all other antidiabetic agents.
    Dichlorphenamide: (Moderate) Use dichlorphenamide and metformin together with caution. Lactic acidosis, a rare and serious form of metabolic acidosis, has been reported with the use of metformin, and metabolic acidosis has been reported with the use of dichlorphenamide. Concurrent use may increase the severity of metabolic acidosis. Measure sodium bicarbonate concentrations at baseline and periodically during dichlorphenamide treatment. If metabolic acidosis occurs or persists, consider reducing the dose or discontinuing dichlorphenamide therapy.
    Dienogest; Estradiol valerate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Diethylpropion: (Moderate) Diethylpropion exhibits intrinsic hypoglycemic activity and can lower postprandial blood glucose concentrations. Diethylpropion should be used cautiously in diabetic patients who are stabilized on antidiabetic agents. (Moderate) Diethylpropion exhibits intrinsic hypoglycemic activity and can lower postprandial blood glucose concentrations. Diethylpropion should be used cautiously in diabetic patients who are stabilized on antidiabetic agents.
    Diethylstilbestrol, DES: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Digoxin: (Moderate) Concentrations of digoxin may be increased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of digoxin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with digoxin 0.2 mg twice daily (loading dose) then 0.25 mg daily (maintenance dose, 7 days) resulted in a 15% and 17% increase in digoxin AUC and Cmax, respectively. Carefully monitor serum digoxin concentrations; observe patients carefully for signs of digoxin toxicity.
    Dihydrocodeine; Guaifenesin; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Disopyramide: (Moderate) Disopyramide may enhance the hypoglycemic effects of antidiabetic agents. Patients receiving disopyramide concomitantly with antidiabetic agents should be monitored for changes in glycemic control.
    Dobutamine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Dofetilide: (Major) Dofetilide should be co-administered with metformin with caution since both drugs are actively secreted via cationic secretion and could compete for common renal tubular transport systems. This results in a possible increase in plasma concentrations of either drug. Reduced clearance of metformin may increase the risk for lactic acidosis; increased concentrations of dofetilide may increase the risk for side effects including proarrhythmia. Careful patient monitoring and dose adjustment of metformin and dofetilide is recommended.
    Dolutegravir: (Major) Avoid concurrent use of dolutegravir with pioglitazone, as coadministration may result in decreased dolutegravir plasma concentrations. Pioglitazone is a weak inducer of CYP3A, dolutegravir is partially metabolized by this isoenzyme. (Major) Caution is advised when administering dolutegravir with metformin, as coadministration may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. If these drugs are used in combination, the total daily dose of metformin must not exceed 1000 mg/day. Close monitoring of blood glucose and patient clinical status is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin was administered at a dose of 500 mg PO twice daily. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Donepezil; Memantine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
    Dopamine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Dorzolamide; Timolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Doxorubicin: (Major) Pioglitazone is a mild CYP3A4 inhibitor and doxorubicin is a major substrate of CYP3A4. Clinically significant interactions have been reported when doxorubicin was coadministered with inhibitors of CYP3A4, resulting in increased concentration and clinical effect of doxorubicin. Avoid coadministration of pioglitazone and doxorubicin if possible. If not possible, closely monitor for increased side effects of doxorubicin including myelosuppression and cardiotoxicity.
    Dronabinol, THC: (Moderate) Use caution if coadministration of dronabinol with pioglitazone is necessary, and monitor for a decrease in the efficacy of dronabinol. Dronabinol is a CYP2C9 and 3A4 substrate; pioglitazone is a weak inducer of CYP3A4. Concomitant use may result in decreased plasma concentrations of dronabinol.
    Dronedarone: (Major) The concomitant use of dronedarone and CYP3A4 inducers should be avoided. Dronedarone is metabolized by CYP3A and is an inhibitor of CYP3A. Pioglitazone induces and is a substrate for CYP3A4. Coadministration of CYP3A4 inducers, such as pioglitazone, with dronedarone may result in reduced plasma concentration and subsequent reduced effectiveness of dronedarone therapy; the plasma concentrations of pioglitazone may also be increased.
    Drospirenone; Estradiol: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Drospirenone; Ethinyl Estradiol: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Drospirenone; Ethinyl Estradiol; Levomefolate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Efavirenz; Emtricitabine; Tenofovir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Elbasvir; Grazoprevir: (Moderate) Caution is advised when administering elbasvir; grazoprevir with pioglitazone. Pioglitazone is a mild CYP3A inducer, while both elbasvir and grazoprevir are substrates of CYP3A. Use of these drugs together may decrease the plasma concentrations of both elbasvir and grazoprevir, and could result in decreased virologic response. Conversely, concentrations of pioglitazone (also a CYP3A substrate) may be increased when given with grazoprevir (a weak CYP3A inhibitor).
    Elvitegravir: (Major) Coadministration of elvitegravir with pioglitazone is not recommended as there is a potential for decreased elvitegravir concentrations. Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Pioglitazone is a CYP3A4 inducer, while elvitegravir is a substrate of CYP3A4.
    Empagliflozin; Linagliptin: (Major) Inducers of CYP3A4 (e.g., pioglitazone) can decrease exposure to linagliptin to subtherapeutic and likely ineffective concentrations. For patients requiring use of such drugs, an alternative to linagliptin is strongly recommended.
    Emtricitabine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Close clinical monitoring is advised when administering pioglitazone with rilpivirine due to the potential for rilpivirine treatment failure. Although this interaction has not been studied, predictions can be made based on metabolic pathways. Pioglitazone is an inducer of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in decreased rilpivirine serum concentrations and impaired virologic response.
    Emtricitabine; Rilpivirine; Tenofovir disoproxil fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Close clinical monitoring is advised when administering pioglitazone with rilpivirine due to the potential for rilpivirine treatment failure. Although this interaction has not been studied, predictions can be made based on metabolic pathways. Pioglitazone is an inducer of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in decreased rilpivirine serum concentrations and impaired virologic response.
    Emtricitabine; Tenofovir alafenamide: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Emtricitabine; Tenofovir disoproxil fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as emtricitabine, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended. (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Enalapril, Enalaprilat: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Enalapril; Felodipine: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Entecavir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion (e.g., entecavir) may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Ephedrine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Epinephrine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Eprosartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Erlotinib: (Major) Avoid the coadministration of erlotinib with pioglitazone if possible due to the risk of decreased erlotinib efficacy; if concomitant use is unavoidable, the manufacturer recommends increasing the dose of erlotinib by 50 mg increments at 2-week intervals, to a maximum of 450 mg. Erlotinib is primarily metabolized by CYP3A4, and to a lesser extent by CYP1A2. Pioglitazone is a weak CYP3A4 inducer. The AUC and Cmax of another CYP3A4 substrate, midazolam, were each decreased by 26% when administered with pioglitazone. The erlotinib AUC was decreased by 58% to 80% when preceded by administration of rifampicin, a strong CYP3A4 inducer, for 7 to 11 days; coadministration with pioglitazone may also decrease erlotinib exposure.
    Erythromycin; Sulfisoxazole: (Moderate) Sulfonamides may induce hypoglycemia by increasing the secretion of insulin from the pancreas. Therefore, a pharmacodynamic interaction leading to an increased risk of hypoglycemia may occur in patients taking antidiabetic agents and sulfonamides. (Moderate) Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides. Patients should be closely monitored while receiving any of these drugs in combination with antidiabetic agents.
    Esmolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Esterified Estrogens: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Esterified Estrogens; Methyltestosterone: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Estradiol Cypionate; Medroxyprogesterone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estradiol: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Estradiol; Levonorgestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estradiol; Norethindrone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estradiol; Norgestimate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Estramustine: (Moderate) Estramustine may decrease glucose tolerance leading to hyperglycemia. Patients receiving antidiabetic agents should monitor their blood glucose levels frequently due to this potential pharmacodynamic interaction. (Minor) Estramustine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Estramustine may decrease glucose tolerance leading to hyperglycemia.
