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    Potassium-Sparing and Thiazide Diuretic Combinations

    DEA CLASS

    Rx

    DESCRIPTION

    Combination oral diuretic product; potassium-sparing diuretic (aldosterone antagonist) and thiazide diuretic
    For treatment of hypertension or edema (not initial treatment)
    Useful for patients with hyperaldosteronism or hypokalemia

    COMMON BRAND NAMES

    Aldactazide

    HOW SUPPLIED

    Aldactazide/Spironolactone, Hydrochlorothiazide Oral Tab: 25-25mg, 50-50mg

    DOSAGE & INDICATIONS

    For the treatment of edema associated with cirrhosis of the liver, congestive heart failure, or the nephrotic syndrome.
    NOTE: The dosage must be determined by individual titration of the separate components. Spironolactone; hydrochlorothiazide is not indicated for initial therapy. Since the onset of action of spironolactone is gradual, partially explained by the long half-life of canrenone (active metabolite), several days should elapse between dosage adjustments. Dose requirements may change over time due to patient specific factors.
    NOTE: Spironolactone should not be used to prevent anticipated hypokalemia from hydrochlorothiazide. Most patients will not develop hypokalemia with hydrochlorothiazide doses of 12.5 to 25 mg daily.
    NOTE: Spironolactone addition to hydrochlorothiazide has yielded a greater natriuretic effect for patients with a low urinary sodium amount and a high urine potassium amount. Negligible benefit was obtained for patients with a low urine sodium and potassium amount.
    NOTE: Patients with cirrhosis may only need spironolactone due to secondary hyperaldosteronism being an important cause of sodium and water retention. Increasing the dose of hydrochlorothiazide may result in intravascular volume depletion. Intermittent large volume paracentesis may be more appropriate for ascites management.
    NOTE: Treatment of the underlying disease along with restriction of sodium and fluid intake is paramount.
    Oral dosage
    Adults

    Initially, 1 Aldactazide 25/25 mg tablet or equivalent generic tablet (25 mg spironolactone and 25 mg hydrochlorothiazide) PO once daily. The usual maintenance dose is 100 mg/day PO of each component, administered as a single dose or in divided doses. However, the dosage may range from 25 to 200 mg/day PO for each component, depending on response to the initial titration. Aldactazide is also available as 50/50 mg tablets containing 50 mg spironolactone and 50 mg hydrochlorothiazide. Once an initial diuresis has been achieved, dosage adjustment may be needed. The maintenance therapy dosage schedule may be on an intermittent basis.

    Geriatric

    See adult dosage. Geriatric patients may be more sensitive to the effects of the usual adult dosage.

    For the treatment of essential hypertension.
    NOTE: Spironolactone should not be used to prevent anticipated hypokalemia from hydrochlorothiazide. Most patients will not develop hypokalemia with hydrochlorothiazide doses of 12.5 to 25 mg daily.
    NOTE: Hydrochlorothiazide has a relatively flat dose-response curve with little difference in the fraction of excreted sodium between the daily dosage range of 12.5 to 50 mg. Higher doses usually do not increase efficacy but do increase the risk of adverse effects. Spironolactone is indicated for the treatment of essential hypertension, usually in combination with other antihypertensives (e.g., HCTZ, ACE inhibitors).
    Oral dosage
    Adults

    Initially, 1 Aldactazide 25/25 mg tablet or equivalent generic tablet (25 mg spironolactone and 25 mg hydrochlorothiazide) PO once daily. Many patients have an optimal response at 50 to 100 mg/day PO of each component, given as a single dose or in 2 divided doses. Aldactazide is also available as 50/50 mg tablets containing 50 mg spironolactone and 50 mg hydrochlorothiazide.

    Geriatric

    See adult dosage. Geriatric patients may be more sensitive to the effects of the usual adult dosage.

    For the treatment of chronic lung disease (CLD)†.
    NOTE: Spironolactone has been shown to be a tumorigen in rats. Unnecessary use of this drug should be avoided.
    NOTE: There is currently no comparative information regarding the use of spironolactone with hydrochlorothiazide versus hydrochlorothiazide alone.
    NOTE: Due to the need to individualize drug doses in pediatric patients, fixed-dose combination products should generally be avoided. The separate components should be titrated to optimize clinical response.
    Oral dosage
    Infants and Neonates

    In one study, 1.5 mg/kg PO of spironolactone and 2 mg/kg PO of hydrochlorothiazide every 12 hours for 8 weeks improved lung compliance, increased survival, and improved oxygenation for patients that received the diuretic combination relative to patients that received placebo. No differences between the groups were found for the length of hospitalization or ventilator dependence. The patients were at least 30 days old, had radiographic evidence of BPD, and were mechanically ventilated with at least 30% inspired oxygen.

    †Indicates off-label use

    MAXIMUM DOSAGE

    Adults

    200 mg/day PO spironolactone and 200 mg/day PO hydrochlorothiazide.

    Geriatric

    200 mg/day PO spironolactone and 200 mg/day PO hydrochlorothiazide.

    Adolescents

    Safety and efficacy have not been established.

    Children

    Safety and efficacy have not been established.

    Infants

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed. Spironolactone; hydrochlorothiazide should be used with caution in patients with hepatic disease since minor alterations of fluid and electrolyte balance may precipitate hepatic coma.

    Renal Impairment

    CrCl more than 50 mL/min: No dosage adjustment needed.
    CrCl 30 to 50 mL/min: No dosage adjustment needed, but 50 to 100 mg/day of hydrochlorothiazide may be needed. Hydrochlorothiazide must reach the nephron lumen to be effective; monitor serum potassium closely.
    CrCl 10 to 29 mL/min: Avoid spironolactone use due to the risk of hyperkalemia. In addition, hydrochlorothiazide is generally not effective in this setting.
    CrCl less than 10 mL/min: Contraindicated in patients with renal failure or anuria.

    ADMINISTRATION

    Oral Administration

    Food significantly increases the bioavailability of spironolactone.[29016] Based on these results, it may be prudent for a patient to take the drug consistently with or without food. In one study, the presence of food did not alter the effect of spironolactone on blood pressure control or heart rate; however, the authors suggested spironolactone be taken with food to minimize the possibility of gastric irritation, which was observed to be common.[45479]
    Usually administered upon arising to prevent/minimize nocturia.

    Extemporaneous Compounding-Oral

    Extemporaneous formula for oral suspension: The oral suspension of spironolactone; hydrochlorothiazide is not FDA-approved. An oral suspension can be compounded using spironolactone; hydrochlorothiazide tablets and one of the following vehicles: a 1:1 mixture of Ora-Sweet and Ora-Plus, a 1:1 mixture of Ora-Sweet SF and Ora-Plus, or cherry syrup. Pulverize twenty-four 25 mg tablets; add 25 mL of vehicle and mix to a uniform paste. Add in geometric portions of the vehicle almost to a volume of 120 mL; mix thoroughly after each addition. Transfer to a calibrated, polyethylene terephthalate bottle, and add more vehicle to get a total volume of 120 mL. Shake well and protect from light. The resulting suspension (5 mg/mL each of spironolactone and hydrochlorothiazide) is stable for 2 months at room temperature (25 degrees C) or refrigerated (5 degrees C).

    STORAGE

    Aldactazide:
    - Protect from light
    - Store at 77 degrees F

    CONTRAINDICATIONS / PRECAUTIONS

    Asthma, penicillin hypersensitivity, sulfonamide hypersensitivity, thiazide diuretic hypersensitivity

    Aldactazide is a combination product containing spironolactone and hydrochlorothiazide. Thiazide diuretics, such as spironolactone; hydrochlorothiazide, are contraindicated in patients with known thiazide diuretic hypersensitivity. According to the manufacturer, hydrochlorothiazide is specifically contraindicated in patients with sulfonamide hypersensitivity. Hypersensitivity reactions may occur in patients with or without a history of allergy or bronchial asthma; however, reactions are more likely to occur in patients with such history. Although thiazide diuretics are sulfonamide derivatives, sulfonamide cross-sensitivity has been rarely documented. Until further data are available, thiazide diuretics should be used with caution in patients with sulfonamide hypersensitivity. Thiazide diuretics do not contain the N4-aromatic amine or the N1-substituent which are present in sulfonamide antibiotics. Non-arylamine sulfonamide derivatives, such as thiazide diuretics, have been proposed to have a lower risk of allergic reactions in patients with sulfonamide allergy, presumably due to lack of an arylamine group at the N4 position (a proposed structural site of action for sulfonamide allergy). One large retrospective cohort study has reported that in patients with the presence of an allergic reaction after exposure to a sulfonamide antibiotic, 9.9% had an allergic reaction after receiving a non-antibiotic sulfonamide derivative, while in patients who lacked an allergic reaction after sulfonamide antibiotic exposure, 1.6% had an allergic reaction after administration of a non-antibiotic sulfonamide derivative (adjusted odds ratio 2.8; 95% CI, 2.1 to 3.7). A causal relationship between sulfonamide hypersensitivity and allergic reactions with non-arylamine sulfonamide derivatives has not been definitively established and remains controversial. In general, patients with a documented sulfonamide allergy are considered to be predisposed for development of allergic drug reactions. Also, patients with a history of sulfonamide hypersensitivity or penicillin hypersensitivity who receive hydrochlorothiazide may also be at increased risk for the development of an idiosyncratic reaction resulting in myopia and acute angle-closure glaucoma. Discontinue hydrochlorothiazide promptly if this reaction occurs.

    Electrolyte imbalance

    Patients receiving diuretics, like spironolactone; hydrochlorothiazide, should be monitored closely for clinical signs of fluid or electrolyte imbalance.

    Adrenal insufficiency, anuria, diabetes mellitus, hyperkalemia, hypomagnesemia, hyponatremia, renal failure, renal impairment

    Spironolactone; hydrochlorothiazide is contraindicated in patients with anuria, acute renal failure, significant impairment of renal excretory function, hyperkalemia, Addison's disease (chronic adrenal insufficiency) or other conditions associated with hyperkalemia. The Endocrine Society guidelines on the diagnosis and treatment of primary adrenal insufficiency state that use of aldosterone antagonists, such as spironolactone, are contraindicated in patients with adrenal insufficiency (Addison's disease). Hyperkalemia stimulates aldosterone production and aldosterone, in turn, enhances sodium and water reabsorption in exchange for potassium excretion in the distal tubule and collecting duct of the kidney. In Addison's disease, aldosterone deficiency results in hyponatremia, hypovolemia, hypotension and hyperkalemia. Thus, spironolactone therapy will exacerbate the hyponatremia, hypovolemia, hypotension and hyperkalemia seen in adrenal insufficiency and worsen the signs and symptoms of the disease. Spironolactone-induced hyperkalemia can cause life-threatening cardiac arrhythmias and is more likely to occur in patients with renal impairment, diabetes mellitus, or with concomitant use of drugs that raise serum potassium. Patients receiving spironolactone; hydrochlorothiazide should generally not receive potassium supplementation or increase their dietary intake of potassium; excessive potassium intake may cause hyperkalemia in patients receiving spironolactone; hydrochlorothiazide. Hydrochlorothiazide can cause hypokalemia and hyponatremia. The risk of hypokalemia may be increased in patients with cirrhosis, brisk diuresis, or with concomitant use of drugs that lower serum potassium. Hypomagnesemia can result in hypokalemia which appears difficult to treat despite potassium repletion. Monitor serum electrolytes periodically in patients taking spironolactone; hydrochlorothiazide.

    Hypercalcemia, hyperparathyroidism

    Spironolactone; hydrochlorothiazide is contraindicated in patients with hypercalcemia. Patients with hypercalcemia, such as those with hyperparathyroidism, may have further increases in their serum calcium concentration due to hydrochlorothiazide. Hydrochlorothiazide should be discontinued before carrying out tests for parathyroid function.

    Hepatic disease

    Due to electrolyte changes, spironolactone; hydrochlorothiazide can precipitate hepatic encephalopathy in susceptible patients. Hyperkalemia reduces ammonium production, but it decreases renal excretion. Spironolactone; hydrochlorothiazide may be contraindicated in patients with acute or severe hepatic failure, and it should be used with caution in patients with less severe hepatic disease. Patients with liver impairment, hyperbilirubinemia, or cholestasis may not be good candidates for spironolactone receipt, since cytolytic and cholestatic liver damage have been linked to the drug, albeit rarely.

    Gout, hyperuricemia

    Aldactazide is a combination product containing spironolactone and hydrochlorothiazide. Hydrochlorothiazide reduces the clearance of uric acid in a dose-dependent manner. The increase in serum uric acid concentrations is not problematic for most patients; however, patients with baseline hyperuricemia or gout may become develop signs and symptoms of uric acid crystallization.

    Hypercholesterolemia, hypertriglyceridemia

    Aldactazide is a combination product containing spironolactone and hydrochlorothiazide. Patients with hypercholesterolemia or hypertriglyceridemia may have further increases in their total cholesterol or triglyceride concentration while taking hydrochlorothiazide. Thiazide diuretics have been associated with a slight increase in serum cholesterol and triglyceride concentrations. Data from long-term studies, however, suggest diuretic-induced cholesterol changes are not clinically significant and do not contribute to coronary heart disease risk.

    Systemic lupus erythematosus (SLE)

    Aldactazide is a combination product containing spironolactone and hydrochlorothiazide. Thiazide diuretics have been reported to activate or exacerbate systemic lupus erythematosus (SLE). Hydrochlorothiazide should be used with caution in patients with a history of SLE.