    Estrogens: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Estropipate: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Ethacrynic Acid: (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations.Patients receiving antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Ethanol: (Moderate) A single administration of a moderate amount of alcohol did not increase the risk of acute hypoglycemia in type 2 diabetes mellitus patients treated with thiazolidinediones in clinical studies. However, in general, excessive amounts of alcoholic beverages can increase the risk of low blood sugar in patients with diabetes, The calories in these beverages also need consideration, as increased blood sugar may occur due to the caloric intake. (Moderate) Patients should be advised to limit their use of ethanol during use of metformin. Blood lactate concentrations and the lactate to pyruvate ratio are increased during excessive (acute or chronic) intake of alcohol with metformin. Elevated lactic acid concentrations are associated with increased morbidity rates as the risk for lactic acidosis is increased. Many non-prescription drug products may be formulated with alcohol; have patients scrutinize product labels prior to consumption. In patients with diabetes, alcohol intake can also cause hypoglycemia or worsen glycemic control as it provides a source of additional calories.
    Ethinyl Estradiol: (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
    Ethinyl Estradiol; Desogestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Ethynodiol Diacetate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Etonogestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Levonorgestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Levonorgestrel; Folic Acid; Levomefolate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norelgestromin: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norethindrone Acetate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norethindrone Acetate; Ferrous fumarate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norethindrone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norethindrone; Ferrous fumarate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norgestimate: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethinyl Estradiol; Norgestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ethotoin: (Minor) Ethotoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients. (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Etonogestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Etoposide, VP-16: (Major) Monitor for clinical efficacy of etoposide if used concomitantly with pioglitazone. Pioglitazone is a weak inducer of CYP3A4; etoposide, VP-16 is a CYP3A4 substrate. Coadministration of etoposide with a strong CYP3A4 inducer (phenytoin) resulted in increased etoposide clearance and reduced efficacy, as did coadministration with a weak inducer of CYP3A4 and P-glycoprotein (P-gp) (valproic acid).
    Famotidine: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Famotidine; Ibuprofen: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Fenofibrate: (Moderate) Fibric acid derivatives may enhance the hypoglycemic effects antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion. (Moderate) Fibric acid derivatives may enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion; monitor for changes in glycemic control and for needed dose adjustments.
    Fenofibric Acid: (Moderate) Fibric acid derivatives may enhance the hypoglycemic effects antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion. (Moderate) Fibric acid derivatives may enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion; monitor for changes in glycemic control and for needed dose adjustments.
    Fexofenadine: (Minor) Concentrations of fexofenadine may be increased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of fexofenadine was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with fexofenadine 60 mg twice daily for 7 days resulted in a 30% and 37% increase in fexofenadine AUC and Cmax, respectively. Patients should be monitored for increased side effects from fexofenadine.
    Fexofenadine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Minor) Concentrations of fexofenadine may be increased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of fexofenadine was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with fexofenadine 60 mg twice daily for 7 days resulted in a 30% and 37% increase in fexofenadine AUC and Cmax, respectively. Patients should be monitored for increased side effects from fexofenadine.
    Fibric acid derivatives: (Moderate) Fibric acid derivatives may enhance the hypoglycemic effects antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion.
    Flibanserin: (Major) The concomitant use of flibanserin with CYP3A4 inducers significantly decreases flibanserin exposure compared to the use of flibanserin alone. Therefore, concurrent use of flibanserin and CYP3A4 inducers, such as pioglitazone, is not recommended.
    Fluconazole: (Moderate) Fluconazole is an inhibitor of CYP3A4 and CYP2C9. Because pioglitazone is a substrate of CYP3A4, concomitant use with fluconazole may increase plasma concentrations of pioglitazone. Patients should be monitored for changes in glycemic control if pioglitazone is coadministered with fluconazole.
    Fludrocortisone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Flunisolide: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Fluoxetine: (Moderate) Fluoxetine may enhance the hypoglycemic effects of antidiabetic agents. Serum glucose should be monitored closely when fluoxetine is added to any regimen containing antidiabetic agents. (Moderate) Fluoxetine may enhance the hypoglycemic effects of antidiabetic agents. Serum glucose should be monitored closely when fluoxetine is added to any regimen containing antidiabetic agents.
    Fluoxetine; Olanzapine: (Moderate) Fluoxetine may enhance the hypoglycemic effects of antidiabetic agents. Serum glucose should be monitored closely when fluoxetine is added to any regimen containing antidiabetic agents. (Moderate) Fluoxetine may enhance the hypoglycemic effects of antidiabetic agents. Serum glucose should be monitored closely when fluoxetine is added to any regimen containing antidiabetic agents. (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when olanzapine is instituted. Atypical antipsychotics have been associated with causing metabolic changes, including hyperglycemia, even diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Fluoxymesterone: (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Fluticasone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Fluticasone; Salmeterol: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Fluticasone; Umeclidinium; Vilanterol: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Fluticasone; Vilanterol: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Folic Acid, Vitamin B9: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together.
    Food: (Moderate) The incidence of marijuana associated adverse effects may change following coadministration with pioglitazone. Pioglitazone is an inducer of CYP3A4, an isoenzyme partially responsible for the metabolism of marijuana's most psychoactive compound, delta-9-tetrahydrocannabinol (Delta-9-THC). When given concurrently with pioglitazone, the amount of Delta-9-THC converted to the active metabolite 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC) may be increased. These changes in Delta-9-THC and 11-OH-THC plasma concentrations may result in an altered marijuana adverse event profile.
    Formoterol; Mometasone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Fosamprenavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Fosinopril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Fosphenytoin: (Minor) Fosphenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients. (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Furosemide: (Minor) Furosemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. (Minor) Furosemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between furosemide and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Gadoterate meglumine: (Severe) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Garlic, Allium sativum: (Moderate) Limited animal data suggest that selected constituents in Garlic, Allium sativum might have some antidiabetic activity, resulting in increased serum insulin concentrations and increased glycogen storage in the liver. Patients with diabetes frequently purchase alternative remedies that have been purported to improve glycemic control, but there is no scientific or controlled evidence in humans of this action. Limited clinical evidence suggests that garlic does not affect blood glucose in those without diabetes. Until more data are available, individuals receiving antidiabetic agents should use caution in consuming dietary supplements containing garlic, and follow their normally recommended strategies for blood glucose monitoring. (Moderate) Selected constituents in Garlic, Allium sativum might have some antidiabetic activity, resulting in increased serum insulin concentrations and increased glycogen storage in the liver. Until more data are available, individuals receiving antidiabetic agents should use caution in consuming dietary supplements containing garlic, and follow their normally recommended strategies for blood glucose monitoring.
    Gefitinib: (Moderate) Monitor for clinical response of gefitinib if used concomitantly with pioglitazone. Gefitinib is metabolized significantly by CYP3A4 and pioglitazone is a weak CYP3A4 inducer; coadministration may increase gefitinib metabolism and decrease gefitinib concentrations. This also applies to combination products containing pioglitazone, such as alogliptin; pioglitazone, glimepiride; pioglitazone; metformin; pioglitazone. While the manufacturer has provided no guidance regarding the use of gefitinib with mild or moderate CYP3A4 inducers, administration of a single 500 mg gefitinib dose with a concurrent strong CYP3A4 inducer (rifampin) resulted in reduced mean AUC of gefitinib by 83%.
    Gemfibrozil: (Major) Do not exceed 15 mg per day PO of pioglitazone if coadministered with gemfibrozil; monitor for changes in glycemic control. The exposure to pioglitazone is increased approximately 3-fold when combined with gemfibrozil. Gemfibrozil is a strong CYP2C8 inhibitor and pioglitazone is a CYP2C8 substrate. Fibric acid derivatives may also enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion. (Moderate) Fibric acid derivatives may enhance the hypoglycemic effects antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion.
    Gemifloxacin: (Moderate) Hyperglycemia and hypoglycemia have been reported in patients treated concomitantly with quinolones and antidiabetic agents. Rare cases of severe hypoglycemia have been reported with concomitant use of quinolones and glyburide. Therefore, careful monitoring of blood glucose is recommended when gemifloxacin and antidiabetic agents are coadministered. (Moderate) Hyperglycemia and hypoglycemia have been reported in patients treated concomitantly with quinolones and antidiabetic agents. Rare cases of severe hypoglycemia have been reported with concomitant use of quinolones and glyburide. Therefore, careful monitoring of blood glucose is recommended when gemifloxacin and antidiabetic agents are coadministered.
    Glucagon: (Minor) Glucagon administration results in increases in blood glucose concentrations thereby decreasing the hypoglycemic effect of metformin. (Minor) Glucagon increases blood glucose concentrations thereby decreasing the hypoglycemic effect of antidiabetic agents. Patients receiving antidiabetic agents should be closely monitored for signs indicating loss of diabetic control when therapy with glucagon is instituted.
    Glycopyrrolate: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Glycopyrrolate; Formoterol: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Green Tea: (Moderate) Green tea catechins have been shown to decrease serum glucose concentrations in vitro. Patients with diabetes mellitus taking antidiabetic agents should be monitored closely for hypoglycemia if consuming green tea products. (Moderate) Green tea catechins have been shown to decrease serum glucose concentrations in vitro. Patients with diabetes mellitus taking antidiabetic agents should be monitored closely for hypoglycemia if consuming green tea products.
    Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Guaifenesin; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Guaifenesin; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Hydantoins: (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Hydralazine; Hydrochlorothiazide, HCTZ: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Irbesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Lisinopril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Losartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Metoprolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Propranolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Quinapril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Spironolactone: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Telmisartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Triamterene: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Triamterene can interfere with the hypoglycemic effects of antidiabetic agents. This can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Hydrocodone; Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Hydrocodone; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Hydrocortisone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Hydroxychloroquine: (Major) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including metformin, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent. (Major) Careful monitoring of blood glucose is recommended when hydroxychloroquine and antidiabetic agents, including the thiazolidinediones, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with hydroxychloroquine and an antidiabetic agent.
    Hydroxyprogesterone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Ibuprofen; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Idelalisib: (Major) Avoid concomitant use of idelalisib, a strong CYP3A inhibitor, with pioglitazone, a CYP3A substrate, as pioglitazone toxicities may be significantly increased. The AUC of a sensitive CYP3A substrate was increased 5.4-fold when coadministered with idelalisib.
    Iloperidone: (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when iloperidone is instituted. Atypical antipsychotics have been associated with metabolic changes including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma in some instances. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Indacaterol; Glycopyrrolate: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Indapamide: (Moderate) A potential pharmacodynamic interaction exists between indapamide and antidiabetic agents, like metformin. Indapamide can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. (Moderate) A potential pharmacodynamic interaction exists between indapamide and antidiabetic agents, such as thiazolidinediones. Indapamide can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia.
    Indinavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Insulins: (Major) The risk of heart failure and/or edema is increased when thiazolidinediones (including pioglitazone) are combined with insulins; monitor combined therapy closely for signs or symptoms of congestive heart failure. Pioglitazone should be discontinued if any deterioration in cardiac status occurs. If heart failure develops in a patient receiving insulin and a thiazoladinedione, manage the patient according to standards of care, and discontinue or consider reducing the dose of the thiazoladinedione. Since the incidence of hypoglycemia may also be higher with combined therapy, patients should also be instructed to monitor blood glucose concentrations more frequently.
    Iodipamide Meglumine: (Severe) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Ionic Contrast Media: (Severe) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Ioxaglate Meglumine; Ioxaglate Sodium: (Severe) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Irbesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Irinotecan: (Major) Pioglitazone is a mild inducer of CYP3A4; irinotecan is a CYP3A4 substrate. Coadministration could potentially decrease irinotecan exposure, although coadministration of irinotecan with dexamethasone, a moderate CYP3A4 inducer, did not aaffect irinotecan pharmacokinetics. Monitor for efficacy of chemotherapy.
    Isavuconazonium: (Major) Coadministration of isavuconazonium with pioglitazone is not recommended as there is a potential for elevated pioglitazone concentrations and decreased isavuconazonium concentrations. Decreased isavuconazonium concentrations may lead to a reduction of antifungal efficacy and the potential for treatment failure. Pioglitazone is a CYP3A4 substrate/inducer. Isavuconazole, the active moiety of isavuconazonium, is a sensitive substrate and moderate inhibitor of this enzyme.
    Isocarboxazid: (Moderate) Animal data indicate that monoamine oxidase inhibitors (MAO inhibitors) may stimulate insulin secretion. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and oral sulfonylureas. Serum glucose should be monitored closely when MAOI-type medications, including the selective MAO-B inhibitor selegiline, are added to any regimen containing antidiabetic agents.Although at low doses selegiline is selective for MAO type B, in doses above 30 to 40 mg/day, this selectivity is lost.
    Isoniazid, INH: (Minor) Isoniazid, INH may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when this drug is initiated. (Minor) Isoniazid, INH may increase blood sugar. Patients receiving antidiabetic drugs should be closely monitored for loss of diabetic control when this drug is initiated.
    Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Minor) Concomitant administration of rifampin with pioglitazone resulted in a decrease in the AUC of pioglitazone. Patients receiving rifampin with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary. (Minor) Isoniazid, INH may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when this drug is initiated. (Minor) Isoniazid, INH may increase blood sugar. Patients receiving antidiabetic drugs should be closely monitored for loss of diabetic control when this drug is initiated.
    Isoniazid, INH; Rifampin: (Minor) Concomitant administration of rifampin with pioglitazone resulted in a decrease in the AUC of pioglitazone. Patients receiving rifampin with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary. (Minor) Isoniazid, INH may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when this drug is initiated. (Minor) Isoniazid, INH may increase blood sugar. Patients receiving antidiabetic drugs should be closely monitored for loss of diabetic control when this drug is initiated.
    Isoproterenol: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Itraconazole: (Moderate) Itraconazole should be used cautiously with oral antidiabetic agents. The combination of itraconazole and oral antidiabetic agents has resulted in severe hypoglycemia. Blood glucose concentrations should be monitored and possible dose adjustments of hypoglycemics may need to be made.
    Ivabradine: (Major) Avoid coadministration of ivabradine and pioglitazone. Ivabradine is primarily metabolized by CYP3A4; pioglitazone is a weak inducer of CYP3A4. Coadministration may decrease the plasma concentrations of ivabradine resulting in the potential for treatment failure.
    Ivacaftor: (Moderate) Use caution when administering ivacaftor and pioglitazone concurrently; the clinical impact of this interaction has not yet been determined. Ivacaftor is an inhibitor of CYP3A, and pioglitazone is partially metabolized by CYP3A. Co-administration may increase pioglitazone exposure leading to increased or prolonged therapeutic effects and adverse events. In addition, ivacaftor is a CYP3A substrate and pioglitazone is a mild CYP3A inducer. Administration of ivacaftor with strong CYP3A inducers is not recommended because sub-therapeutic ivacaftor exposure could result; the impact of mild inducers is not known.
    Ketoconazole: (Moderate) Ketoconazole appears to significantly inhibit the metabolism of pioglitazone. It is recommended that patients receiving both pioglitazone and ketoconazole be evaluated more frequently with respect to glycemic control.
    Labetalol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Lamivudine, 3TC: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Lamotrigine: (Moderate) Coadministration of metformin and lamotrigine may decrease metformin clearance, resulting in increased plasma concentrations and the potential for adverse events, including hypoglycemia. Lamotrigine is an inhibitor of renal tubular secretion via organic cationic transporter 2 (OCT2) proteins, and metformin is excreted via this route.
    Lanreotide: (Moderate) Monitor blood glucose levels if administration of lanreotide is necessary with antidiabetic agents; adjust the dosage of the antidiabetic agent as clinically appropriate. Lanreotide inhibits the secretion of insulin and glucagon.
    Leuprolide; Norethindrone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levobetaxolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Levobunolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Levocarnitine: (Moderate) Chromium dietary supplements may lower blood glucose. As part of the glucose tolerance factor molecule, chromium appears to facilitate the binding of insulin to insulin receptors in tissues and to aid in glucose metabolism. Because blood glucose may be lowered by the use of chromium, patients who are on antidiabetic agents may need dose adjustments. Close monitoring of blood glucose is recommended.
    Levofloxacin: (Moderate) Careful monitoring of blood glucose is recommended when levofloxacin and antidiabetic agents, including metformin, are coadministered. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. (Moderate) Careful monitoring of blood glucose is recommended when levofloxacin and antidiabetic agents, including the thiazolidinediones, are coadministered. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent.
    Levomefolate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together.
    Levomefolate; Mecobalamin; Pyridoxal-5-phosphate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together.
    Levonorgestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levothyroxine: (Minor) Addition of thyroid hormones to metformin may result in increased dosage requirements of metformin. Monitor blood sugars carefully when thyroid therapy is added, discontinued or doses changed.
    Lidocaine: (Moderate) Concomitant use of systemic lidocaine and pioglitazone may decrease lidocaine plasma concentrations. Higher lidocaine doses may be required; titrate to effect. Lidocaine is a CYP3A4 and CYP1A2 substrate; pioglitazone induces CYP3A4.