    Hypotension, hypovolemia, orthostatic hypotension, sympathectomy, syncope

    Aldactazide is a combination product containing spironolactone and hydrochlorothiazide. Patients with pre-existing hypovolemia or hypotension should have their condition corrected before diuretics are initiated. Orthostatic hypotension may occur during treatment with thiazide diuretics. Orthostatic hypotension can be exacerbated by concurrent use of alcohol, narcotics, or antihypertensive drugs. Excessive hypotension during thiazide diuretic therapy can result in syncope. An increased risk of falls has been reported for elderly patients receiving thiazide diuretics. The antihypertensive effects of thiazides may be enhanced in other patients predisposed for orthostatic hypotension, including the post-sympathectomy patient.

    Preeclampsia, pregnancy

    Avoid spironolactone; hydrochlorothiazide in pregnancy or advise pregnant women of the potential risk to a male fetus. Because of its anti-androgenic activity and the requirement of testosterone for male morphogenesis, spironolactone may have the potential for adversely affecting sex differentiation of the male during embryogenesis. There are no adequate, well-controlled studies on spironolactone; hydrochlorothiazide use in pregnant women. Spironolactone has known endocrine effects in animals including progestational and antiandrogenic effects. The antiandrogenic effects can result in apparent estrogenic side effects in humans, such as gynecomastia. In general, the bulk of the evidence does not indicate that thiazide diuretics are teratogenic in the 1st trimester, although, many experts limit their use to the 2nd and 3rd trimesters.[30736] The American College of Obstetricians and Gynecologists lists hydrochlorothiazide as a second- or third-line agent for the treatment of chronic hypertension in pregnant women.[63903] The risks of thiazide diuretic use in pregnancy increases for those pregnant patients with reduced uteroplacental perfusion (e.g., preeclampsia or intrauterine growth retardation (IUGR)).[30735] [30736] Neonatal thrombocytopenia has been reported following maternal use of thiazide diuretics near term. Hydrochlorothiazide does and spironolactone or its metabolites may cross the placenta and appear in cord blood. Potential risks from thiazide use include electrolyte imbalances in the newborn, pancreatitis, or neonatal complications resulting from such maternal complications as hyperglycemia, electrolyte imbalance, or hypotension. Possible risks of spironolactone; hydrochlorothiazide use in pregnancy include fetal or neonatal jaundice, thrombocytopenia, and other adverse events that have been reported in adults. In general, the routine use of diuretics is not appropriate in pregnant women with mild edema that is unresponsive to supportive measures (elevation of the lower extremities and the use of support hose), and edema that is not associated with more severe disease. Diuretics do not prevent the development of toxemia of pregnancy and there is no satisfactory evidence that they are useful in the treatment of developing toxemia.[48413]

    Breast-feeding

    Spironolactone is not present in breast milk; however, canrenone, the major metabolite of spironolactone, does appear in breast milk in low amounts that are not expected to be clinically relevant. It has been estimated that the amount of canrenone a breast-feeding infant would ingest is no more than 0.2% of the mother's total daily dose of spironolactone.[48406] Thiazide diuretics distribute into breast milk, and it has been recommended by some manufacturers that women not nurse while receiving selected thiazide diuretics. High doses of some thiazide diuretics have been used off-label to suppress lactation, and thus should be used with caution during the establishment of breast-feeding. Some experts consider doses of 50 mg/day or less to be compatible with breast-feeding. Previous American Academy of Pediatrics recommendations classified spironolactone and hydrochlorothiazide as usually compatible with breast-feeding.[27500] The manufacturer does not recommend use of spironolactone; hydrochlorothiazide during breast-feeding; however, if it is utilized, the lowest possible doses should be used.[48413]

    Children

    Safe and effective use of spironolactone; hydrochlorothiazide in children has not been established. Due to the need to individualize drug doses in pediatric patients, fixed-dose combination products are generally be avoided.

    Menstrual irregularity

    Aldactazide is a combination product containing spironolactone and hydrochlorothiazide. Spironolactone can cause antiandrogenic and endocrine effects and should be used with caution in patients with menstrual irregularity or breast enlargement. These effects are usually seen with doses of spironolactone greater than 50 mg/day.

    Water intoxication

    Aldactazide is a combination product containing spironolactone and hydrochlorothiazide. Hydrochlorothiazide prevents production of a maximally dilute urine. Patients with psychogenic polydipsia or water intoxication should probably not receive hydrochlorothiazide. Dilutional hyponatremia is treated with water restriction and sodium repletion, if a total body sodium deficit is present.

    Skin cancer, sunlight (UV) exposure

    Instruct patients taking hydrochlorothiazide to avoid excessive sunlight (UV) exposure and undergo regular skin cancer screening. Hydrochlorothiazide has been associated with an increased risk of non-melanoma skin cancer. An FDA Sentinel Initiative study found that increased risk was mostly for squamous cell carcinoma and in White patients taking large cumulative doses. The increased risk for the overall population was approximately 1 additional case per 16,000 patients per year. For White patients taking a cumulative dose more than 50,000 mg, the risk increased to approximately 1 additional case per 6,700 patients per year. Photosensitivity has been reported with thiazide diuretics like spironolactone; hydrochlorothiazide.

    Driving or operating machinery

    Somnolence and dizziness have been reported to occur in some patients taking spironolactone; hydrochlorothiazide. Therefore, caution is advised when driving or operating machinery until the response to initial treatment with spironolactone; hydrochlorothiazide has been determined.

    Geriatric

    Geriatric patients may be more sensitive to hypotensive and diuretic effects of spironolactone; hydrochlorothiazide than younger adults. Periodic assessments of renal function and serum electrolytes should be done at appropriate intervals to screen for electrolyte imbalances, particularly in the elderly. According to the Beers Criteria, diuretics are considered potentially inappropriate medications (PIMs) in geriatric patients and should be used with caution due to the potential for causing or exacerbating SIADH or hyponatremia. Sodium levels should be closely monitored when starting or changing dosages of diuretics in older adults. In addition, the Beers expert panel considers spironolactone to be a PIM in geriatric patients with a creatinine clearance less than 30 mL/min and recommends avoidance of the drug in this population due to the potential for increased serum potassium.

    Prostate cancer

    Use spironolactone with caution in patients with prostate cancer. In addition to being an aldosterone antagonist, it has been shown to have some antiandrogenic activity. However, in vitro and in animal studies have confirmed that spironolactone is only a weak and partial androgen antagonist, and has intrinsic androgenic activity. One case report has been published regarding a patient with progression of heavily pretreated castration-refractory prostate cancer (CRPC) after the addition of spironolactone for heart failure to abiraterone therapy; this patient's PSA returned to its previous level 2 weeks after discontinuation of spironolactone. In another case, a patient with progressive metastatic CRPC on abiraterone and subsequent enzalutamide therapy twice had significant decreases in PSA and stabilization of visceral disease after discontinuation of spironolactone.

    Infertility

    In animal studies involving female rats, spironolactone was associated with a reduction in circulating estrogen levels and retarded ovarian follicle development. Inhibition of ovulation and reduction in number of implanted embryos were observed with spironolactone administration to female mice. The potential for infertility with spironolactone in humans is unknown. Hydrochlorothiazide has not been shown to adversely affect fertility.[48413]

    ADVERSE REACTIONS

    Severe

    hyperkalemia / Delayed / Incidence not known
    hepatic failure / Delayed / Incidence not known
    hemolytic anemia / Delayed / Incidence not known
    agranulocytosis / Delayed / Incidence not known
    aplastic anemia / Delayed / Incidence not known
    pancreatitis / Delayed / Incidence not known
    azotemia / Delayed / Incidence not known
    renal failure (unspecified) / Delayed / Incidence not known
    interstitial nephritis / Delayed / Incidence not known
    vasculitis / Delayed / Incidence not known
    Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) / Delayed / Incidence not known
    toxic epidermal necrolysis / Delayed / Incidence not known
    erythema multiforme / Delayed / Incidence not known
    lupus-like symptoms / Delayed / Incidence not known
    anaphylactoid reactions / Rapid / Incidence not known
    Stevens-Johnson syndrome / Delayed / Incidence not known
    ocular hypertension / Delayed / Incidence not known
    new primary malignancy / Delayed / Incidence not known
    skin cancer / Delayed / Incidence not known

    Moderate

    hyponatremia / Delayed / Incidence not known
    hypomagnesemia / Delayed / Incidence not known
    hyperglycemia / Delayed / Incidence not known
    glycosuria / Early / Incidence not known
    hypercalcemia / Delayed / Incidence not known
    hyperuricemia / Delayed / Incidence not known
    gout / Delayed / Incidence not known
    jaundice / Delayed / Incidence not known
    cholestasis / Delayed / Incidence not known
    leukopenia / Delayed / Incidence not known
    thrombocytopenia / Delayed / Incidence not known
    hemolysis / Early / Incidence not known
    sialadenitis / Delayed / Incidence not known
    gastritis / Delayed / Incidence not known
    constipation / Delayed / Incidence not known
    confusion / Early / Incidence not known
    ataxia / Delayed / Incidence not known
    hypovolemia / Early / Incidence not known
    hypertriglyceridemia / Delayed / Incidence not known
    hypercholesterolemia / Delayed / Incidence not known
    erythema / Early / Incidence not known
    infertility / Delayed / Incidence not known
    postmenopausal bleeding / Delayed / Incidence not known
    impotence (erectile dysfunction) / Delayed / Incidence not known
    myopia / Delayed / Incidence not known
    blurred vision / Early / Incidence not known
    xanthopsia / Delayed / Incidence not known
    tumorigenicity / Delayed / Incidence not known

    Mild

    diarrhea / Early / Incidence not known
    anorexia / Delayed / Incidence not known
    vomiting / Early / Incidence not known
    nausea / Early / Incidence not known
    abdominal pain / Early / Incidence not known
    weakness / Early / Incidence not known
    headache / Early / Incidence not known
    restlessness / Early / Incidence not known
    paresthesias / Delayed / Incidence not known
    drowsiness / Early / Incidence not known
    lethargy / Early / Incidence not known
    dizziness / Early / Incidence not known
    vertigo / Early / Incidence not known
    polyuria / Early / Incidence not known
    fever / Early / Incidence not known
    urticaria / Rapid / Incidence not known
    pruritus / Rapid / Incidence not known
    photosensitivity / Delayed / Incidence not known
    rash / Early / Incidence not known
    alopecia / Delayed / Incidence not known
    maculopapular rash / Early / Incidence not known
    libido decrease / Delayed / Incidence not known
    mastalgia / Delayed / Incidence not known
    amenorrhea / Delayed / Incidence not known
    gynecomastia / Delayed / Incidence not known
    menstrual irregularity / Delayed / Incidence not known
    muscle cramps / Delayed / Incidence not known