    Linagliptin: (Major) Inducers of CYP3A4 (e.g., pioglitazone) can decrease exposure to linagliptin to subtherapeutic and likely ineffective concentrations. For patients requiring use of such drugs, an alternative to linagliptin is strongly recommended.
    Linagliptin; Metformin: (Major) Inducers of CYP3A4 (e.g., pioglitazone) can decrease exposure to linagliptin to subtherapeutic and likely ineffective concentrations. For patients requiring use of such drugs, an alternative to linagliptin is strongly recommended.
    Linezolid: (Moderate) Hypoglycemia, including symptomatic episodes, has been noted in post-marketing reports with linezolid in patients with diabetes mellitus receiving therapy with antidiabetic agents, such as insulin and oral hypoglycemic agents. Diabetic patients should be monitored for potential hypoglycemic reactions while on linezolid. If hypoglycemia occurs, discontinue or decrease the dose of the antidiabetic agent or discontinue the linezolid therapy. Linezolid is a reversible, nonselective MAO inhibitor and other MAO inhibitors have been associated with hypoglycemic episodes in diabetic patients receiving insulin or oral hypoglycemic agents.
    Liothyronine: (Minor) Addition of thyroid hormones to metformin may result in increased dosage requirements of metformin. Monitor blood sugars carefully when thyroid therapy is added, discontinued or doses changed.
    Liotrix: (Minor) Addition of thyroid hormones to metformin may result in increased dosage requirements of metformin. Monitor blood sugars carefully when thyroid therapy is added, discontinued or doses changed.
    Lisdexamfetamine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia. (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Lisinopril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Lithium: (Moderate) Lithium may cause variable effects on glycemic control when used in patients receiving antidiabetic agents. Monitor blood glucose concentrations closely if lithium is coadministered with antidiabetic agents. Dosage adjustments of antidiabetic agents may be necessary. (Moderate) Lithium may cause variable effects on glycemic control when used in patients receiving antidiabetic agents. Monitor blood glucose concentrations closely if lithium is coadministered with antidiabetic agents. Dosage adjustments of antidiabetic agents may be necessary.
    Lomefloxacin: (Moderate) Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. Therefore, careful monitoring of blood glucose is recommended when quinolones and antidiabetic agents are co-administered.
    Loperamide: (Moderate) The plasma concentration and efficacy of loperamide may be reduced when administered concurrently with pioglitazone. Loperamide is metabolized by the hepatic enzyme CYP3A4; pioglitazone is a mild inducer of this enzyme.
    Loperamide; Simethicone: (Moderate) The plasma concentration and efficacy of loperamide may be reduced when administered concurrently with pioglitazone. Loperamide is metabolized by the hepatic enzyme CYP3A4; pioglitazone is a mild inducer of this enzyme.
    Lopinavir; Ritonavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Loratadine; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Lorcaserin: (Moderate) In general, weight reduction may increase the risk of hypoglycemia in patients with type 2 diabetes mellitus treated with antidiabetic agents, such as insulin and/or insulin secretagogues (e.g., sulfonylureas). In clinical trials, lorcaserin use was associated with reports of hypoglycemia. Blood glucose monitoring is warranted in patients with type 2 diabetes prior to starting and during lorcaserin treatment. Dosage adjustments of anti-diabetic medications should be considered. If a patient develops hypoglycemia during treatment, adjust anti-diabetic drug regimen accordingly. Of note, lorcaserin has not been studied in combination with insulin.
    Losartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Lovastatin; Niacin: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Lumacaftor; Ivacaftor: (Moderate) Lumacaftor; ivacaftor may decrease the therapeutic effects of pioglitazone by decreasing its systemic exposure. If used together, monitor blood glucose concentrations closely; a pioglitazone dosage adjustment may be required to obtain the desired therapeutic effect. Do not exceed the maximum recommended dose. Pioglitazone is a substrate of CYP3A4 and CYP2C8. Lumacaftor is a strong CYP3A inducer; in vitro data also suggest that lumacaftor may induce and/or inhibit CYP2C8. (Moderate) Use caution when administering ivacaftor and pioglitazone concurrently; the clinical impact of this interaction has not yet been determined. Ivacaftor is an inhibitor of CYP3A, and pioglitazone is partially metabolized by CYP3A. Co-administration may increase pioglitazone exposure leading to increased or prolonged therapeutic effects and adverse events. In addition, ivacaftor is a CYP3A substrate and pioglitazone is a mild CYP3A inducer. Administration of ivacaftor with strong CYP3A inducers is not recommended because sub-therapeutic ivacaftor exposure could result; the impact of mild inducers is not known.
    Lumacaftor; Ivacaftor: (Moderate) Lumacaftor; ivacaftor may decrease the therapeutic effects of pioglitazone by decreasing its systemic exposure. If used together, monitor blood glucose concentrations closely; a pioglitazone dosage adjustment may be required to obtain the desired therapeutic effect. Do not exceed the maximum recommended dose. Pioglitazone is a substrate of CYP3A4 and CYP2C8. Lumacaftor is a strong CYP3A inducer; in vitro data also suggest that lumacaftor may induce and/or inhibit CYP2C8.
    Lurasidone: (Moderate) Patients taking pioglitazone should be closely monitored for worsening glycemic control when treatment with lurasidone is instituted. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported. In addition, lurasidone is a CYP3A4 substrate and pioglitazone is a CYP3A4 inducer, and theoretically these agents for diabetes might decrease the concentrations of lurasidone; an interaction has not been established. Monitor the patient clinically. A dosage adjustment of lurasidone may be necessary if pioglitazone is used concomitantly.
    Maraviroc: (Minor) Use caution if coadministration of maraviroc with pioglitazone is necessary, due to a possible decrease in maraviroc exposure. Maraviroc is a CYP3A substrate and pioglitazone is a weak CYP3A4 inducer. Monitor for a decrease in efficacy with concomitant use.
    Mecasermin rinfabate: (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 and mecasermin rinfabate (rh-IGF-1/rh-IGFBP-3) with antidiabetic agents. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. Although the rh-IGF-1/rh-IGFBP-3 complex has less propensity to rapidly lower blood glucose compared to unbound mecasermin, hypoglycemia is possible with either agent. The amino acid sequence of mecasermin (rh-IGF-1) is approximately 50 percent homologous to insulin and cross binding with either receptor is possible. Treatment with mecasermin (rh-IGF-1) has been shown to improve insulin sensitivity and to improve glycemic control in patients with either Type 1 or Type 2 diabetes mellitus when used alone or in conjunction with insulins. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms. (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 and mecasermin rinfabate with antidiabetic agents. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms.
    Mecasermin, Recombinant, rh-IGF-1: (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 and mecasermin rinfabate (rh-IGF-1/rh-IGFBP-3) with antidiabetic agents. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. Although the rh-IGF-1/rh-IGFBP-3 complex has less propensity to rapidly lower blood glucose compared to unbound mecasermin, hypoglycemia is possible with either agent. The amino acid sequence of mecasermin (rh-IGF-1) is approximately 50 percent homologous to insulin and cross binding with either receptor is possible. Treatment with mecasermin (rh-IGF-1) has been shown to improve insulin sensitivity and to improve glycemic control in patients with either Type 1 or Type 2 diabetes mellitus when used alone or in conjunction with insulins. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms. (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 and mecasermin rinfabate with antidiabetic agents. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms.
    Medroxyprogesterone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Megestrol: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Memantine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
    Meperidine; Promethazine: (Minor) Promethazine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Phenothiazines have been reported to increase blood glucose concentrations. (Minor) The phenothiazines such as promethazine may increase blood sugar. Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when a phenothiazine is instituted.
    Mestranol; Norethindrone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Moderate) Coadministration of pioglitazone with oral contraceptives can increase the elimination of estrogens. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Estrogens can decrease the hypoglycemic effects of metformin by impairing glucose tolerance. Patients receiving metformin should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Methamphetamine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Methazolamide: (Moderate) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide, and similar effects may be noted with methazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction. Carbonic anhydrase inhibitors frequently decrease serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Use these drugs with caution in patients treated with metformin, as the risk of lactic acidosis may increase. Monitor electrolytes and renal function. (Minor) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Methyclothiazide: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Methylphenidate: (Moderate) Sympathomimetics, such as methylphenidate, may increase blood sugar via stimulation of beta-2 receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Methylprednisolone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Methyltestosterone: (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Metoclopramide: (Moderate) Because metoclopramide can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. The dosing of metformin may require adjustment in patients who receive metoclopramide concomitantly. (Moderate) Because metoclopramide can enhance gastric emptying in patients with diabetes, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. The dosing of antidiabetic agents may require adjustment in patients who receive metoclopramide concomitantly.
    Metolazone: (Moderate) Thiazide diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose levels. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary.
    Metoprolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Metyrapone: (Moderate) In patients taking insulin or other antidiabetic agents, the signs and symptoms of acute metyrapone toxicity (e.g., symptoms of acute adrenal insufficiency) may be aggravated or modified.
    Midazolam: (Minor) Administration of pioglitazone for 15 days followed by a single dose midazolam syrup, 7.5 mg PO, resulted in a 26% reduction in the midazolam AUC. Higher doses of midazolam may be necessary when coadministered with pioglitazone.
    Midodrine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, like midodrine, may decrease metformin elimination by competing for common renal tubular transport systems. Careful patient monitoring and dose adjustment of metformin and/or midodrine is recommended. (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Mitotane: (Moderate) Use caution if mitotane and pioglitazone are used concomitantly, and monitor for decreased efficacy of pioglitazone and a possible change in dosage requirements. Mitotane is a strong CYP3A4 inducer and pioglitazone is a minor CYP3A4 substrate; coadministration may result in decreased plasma concentrations of pioglitazone.
    Moexipril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Mometasone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Monoamine oxidase inhibitors: (Moderate) Animal data indicate that monoamine oxidase inhibitors (MAO inhibitors) may stimulate insulin secretion. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and oral sulfonylureas. Serum glucose should be monitored closely when MAOI-type medications, including the selective MAO-B inhibitor selegiline, are added to any regimen containing antidiabetic agents. Although at low doses selegiline is selective for MAO type B, in doses above 30 to 40 mg/day, this selectivity is lost. (Moderate) Animal data indicate that monoamine oxidase inhibitors (MAO inhibitors) may stimulate insulin secretion. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and oral sulfonylureas. Serum glucose should be monitored closely when MAOI-type medications, including the selective MAO-B inhibitor selegiline, are added to any regimen containing antidiabetic agents.Although at low doses selegiline is selective for MAO type B, in doses above 30 to 40 mg/day, this selectivity is lost.
    Montelukast: (Moderate) It is possible that an increase in the exposure of pioglitazone may occur when coadministered with other drugs that inhibit CYP2C8 such as montelukast.
    Moxifloxacin: (Moderate) Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. Monitor blood glucose when quinolones and antidiabetic agents are coadministered. (Moderate) Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. Monitor blood glucose when quinolones and antidiabetic agents are coadministered.
    Nadolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Nandrolone Decanoate: (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Naproxen; Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Nebivolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Nebivolol; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Nelfinavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Niacin, Niacinamide: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Niacin; Simvastatin: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Nicotine: (Minor) Blood glucose concentrations should be monitored more closely whenever a change in either nicotine intake or smoking status occurs; dosage adjustments of metformin may be needed. Nicotine may increase plasma glucose; tobacco smoking is known to aggravate insulin resistance. The cessation of nicotine therapy or tobacco smoking may result in a decrease in blood glucose. (Minor) Nicotine may increase plasma glucose. Blood glucose concentrations should be monitored more closely whenever a change in either nicotine intake or smoking status occurs; dosage adjustments in antidiabetic agents may be needed.
    Nifedipine: (Minor) Concentrations of nifedipine may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of nifedipine ER was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with nifedipine ER 30 mg once daily for 4 days resulted in a 13% and 17% reduction in nifedipine ER AUC and Cmax, respectively. In addition, coadministration for 7 days resulted in a 5% and 4% increase in pioglitazone AUC and Cmax, respectively. Patients should be monitored for the desired cardiovascular effects on heart rate, chest pain, or blood pressure; nifedipine dosages may need to be adjusted while the patient is receiving pioglitazone. Close monitoring of blood glucose is also recommended; dosage adjustments in pioglitazone may be needed. (Minor) Nifedipine may increase the plasma metformin Cmax and AUC and increase the amount of metformin excreted in the urine. Metformin half-life is unaffected. Nifedipine appears to enhance the absorption of metformin.
    Nintedanib: (Major) Pioglitazone is a mild CYP3A4 inducer and nintedanib is a minor CYP3A4 substrate. Coadministration of nintedanib with CYP3A4 inducers such as pioglitazone should be avoided as these drugs may decrease exposure to nintedanib and compromise its efficacy.
    Non-Ionic Contrast Media: (Severe) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated radiopaque contrast agents. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after iodinated contrast media.
    Norepinephrine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Norethindrone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Norfloxacin: (Moderate) Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. Monitor blood glucose when quinolones and antidiabetic agents are coadministered. (Moderate) Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones like norfloxacin and an antidiabetic agent like metformin. Monitor blood glucose when norfloxacin and metformin are coadministered.
    Norgestrel: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Octreotide: (Moderate) Administration of octreotide to patients receiving oral antidiabetic agents or insulin can produce hypoglycemia due to slowing of gut motility which leads to decreased postprandial glucose concentrations. Patients should be monitored closely and doses of these medications adjusted accordingly if octreotide is added. (Moderate) Administration of octreotide to patients receiving oral antidiabetic agents or insulin can produce hypoglycemia due to slowing of gut motility which leads to decreased postprandial glucose concentrations. Patients should be monitored closely and doses of these medications adjusted accordingly if octreotide is added.
    Ofloxacin: (Moderate) Hyperglycemia and hypoglycemia have been reported in patients treated concomitantly with quinolones and antidiabetic agents. Therefore, careful monitoring of blood glucose is recommended when quinolones and antidiabetic agents are coadministered. (Moderate) Hyperglycemia and hypoglycemia have been reported in patients treated concomitantly with quinolones and antidiabetic agents. Therefore, careful monitoring of blood glucose is recommended when quinolones and antidiabetic agents are coadministered.
    Olanzapine: (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when olanzapine is instituted. Atypical antipsychotics have been associated with causing metabolic changes, including hyperglycemia, even diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Olmesartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Ombitasvir; Paritaprevir; Ritonavir: (Major) Concurrent administration of pioglitazone with dasabuvir; ombitasvir; paritaprevir; ritonavir may result in elevated pioglitazone plasma concentrations and decreased concentrations of dasabuvir, paritaprevir, and ritonavir. Pioglitazone is an inducer of the hepatic isoenzyme CYP3A4; ritonavir, paritaprevir, and dasabuvir (minor) are CYP3A4 substrates. In addition, pioglitazone is metabolized by CYP3A4; ritonavir is a potent inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are administered together. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Ombitasvir; Paritaprevir; Ritonavir: (Major) The manufacturer recommends against concurrent administration of ombitasvir; paritaprevir; ritonavir and metformin in patients with hepatic or renal impairment. If these drugs are given together, closely monitor blood glucose concentrations and for signs of lactic acidosis (i.e., abdominal or respiratory distress, worsening renal function, somnolence).
    Oritavancin: (Moderate) Pioglitazone is metabolized by CYP3A4; oritavancin is a weak CYP3A4 inducer. Plasma concentrations and efficacy of pioglitazone may be reduced if these drugs are administered concurrently.
    Orlistat: (Moderate) Changes in dietary intake and weight loss induced by orlistat may improve metabolic control in obese diabetic patients, which may be additive to the effects of metformin. Lower blood glucose as a result of orlistat-induced changes in body composition may necessitate a dosage reduction of metformin with time. (Minor) Changes in dietary intake and weight loss induced by orlistat may improve metabolic control in diabetic patients. Lower blood glucose may necessitate a dosage reduction of antidiabetic agents.
    Oxandrolone: (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Oxymetholone: (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Paliperidone: (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when paliperidone is instituted. Paliperidone has been associated with metabolic changes including hyperglycemia, even diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma in some instances. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Pasireotide: (Major) Pasireotide may cause hyperglycemia. Closely monitor patients receiving antidiabetic therapy for changes in glycemic control; adjustments in the dosage of antidiabetic agents may be necessary during pasireotide receipt and after its discontinuation.
    Pazopanib: (Moderate) Pazopanib is a substrate for and a weak inhibitor of CYP3A4 and CYP2C8. Coadministration of pazopanib and pioglitazone, a CYP3A4 and CYP2C8 substrate, may cause an increase in systemic concentrations of pioglitazone. In addition, pioglitazone is a weak inhibitor of CYP3A4 and may cause an increase in systemic concentrations of pazopanib. Use caution when administering these drugs concomitantly.