    DRUG INTERACTIONS

    Acarbose: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) Consider a reduced dose of dihydrocodeine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the dihydrocodeine dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Concomitant use of dihydrocodeine with spironolactone may increase dihydrocodeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased dihydromorphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Spironolactone is a weak inhibitor of CYP3A, an isoenzyme partially responsible for the metabolism of dihydrocodeine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with dihydrocodeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia.
    Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Acetaminophen; Codeine: (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Acetaminophen; Dichloralphenazone; Isometheptene: (Major) Isometheptene has sympathomimetic properties. Patients taking antihypertensive agents may need to have their therapy modified. Careful blood pressure monitoring is recommended.
    Acetaminophen; Guaifenesin; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Acetaminophen; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Acetaminophen; Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the oxycodone dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oxycodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like spironolactone can increase oxycodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of oxycodone. If spironolactone is discontinued, oxycodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to oxycodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with oxycodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with oxycodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Acetaminophen; Pentazocine: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Acetaminophen; Propoxyphene: (Moderate) Opiate agonists may potentiate orthostatic hypotension when given concomitantly with spironolactone.
    Acetaminophen; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Acetazolamide: (Moderate) Acetazolamide promotes electrolyte excretion including hydrogen ions, sodium, and potassium. It can enhance the sodium depleting effects of other diuretics when used concurrently. Pre-existing hypokalemia and hyperuricemia can also be potentiated by carbonic anhydrase inhibitors. Monitor serum potassium to determine the need for potassium supplementation and alteration in drug therapy. (Moderate) Carbonic anhydrase inhibitors promote electrolyte excretion including hydrogen ions, sodium, and potassium. They can enhance the sodium depleting effects of other diuretics when used concurrently. Pre-existing hypokalemia and hyperuricemia can also be potentiated by carbonic anhydrase inhibitors. Monitor serum potassium to determine the need for potassium supplementation and alteration in drug therapy.
    Acetohexamide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Aclidinium; Formoterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Acrivastine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Albiglutide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Albuterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Aldesleukin, IL-2: (Moderate) Potassium sparing diuretics may potentiate the hypotension seen with aldesleukin, IL 2. (Moderate) Thiazide diuretics may potentiate the hypotension seen with aldesleukin, IL 2.
    Alemtuzumab: (Moderate) Alemtuzumab may cause hypotension. Careful monitoring of blood pressure and hypotensive symptoms is recommended especially in patients with ischemic heart disease and in patients on antihypertensive agents. (Moderate) Alemtuzumab may cause hypotension. Careful monitoring of blood pressure and hypotensive symptoms is recommended especially in patients with ischemic heart disease and in patients on antihypertensive agents.
    Alendronate; Cholecalciferol: (Moderate) Dose adjustment of vitamin D or vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D or vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
    Alfentanil: (Moderate) Consider a reduced dose of alfentanil with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the alfentanil dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Alfentanil is a sensitive CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase alfentanil exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of alfentanil. If spironolactone is discontinued, alfentanil plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to alfentanil. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with alfentanil. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with alfentanil. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Aliskiren: (Moderate) Due to the risk of hyperkalemia, drugs that increase serum potassium concentration, such as potassium-sparing diuretics, should be used cautiously in patients taking aliskiren. Electrolytes should be routinely monitored in patients receiving aliskiren. Aliskiren can enhance the effects of diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Also, patients with hyponatremia or hypovolemia may become hypotensive and/or develop reversible renal insufficiency when given aliskiren and diuretics.
    Aliskiren; Amlodipine: (Moderate) Due to the risk of hyperkalemia, drugs that increase serum potassium concentration, such as potassium-sparing diuretics, should be used cautiously in patients taking aliskiren. Electrolytes should be routinely monitored in patients receiving aliskiren. Aliskiren can enhance the effects of diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Also, patients with hyponatremia or hypovolemia may become hypotensive and/or develop reversible renal insufficiency when given aliskiren and diuretics.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Due to the risk of hyperkalemia, drugs that increase serum potassium concentration, such as potassium-sparing diuretics, should be used cautiously in patients taking aliskiren. Electrolytes should be routinely monitored in patients receiving aliskiren. Aliskiren can enhance the effects of diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Also, patients with hyponatremia or hypovolemia may become hypotensive and/or develop reversible renal insufficiency when given aliskiren and diuretics.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Due to the risk of hyperkalemia, drugs that increase serum potassium concentration, such as potassium-sparing diuretics, should be used cautiously in patients taking aliskiren. Electrolytes should be routinely monitored in patients receiving aliskiren. Aliskiren can enhance the effects of diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Also, patients with hyponatremia or hypovolemia may become hypotensive and/or develop reversible renal insufficiency when given aliskiren and diuretics.
    Aliskiren; Valsartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients. (Moderate) Due to the risk of hyperkalemia, drugs that increase serum potassium concentration, such as potassium-sparing diuretics, should be used cautiously in patients taking aliskiren. Electrolytes should be routinely monitored in patients receiving aliskiren. Aliskiren can enhance the effects of diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Also, patients with hyponatremia or hypovolemia may become hypotensive and/or develop reversible renal insufficiency when given aliskiren and diuretics.
    Allopurinol: (Moderate) The occurrence of certain hypersensitivity reactions may be increased in patients with renal impairment who receive allopurinol and thiazide diuretics in combination. The precise mechanism for such events is unclear but likely immune-mediated and may be related to an effect of oxypurinol; elevated oxypurinol concentrations appear to be associated with hypersensitivity reactions; decreased clearance of this metabolite may occur with renal impairment and with the concurrent use of thiazide diuretics. Severe skin reactions include exfoliative dermatitis, toxic epidermal necrolysis and Steven's Johnson syndrome; some reactions have been fatal. In addition, thiazide diuretics, like hydrochlorothiazide, can cause hyperuricemia. Since thiazides reduce the clearance of uric acid, patients with gout or hyperuricemia may have exacerbations of their disease.
    Alogliptin: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Alogliptin; Metformin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Alogliptin; Pioglitazone: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Alpha-glucosidase Inhibitors: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Alprazolam: (Major) Avoid coadministration of alprazolam and spironolactone due to the potential for elevated alprazolam concentrations, which may cause prolonged sedation and respiratory depression. If coadministration is necessary, consider reducing the dose of alprazolam as clinically appropriate and monitor for an increase in alprazolam-related adverse reactions. Lorazepam, oxazepam, or temazepam may be safer alternatives if a benzodiazepine must be administered in combination with spironolactone, as these benzodiazepines are not oxidatively metabolized. Alprazolam is a CYP3A substrate and spironolactone is a weak CYP3A inhibitor. Coadministration with another weak CYP3A inhibitor increased alprazolam maximum concentration by 82%, decreased clearance by 42%, and increased half-life by 16%.
    Alprostadil: (Minor) The concomitant use of systemic alprostadil injection and antihypertensive agents, such as spironolactone or other potassium-sparing diuretics, may cause additive hypotension. Caution is advised with this combination. Systemic drug interactions with the urethral suppository (MUSE) or alprostadil intracavernous injection are unlikely in most patients because low or undetectable amounts of the drug are found in the peripheral venous circulation following administration. In those men with significant corpora cavernosa venous leakage, hypotension might be more likely. Use caution with in-clinic dosing for erectile dysfunction (ED) and monitor for the effects on blood pressure. In addition, the presence of medications in the circulation that attenuate erectile function may influence the response to alprostadil. However, in clinical trials with alprostadil intracavernous injection, anti-hypertensive agents had no apparent effect on the safety and efficacy of alprostadil. (Minor) The concomitant use of systemic alprostadil injection and antihypertensive agents, such as thiazide diuretics, may cause additive hypotension. Caution is advised with this combination. Systemic drug interactions with the urethral suppository (MUSE) or alprostadil intracavernous injection are unlikely in most patients because low or undetectable amounts of the drug are found in the peripheral venous circulation following administration. In those men with significant corpora cavernosa venous leakage, hypotension might be more likely. Use caution with in-clinic dosing for erectile dysfunction (ED) and monitor for the effects on blood pressure. In addition, the presence of medications in the circulation that attenuate erectile function may influence the response to alprostadil. However, in clinical trials with alprostadil intracavernous injection, anti-hypertensive agents had no apparent effect on the safety and efficacy of alprostadil.
    Aluminum Hydroxide; Magnesium Hydroxide: (Moderate) Long-term use of potassium-sparing diuretics has been found to increase renal tubular reabsorption of magnesium which may cause hypermagnesemia in patients also receiving magnesium supplements, especially in patients with renal insufficiency.
    Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Moderate) Long-term use of potassium-sparing diuretics has been found to increase renal tubular reabsorption of magnesium which may cause hypermagnesemia in patients also receiving magnesium supplements, especially in patients with renal insufficiency.
    Ambrisentan: (Moderate) Although no specific interactions have been documented, ambrisentan has vasodilatory effects and may contribute additive hypotensive effects when given with other antihypertensive agents. Patients receiving ambrisentan in combination with other antihypertensive agents should be monitored for decreases in blood pressure.
    Amifostine: (Major) Patients receiving antihypertensive agents should be closely monitored during amifostine infusions due to additive effects. If possible, patients should not take their antihypertensive medication 24 hours before receiving amifostine. Patients who can not stop their antihypertensive agents should not receive amifostine or be closely monitored during the infusion and, possibly, given lower doses.
    Aminolevulinic Acid: (Moderate) Thiazide diuretics may cause photosensitivity and may increase the photosensitization effects of photosensitizing agents used in photodynamic therapy. Prevention of photosensitivity includes adequate protection from sources of UV radiation (e.g., avoiding sun exposure and tanning booths) and the use of protective clothing and sunscreens on exposed skin.
    Aminosalicylate sodium, Aminosalicylic acid: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia.
    Amiodarone: (Major) Since antiarrhythmic drugs may be ineffective or may be arrhythmogenic in patients with hypokalemia, any potassium or magnesium deficiency should be corrected before instituting and during amiodarone therapy. Use caution when coadministering amiodarone with drugs which may induce hypokalemia and, or hypomagnesemia including thiazide diuretics.
    Amlodipine; Atorvastatin: (Minor) Because HMG-CoA reductase inhibitors may theoretically blunt adrenal and/or gonadal steroid production by interfering with cholesterol synthesis, the manufacturer recommends that caution should be exercised when atorvastatin is administered concomitantly with drugs that may decrease the concentrations or activity of endogenous hormones, such as spironolactone. The clinical relevance of these potential interactions has not been established.
    Amlodipine; Benazepril: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Amlodipine; Celecoxib: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Amlodipine; Olmesartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Amlodipine; Valsartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Amobarbital: (Moderate) Concurrent use of amobarbital with antihypertensive agents may lead to hypotension. Monitor for decreases in blood pressure during times of coadministration.
    Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Amphetamine: (Minor) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
    Amphetamine; Dextroamphetamine Salts: (Minor) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
    Amphetamine; Dextroamphetamine: (Minor) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
    Amphotericin B cholesteryl sulfate complex (ABCD): (Moderate) The risk of developing severe hypokalemia can be increased when amphotericin B is coadministered with thiazide diuretics. Monitoring serum potassium levels and cardiac function is advised, and potassium supplementation may be required.
    Amphotericin B lipid complex (ABLC): (Moderate) The risk of developing severe hypokalemia can be increased when amphotericin B is coadministered with thiazide diuretics. Monitoring serum potassium levels and cardiac function is advised, and potassium supplementation may be required.
    Amphotericin B liposomal (LAmB): (Moderate) The risk of developing severe hypokalemia can be increased when amphotericin B is coadministered with thiazide diuretics. Monitoring serum potassium levels and cardiac function is advised, and potassium supplementation may be required.
    Amphotericin B: (Moderate) The risk of developing severe hypokalemia can be increased when amphotericin B is coadministered with thiazide diuretics. Monitoring serum potassium levels and cardiac function is advised, and potassium supplementation may be required.
    Amyl Nitrite: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary. (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Angiotensin II receptor antagonists: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Angiotensin-converting enzyme inhibitors: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Anticholinergics: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Apomorphine: (Moderate) Use of potassium-sparing diuretics and apomorphine together can increase the hypotensive effects of apomorphine. Monitor blood pressure regularly during use of this combination. (Moderate) Use of thiazide diuretics and apomorphine together can increase the hypotensive effects of apomorphine. Monitor blood pressure regularly during use of this combination.
    Apraclonidine: (Minor) Alpha blockers as a class may reduce heart rate and blood pressure. While no specific drug interactions have been identified with systemic agents and apraclonidine during clinical trials, it is theoretically possible that additive blood pressure reductions could occur when apraclonidine is combined with the use of antihypertensive agents. Patients using cardiovascular drugs concomitantly with apraclonidine should have their pulse and blood pressure monitored periodically.
    Ardeparin: (Moderate) Coadministration of spironolactone with heparin or low-molecular weight heparins (LMWHs) increases the risk of developing severe hyperkalemia, especially in the presence of renal impairment (renal disease, elderly patients). Use together with caution and monitor serum potassium concentrations.
    Arformoterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Aripiprazole: (Major) Monitor for aripiprazole-related adverse reactions during concurrent use of spironolactone. Reduce the oral aripiprazole dosage to one-quarter (25%) of the usual dose with subsequent adjustments based upon clinical response in patients also receiving a CYP2D6 inhibitor. Adults receiving a combination of a CYP2D6 inhibitor and spironolactone for more than 14 days should have their Abilify Maintena dose reduced from 400 mg/month to 200 mg/month or from 300 mg/month to 160 mg/month, respectively. There are no dosing recommendations for Aristada or Aristada Initio during use of a mild to moderate CYP3A4 inhibitor alone. Aripiprazole is a substrate for CYP2D6 and CYP3A4; spironolactone is a weak CYP3A4 inhibitor. Additionally, monitor blood pressure and adjust spironolactone dose accordingly as aripiprazole may enhance the hypotensive effects of antihypertensive agents. (Minor) Aripiprazole may enhance the hypotensive effects of antihypertensive agents.
    Arsenic Trioxide: (Moderate) Concomitant use of thiazide diuretics and arsenic trioxide should be done cautiously. Electrolyte abnormalities, such as hypokalemia and hypomagnesemia, may increase the risk for QT prolongation and torsade de pointes. (Moderate) Use caution when using arsenic trioxide with potassium-sparing diuretics. Electrolyte abnormalities, such as increased potassium, may increase the risk for QT prolongation and torsade de pointes.