    Pegvisomant: (Moderate) Patients who have both acromegaly and diabetes mellitus and are being treated with antidiabetic agents may require dose reductions of these medications after the initiation of pegvisomant. Growth hormone decreases insulin sensitivity by opposing the effects of insulin on carbohydrate metabolism; therefore, pegvisomant, which antagonizes growth hormone, is expected to have the opposite effect. Although none of the acromegalic patients with diabetes mellitus who were treated with pegvisomant during the clinical studies developed clinically relevant hypoglycemia, such patients should monitor their blood glucose regularly, with doses of anti-diabetic medications reduced as necessary. (Moderate) Patients who have both acromegaly and diabetes mellitus and are being treated with oral antidiabetic agents may require dose reductions of these medications after the initiation of pegvisomant. Growth hormone decreases insulin sensitivity by opposing the effects of insulin on carbohydrate metabolism; therefore, pegvisomant, which antagonizes growth hormone, is expected to have the opposite effect. Although none of the acromegalic patients with diabetes mellitus who were treated with pegvisomant during the clinical studies developed clinically relevant hypoglycemia, such patients should monitor their blood glucose regularly, with doses of anti-diabetic medications reduced as necessary.
    Penbutolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Pentamidine: (Moderate) Pentamidine can be harmful to pancreatic cells. This effect may lead to hypoglycemia acutely, followed by hyperglycemia with prolonged pentamidine therapy. Patients on antidiabetic agents should be monitored for the need for dosage adjustments during the use of pentamidine.
    Pentoxifylline: (Moderate) Pentoxiphylline has been used concurrently with antidiabetic agents without observed problems, but it may enhance the hypoglycemic action of antidiabetic agents. Patients should be monitored for changes in glycemic control while receiving pentoxifylline in combination with antidiabetic agents.
    Perindopril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Perindopril; Amlodipine: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control. (Minor) Coadministration of CYP3A4 inducers with amlodipine can theoretically increase the hepatic metabolism of amlodipine (a CYP3A4 substrate). Caution should be used when CYP3A4 inducers, such as pioglitazone, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased.
    Phendimetrazine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Phenelzine: (Moderate) Animal data indicate that monoamine oxidase inhibitors (MAO inhibitors) may stimulate insulin secretion. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and oral sulfonylureas. Serum glucose should be monitored closely when MAOI-type medications, including the selective MAO-B inhibitor selegiline, are added to any regimen containing antidiabetic agents.Although at low doses selegiline is selective for MAO type B, in doses above 30 to 40 mg/day, this selectivity is lost.
    Phenobarbital: (Minor) It is possible that a decrease in exposure of pioglitazone will occur when coadministered with drugs that induce CYP2C8 including phenobarbital. Patients receiving phenobarbital in combination with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Phenothiazines: (Minor) The phenothiazines may increase blood sugar. Patients should be closely monitored for worsening glycemic control when any of these antipsychotics is instituted. (Minor) The phenothiazines may increase blood sugar. Patients who are receiving antidiabetic agents should be closely monitored for worsening glycemic control when a phenothiazine is instituted.
    Phentermine: (Moderate) Phentermine may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Diabetic patients may have decreased requirements of antidiabetic agents in association with the use of phentermine. (Moderate) Use caution in combining with phentermine with antidiabetic agents, as requirements for antidiabetic agents may be altered. Phentermine exhibits sympathomimetic activity. Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Additionally, diabetic patients may have decreased requirements of insulins, sulfonylureas, or other antidiabetic agents in association with the use of phentermine and the concomitant dietary regimen and weight loss. As long as blood glucose is carefully monitored to avoid hypoglycemia or hyperglycemia, it appears that phentermine can be used concurrently.
    Phentermine; Topiramate: (Major) Concurrent use of topiramate and metformin is contraindicated in patients with metabolic acidosis. Topiramate frequently causes metabolic acidosis, a condition for which the use of metformin is contraindicated. During a drug interaction study evaluating concurrent use of topiramate and metformin in healthy volunteers, the following changes in metformin pharmacokinetics were observed: the mean Cmax was increased by 17%, the mean AUC was increased by 25%, and the oral plasma clearance was decreased by 20%. The oral plasma clearance of topiramate was reduced, but the extent of the change is unknown. (Moderate) Phentermine may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Diabetic patients may have decreased requirements of antidiabetic agents in association with the use of phentermine. (Moderate) Reductions in AUC and Cmax have been noted in pioglitazone and the active metabolites when coadministered with topiramate. The clinician may suggest that the patient more frequently monitor blood glucose when these drugs are added or deleted from therapy. (Moderate) Use caution in combining with phentermine with antidiabetic agents, as requirements for antidiabetic agents may be altered. Phentermine exhibits sympathomimetic activity. Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Additionally, diabetic patients may have decreased requirements of insulins, sulfonylureas, or other antidiabetic agents in association with the use of phentermine and the concomitant dietary regimen and weight loss. As long as blood glucose is carefully monitored to avoid hypoglycemia or hyperglycemia, it appears that phentermine can be used concurrently.
    Phenylephrine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Phenylephrine; Promethazine: (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Minor) Promethazine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Phenothiazines have been reported to increase blood glucose concentrations. (Minor) The phenothiazines such as promethazine may increase blood sugar. Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when a phenothiazine is instituted.
    Phenytoin: (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients. (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Pindolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Posaconazole: (Major) Posaconazole and pioglitazone should be coadministered with caution due to an increased potential for pioglitazone-related adverse events including ypoglycemia. Posaconazole is a potent inhibitor of CYP3A4, an isoenzyme partially responsible for the metabolism of pioglitazone. These drugs used in combination may result in elevated pioglitazone plasma concentrations, causing an increased risk for pioglitazone-related adverse events. Monitor patients carefully with respect to glycemic control if these drugs are administered together.
    Prasterone, Dehydroepiandrosterone, DHEA (Dietary Supplements): (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Prasterone, Dehydroepiandrosterone, DHEA (FDA-approved): (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia. However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary. (Moderate) Exogenously administered androgens have variable effects on blood glucose control in patients with diabetes mellitus. In general, low testosterone concentrations are associated with insulin resistance, and may worsen hyperglycemia.However, when hypogonadal men (with or without diabetes) are administered exogenous androgens, glycemic control typically improves as indicated by significant reductions in fasting plasma glucose concentrations and HbA1c. Some patients may experience hypoglycemia. Other patients receiving androgen replacement may not have significant changes in blood glucose. Moniitor blood glucose and HbA1C in patients receiving antidiabetic agents and androgens. In some cases, dosage adjustments of the antidiabetic agent may be necessary.
    Praziquantel: (Major) In vitro and drug interactions studies suggest that the CYP3A4 isoenzyme is the major enzyme involved in praziquantel metabolism. Therefore, use of praziquantel with pioglitazone, a weak CYP3A4 inducer, should be done with caution as concomitant use may produce therapeutically ineffective concentrations of praziquantel.
    Prednisolone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Prednisone: (Moderate) Drugs which may cause hyperglycemia, including corticosteroids, may cause temporary loss of glycemic control. Diabetic patients who are administered systemic corticosteroid therapy may require an adjustment in the dosing of the antidiabetic agent.
    Pregabalin: (Moderate) Higher rates of peripheral edema and weight gain may occur in patients who concomitantly use thiazolidinediones with pregabalin. As the thiazolidinediones and pregabalin can both cause weight gain and/or fluid retention, possibly exacerbating or leading to heart failure, care should be taken when co-administering these agents.
    Prilocaine; Epinephrine: (Moderate) Sympathomimetics may increase blood glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Progesterone: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Progestins: (Major) Coadministration of pioglitazone with oral contraceptives can accelerate the rate of metabolism of hormonal contraceptives. Higher-dosage oral contraceptive formulations may be needed to increase contraceptive efficacy during pioglitazone use or the use of an alternative or additional method of contraception can be considered. In addition, estrogens, progestins, and oral contraceptives may alter glucose tolerance, necessitating monitoring of blood glucose on hormone initiation. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Promethazine: (Minor) Promethazine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Phenothiazines have been reported to increase blood glucose concentrations. (Minor) The phenothiazines such as promethazine may increase blood sugar. Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when a phenothiazine is instituted.