    Articaine; Epinephrine: (Moderate) Potassium-sparing diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine. (Moderate) Thiazide diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine.
    Asenapine: (Moderate) Secondary to alpha-blockade, asenapine can produce vasodilation that may result in additive effects during concurrent use of antihypertensive agents. The potential reduction in blood pressure can precipitate orthostatic hypotension and associated dizziness, tachycardia, and syncope. If concurrent use of asenapine and antihypertensive agents is necessary, patients should be counseled on measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning and rising slowly from a seated position. Close monitoring of blood pressure is recommended until the full effects of the combination therapy are known.
    Aspirin, ASA: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Aspirin, ASA; Butalbital; Caffeine: (Moderate) Barbiturates, such as butalbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone. (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Aspirin, ASA; Butalbital; Caffeine; Codeine: (Moderate) Barbiturates, such as butalbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone. (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia. (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Aspirin, ASA; Caffeine: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Aspirin, ASA; Caffeine; Dihydrocodeine: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia. (Moderate) Consider a reduced dose of dihydrocodeine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the dihydrocodeine dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Concomitant use of dihydrocodeine with spironolactone may increase dihydrocodeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased dihydromorphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Spironolactone is a weak inhibitor of CYP3A, an isoenzyme partially responsible for the metabolism of dihydrocodeine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with dihydrocodeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Aspirin, ASA; Carisoprodol: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia. (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Aspirin, ASA; Dipyridamole: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Aspirin, ASA; Omeprazole: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia. (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Aspirin, ASA; Oxycodone: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia. (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the oxycodone dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oxycodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like spironolactone can increase oxycodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of oxycodone. If spironolactone is discontinued, oxycodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to oxycodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with oxycodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with oxycodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Aspirin, ASA; Pravastatin: (Moderate) Concomitant use of aspirin and spironolactone may decrease the efficacy of spironolactone due to possible inhibition of tubular secretion of canrenone. Monitor patient closely during coadministration for desired effect; a higher maintenance dose may be necessary. In drug interaction studies, a single dose of 600 mg of aspirin inhibited the natriuretic effect of spironolactone. Salicylates can also increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. This combination may cause hyperkalemia.
    Atorvastatin: (Minor) Because HMG-CoA reductase inhibitors may theoretically blunt adrenal and/or gonadal steroid production by interfering with cholesterol synthesis, the manufacturer recommends that caution should be exercised when atorvastatin is administered concomitantly with drugs that may decrease the concentrations or activity of endogenous hormones, such as spironolactone. The clinical relevance of these potential interactions has not been established.
    Atorvastatin; Ezetimibe: (Minor) Because HMG-CoA reductase inhibitors may theoretically blunt adrenal and/or gonadal steroid production by interfering with cholesterol synthesis, the manufacturer recommends that caution should be exercised when atorvastatin is administered concomitantly with drugs that may decrease the concentrations or activity of endogenous hormones, such as spironolactone. The clinical relevance of these potential interactions has not been established.
    Atracurium: (Moderate) Concomitant use of neuromuscular blockers and thiazide diuretics may prolong neuromuscular blockade, possibly due to hypokalemia or alterations in potassium concentrations across the end-plate membrane.
    Atropine: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia. (Moderate) Thiazide diuretics may cause the urine to become alkaline. This may reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde. (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Atropine; Difenoxin: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Atropine; Edrophonium: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Azelastine; Fluticasone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Azilsartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Azilsartan; Chlorthalidone: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Baclofen: (Moderate) Baclofen has been associated with hypotension. Concurrent use with baclofen and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
    Barbiturates: (Moderate) Barbiturates may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Beclomethasone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Moderate) Barbiturates, such as phenobarbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone. (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Belladonna; Opium: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with opium. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with opium. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Benazepril: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Benazepril; Hydrochlorothiazide, HCTZ: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Benzhydrocodone; Acetaminophen: (Moderate) Consider a reduced dose of benzhydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Benzhydrocodone is a prodrug for hydrocodone. Hydrocodone is a CYP3A substrate, and coadministration with weak CYP3A inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of benzhydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to benzhydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with benzhydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with benzhydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia. (Moderate) Thiazide diuretics may cause the urine to become alkaline. This may reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde. (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Benzphetamine: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
    Benztropine: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Beta-agonists: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Betamethasone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Bismuth Subsalicylate: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia.
    Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia.
    Bortezomib: (Moderate) Patients on antihypertensive agents receiving bortezomib treatment may require close monitoring of their blood pressure and dosage adjustment of their medication. During clinical trials of bortezomib, hypotension was reported in roughly 12 percent of patients. (Moderate) Patients on antihypertensive agents receiving bortezomib treatment may require close monitoring of their blood pressure and dosage adjustment of their medication. During clinical trials of bortezomib, hypotension was reported in roughly 12 percent of patients.
    Bosentan: (Moderate) Although no specific interactions have been documented, bosentan has vasodilatory effects and may contribute additive hypotensive effects when given with diuretics.
    Brexpiprazole: (Moderate) Due to brexpiprazole's antagonism at alpha 1-adrenergic receptors, the drug may enhance the hypotensive effects of alpha-blockers and other antihypertensive agents.
    Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Brompheniramine; Guaifenesin; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Brompheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Brompheniramine; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Brompheniramine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Budesonide: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Budesonide; Formoterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated. (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Budesonide; Glycopyrrolate; Formoterol: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms. (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated. (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Bupivacaine; Epinephrine: (Moderate) Potassium-sparing diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine. (Moderate) Thiazide diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine.
    Bupivacaine; Lidocaine: (Moderate) Monitor for lidocaine toxicity if coadministration with spironolactone is necessary as concurrent use may increase lidocaine exposure. Lidocaine is a CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor.
    Bupivacaine; Meloxicam: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Buprenorphine: (Moderate) Concomitant use of buprenorphine and spironolactone can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when spironolactone is added after a stable buprenorphine dose is achieved. If concurrent use is necessary, consider dosage reduction of buprenorphine until stable drug effects are achieved. Monitor patient for respiratory depression and sedation at frequent intervals. When stopping spironolactone, the buprenorphine concentration may decrease, potentially resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependency. If spironolactone is discontinued, consider increasing buprenorphine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. Buprenorphine is a substrate of CYP3A4 and spironolactone is a CYP3A4 inhibitor. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with buprenorphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with buprenorphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Buprenorphine; Naloxone: (Moderate) Concomitant use of buprenorphine and spironolactone can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when spironolactone is added after a stable buprenorphine dose is achieved. If concurrent use is necessary, consider dosage reduction of buprenorphine until stable drug effects are achieved. Monitor patient for respiratory depression and sedation at frequent intervals. When stopping spironolactone, the buprenorphine concentration may decrease, potentially resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependency. If spironolactone is discontinued, consider increasing buprenorphine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. Buprenorphine is a substrate of CYP3A4 and spironolactone is a CYP3A4 inhibitor. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with buprenorphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with buprenorphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Butabarbital: (Moderate) Barbiturates, such as butalbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone.
    Butalbital; Acetaminophen: (Moderate) Barbiturates, such as butalbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone.
    Butalbital; Acetaminophen; Caffeine: (Moderate) Barbiturates, such as butalbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone.
    Butalbital; Acetaminophen; Caffeine; Codeine: (Moderate) Barbiturates, such as butalbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone. (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Cabergoline: (Moderate) Cabergoline should be used cautiously with antihypertensive agents, including potassium-sparing diuretics. Cabergoline has been associated with hypotension. Initial doses of cabergoline higher than 1 mg may produce orthostatic hypotension. It may be advisable to monitor blood pressure. (Moderate) Cabergoline should be used cautiously with antihypertensive agents, including thiazide diuretics. Cabergoline has been associated with hypotension. Initial doses of cabergoline higher than 1 mg may produce orthostatic hypotension. It may be advisable to monitor blood pressure.
    Calcium Phosphate, Supersaturated: (Moderate) Concomitant use of medicines with potential to alter renal perfusion or function such as diuretics may increase the risk of acute phosphate nephropathy in patients receiving sodium phosphate monobasic monohydrate; sodium phosphate dibasic anhydrous. (Moderate) Concomitant use of medicines with potential to alter renal perfusion or function such as diuretics, may increase the risk of acute phosphate nephropathy in patients taking sodium phosphate monobasic monohydrate; sodium phosphate dibasic anhydrous.
    Calcium: (Moderate) The simultaneous administration of thiazide diuretics and calcium salts or calcium carbonate may lead to hypercalcemia. Thiazides cause a decrease in renal tubular excretion of calcium as well as increase in distal tubular reabsorption. Moderate increases in serum calcium have been seen during the treatment with thiazides; if calcium salts are used concomitantly, careful monitoring of serum calcium in recommended.
    Calcium; Vitamin D: (Moderate) Dose adjustment of vitamin D or vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D or vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
    Canagliflozin: (Major) When canagliflozin is initiated in patients already receiving diuretics, symptomatic hypotension can occur. Patients with impaired renal function (eGFR < 60 ml/min/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Before initiating canagliflozin in patients with one or more of these characteristics, volume status should be assessed and corrected. Monitor for signs and symptoms after initiating therapy. In addition, canagliflozin can lead to hyperkalemia. Patients treated with canagliflozin 300 mg/day were more likely to experience increases in potassium. Patients with moderate renal impairment who are taking medications that interfere with potassium excretion, such as potassium-sparing diuretics, are more likely to develop hyperkalemia. Monitor serum potassium levels periodically after initiating canagliflozin in patients with impaired renal function and in patients predisposed to hyperkalemia due to medications or other medical conditions. (Moderate) When canagliflozin is initiated in patients already receiving diuretics, symptomatic hypotension can occur. Patients with impaired renal function (eGFR < 60 ml/min/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Before initiating canagliflozin in patients with one or more of these characteristics, volume status should be assessed and corrected. Monitor for signs and symptoms after initiating therapy. In addition, thiazide diuretics, can also decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. 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. Thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients receiving canagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Canagliflozin; Metformin: (Major) When canagliflozin is initiated in patients already receiving diuretics, symptomatic hypotension can occur. Patients with impaired renal function (eGFR < 60 ml/min/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Before initiating canagliflozin in patients with one or more of these characteristics, volume status should be assessed and corrected. Monitor for signs and symptoms after initiating therapy. In addition, canagliflozin can lead to hyperkalemia. Patients treated with canagliflozin 300 mg/day were more likely to experience increases in potassium. Patients with moderate renal impairment who are taking medications that interfere with potassium excretion, such as potassium-sparing diuretics, are more likely to develop hyperkalemia. Monitor serum potassium levels periodically after initiating canagliflozin in patients with impaired renal function and in patients predisposed to hyperkalemia due to medications or other medical conditions. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) When canagliflozin is initiated in patients already receiving diuretics, symptomatic hypotension can occur. Patients with impaired renal function (eGFR < 60 ml/min/1.73 m2), low systolic blood pressure, or who are elderly may also be at a greater risk. Before initiating canagliflozin in patients with one or more of these characteristics, volume status should be assessed and corrected. Monitor for signs and symptoms after initiating therapy. In addition, thiazide diuretics, can also decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. 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. Thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients receiving canagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Candesartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Candesartan; Hydrochlorothiazide, HCTZ: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Captopril: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Captopril; Hydrochlorothiazide, HCTZ: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Carbamazepine: (Moderate) Both thiazide diuretics and carbamazepine are associated with hyponatremia. Coadministration may result in an additive risk of developing hyponatremia. When concurrent therapy with a thiazide diuretic and carbamazepine is necessary, monitor patients for hyponatremia. (Moderate) Monitor carbamazepine concentrations closely during coadministration of spironolactone; carbamazepine dose adjustments may be needed. Concomitant use may increase carbamazepine concentrations. Carbamazepine is a CYP3A substrate and spironolactone is a CYP3A inhibitor.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Carbetapentane; Guaifenesin; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Carbetapentane; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Carbetapentane; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Carbidopa; Levodopa: (Moderate) Concomitant use of antihypertensive agents with levodopa can result in additive hypotensive effects.
    Carbidopa; Levodopa; Entacapone: (Moderate) Concomitant use of antihypertensive agents with levodopa can result in additive hypotensive effects.
    Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Carbinoxamine; Hydrocodone; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Carbinoxamine; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Carbinoxamine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Carbonic anhydrase inhibitors: (Moderate) Carbonic anhydrase inhibitors promote electrolyte excretion including hydrogen ions, sodium, and potassium. They can enhance the sodium depleting effects of other diuretics when used concurrently. Pre-existing hypokalemia and hyperuricemia can also be potentiated by carbonic anhydrase inhibitors. Monitor serum potassium to determine the need for potassium supplementation and alteration in drug therapy.