    Propantheline: (Moderate) Propantheline slows GI motility, which may increase the absorption of metformin from the small intestine. A 19% increase in metformin AUC has been reported in studies of this interaction in healthy volunteers. However, no serious side effects resulted.
    Propoxyphene: (Moderate) Propoxyphene may enhance the hypoglycemic action of antidiabetic agents. Patients should be closely monitored for changes in glycemic control while receiving propoxyphene in combination with antidiabetic agents.
    Propranolol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Protease inhibitors: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Pseudoephedrine: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Pyrimethamine; Sulfadoxine: (Moderate) Sulfonamides may induce hypoglycemia by increasing the secretion of insulin from the pancreas. Therefore, a pharmacodynamic interaction leading to an increased risk of hypoglycemia may occur in patients taking antidiabetic agents and sulfonamides. (Moderate) Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides. Patients should be closely monitored while receiving any of these drugs in combination with antidiabetic agents.
    Quetiapine: (Moderate) Patients taking antidiabetic agents should be closely monitored for worsening glycemic control when quetiapine is instituted. Atypical antipsychotics have been associated with causing hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. While a causal relationship has not been established, temporal associations of atypical antipsychotic therapy with the aggravation of diabetes mellitus have been reported.
    Quinapril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Racepinephrine: (Moderate) Sympathomimetics may increase blood sugar via stimulation of beta2-receptors which leads to increased glycogenolysis. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Ramipril: (Moderate) ACE inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin-converting enzyme (ACE) inhibitors may enhance the hypoglycemic effects of insulin or other antidiabetic agents by improving insulin sensitivity. Patients receiving antidiabetic agents can become hypoglycemic if ACE inhibitors are administered concomitantly. ACE inhibitors may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Ranitidine: (Minor) Concentrations of pioglitazone may be decreased with concomitant use of ranitidine. The effect of capistration on the systemic exposure of pioglitazone was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with ranitidine 150 mg twice daily for 4 days resulted in a 13% and 16% reduction in pioglitazone AUC and Cmax, respectively. Close monitoring of blood glucose is recommended; dosage adjustments in pioglitazone may be needed.
    Ranolazine: (Major) Limit the dose of metformin to 1700 mg/day if coadministered with ranolazine 1000 mg twice daily. Coadministration of metformin and ranolazine 1000 mg twice daily results in increased plasma concentrations of metformin. Monitor blood glucose concentrations, for common metformin side effects such as gastrointestinal complaints. There is potential for an increased risk for lactic acidosis, which is associated with high metformin concentrations. Doses of metformin do not require reduction if coadministered with ranolazine 500 mg twice daily, as metformin exposure was not significantly increased when coadministered with this lower dose of ranolazine. Ranolazine inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Rasagiline: (Moderate) Animal data indicate that monoamine oxidase inhibitors (MAO inhibitors) may stimulate insulin secretion. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and oral sulfonylureas. Serum glucose should be monitored closely when MAOI-type medications, including the selective MAO-B inhibitor rasagiline, are added to any regimen containing antidiabetic agents.
    Reserpine: (Moderate) Reserpine may mask the signs and symptoms of hypoglycemia. Patients receiving these drugs concomitantly should be monitored for changes in glycemic control. (Moderate) Reserpine may mask the signs and symptoms of hypoglycemia. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control.
    Ribociclib: (Moderate) Coadminister ribociclib and pioglitazone with caution, as the systemic exposure of pioglitazone may be increased resulting in pioglitazone-related adverse reactions; adjust the dose of pioglitazone if necessary. Exposure to ribociclib may also decrease, resulting in reduced efficacy. Ribociclib is extensively metabolized by CYP3A4 and is a moderate CYP3A4 inhibitor in vitro; pioglitazone is a CYP3A4 substrate and inducer.
    Ribociclib; Letrozole: (Moderate) Coadminister ribociclib and pioglitazone with caution, as the systemic exposure of pioglitazone may be increased resulting in pioglitazone-related adverse reactions; adjust the dose of pioglitazone if necessary. Exposure to ribociclib may also decrease, resulting in reduced efficacy. Ribociclib is extensively metabolized by CYP3A4 and is a moderate CYP3A4 inhibitor in vitro; pioglitazone is a CYP3A4 substrate and inducer.
    Rifampin: (Minor) Concomitant administration of rifampin with pioglitazone resulted in a decrease in the AUC of pioglitazone. Patients receiving rifampin with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Rilpivirine: (Moderate) Close clinical monitoring is advised when administering pioglitazone with rilpivirine due to the potential for rilpivirine treatment failure. Although this interaction has not been studied, predictions can be made based on metabolic pathways. Pioglitazone is an inducer of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in decreased rilpivirine serum concentrations and impaired virologic response.
    Risperidone: (Moderate) Because risperidone has been associated with hyperglycemia, diabetic ketoacidosis, hyperosmolar hyperglycemic states, diabetic coma, and overall worsening of glycemic control, patients taking antidiabetic agents such as thiazolidinediones should be closely monitored for worsening glycemic control when risperidone is instituted. Possible mechanisms for risperidone-related effects on glycemic control include insulin resistance or direct beta-cell inhibition.
    Ritodrine: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. Racepinephrine may increase blood glucose concentrations by a similar mechanism. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Intravenous administration of ritodrine has been shown to elevate plasma insulin and glucose concentrations. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with ritodrine is instituted.
    Ritonavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Rivaroxaban: (Minor) Coadministration of rivaroxaban and pioglitazone may result in decreased rivaroxaban exposure and may decrease the efficacy of rivaroxaban. Pioglitazone is a mild inducer of CYP3A4, and rivaroxaban is a substrate of CYP3A4. If these drugs are administered concurrently, monitor the patient for signs of lack of efficacy of rivaroxaban.
    Romidepsin: (Moderate) Romidepsin is a substrate for CYP3A4. Coadministration of a CYP3A4 inducer, like pioglitazone, may decrease systemic concentrations of romidepsin. Use caution when concomitant administration of these agents is necessary.
    Sacubitril; Valsartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Salicylates: (Moderate) Large doses of salicylates may enhance hypoglycemia in diabetic patients via inhibition of prostaglandin synthesis. If these agents are administered or discontinued in patients receiving oral antidiabetic agents, patients should be monitored for hypoglycemia or loss of blood glucose control. (Moderate) Salicylates can indirectly increase insulin secretion. Thus, salicylates can decrease blood sugar. In large doses, salicylates can cause hyperglycemia and glycosuria.
    Saquinavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Selegiline: (Moderate) Animal data indicate that monoamine oxidase inhibitors (MAO inhibitors) may stimulate insulin secretion. Inhibitors of MAO type A have been shown to prolong the hypoglycemic response to insulin and oral sulfonylureas. Serum glucose should be monitored closely when MAOI-type medications, including the selective MAO-B inhibitor selegiline, are added to any regimen containing antidiabetic agents.Although at low doses selegiline is selective for MAO type B, in doses above 30 to 40 mg/day, this selectivity is lost.
    Simeprevir: (Moderate) Use caution with concurrent use of simeprevir and pioglitazone. Pioglitazone is a weak CYP3A4 inducer in vitro, and the FDA labeling states that moderate or strong inducers may significantly reduce the plasma concentrations of simeprevir, resulting in treatment failure. Additionally, simeprevir, a mild intestinal CYP3A4 inhibitor, may increase the side effects of pioglitazone, which is a CYP3A4 substrate. Monitor patients for adverse effects of pioglitazone, such as hypoglycemia.
    Sofosbuvir; Velpatasvir: (Major) Use caution when administering velpatasvir with pioglitazone. Taking these drugs together may decrease velpatasvir plasma concentrations, potentially resulting in loss of antiviral efficacy. Velpatasvir is a CYP3A4 substrate; pioglitazone is a weak inducer of CYP3A4.
    Sofosbuvir; Velpatasvir; Voxilaprevir: (Major) Use caution when administering velpatasvir with pioglitazone. Taking these drugs together may decrease velpatasvir plasma concentrations, potentially resulting in loss of antiviral efficacy. Velpatasvir is a CYP3A4 substrate; pioglitazone is a weak inducer of CYP3A4.
    Somatropin, rh-GH: (Minor) Administration of somatropin may result in increases in blood glucose concentrations, thereby decreasing the hypoglycemic effect of antidiabetic agents. Patients receiving antidiabetic agents should be closely monitored for signs indicating loss of diabetic control when therapy with somatropin, rh-GH is instituted. (Minor) Coadministration of metformin and somatropin may result in increases in blood glucose concentrations, thereby decreasing the hypoglycemic effect of metformin. Patients receiving metformin should be closely monitored for signs indicating loss of diabetic control when therapy with somatropin is instituted.
    Sonidegib: (Moderate) Use caution with the concomitant use of sonidegib and pioglitazone; sonidegib levels may be decreased and its efficacy reduced. Sonidegib is a CYP3A4 substrate and pioglitazone is a weak CYP3A4 inducer. Physiologic-based pharmacokinetics (PBPK) simulations indicate that the sonidegib geometric mean steady-state AUC (0-24 hours) would decrease by 56% in cancer patients who received 14 days of sonidegib 200 mg/day with a moderate CYP3A inducer. Additionally, the PBPK model predicts that the sonidegib geometric mean steady-state AUC (0-24 hours) would decrease by 69% in cancer patients who received sonidegib 200 mg/day with a moderate CYP3A inducer for 4 months.
    Sotalol: (Moderate) Beta-blockers can prolong hypoglycemia by interfering with glycogenolysis or can promote hyperglycemia. Also, beta-blockers can blunt the tachycardic response and exaggerate the hypertensive response to hypoglycemia. Patients receiving beta-blockers and antidiabetic agents concomitantly should be closely monitored for an inappropriate response.
    Sparfloxacin: (Moderate) Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones like sparfloxacin and an antidiabetic agent like metformin. Monitor blood glucose when sparfloxacin and metformin are coadministered. (Moderate) Hyperglycemia and hypoglycemia have been reported in patients treated concomitantly with quinolones and antidiabetic agents. Therefore, careful monitoring of blood glucose is recommended when quinolones and antidiabetic agents are coadministered.
    Sulfadiazine: (Moderate) Sulfonamides may induce hypoglycemia by increasing the secretion of insulin from the pancreas. Therefore, a pharmacodynamic interaction leading to an increased risk of hypoglycemia may occur in patients taking antidiabetic agents and sulfonamides. (Moderate) Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides. Patients should be closely monitored while receiving any of these drugs in combination with antidiabetic agents.
    Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Moderate) It is possible that an increase in the exposure of pioglitazone may occur when coadministered with other drugs that inhibit CYP2C8 such as trimethoprim. Monitor for changes in glycemic control if trimethoprim is coadministered with pioglitazone. (Moderate) Sulfonamides may induce hypoglycemia by increasing the secretion of insulin from the pancreas. Therefore, a pharmacodynamic interaction leading to an increased risk of hypoglycemia may occur in patients taking antidiabetic agents and sulfonamides. (Moderate) Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides. Patients should be closely monitored while receiving any of these drugs in combination with antidiabetic agents.
    Sulfasalazine: (Moderate) Sulfonamides may induce hypoglycemia by increasing the secretion of insulin from the pancreas. Therefore, a pharmacodynamic interaction leading to an increased risk of hypoglycemia may occur in patients taking antidiabetic agents and sulfonamides. (Moderate) Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides. Patients should be closely monitored while receiving any of these drugs in combination with antidiabetic agents.
    Sulfisoxazole: (Moderate) Sulfonamides may induce hypoglycemia by increasing the secretion of insulin from the pancreas. Therefore, a pharmacodynamic interaction leading to an increased risk of hypoglycemia may occur in patients taking antidiabetic agents and sulfonamides. (Moderate) Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides. Patients should be closely monitored while receiving any of these drugs in combination with antidiabetic agents.
    Sulfonamides: (Moderate) Sulfonamides may induce hypoglycemia by increasing the secretion of insulin from the pancreas. Therefore, a pharmacodynamic interaction leading to an increased risk of hypoglycemia may occur in patients taking antidiabetic agents and sulfonamides. (Moderate) Sulfonamides may induce hypoglycemia in some patients by increasing the secretion of insulin from the pancreas. Patients at risk include those with compromised renal function, those fasting for prolonged periods, those that are malnourished, and those receiving high or excessive doses of sulfonamides. Patients should be closely monitored while receiving any of these drugs in combination with antidiabetic agents.
    Tacrolimus: (Moderate) Patients should be monitored for worsening of glycemic control if therapy with tacrolimus is initiated in patients receiving antidiabetic agents. (Moderate) Tacrolimus has been reported to cause hyperglycemia. Furthermore, tacrolimus has been implicated in causing insulin-dependent diabetes mellitus in patients after renal transplantation. Tacrolimus may have direct beta-cell toxicity. Patients should be monitored for worsening of glycemic control if Tacrolimus is initiated in patients receiving antidiabetic agents.
    Tamoxifen: (Major) Pioglitazone is a mild CYP3A4 inducer. Tamoxifen is metabolized by CYP3A4, CYP2D6, and to a lesser extent by both CYP2C9 and CYP2C19, to other potent, active metabolites including endoxifen, which have up to 33 times more affinity for the estrogen receptor than tamoxifen. These metabolites are then inactivated by sulfotransferase 1A1 (SULT1A1). Pioglitazone may induce the CYP3A4 metabolism of tamoxifen to these metabolites; plasma concentrations of tamoxifen and its active metabolites have been reduced when coadministered other CYP3A4 inducers. If coadministration cannot be avoided, monitor for changes to the therapeutic effects of tamoxifen.
    Tegaserod: (Moderate) Because tegaserod can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. The dosing of antidiabetic agents may require adjustment in patients who receive GI prokinetic agents concomitantly. (Moderate) Because tegaserod can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic drugs, such as pioglitazone.
    Telaprevir: (Moderate) Close clinical monitoring is advised when administering pioglitazone with telaprevir due to an increased potential for pioglitazone-related adverse events and the potential for telaprevir treatment failure. If pioglitazone dose adjustments are made, re-adjust the dose upon completion of telaprevir treatment. Although this interaction has not been studied, predictions about the interaction can be made based on the metabolic pathways of pioglitazone and telaprevir. Pioglitazone is a substrate and inducer of the hepatic isoenzyme CYP3A4; telaprevir is a substrate and an inhibitor of this isoenzyme. When used in combination, the plasma concentrations of pioglitazone may increase and the plasma concentrations of telaprevir may decrease.
    Telmisartan: (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of antidiabetic agents by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. Patients receiving an ARB in combination with antidiabetic agents should be monitored for changes in glycemic control. (Moderate) Angiotensin II receptor antagonists (ARBs) may enhance the hypoglycemic effects of metformin by improving insulin sensitivity. In addition, angiotensin II receptor antagonists have been associated with a reduced incidence in the development of new-onset diabetes in patients with hypertension or other cardiac disease. ARBs may rarely reduce renal function, a risk factor for reduced renal clearance of metformin. Patients receiving these drugs together should be monitored for changes in renal function and glycemic control.
    Telotristat Ethyl: (Moderate) Use caution if coadministration of telotristat ethyl and pioglitazone is necessary, as the systemic exposure of pioglitazone may be decreased resulting in reduced efficacy. If these drugs are used together, monitor patients for suboptimal efficacy of pioglitazone; consider increasing the dose of pioglitazone if necessary. Pioglitazone is a CYP3A4 substrate. The mean Cmax and AUC of another sensitive CYP3A4 substrate was decreased by 25% and 48%, respectively, when coadministered with telotristat ethyl; the mechanism of this interaction appears to be that telotristat ethyl increases the glucuronidation of the CYP3A4 substrate.
    Tenofovir Alafenamide: (Moderate) According to the manufacturer, interactions are not expected when metformin is administered with tenofovir alafenamide; however, because tenofovir and metformin can compete for elimination through the kidneys, use of these medications together may increase the risk for side effects, such as lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir alafenamide, may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Tenofovir, PMPA: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion, such as tenofovir, PMPA may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Terbinafine: (Moderate) Due to the risk for breakthrough fungal infections, caution is advised when administering terbinafine with pioglitazone. Although this interaction has not been studied by the manufacturer, and published literature suggests the potential for interactions to be low, taking these drugs together may decrease the systemic exposure of terbinafine. Predictions about the interaction can be made based on the metabolic pathways of both drugs. Terbinafine is metabolized by at least 7 CYP isoenyzmes, with major contributions coming from CYP3A4; pioglitazone induces this enzyme. Monitor patients for breakthrough fungal infections.
    Teriflunomide: (Moderate) Increased monitoring is recommended if teriflunomide is administered concurrently with CYP2C8 substrates, such as pioglitazone. In vivo