    Cardiac glycosides: (Moderate) Monitor for an increase in digoxin-related adverse effects and consider empirically decreasing the digoxin dose by approximately 15 to 30% or modifying digoxin dosing frequency. It is unknown to what extent, if any, spironolactone may increase actual digoxin exposure. Spironolactone and its metabolites interfere with some radioimmunoassays for digoxin. Spironolactone may be falsely detected as digoxin at levels up to 0.5 ng/mL. Although less common, digoxin results may also appear to be falsely reduced. Digoxin assays that use an LC/MS/MS method may be less likely to interact with spironolactone. (Moderate) Thiazide diuretics can cause hypokalemia, hypomagnesemia, or hypercalcemia which may increase digoxin's pharmacologic effect. Close monitoring of serum digoxin concentrations is essential to avoid enhanced toxicity. It is also recommended that serum potassium, magnesium, and calcium be monitored regularly in patients receiving digoxin.
    Cariprazine: (Moderate) Orthostatic vital signs should be monitored in patients who are at risk for hypotension, such as those receiving cariprazine in combination with antihypertensive agents. Atypical antipsychotics may cause orthostatic hypotension and syncope, most commonly during treatment initiation and dosage increases. Patients should be informed about measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning, or rising slowly from a seated position. Consider a cariprazine dose reduction if hypotension occurs.
    Celecoxib: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Celecoxib; Tramadol: (Moderate) Consider a tramadol dosage reduction until stable drug effects are achieved if coadministration with spironolactone is necessary. Closely monitor for seizures, serotonin syndrome, and signs of sedation and respiratory depression. Respiratory depression from increased tramadol exposure may be fatal. Concurrent use of spironolactone, a weak CYP3A inhibitor, may increase tramadol exposure and result in greater CYP2D6 metabolism thereby increasing exposure to the active metabolite M1, which is a more potent mu-opioid agonist. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with tramadol. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with tramadol. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Cetirizine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlophedianol; Guaifenesin; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Chlordiazepoxide; Clidinium: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Chloroprocaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Chlorpheniramine; Codeine: (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Consider a reduced dose of dihydrocodeine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the dihydrocodeine dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Concomitant use of dihydrocodeine with spironolactone may increase dihydrocodeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased dihydromorphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Spironolactone is a weak inhibitor of CYP3A, an isoenzyme partially responsible for the metabolism of dihydrocodeine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with dihydrocodeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Chlorpheniramine; Dihydrocodeine; Pseudoephedrine: (Moderate) Consider a reduced dose of dihydrocodeine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the dihydrocodeine dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Concomitant use of dihydrocodeine with spironolactone may increase dihydrocodeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased dihydromorphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Spironolactone is a weak inhibitor of CYP3A, an isoenzyme partially responsible for the metabolism of dihydrocodeine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with dihydrocodeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlorpheniramine; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlorpheniramine; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Chlorpheniramine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Chlorpropamide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Cholestyramine: (Moderate) Cholestyramine, an ion exchange resin, binds hydrochlorothiazide and reduces its absorption from the gastrointestinal tract by up to 85% when co-administered as single doses. Although the manufacturer for Questran recommends that other medicines be taken at least 1 hour before or 4-6 hours after cholestyramine, it has been recommended that thiazides be administered at least 4 hours before or after cholestyramine to minimize the reduction in absorption. By administering hydrochlorothiazide at least 4 hours before cholestyramine, the decrease in absorption of hydrochlorothiazide is approximately 30-35%. (Moderate) Use caution if spironolactone is administered concurrently with cholestyramine. Hyperkalemic metabolic acidosis has been reported in patients given spironolactone concurrently with cholestyramine.
    Choline Salicylate; Magnesium Salicylate: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia.
    Ciclesonide: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Cidofovir: (Contraindicated) The administration of cidofovir with another potentially nephrotoxic agent, such as diuretics, is contraindicated. Diuretics should be discontinued at least 7 days prior to beginning cidofovir.
    Cisapride: (Major) Cisapride should be used with great caution in patients receiving thiazide diuretics. Drugs that are associated with depletion of electrolytes may cause cisapride-induced cardiac arrhythmias. Serum electrolytes and creatinine should be assessed prior to administration of cisapride and whenever conditions develop that may affect electrolyte imbalance or renal function.
    Cisatracurium: (Moderate) Concomitant use of neuromuscular blockers and thiazide diuretics may prolong neuromuscular blockade, possibly due to hypokalemia or alterations in potassium concentrations across the end-plate membrane.
    Citalopram: (Moderate) Citalopram causes dose-dependent QT interval prolongation. Concurrent use of citalopram and medications known to cause electrolyte imbalance may increase the risk of developing QT prolongation. Therefore, caution is advisable during concurrent use of citalopram and diuretics. In addition, patients receiving a diuretic during treatment with citalopram may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH has been reported during therapy with SSRIs. Cases involving serum sodium levels lower than 110 mmol/l have occurred. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of citalopram should be considered in patients who develop symptomatic hyponatremia.
    Clindamycin; Tretinoin: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
    Clozapine: (Moderate) Caution is advisable during concurrent use of clozapine and thiazide diuretics as concurrent use may increase the risk and severity of hypotension. In addition, electrolyte imbalance caused by thiazide diuretics may increase the risk of QT prolongation by clozapine. (Moderate) Consider a clozapine dose reduction if coadministered with spironolactone and monitor for adverse reactions. If spironolactone is discontinued, monitor for lack of clozapine effect, and increase dose if necessary. A clinically relevant increase in the plasma concentration of clozapine may occur during concurrent use. Clozapine is partially metabolized by CYP3A. Spironolactone is a weak CYP3A inhibitor. Additionally, monitor blood pressure and adjust spironolactone dose accordingly as clozapine may enhance the hypotensive effects of antihypertensive agents.
    Cocaine: (Major) Use of cocaine with antihypertensive agents may increase the antihypertensive effects of the antihypertensive medications or may potentiate cocaine-induced sympathetic stimulation.
    Codeine: (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Codeine; Guaifenesin: (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Codeine; Phenylephrine; Promethazine: (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Codeine; Promethazine: (Moderate) Concomitant use of codeine with spironolactone may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of spironolactone could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. spironolactone is a weak inhibitor of CYP3A4. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Co-Enzyme Q10, Ubiquinone: (Moderate) Co-enzyme Q10, ubiquinone (CoQ10) may lower blood pressure. CoQ10 use in combination with antihypertensive agents may lead to additional reductions in blood pressure in some individuals. Patients who choose to take CoQ10 concurrently with antihypertensive medications should receive periodic blood pressure monitoring. Patients should be advised to inform their prescriber of their use of CoQ10.
    Colestipol: (Moderate) Although to a lesser extent than cholestyramine, colestipol also has been shown to inhibit the GI absorption and therapeutic response of thiazide diuretics. Single doses of colestipol resins reduce the absorption of HCTZ by up to 43%. Administering thiazide diuretics at least 2 hours before colestipol has been suggested to minimize the interaction.
    Corticosteroids: (Moderate) Additive hypokalemia may occur when non-potassium sparing diuretics, including thiazide diuretics, are coadministered with other drugs with a significant risk of hypokalemia, such as corticosteroids. Monitoring serum potassium levels and cardiac function is advised, and potassium supplementation may be required. (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Cortisone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Cosyntropin: (Major) Patients receiving spironolactone should omit their pre-test doses on the day selected for testing. Patients taking inadvertent doses of spironolactone may exhibit abnormally high basal plasma cortisol concentrations and a decreased response to the test. (Moderate) Use cosyntropin cautiously in patients receiving diuretics. Cosyntropin may accentuate the electrolyte loss associated with diuretic therapy.
    Cyclophosphamide: (Moderate) Closely monitor complete blood counts if coadministration of cyclophosphamide with thiazide diuretics is necessary as there is an increased risk of hematologic toxicity and immunosuppression.
    Cyclosporine: (Major) Avoid concomitant use of cyclosporine and potassium-sparing diuretics, such as spironolactone, due to the risk of hyperkalemia. If concomitant use is necessary, closely monitor serum potassium concentrations. Additionally, closely monitor cyclosporine whole blood trough concentrations as appropriate and watch for cyclosporine-related adverse reactions as concurrent use may increase cyclosporine exposure. The dose of cyclosporine may need to be adjusted. Cyclosporine is a CYP3A substrate and spironolactone is a weak CYP3A inhibitor.
    Dalteparin: (Moderate) Coadministration of spironolactone with heparin or low-molecular weight heparins (LMWHs) increases the risk of developing severe hyperkalemia, especially in the presence of renal impairment (renal disease, elderly patients). Use together with caution and monitor serum potassium concentrations.
    Dapagliflozin: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Dapagliflozin; Metformin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Dapagliflozin; Saxagliptin: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Darifenacin: (Minor) Diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Deflazacort: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Desloratadine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Desvenlafaxine: (Moderate) Patients receiving a diuretic during treatment with a Serotonin norepinephrine reuptake inhibitor (SNRI) may be at greater risk of developing hyponatremia and/or the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs. Cases involving serum sodium levels lower than 110 mmol/L have been reported. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Dexamethasone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Dexbrompheniramine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Dexlansoprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Dextroamphetamine: (Minor) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Dextromethorphan; Quinidine: (Moderate) Quinidine can decrease blood pressure and should be used cautiously in patients receiving antihypertensive agents due to the potential for additive hypotension. (Moderate) Quinidine can decrease blood pressure and should be used cautiously in patients receiving antihypertensive agents due to the potential for additive hypotension.
    Diazepam: (Moderate) Monitor for an increase in diazepam-related adverse reactions, including sedation and respiratory depression, if coadministration with spironolactone is necessary. Concurrent use may increase diazepam exposure. Diazepam is a CYP3A substrate and spironolactone is a CYP3A inhibitor.
    Diazoxide: (Moderate) Additive hypotensive effects can occur with the concomitant administration of diazoxide with other antihypertensive agents. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly. The manufacturer advises that IV diazoxide should not be administered to patients within 6 hours of receiving other antihypertensive agents. (Moderate) Enhanced hyperglycemia is possible during concurrent use of diazoxide and thiazide diuretics. Additive hypotensive effects can also occur with the concomitant administration of diazoxide with thiazide diuretics.
    Dichlorphenamide: (Moderate) Use dichlorphenamide and diuretics together with caution. Dichlorphenamide increases potassium excretion and can cause hypokalemia and should be used cautiously with other drugs that may cause hypokalemia including loop diuretics and thiazide diuretics. Measure potassium concentrations at baseline and periodically during dichlorphenamide treatment. If hypokalemia occurs or persists, consider reducing the dose or discontinuing dichlorphenamide therapy. (Moderate) Use dichlorphenamide and spironolactone together with caution. Metabolic acidosis is associated with the use of dichlorphenamide and has been reported with spironolactone in patients with decompensated hepatic cirrhosis. 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.
    Diclofenac: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Diclofenac; Misoprostol: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Dicyclomine: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Diethylpropion: (Major) Diethylpropion has vasopressor effects and may limit the benefit of thiazide diuretics. Although leading drug interaction texts differ in the potential for an interaction between diethylpropion and this group of antihypertensive agents, these effects are likely to be clinically significant and have been described in hypertensive patients on these medications.
    Diflunisal: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Digitoxin: (Moderate) Monitor for an increase in digoxin-related adverse effects and consider empirically decreasing the digoxin dose by approximately 15 to 30% or modifying digoxin dosing frequency. It is unknown to what extent, if any, spironolactone may increase actual digoxin exposure. Spironolactone and its metabolites interfere with some radioimmunoassays for digoxin. Spironolactone may be falsely detected as digoxin at levels up to 0.5 ng/mL. Although less common, digoxin results may also appear to be falsely reduced. Digoxin assays that use an LC/MS/MS method may be less likely to interact with spironolactone. (Moderate) Thiazide diuretics can cause hypokalemia, hypomagnesemia, or hypercalcemia which may increase digoxin's pharmacologic effect. Close monitoring of serum digoxin concentrations is essential to avoid enhanced toxicity. It is also recommended that serum potassium, magnesium, and calcium be monitored regularly in patients receiving digoxin.
    Digoxin: (Moderate) Monitor for an increase in digoxin-related adverse effects and consider empirically decreasing the digoxin dose by approximately 15 to 30% or modifying digoxin dosing frequency. It is unknown to what extent, if any, spironolactone may increase actual digoxin exposure. Spironolactone and its metabolites interfere with some radioimmunoassays for digoxin. Spironolactone may be falsely detected as digoxin at levels up to 0.5 ng/mL. Although less common, digoxin results may also appear to be falsely reduced. Digoxin assays that use an LC/MS/MS method may be less likely to interact with spironolactone. (Moderate) Thiazide diuretics can cause hypokalemia, hypomagnesemia, or hypercalcemia which may increase digoxin's pharmacologic effect. Close monitoring of serum digoxin concentrations is essential to avoid enhanced toxicity. It is also recommended that serum potassium, magnesium, and calcium be monitored regularly in patients receiving digoxin.
    Dihydrocodeine; Guaifenesin; Pseudoephedrine: (Moderate) Consider a reduced dose of dihydrocodeine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the dihydrocodeine dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Concomitant use of dihydrocodeine with spironolactone may increase dihydrocodeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased dihydromorphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If spironolactone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Spironolactone is a weak inhibitor of CYP3A, an isoenzyme partially responsible for the metabolism of dihydrocodeine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with dihydrocodeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Diphenhydramine; Ibuprofen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Diphenhydramine; Naproxen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Diphenhydramine; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Diphenoxylate; Atropine: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Disopyramide: (Moderate) Monitor for an increase in disopyramide-related adverse reactions if coadministration with spironolactone is necessary as concurrent use may increase disopyramide exposure. Disopyramide is a CYP3A substrate and spironolactone is a weak CYP3A inhibitor. Although specific drug interaction studies have not been done for disopyramide, cases of life-threatening interactions have been reported when disopyramide was coadministered with moderate and strong CYP3A inhibitors.
    Dobutamine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives such as metolazone when administered concomitantly.
    Dofetilide: (Contraindicated) Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting drugs such as loop diuretics and thiazide diuretics, increasing the potential for dofetilide-induced torsade de pointes. Additionally, in patients treated with either hydrochlorothiazide 50 mg or hydrochlorothiazide/triamterene 50 mg/100 mg daily in combination with dofetilide 500 mcg twice daily for 5 days, dofetilide AUC and Cmax concentrations increased by 27% and 21%, respectively, for the hydrochlorothiazide alone group and by 30% and 16%, respectively, for the hydrochlorothiazide/triamterene group. Furthermore, a 197% and 190% QTc increase over time was seen in the hydrochlorothiazide and hydrochlorothiazide/triamterene groups, respectively. Based on these findings, the manufacturer of dofetilide contraindicates the concomitant use of hydrochlorothiazide (alone or in combination with other drugs such as triamterene); these findings can be explained both by an increase in the plasma concentration of dofetilide and a reduction in the serum potassium concentration. In a population pharmacokinetic analysis of plasma dofetilide concentrations, the mean dofetilide clearance of dofetilide was 16% lower in patients on thiazide diuretics. It is prudent to avoid the use of any thiazide diuretic in combination with dofetilide. (Moderate) Monitor for an increase in dofetilide-related adverse reactions, including QT prolongation, if coadministration with spironolactone is necessary as concurrent use may increase dofetilide exposure. Spironolactone is a weak CYP3A4 inhibitor. Dofetilide is a minor CYP3A4 substrate; however, because there is a linear relationship between dofetilide plasma concentration and QTc, concomitant administration of CYP3A4 inhibitors may increase the risk of arrhythmia (torsade de pointes).
    Dolasetron: (Moderate) Caution is advisable during concurrent use of dolasetron and thiazide diuretics as electrolyte imbalance caused by diuretics may increase the risk of QT prolongation with dolasetron.
    Donepezil; Memantine: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
    Dopamine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives such as metolazone when administered concomitantly.
    Doxacurium: (Moderate) Concomitant use of neuromuscular blockers and thiazide diuretics may prolong neuromuscular blockade, possibly due to hypokalemia or alterations in potassium concentrations across the end-plate membrane.
    Droperidol: (Moderate) Caution is advised when using droperidol in combination with thiazide diuretics which may lead to electrolyte abnormalities, especially hypokalemia or hypomagnesemia, as such abnormalities may increase the risk for QT prolongation or cardiac arrhythmias.
    Drospirenone: (Moderate) Drospirenone has antimineralocorticoid effects and may increase serum potassium, therefore concurrent use of potassium-sparing diuretics may increase the risk of hyperkalemia, especially in the presence of renal impairment. Monitor serum potassium during the 1st month of drospirenone treatment if potassium-sparing diuretics are used concurrently and thereafter as clinically indicated. Also monitor for any changes in blood pressure, fluid retention, or renal function.
    Drospirenone; Estetrol: (Moderate) Drospirenone has antimineralocorticoid effects and may increase serum potassium, therefore concurrent use of potassium-sparing diuretics may increase the risk of hyperkalemia, especially in the presence of renal impairment. Monitor serum potassium during the 1st month of drospirenone treatment if potassium-sparing diuretics are used concurrently and thereafter as clinically indicated. Also monitor for any changes in blood pressure, fluid retention, or renal function.
    Drospirenone; Estradiol: (Moderate) Drospirenone has antimineralocorticoid effects and may increase serum potassium, therefore concurrent use of potassium-sparing diuretics may increase the risk of hyperkalemia, especially in the presence of renal impairment. Monitor serum potassium during the 1st month of drospirenone treatment if potassium-sparing diuretics are used concurrently and thereafter as clinically indicated. Also monitor for any changes in blood pressure, fluid retention, or renal function.
    Drospirenone; Ethinyl Estradiol: (Moderate) Drospirenone has antimineralocorticoid effects and may increase serum potassium, therefore concurrent use of potassium-sparing diuretics may increase the risk of hyperkalemia, especially in the presence of renal impairment. Monitor serum potassium during the 1st month of drospirenone treatment if potassium-sparing diuretics are used concurrently and thereafter as clinically indicated. Also monitor for any changes in blood pressure, fluid retention, or renal function.
    Drospirenone; Ethinyl Estradiol; Levomefolate: (Moderate) Drospirenone has antimineralocorticoid effects and may increase serum potassium, therefore concurrent use of potassium-sparing diuretics may increase the risk of hyperkalemia, especially in the presence of renal impairment. Monitor serum potassium during the 1st month of drospirenone treatment if potassium-sparing diuretics are used concurrently and thereafter as clinically indicated. Also monitor for any changes in blood pressure, fluid retention, or renal function.
    Dulaglutide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Duloxetine: (Moderate) Patients receiving a diuretic during treatment with a Serotonin norepinephrine reuptake inhibitor (SNRI) may be at greater risk of developing hyponatremia and/or the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs. Cases involving serum sodium levels lower than 110 mmol/L have been reported. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Eliglustat: (Major) Coadministration of eliglustat and spironolactone is not recommended in poor CYP2D6 metabolizers (PMs). In extensive CYP2D6 metabolizers (EM) with mild hepatic impairment, coadministration of these agents requires dosage reduction of eliglustat to 84 mg PO once daily. Spironolactone is a weak CYP3A inhibitor; eliglustat is a CYP3A and CYP2D6 substrate. Because CYP3A plays a significant role in the metabolism of eliglustat in CYP2D6 PMs, coadministration of eliglustat with CYP3A inhibitors may increase eliglustat exposure and the risk of serious adverse events (e.g., QT prolongation and cardiac arrhythmias).
    Empagliflozin: (Moderate) Administer empagliflozin; metformin with caution in patients receiving diuretics. When empagliflozin is initiated in patients already receiving diuretics, volume depletion can occur. Patients with impaired renal function, low systolic blood pressure, or who are elderly may also be at a greater risk for volume depletion and perhaps symptomatic hypotension. Before initiating empagliflozin in patients with one or more of these characteristics, assess volume status and correct if necessary. Monitor for signs and symptoms after initiating therapy. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Empagliflozin; Linagliptin: (Moderate) Administer empagliflozin; metformin with caution in patients receiving diuretics. When empagliflozin is initiated in patients already receiving diuretics, volume depletion can occur. Patients with impaired renal function, low systolic blood pressure, or who are elderly may also be at a greater risk for volume depletion and perhaps symptomatic hypotension. Before initiating empagliflozin in patients with one or more of these characteristics, assess volume status and correct if necessary. Monitor for signs and symptoms after initiating therapy. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Empagliflozin; Linagliptin; Metformin: (Moderate) Administer empagliflozin; metformin with caution in patients receiving diuretics. When empagliflozin is initiated in patients already receiving diuretics, volume depletion can occur. Patients with impaired renal function, low systolic blood pressure, or who are elderly may also be at a greater risk for volume depletion and perhaps symptomatic hypotension. Before initiating empagliflozin in patients with one or more of these characteristics, assess volume status and correct if necessary. Monitor for signs and symptoms after initiating therapy. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Empagliflozin; Metformin: (Moderate) Administer empagliflozin; metformin with caution in patients receiving diuretics. When empagliflozin is initiated in patients already receiving diuretics, volume depletion can occur. Patients with impaired renal function, low systolic blood pressure, or who are elderly may also be at a greater risk for volume depletion and perhaps symptomatic hypotension. Before initiating empagliflozin in patients with one or more of these characteristics, assess volume status and correct if necessary. Monitor for signs and symptoms after initiating therapy. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Enalapril, Enalaprilat: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Enalapril; Felodipine: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Concurrent use of felodipine and spironolactone should be approached with caution and conservative dosing of felodipine due to the potential for significant increases in felodipine exposure. Monitor for evidence of increased felodipine effects including decreased blood pressure and increased heart rate. Felodipine is a sensitive CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor. Concurrent use of another weak CYP3A4 inhibitor increased felodipine AUC and Cmax by approximately 50%. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Enalapril; Hydrochlorothiazide, HCTZ: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Enflurane: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents. (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Enoxaparin: (Moderate) Coadministration of spironolactone with heparin or low-molecular weight heparins (LMWHs) increases the risk of developing severe hyperkalemia, especially in the presence of renal impairment (renal disease, elderly patients). Use together with caution and monitor serum potassium concentrations.
    Ephedrine: (Major) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by potassium-sparing diuretics. Blood pressure and heart rates should be monitored closely to confirm that the desired antihypertensive effect is achieved. (Major) The cardiovascular effects of sympathomimetics, such as ephedrine, may reduce the antihypertensive effects produced by thiazide diuretics. Blood pressure and heart rates should be monitored closely to confirm that the desired antihypertensive effect is achieved.
    Ephedrine; Guaifenesin: (Major) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by potassium-sparing diuretics. Blood pressure and heart rates should be monitored closely to confirm that the desired antihypertensive effect is achieved. (Major) The cardiovascular effects of sympathomimetics, such as ephedrine, may reduce the antihypertensive effects produced by thiazide diuretics. Blood pressure and heart rates should be monitored closely to confirm that the desired antihypertensive effect is achieved.
    Epinephrine: (Moderate) Potassium-sparing diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine. (Moderate) Thiazide diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine.
    Eplerenone: (Contraindicated) Eplerenone should not be used concomitantly with potassium-sparing diuretics (e.g., amiloride, spironolactone, triamterene) because of the increased risk of developing hyperkalemia. The combine use of these medications in patients with hypertension or renal impairment contraindicated.
    Epoprostenol: (Moderate) Epoprostenol can have additive effects when administered with other antihypertensive agents. These effects can be used to therapeutic advantage, but dosage adjustments may be necessary.
    Eprosartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Ertugliflozin; Metformin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients.
    Ertugliflozin; Sitagliptin: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Escitalopram: (Moderate) Patients receiving a diuretic during treatment with escitalopram may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH has been reported during therapy with SSRIs. Cases involving serum sodium levels lower than 110 mmol/l have occurred. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of escitalopram should be considered in patients who develop symptomatic hyponatremia.
    Esomeprazole: (Moderate) Proton pump inhibitors, such as esomeprazole, have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Estradiol Cypionate; Medroxyprogesterone: (Minor) Estrogens can induce fluid retention and may increase blood pressure in some patients; patients who are receiving antihypertensive agents concurrently with hormone therapy should be monitored for antihypertensive effectiveness.
    Estradiol: (Minor) Estrogens can induce fluid retention and may increase blood pressure in some patients; patients who are receiving antihypertensive agents concurrently with hormone therapy should be monitored for antihypertensive effectiveness.
    Ethanol: (Moderate) Patients should be cautioned that ingesting alcohol can increase the chance of low blood pressure and dizziness when taking a thiazide diuretic or the related drug, metolazone. Patients may wish to limit alcohol ingestion while taking one of these diuretics and should be monitored for signs or symptoms of hypotension, including postural hypotension and dizziness. (Moderate) Patients should be cautioned that ingesting alcohol can increase the chance of low blood pressure and dizziness when taking spironolactone. Patients may wish to limit alcohol ingestion while taking this drug and should be monitored for signs or symptoms of hypotension, including postural hypotension and dizziness.
    Etodolac: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Etomidate: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents. (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Exenatide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Famotidine; Ibuprofen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Felodipine: (Moderate) Concurrent use of felodipine and spironolactone should be approached with caution and conservative dosing of felodipine due to the potential for significant increases in felodipine exposure. Monitor for evidence of increased felodipine effects including decreased blood pressure and increased heart rate. Felodipine is a sensitive CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor. Concurrent use of another weak CYP3A4 inhibitor increased felodipine AUC and Cmax by approximately 50%.
    Fenoprofen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Fentanyl: (Moderate) Consider a reduced dose of fentanyl with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the fentanyl dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Fentanyl is a CYP3A substrate, and coadministration with CYP3A inhibitors like spironolactone can increase fentanyl exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of fentanyl. If spironolactone is discontinued, fentanyl plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to fentanyl. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with fentanyl. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with fentanyl. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Fexofenadine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Finerenone: (Moderate) Monitor serum potassium during initiation or dose adjustment of either finerenone or spironolactone; a finerenone dosage reduction may be necessary. Concomitant use may increase finerenone exposure and the risk of hyperkalemia. Finerenone is a CYP3A substrate and spironolactone is a weak CYP3A inhibitor. Coadministration with another weak CYP3A inhibitor increased overall exposure to finerenone by 21%.
    Fish Oil, Omega-3 Fatty Acids (Dietary Supplements): (Moderate) High doses of fish oil supplements may produce a blood pressure lowering effect. It is possible that additive reductions in blood pressure may be seen when fish oils are used in a patient already taking antihypertensive agents. (Moderate) High doses of fish oil supplements may produce a blood pressure lowering effect. It is possible that additive reductions in blood pressure may be seen when fish oils are used in a patient already taking antihypertensive agents.
    Flavoxate: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Flibanserin: (Moderate) The concomitant use of flibanserin and multiple weak CYP3A4 inhibitors, including spironolactone, may increase flibanserin concentrations, which may increase the risk of flibanserin-induced adverse reactions. Therefore, patients should be monitored for hypotension, syncope, somnolence, or other adverse reactions, and the potential outcomes of combination therapy with multiple weak CYP3A4 inhibitors and flibanserin should be discussed with the patient.
    Fluconazole: (Moderate) Hydrochlorothiazide may decrease the renal clearance of fluconazole. Coadministration of fluconazole 100 mg PO and hydrochlorothiazide 50 mg PO for 10 days in normal volunteers (n=13) resulted in a significant increase in fluconazole AUC and Cmax compared to fluconazole given alone. There was a mean +/- SD increase in fluconazole AUC and Cmax of 45 +/- 31% and 43 +/- 31%, respectively. These changes are attributed to a mean +/- SD reduction in fluconazole renal clearance of 30% +/- 12%.
    Fludrocortisone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Flunisolide: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Fluocinolone; Hydroquinone; Tretinoin: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
    Fluoxetine: (Moderate) Patients receiving a diuretic during treatment with fluoxetine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH has been reported during therapy with SSRIs. Cases involving serum sodium levels lower than 110 mmol/l have occurred. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of fluoxetine should be considered in patients who develop symptomatic hyponatremia.
    Flurbiprofen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Fluticasone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Fluticasone; Salmeterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated. (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Fluticasone; Umeclidinium; Vilanterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated. (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Fluticasone; Vilanterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated. (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Fluvoxamine: (Moderate) Patients receiving a diuretic during treatment with fluvoxamine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH has been reported during therapy with SSRIs. Cases involving serum sodium levels lower than 110 mmol/L have occurred. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of fluvoxamine should be considered in patients who develop symptomatic hyponatremia.
    Food: (Major) Licorice extract, which contains glycyrrhizic acid, possesses aldosterone-like properties. Thus, licorice candy and foods containing licorice extract should be avoided by patients taking spironolactone in order to not antagonize the drug's therapeutic actions.
    Formoterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Formoterol; Mometasone: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated. (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Fosinopril: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Fospropofol: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents. (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Gallium Ga 68 Dotatate: (Major) Avoid use of other diuretics with mannitol, if possible. Concomitant administration may potentiate the renal toxicity of mannitol.
    General anesthetics: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents. (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Glimepiride: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Glimepiride; Rosiglitazone: (Moderate) Monitor for an increase in rosiglitazone-related adverse effects during concomitant use with spironolactone; adjust the dose of rosiglitazone based on clinical response. Coadministration may increase the exposure of rosiglitazone. Rosiglitazone is a CYP2C8 substrate and spironolactone is a CYP2C8 inhibitor. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Glipizide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Glipizide; Metformin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Glyburide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Glyburide; Metformin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Glycopyrrolate: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Glycopyrrolate; Formoterol: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms. (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Granisetron: (Moderate) According to the manufacturer, caution is warranted when administering granisetron to patients with preexisting electrolyte abnormalities. Patients taking certain diuretics may develop an electrolyte abnormality that may lead to cardiac dysrhythmias and/or QT prolongation. Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting drugs such as loop diuretics and thiazide diuretics, increasing the potential for cardiac arrhythmias.
    Guaifenesin; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Guaifenesin; Phenylephrine: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Halobetasol; Tazarotene: (Moderate) The manufacturer states that tazarotene should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
    Halofantrine: (Major) Due to the risks of cardiac toxicity of halofantrine in patients with hypokalemia and/or hypomagnesemia, the use of halofantrine should be avoided when feasible in those patients receiving thiazide diuretics. Electrolyte imbalances may occur while on these diuretics, which may in turn predispose patients to the cardiac effects of halofantrine.
    Haloperidol: (Moderate) Caution is advisable during concurrent use of haloperidol and thiazide diuretics as electrolyte imbalance caused by diuretics may increase the risk of QT prolongation with haloperidol. Concomitant use may also cause additive hypotension. (Moderate) In general, haloperidol should be used cautiously with antihypertensive agents due to the possibility of additive hypotension.
    Halothane: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents. (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Homatropine; Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Hydralazine; Isosorbide Dinitrate, ISDN: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary. (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ; Moexipril: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Hydrocodone: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Hydrocodone; Ibuprofen: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Hydrocodone; Phenylephrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving decongestant sympathomimetics at recommended doses do not appear at high risk for significant elevations in blood pressure, however, increased blood pressure has been reported in some patients.
    Hydrocodone; Potassium Guaiacolsulfonate: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Hydrocodone; Pseudoephedrine: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like spironolactone can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. These effects could be more pronounced in patients also receiving a CYP2D6 inhibitor. If spironolactone is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydrocodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Hydrocortisone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Hydromorphone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with hydromorphone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with hydromorphone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Hyoscyamine: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia. (Moderate) Thiazide diuretics may cause the urine to become alkaline. This may reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde. (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Ibritumomab Tiuxetan: (Major) Avoid coadministration of potassium phosphate and potassium-sparing diuretics as concurrent use may increase the risk of severe and potentially fatal hyperkalemia, particularly in high-risk patients (renal impairment, cardiac disease, adrenal insufficiency). If concomitant use is necessary, closely monitor serum potassium concentrations.
    Ibuprofen lysine: (Moderate) Ibuprofen lysine may reduce the effect of diuretics; diuretics can increase the risk of nephrotoxicity of NSAIDs in dehydrated patients. During coadministration of NSAIDs and diuretic therapy, patients should be monitored for changes in the effectiveness of their diuretic therapy and for signs and symptoms of renal impairment.
    Ibuprofen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Ibuprofen; Oxycodone: (Moderate) Consider a reduced dose of oxycodone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, consider increasing the oxycodone dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Oxycodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like spironolactone can increase oxycodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of oxycodone. If spironolactone is discontinued, oxycodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to oxycodone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with oxycodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with oxycodone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Ibuprofen; Pseudoephedrine: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Icosapent ethyl: (Moderate) Thiazide diuretics may exacerbate hypertriglyceridemia and should be discontinued or changed to alternate therapy, if possible, prior to initiation of icosapent ethyl.
    Iloperidone: (Moderate) Secondary to alpha-blockade, iloperidone can produce vasodilation that may result in additive effects during concurrent use with antihypertensive agents. The potential reduction in blood pressure can precipitate orthostatic hypotension and associated dizziness, tachycardia, and syncope. If concurrent use of iloperidone and antihypertensive agents is necessary, patients should be counseled on measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning and rising slowly from a seated position. Close monitoring of blood pressure is recommended until the full effects of the combination therapy are known.
    Iloprost: (Moderate) Amiloride can have additive effects when administered with other antihypertensive agents. These effects can be used to therapeutic advantage, but dosage adjustments may be necessary.
    Inamrinone: (Moderate) Hypokalemia may occur due to excessive diuresis during inamrinone therapy. Fluid and electrolyte changes and renal function should be carefully monitored during inamrinone therapy. (Moderate) Hypokalemia may occur due to excessive diuresis during inamrinone therapy. Fluid and electrolyte changes and renal function should be carefully monitored during inamrinone therapy.
    Incretin Mimetics: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Indacaterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Indacaterol; Glycopyrrolate: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms. (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Indapamide: (Moderate) The effects of indapamide may be additive when administered with other antihypertensive agents or diuretics. This may be desirable, but occasionally orthostatic hypotension may occur. Dosages should be adjusted based on clinical response.
    Indomethacin: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Inotersen: (Moderate) Use caution with concomitant use of inotersen and diuretics due to the risk of glomerulonephritis and nephrotoxicity.
    Insulin Degludec; Liraglutide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Insulin Glargine; Lixisenatide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Insulins: (Moderate) Monitor patients receiving insulin closely for changes in diabetic control when thiazide diuretics are instituted or discontinued; dosage adjustments may be required. Thiazide diuretics can decrease the hypoglycemic effects of insulin 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes.
    Intravenous Lipid Emulsions: (Moderate) High doses of fish oil supplements may produce a blood pressure lowering effect. It is possible that additive reductions in blood pressure may be seen when fish oils are used in a patient already taking antihypertensive agents. (Moderate) High doses of fish oil supplements may produce a blood pressure lowering effect. It is possible that additive reductions in blood pressure may be seen when fish oils are used in a patient already taking antihypertensive agents.
    Ipratropium; Albuterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Irbesartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Irbesartan; Hydrochlorothiazide, HCTZ: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Isocarboxazid: (Moderate) Additive hypotensive effects may be seen when monoamine oxidase inhibitors (MAOIs) are combined with antihypertensives. Careful monitoring of blood pressure is suggested during concurrent therapy of MAOIs with diuretics. Patients should be instructed to rise slowly from a sitting position, and to report syncope or changes in blood pressure or heart rate to their health care provider. (Moderate) Additive hypotensive effects may be seen when monoamine oxidase inhibitors (MAOIs) are combined with antihypertensives. Careful monitoring of blood pressure is suggested during concurrent therapy of MAOIs with diuretics. Patients should be instructed to rise slowly from a sitting position, and to report syncope or changes in blood pressure or heart rate to their health care provider.
    Isoflurane: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents. (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Isoproterenol: (Moderate) The pharmacologic effects of isoproterenol may cause an increase in blood pressure. If isoproterenol is used concomitantly with antihypertensives, the blood pressure should be monitored as the administration of isoproterenol can compromise the effectiveness of antihypertensive agents. (Moderate) The pharmacologic effects of isoproterenol may cause an increase in blood pressure. If isoproterenol is used concomitantly with antihypertensives, the blood pressure should be monitored as the administration of isoproterenol can compromise the effectiveness of antihypertensive agents.
    Isosorbide Dinitrate, ISDN: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary. (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Isosorbide Mononitrate: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary. (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Isradipine: (Minor) Monitor for an increase in isradipine-related adverse reactions including hypotension if coadministration with spironolactone is necessary. Concomitant use may increase isradipine exposure. Isradipine is a CYP3A substrate and spironolactone is a weak CYP3A inhibitor.
    Ixabepilone: (Moderate) Frequently monitor peripheral blood counts between cycles of ixabepilone, and for other acute ixabepilone-related adverse reactions if coadministration with spironolactone is necessary; consider the use of an alternative agent to spironolactone that does not inhibit CYP3A4. Ixabepilone is a CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor. The effect of weak CYP3A4 inhibitors on exposure to ixabepilone has not been studied.
    Ketamine: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents. (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Ketoprofen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Ketorolac: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Lansoprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Lansoprazole; Naproxen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Lemborexant: (Major) Limit the dose of lemborexant to 5 mg PO once daily if coadministered with spironolactone as concurrent use may increase lemborexant exposure and the risk of adverse effects. Lemborexant is a CYP3A4 substrate; spironolactone is a weak CYP3A4 inhibitor. Coadministration with a weak CYP3A4 inhibitor is predicted to increase lemborexant exposure by less than 2-fold.
    Lesinurad; Allopurinol: (Moderate) The occurrence of certain hypersensitivity reactions may be increased in patients with renal impairment who receive allopurinol and thiazide diuretics in combination. The precise mechanism for such events is unclear but likely immune-mediated and may be related to an effect of oxypurinol; elevated oxypurinol concentrations appear to be associated with hypersensitivity reactions; decreased clearance of this metabolite may occur with renal impairment and with the concurrent use of thiazide diuretics. Severe skin reactions include exfoliative dermatitis, toxic epidermal necrolysis and Steven's Johnson syndrome; some reactions have been fatal. In addition, thiazide diuretics, like hydrochlorothiazide, can cause hyperuricemia. Since thiazides reduce the clearance of uric acid, patients with gout or hyperuricemia may have exacerbations of their disease.
    Levalbuterol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Levodopa: (Moderate) Concomitant use of antihypertensive agents with levodopa can result in additive hypotensive effects.
    Levomethadyl: (Moderate) Caution is advised when using levomethadyl in combination with other agents that may lead to electrolyte abnormalities, especially hypokalemia or hypomagnesemia. Agents that require monitoring for potential hypokalemia include thiazide diuretics.
    Levomilnacipran: (Moderate) Patients receiving a diuretic during treatment with a Serotonin norepinephrine reuptake inhibitor (SNRI) may be at greater risk of developing hyponatremia and/or the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs. Cases involving serum sodium levels lower than 110 mmol/L have been reported. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Levorphanol: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with levorphanol. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with levorphanol. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Lidocaine: (Moderate) Monitor for lidocaine toxicity if coadministration with spironolactone is necessary as concurrent use may increase lidocaine exposure. Lidocaine is a CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor.
    Lidocaine; Epinephrine: (Moderate) Monitor for lidocaine toxicity if coadministration with spironolactone is necessary as concurrent use may increase lidocaine exposure. Lidocaine is a CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor. (Moderate) Potassium-sparing diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine. (Moderate) Thiazide diuretics may antagonize the pressor effects and potentiate the arrhythmogenic effects of epinephrine.
    Lidocaine; Prilocaine: (Moderate) Monitor for lidocaine toxicity if coadministration with spironolactone is necessary as concurrent use may increase lidocaine exposure. Lidocaine is a CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor.
    Linagliptin: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Linagliptin; Metformin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Liraglutide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Lisdexamfetamine: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Lisedexamfetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
    Lisinopril: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Lisinopril; Hydrochlorothiazide, HCTZ: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Lithium: (Major) Concurrent use of lithium and thiazide diuretics may result in lithium toxicity. Therapeutic doses of thiazide diuretics can result in an approximate 25% to 40% decrease in lithium clearance, potentially leading to significant toxicity. Lithium is primarily re-absorbed from the proximal tubules, and thiazide diuretics block sodium reabsorption at the distal tubule, which results in sodium depletion and subsequent compensatory reabsorption of sodium and lithium at the proximal tubules. If treatment with lithium and a thiazide diuretic cannot be avoided, patients should have their serum lithium concentrations closely monitored, and the lithium dosage adjusted if necessary. Monitoring for changes in lithium effectiveness as well as careful assessment of lithium concentrations is advisable, particularly during initial co-administration and after dose changes or discontinuation of the diuretic. In some cases, thiazide diuretics may be used to counteract lithium-induced polyuria, although close monitoring is necessary if such treatment is initiated. There is a lack of evidence to evaluate the safety of lithium and metolazone, a thiazide-like diuretic. The manufacturer of metolazone recommends general avoidance of diuretics and lithium due to the potential for lithium toxicity. (Minor) The risk of lithium toxicity may be increased in patients receiving medications that affect kidney function and sodium excretion, such as diuretics. However, concurrent use of potassium-sparing diuretics (e.g., amiloride, spironolactone, triamterene) with lithium is generally regarded as safe. Lithium is primarily reabsorbed from the proximal tubules whereas potassium-sparing diuretics inhibit the endothelial sodium channel in the renal collecting duct thereby inhibiting reabsorption of sodium and lithium. In one small study evaluating concurrent use of lithium and spironolactone, lithium clearance was increased by 16%, which was not considered clinically significant. Amiloride has been safely used as a reversal agent for lithium-induced nephrogenic diabetes insipidus. There is a lack of evidence to evaluate the effect of lithium and triamterene co-administration, however, a significant interaction would not be expected due to the pharmacologic similarities with other potassium-sparing diuretics.
    Lixisenatide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Lomitapide: (Major) Decrease the dose of lomitapide by one-half not to exceed 30 mg/day PO if coadministration with spironolactone is necessary. Concomitant use may significantly increase the serum concentration of lomitapide. Spironolactone is a weak CYP3A4 inhibitor; the exposure to lomitapide is increased by approximately 2-fold in the presence of weak CYP3A4 inhibitors.
    Lonafarnib: (Major) Avoid coadministration of lonafarnib and spironolactone; concurrent use may increase the exposure of lonafarnib and the risk of adverse effects. If coadministration is unavoidable, reduce to or continue lonafarnib at a dosage of 115 mg/m2 and closely monitor patients for lonafarnib-related adverse reactions. Resume previous lonafarnib dosage 14 days after discontinuing spironolactone. Lonafarnib is a sensitive CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor.
    Loop diuretics: (Moderate) Concomitant use of a thiazide diuretiic, or the related drug metolazone, with a loop diuretic can cause additive electrolyte and fluid loss. In patients with creatinine clearances > 30 ml/min, the combinations may also lead to profound fluid and electrolyte loss in some patients. Thus, use cautiously and with monitoring of renal function, blood pressure, cardiac status, electrolytes (especially potassium), and monitor the clinical response for the condition treated.
    Loratadine; Pseudoephedrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Losartan: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Losartan; Hydrochlorothiazide, HCTZ: (Major) Potassium-sparing diuretics, such as spironolactone, should be used with caution in patients taking drugs that may increase serum potassium levels such as angiotensin II receptor antagonists. Concurrent use can cause hyperkalemia, especially in elderly patients or patients with impaired renal function. Coadministration may also result in increases in serum creatinine in heart failure patients.
    Lovastatin; Niacin: (Moderate) Cutaneous vasodilation induced by niacin may become problematic if high-dose niacin is used concomitantly with other antihypertensive agents. This effect is of particular concern in the setting of acute myocardial infarction, unstable angina, or other acute hemodynamic compromise.
    Low Molecular Weight Heparins: (Moderate) Coadministration of spironolactone with heparin or low-molecular weight heparins (LMWHs) increases the risk of developing severe hyperkalemia, especially in the presence of renal impairment (renal disease, elderly patients). Use together with caution and monitor serum potassium concentrations.
    Lurasidone: (Moderate) Due to the antagonism of lurasidone at alpha-1 adrenergic receptors, the drug may enhance the hypotensive effects of alpha-blockers and other antihypertensive agents. If concurrent use of lurasidone and antihypertensive agents is necessary, patients should be counseled on measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning and rising slowly from a seated position. Close monitoring of blood pressure is recommended until the full effects of the combination therapy are known.
    Magnesium Citrate: (Moderate) The use of saline laxatives (e.g., magnesium citrate) with potassium-sparing diuretics may interfere with the potassium-sparing effect of such diuretics due to excess fluid and electrolyte loss. In addition, potassium-sparing diuretics may interfere with the kidneys ability to regulate magnesium concentrations; long-term use of potassium-sparing diuretics has been found to increase renal tubular reabsorption of magnesium which may cause hypermagnesemia, especially in patients with renal insufficiency.
    Magnesium Hydroxide: (Moderate) Long-term use of potassium-sparing diuretics has been found to increase renal tubular reabsorption of magnesium which may cause hypermagnesemia in patients also receiving magnesium supplements, especially in patients with renal insufficiency.
    Magnesium Salicylate: (Moderate) Salicylates can increase the risk of renal insufficiency in patients receiving diuretics, secondary to effects on renal blood flow. Salicylates inhibit renal prostaglandin production, which causes salt and water retention and decreased renal blood flow. Coadministration may cause hyperkalemia.
    Magnesium Salts: (Moderate) Diuretics may interfere with the kidneys ability to regulate magnesium concentrations. Long-term use of thiazide diuretics may impair the magnesium-conserving ability of the kidneys and lead to hypomagnesemia. In addition, use caution when prescribing sulfate salt bowel preps in patients taking medications that may affect renal function such as diuretics. (Moderate) Long-term use of potassium-sparing diuretics has been found to increase renal tubular reabsorption of magnesium which may cause hypermagnesemia in patients also receiving magnesium supplements, especially in patients with renal insufficiency. (Moderate) Long-term use of potassium-sparing diuretics has been found to increase renal tubular reabsorption of magnesium which may cause hypermagnesemia in patients also receiving magnesium supplements, especially in patients with renal insufficiency. In addition, use caution when prescribing sulfate salt bowel preps in patients taking medications that may affect renal function such as diuretics.
    Magnesium Sulfate; Potassium Sulfate; Sodium Sulfate: (Moderate) Use caution when prescribing sulfate salt bowel preparation in patients taking concomitant medications that may affect renal function such as diuretics.
    Mannitol: (Major) Avoid use of other diuretics with mannitol, if possible. Concomitant administration may potentiate the renal toxicity of mannitol.
    Meclofenamate Sodium: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Mefenamic Acid: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Mefloquine: (Moderate) Use mefloquine with caution if coadministration with spironolactone is necessary as concurrent use may increase mefloquine exposure and mefloquine-related adverse events. Mefloquine is a substrate of CYP3A4 and spironolactone is a weak CYP3A4 inhibitor.
    Meglitinides: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Meloxicam: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Memantine: (Minor) Memantine reduced the bioavailability of hydrochlorothiazide by roughly 20% in a drug interaction study. The clinical significance of this pharmacokinetic interaction, if any, is unknown.
    Mepenzolate: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Meperidine: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4 and spironolactone is a weak CYP3A4 inhibitor. Concomitant use with spironolactone can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Meperidine; Promethazine: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4 and spironolactone is a weak CYP3A4 inhibitor. Concomitant use with spironolactone can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
    Mephobarbital: (Moderate) Barbiturates, such as mephobarbital, may potentiate orthostatic hypotension when given concomitantly with spironolactone.
    Mequinol; Tretinoin: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
    Mestranol; Norethindrone: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients; monitor patients receiving concurrent therapy to confirm that the desired antihypertensive effect is being obtained.
    Metaproterenol: (Minor) Hypokalemia associated with thiazide diuretics can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is unknown, use caution when coadministering beta-agonists with thiazide diuretics and monitor serum potassium as clinically indicated.
    Metformin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients.
    Metformin; Repaglinide: (Moderate) A dose reduction of repaglinide and increased frequency of blood glucose monitoring may be required if coadministration with spironolactone is necessary. Repaglinide is a CYP2C8 substrate and spironolactone is a CYP2C8 inhibitor. (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Metformin; Rosiglitazone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Monitor for an increase in rosiglitazone-related adverse effects during concomitant use with spironolactone; adjust the dose of rosiglitazone based on clinical response. Coadministration may increase the exposure of rosiglitazone. Rosiglitazone is a CYP2C8 substrate and spironolactone is a CYP2C8 inhibitor. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Metformin; Saxagliptin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Metformin; Sitagliptin: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be 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 in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. Finally, both thiazides and sulfonylureas have been reported to cause photosensitivity reactions; concomitant use may increase the risk of photosensitivity.
    Methadone: (Moderate) Consider a reduced dose of methadone with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, methadone plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to methadone. Methadone is a substrate of CYP3A4, CYP2B6, CYP2C19, CYP2C9, and CYP2D6; spironolactone is a weak CYP3A inhibitor. Concomitant use with spironolactone can increase methadone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of methadone. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with methadone. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Diuretics can cause electrolyte disturbances such as hypomagnesemia and hypokalemia, which may prolong the QT interval. As methadone may also prolong the QT interval, cautious coadministration with diuretics is needed. In addition, opiate agonists may potentiate orthostatic hypotension when used concurrently with diuretics.
    Methamphetamine: (Minor) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
    Methazolamide: (Moderate) Carbonic anhydrase inhibitors promote electrolyte excretion including hydrogen ions, sodium, and potassium. They can enhance the sodium depleting effects of other diuretics when used concurrently. Pre-existing hypokalemia and hyperuricemia can also be potentiated by carbonic anhydrase inhibitors. Monitor serum potassium to determine the need for potassium supplementation and alteration in drug therapy. (Moderate) Thiazide diuretics may increase the risk of hypokalemia if used concurrently with methazolamide. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy. There may also be an additive diuretic or hyperuricemic effect.
    Methenamine: (Moderate) Thiazide diuretics may cause the urine to become alkaline. This may reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde.
    Methenamine; Sodium Acid Phosphate: (Moderate) Thiazide diuretics may cause the urine to become alkaline. This may reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde.
    Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Moderate) Thiazide diuretics may cause the urine to become alkaline. This may reduce the effectiveness of methenamine by inhibiting its conversion to formaldehyde. (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Methohexital: (Moderate) Concurrent use of methohexital and antihypertensive agents increases the risk of developing hypotension.
    Methotrexate: (Moderate) Coadministration of thiazide diuretics and antineoplastic agents such as methotrexate may result in reduced renal excretion of the antineoplastic agent and therefore increased myelosuppressive effects.
    Methoxsalen: (Moderate) Concomitant administration of methoxsalen and other photosensitizing agents, such as thiazide diuretics, can increase the incidence or severity of photsensitization from either compound.
    Methscopolamine: (Minor) Coadministration of thiazides and antimuscarinics (e.g., atropine and biperiden) may result in increased bioavailability of the thiazide. This is apparently a result of a decrease in gastrointestinal motility and rate of stomach emptying by the antimuscarinic agent. In addition, diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Methylphenidate Derivatives: (Moderate) Periodic evaluation of blood pressure is advisable during concurrent use of methylphenidate derivatives and antihypertensive agents, particularly during initial coadministration and after dosage increases of methylphenidate derivatives. Methylphenidate derivatives can reduce the hypotensive effect of antihypertensive agents such as potassium-sparing diuretics. (Moderate) Periodic evaluation of blood pressure is advisable during concurrent use of methylphenidate derivatives and antihypertensive agents, particularly during initial coadministration and after dosage increases of methylphenidate derivatives. Methylphenidate derivatives can reduce the hypotensive effect of antihypertensive agents such as thiazide diuretics.
    Methylprednisolone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Metoclopramide: (Minor) Coadministration of thiazides and prokinetic agents may result in decreased bioavailability of the thiazide diuretic.
    Midazolam: (Moderate) Use caution when midazolam is coadministered with spironolactone. Concurrent use may increase midazolam exposure leading to prolonged sedation. Midazolam is a sensitive CYP3A4 substrate and spironolactone is a weak CYP3A4 inhibitor.
    Midodrine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Miglitol: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. 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, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Milnacipran: (Moderate) Patients receiving a diuretic during treatment with a Serotonin norepinephrine reuptake inhibitor (SNRI) may be at greater risk of developing hyponatremia and/or the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs. Cases involving serum sodium levels lower than 110 mmol/L have been reported. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Milrinone: (Moderate) Concurrent administration of antihypertensive agents could lead to additive hypotension when administered with milrinone. Titrate milrinone dosage according to hemodynamic response. (Moderate) Concurrent administration of antihypertensive agents could lead to additive hypotension when administered with milrinone. Titrate milrinone dosage according to hemodynamic response.
    Mirtazapine: (Moderate) Hyponatremia has been reported very rarely during mirtazapine administration. Caution is advisable in patients receiving medications known to cause hyponatremia, such as diuretics. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of mirtazapine, as well as implementation of the appropriate medical interventions.
    Mitotane: (Moderate) An isolated case report indicated that mitotane activity might be antagonized by the concurrent administration of spironolactone. Until more data are available to confirm an interaction, the use of spironolactone with mitotane should be approached with caution.
    Mivacurium: (Moderate) Concomitant use of neuromuscular blockers and thiazide diuretics may prolong neuromuscular blockade, possibly due to hypokalemia or alterations in potassium concentrations across the end-plate membrane.
    Moexipril: (Major) Spironolactone should not be used concomitantly with ACE inhibitors, especially in the presence of renal impairment (renal disease, elderly patients). Coadministration of ACE inhibitors and spironolactone, even in the presence of a diuretic, has been associated with severe hyperkalemia. Use together with extreme caution and monitor serum potassium concentrations. (Moderate) Patients with hyponatremia or hypovolemia are more susceptible to developing reversible renal insufficiency when given angiotensin converting enzyme (ACE) inhibitors and diuretics concomitantly.
    Mometasone: (Minor) The manufacturer of spironolactone lists corticosteroids as a potential drug that interacts with spironolactone. Intensified electrolyte depletion, particularly hypokalemia, may occur. However, potassium-sparing diuretics such as spironolactone do not induce hypokalemia. In fact, hypokalemia is one of the indications for potassium-sparing diuretic therapy. Therefore, drugs that induce potassium loss, such as corticosteroids, could counter the hyperkalemic effects of potassium-sparing diuretics.
    Morphine: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a potassium-sparing diuretic is administered with morphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. Morphine may also cause acute urinary retention by causing a spasm of the bladder sphincter; men with enlarged prostates may have a higher risk of this reaction. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with morphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. Morphine may also cause acute urinary retention by causing a spasm of the bladder sphincter; men with enlarged prostates may have a higher risk of this reaction.
    Morphine; Naltrexone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a potassium-sparing diuretic is administered with morphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. Morphine may also cause acute urinary retention by causing a spasm of the bladder sphincter; men with enlarged prostates may have a higher risk of this reaction. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when a thiazide diuretic is administered with morphine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. Morphine may also cause acute urinary retention by causing a spasm of the bladder sphincter; men with enlarged prostates may have a higher risk of this reaction.
    Nabumetone: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Nanoparticle Albumin-Bound Paclitaxel: (Moderate) Monitor for an increase in paclitaxel-related adverse reactions if coadministration of nab-paclitaxel with spironolactone is necessary due to the risk of increased plasma concentrations of paclitaxel. Nab-paclitaxel is a CYP2C8 substrate and spironolactone is a strong/moderate/weak CYP2C8 inhibitor. In vitro, the metabolism of paclitaxel to 6-alpha-hydroxypaclitaxel was inhibited by another inhibitor of CYP2C8.
    Nanoparticle Albumin-Bound Sirolimus: (Major) Reduce the nab-sirolimus dose to 56 mg/m2 if coadministration with spironolactone is necessary. The dose of sirolimus may also need to be reduced with coadministration of spironolactone. Monitor sirolimus serum concentrations as appropriate and watch for sirolimus-related adverse reactions with coadministration of spironolactone. Sirolimus is a sensitive CYP3A substrate with a narrow therapeutic range; spironolactone is a weak CYP3A inhibitor.
    Naproxen: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
    Naproxen; Esomeprazole: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. (Moderate) Proton pump inhibitors, such as esomeprazole, have been associated with hypomagnesemia. Hypomagnesemia occurs with thiazide diuretics (chlorothiazide, hydrochlorothiazide, indapamide, and metolazone). Low serum magnesium may lead to serious adverse events such as muscle spasm, seizures, and arrhythmias. Therefore, clinicians should monitor serum magnesium concentrations periodically in patients taking a PPI and diuretics concomitantly. Patients who develop hypomagnesemia may require PPI discontinuation in addition to magnesium replacement.
    Naproxen; Pseudoephedrine: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Nateglinide: (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby le