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    Loop Diuretics

    DEA CLASS

    Rx

    DESCRIPTION

    Oral and IV loop diuretic; used for ascites, edema, HTN, and CHF; twice as potent as furosemide allowing a 24-hour dosage interval; may lack the paradoxical antidiuresis seen with furosemide.

    COMMON BRAND NAMES

    Demadex

    HOW SUPPLIED

    Demadex/Torsemide Oral Tab: 5mg, 10mg, 20mg, 100mg

    DOSAGE & INDICATIONS

    For the treatment of edema.
    For edema associated with congestive heart failure.
    Oral dosage
    Adults

    Initially, 10 to 20 mg PO once daily. If needed, titrate by doubling the dose up to 200 mg to achieve a satisfactory diuretic response. The safe use of a single dose of 200 mg or more has not been evaluated. Guidelines recommend adding a loop diuretic to standard therapy for reduced ejection fraction heart failure (HFrEF) patients with volume overload. Diuretics should also be used in preserved ejection fraction heart failure (HFpEF).

    Intravenous dosage
    Adults

    Initially, 10 to 20 mg IV once daily. If needed, titrate by doubling the dose up to 200 mg to achieve a satisfactory diuretic response. The safe use of a single dose of 200 mg or more has not been evaluated. Guidelines recommend adding a loop diuretic to standard therapy for reduced ejection fraction heart failure (HFrEF) patients with volume overload. Diuretics should also be used in preserved ejection fraction heart failure (HFpEF).

    Continuous intravenous infusion dosage†
    Adults

    20 mg IV bolus then 5 to 20 mg/hour continuous IV infusion. Guidelines recommend adding a loop diuretic to standard therapy for reduced ejection fraction heart failure (HFrEF) patients with volume overload. Diuretics should also be used in preserved ejection fraction heart failure (HFpEF).

    For edema associated with chronic renal failure.
    Oral dosage
    Adults

    Initially, 10 to 20 mg PO once daily. If needed, titrate by doubling the dose up to 200 mg to achieve a satisfactory diuretic response. The safe use of a single dose of 200 mg or more has not been evaluated.

    Intravenous dosage
    Adults

    Initially, 10 to 20 mg IV once daily. If needed, titrate by doubling the dose up to 200 mg to achieve a satisfactory diuretic response. The safe use of a single dose of 200 mg or more has not been evaluated.

    For the adjunctive treatment of ascites (e.g., due to hepatic cirrhosis) either alone or in combination with spironolactone or amiloride.
    NOTE: Loop diuretics, preferably in combination with an aldosterone antagonist or a potassium-sparing diuretic (e.g., spironolactone or amiloride), are used for the treatment of ascites.
    Oral or Intravenous dosage
    Adults

    Initially, 5—10 mg PO or IV once daily. If needed, titrate upwards by doubling the dose up to 40 mg PO or IV to achieve a satisfactory diuretic response. Doses >= 40 mg have not been evaluated in patients with hepatic cirrhosis. Chronic use in hepatic disease has not been evaluated.

    Geriatric

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

    For the treatment of hypertension.
    Oral dosage
    Adults

    Initially, 5 mg PO once daily. May increase to 10 mg PO once daily if the desired reduction in blood pressure is not achieved in 4—6 weeks, If this dose is insufficient an additional antihypertensive agent should be added to the regimen.

    Geriatric

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

    MAXIMUM DOSAGE

    Adults

    10 mg/day PO or IV for hypertension; 200 mg/dose PO or IV for edema or heart failure; 40 mg/dose PO or IV for ascites. Single doses listed are for acute dosage. No information is available for maximum daily maintenance dosage for edema, heart failure, or ascites.

    Elderly

    10 mg/day PO or IV for hypertension; 200 mg/dose PO or IV for edema or heart failure; 40 mg/dose PO or IV for ascites. Single doses listed are for acute dosage. No information is available for maximum daily maintenance dosage for edema, heart failure, or ascites.

    Adolescents

    Safety and efficacy have not been established.

    Children

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    No dosage adjustment is needed; see the dosage for the treatment of ascites. Diuretics should be used with caution in patients with hepatic disease since minor alterations of fluid and electrolyte balance may precipitate hepatic coma.

    Renal Impairment

    No dosage adjustment is needed; however, high doses may be effective in patients with end-stage renal disease.
     
    Intermittent hemodialysis
    Torsemide is not removed by hemodialysis; no dosage adjustment is needed.

    ADMINISTRATION

    Oral Administration

    May be administered orally without regard to meals.
    NOTE: The oral bioavailability of torsemide is sufficiently high to allow for 1:1 equivalency between the oral and intravenous dosage forms.

    Injectable Administration

    Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.

    Intravenous Administration

    For intravenous use only. Torsemide injection should be administered either slowly as an IV bolus or as a continuous IV infusion.
    NOTE: The bioavailability of torsemide allows for 1:1 equivalency between the oral and intravenous dosage forms. Based on clinical data of diuretic potency, 10—20 mg IV of torsemide is approximately equivalent to 40 mg IV of furosemide.
    Ampuls are single-use containers. Discard any unused portion after opening.
     
    Intravenous Bolus Injection:
    No dilution necessary if given as a slow IV injection.
    Administer slowly over a period of 2 minutes.
    If administered through an IV line, flush the line with 0.9% Sodium Chloride Injection, USP (NS) before and after administration. The torsemide injection is formulated above pH 8.3. Flushing the line is recommended to avoid the potential for incompatibilities caused by differences in pH which could be indicated by color change, haziness or the formation of a precipitate in the solution.
     
    Continuous Intravenous Infusion:
    If administered through an IV line, flush the line with 0.9% Sodium Chloride Injection, USP (NS) before and after administration. The torsemide injection is formulated above pH 8.3. Flushing the line is recommended to avoid the potential for incompatibilities caused by differences in pH which could be indicated by color change, haziness or the formation of a precipitate in the solution.
    If administered as a continuous infusion, stability has been demonstrated through 24 hours at room temperature of 15—30 degrees C (59—86 degrees F), in plastic containers, for the following fluids and concentrations:
    -200 mg Torsemide (10 mg/mL) added to: 250 mL D5W (0.8 mg/ml), 250 mL 0.9% Sodium Chloride (NS) (0.8 mg/ml), or 500 mL 0.45% Sodium Chloride (0.4 mg/ml).
    -50 mg Torsemide (10 mg/mL) added to: 500 mL D5W (0.1 mg/ml), 500 mL 0.9% Sodium Chloride (NS) (0.1 mg/ml), or 500 mL 0.45% Sodium Chloride (0.1 mg/ml).

    STORAGE

    Demadex:
    - Store at controlled room temperature (between 68 and 77 degrees F)

    CONTRAINDICATIONS / PRECAUTIONS

    Sulfonamide hypersensitivity, sulfonylurea hypersensitivity, thiazide diuretic hypersensitivity

    Torsemide is contraindicated in patients with known hypersensitivity to this drug. The torsemide prescribing information specifies sulfonylurea hypersensitivity as a contraindication. Structurally, torsemide is similar to the sulfonylurea nucleus and also contains a sulfonamide substituent. The risk of an allergic reaction after administration of a loop diuretic in a patient with sulfonamide hypersensitivity or thiazide diuretic hypersensitivity appears to be very low. Sulfonamide cross-sensitivity has been rarely documented with torsemide or other loop diuretics. Torsemide does not contain the N4-aromatic amine which is present in sulfonamide antibiotics. Non-arylamine sulfonamide derivatives, such as torsemide, 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—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.

    Hepatic disease

    Torsemide therapy for patients with hepatic disease (e.g., cirrhosis and ascites) should be undertaken cautiously, preferably in a hospital setting. Torsemide is a potent loop diuretic and sudden changes in fluid and electrolyte balance may precipitate hepatic coma. The addition of an aldosterone antagonist or potassium-sparing diuretic is recommended to prevent potassium loss and metabolic alkalosis.

    Anuria, hypovolemia, sympathectomy, syncope

    Torsemide is contraindicated in patients with anuria. Diuretic-induced hypovolemia can precipitate pre-renal azotemia. Patients with pre-existing hypovolemia or hypotension should have their condition corrected before torsemide is initiated. Orthostatic hypotension may occur during treatment with loop diuretics. Excessive hypotension can result in syncope. The antihypertensive effects of diuretics may be enhanced in patients predisposed for orthostatic hypotension, including the post-sympathectomy patient.

    Electrolyte imbalance, hypochloremia, hypokalemia, hypomagnesemia, hyponatremia, ventricular arrhythmias

    Loop diuretics can result in dehydration or hypovolemia, or electrolyte imbalance such as hyponatremia, hypokalemia, hypochloremia, and hypomagnesemia. Fluid and/or electrolyte imbalances should be corrected before torsemide administration. Monitoring of serum electrolytes is recommended during torsemide therapy. Patients with ventricular arrhythmias should be monitored closely since torsemide-induced hypokalemia can exacerbate these conditions.

    Acute myocardial infarction

    Excessive diuresis with torsemide should be avoided in patients with acute myocardial infarction due to the risk of precipitating shock.

    Renal disease, renal failure, renal impairment

    Loop diuretics should be used cautiously in any patient with renal disease associated with severe renal impairment or renal failure (e.g., anuria). Drug-induced hypovolemia can precipitate azotemia in these patients. Torsemide is an effective diuretic for many patients with renal impairment. Renal impairment may reduce clearance and warrant the use of higher doses with extended dosing intervals. Torsemide may be less effective in these patients and delayed excretion of drug may increase the risk of toxicity.

    Hearing impairment

    High doses and accumulation of loop diuretics may cause ototoxicity. Tinnitus and reversible hearing loss have been reported after oral torsemide, although the causal relationship has not been definitively determined. Torsemide should be used with caution in patients with hearing impairment.

    Gout, hyperuricemia

    Loop diuretics can reduce the clearance of uric acid and patients with gout or hyperuricemia can have exacerbations of their disease. Symptomatic gout has been reported in patients receiving torsemide, the incidence was similar to patients receiving placebo.

    Diabetes mellitus, hyperglycemia

    Blood and/or urine glucose levels should be assessed in diabetic patients undergoing torsemide therapy. Hyperglycemia has been reported in patients with diabetes mellitus receiving torsemide, although fasting glucoses were not significantly different from baseline.

    Pregnancy

    There are no data on the use of torsemide in human pregnancy and the risk of major birth defects or miscarriage. Fetal toxicity (decrease in average body weight, increase in fetal resorption, and delayed fetal ossification) occurred in pregnant rats and rabbits administered 50 and 6.8 times the human dose, respectively.

    Breast-feeding

    There are no data regarding the presence of torsemide in human milk or the effects of torsemide on the breast-feeding infant. Diuretics, such as torsemide, may suppress lactation as a result of intense diuresis. Previous American Academy of Pediatrics recommendations considered bendroflumethiazide, chlorthalidone, chlorothiazide, and hydrochlorothiazide as usually compatible with breast-feeding due to lack of noted adverse effects on the breast-feeding infant.

    Children

    Safe and effective use of torsemide in children has not been established.

    Geriatric

    No specific differences in the clinical responsiveness to torsemide of geriatric patients vs. younger adults has been identified. Greater sensitivity to the hypotensive and diuretic effects of torsemide is possible in some geriatric patients. 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. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities; antihypertensive regimens should be individualized to achieve the desired outcome while minimizing adverse effects. Antihypertensives may cause dizziness, postural hypotension, fatigue, and there is an increased risk for falls. In addition, diuretics may cause fluid and electrolyte imbalances and may precipitate or exacerbate urinary incontinence.

    ADVERSE REACTIONS

    Severe

    Stevens-Johnson syndrome / Delayed / 0-1.0
    toxic epidermal necrolysis / Delayed / 0-1.0
    angioedema / Rapid / 0-1.0
    atrial fibrillation / Early / Incidence not known
    ventricular tachycardia / Early / Incidence not known
    thrombosis / Delayed / Incidence not known
    oliguria / Early / Incidence not known
    azotemia / Delayed / Incidence not known
    hearing loss / Delayed / Incidence not known
    GI bleeding / Delayed / Incidence not known
    pancreatitis / Delayed / Incidence not known

    Moderate

    constipation / Delayed / 1.8-1.8
    hypokalemia / Delayed / 1.5-1.5
    angina / Early / 1.2-1.2
    edema / Delayed / 1.1-1.1
    hyperglycemia / Delayed / 0-1.0
    orthostatic hypotension / Delayed / Incidence not known
    hypovolemia / Early / Incidence not known
    hyperuricemia / Delayed / Incidence not known
    gout / Delayed / Incidence not known
    hypercholesterolemia / Delayed / Incidence not known
    hypertriglyceridemia / Delayed / Incidence not known
    leukopenia / Delayed / Incidence not known
    thrombocytopenia / Delayed / Incidence not known

    Mild

    headache / Early / 7.3-7.3
    polyuria / Early / 6.7-6.7
    rhinitis / Early / 2.8-2.8
    dizziness / Early / 2.3-2.3
    cough / Delayed / 2.0-2.0
    diarrhea / Early / 2.0-2.0
    asthenia / Delayed / 2.0-2.0
    nausea / Early / 1.8-1.8
    arthralgia / Delayed / 1.8-1.8
    pharyngitis / Delayed / 1.6-1.6
    dyspepsia / Early / 1.6-1.6
    myalgia / Early / 1.6-1.6
    insomnia / Early / 1.2-1.2
    anxiety / Delayed / 1.1-1.1
    vomiting / Early / Incidence not known
    syncope / Early / Incidence not known
    xerostomia / Early / Incidence not known
    tinnitus / Delayed / Incidence not known
    rash / Early / Incidence not known

    DRUG INTERACTIONS

    Acarbose: (Minor) Loop diuretics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    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) 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; 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; 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; 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) 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; Pseudoephedrine: (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) 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.
    Acrivastine; Pseudoephedrine: (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: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    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.
    Alendronate: (Moderate) When the intravenous formulation of alendronate is used for the treatment of hypercalcemia of malignancy, combination therapy with loop diuretics should be used with caution in order to avoid hypocalcemia. In patients with hypercalcemia of malignancy, the initial treatment typically includes the use of loop diuretics, in combination with saline hydration, however, diuretic therapy should not be employed prior to correction of hypovolemia and dehydration.
    Alendronate; Cholecalciferol: (Moderate) When the intravenous formulation of alendronate is used for the treatment of hypercalcemia of malignancy, combination therapy with loop diuretics should be used with caution in order to avoid hypocalcemia. In patients with hypercalcemia of malignancy, the initial treatment typically includes the use of loop diuretics, in combination with saline hydration, however, diuretic therapy should not be employed prior to correction of hypovolemia and dehydration.
    Aliskiren: (Moderate) Aliskiren can enhance the effects of loop-diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Patients with hyponatremia or hypovolemia may also develop reversible renal insufficiency. When aliskiren is administered in combination with furosemide, the AUC and Cmax of furosemide are reduced by approximately 30% and 50%, respectively; the pharmacokinetics of aliskiren are not affected. Patients should be monitored for loss of effect of furosemide when aliskiren is initiated. Blood pressure and electrolytes should be routinely monitored.
    Aliskiren; Amlodipine: (Moderate) Aliskiren can enhance the effects of loop-diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Patients with hyponatremia or hypovolemia may also develop reversible renal insufficiency. When aliskiren is administered in combination with furosemide, the AUC and Cmax of furosemide are reduced by approximately 30% and 50%, respectively; the pharmacokinetics of aliskiren are not affected. Patients should be monitored for loss of effect of furosemide when aliskiren is initiated. Blood pressure and electrolytes should be routinely monitored.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Aliskiren can enhance the effects of loop-diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Patients with hyponatremia or hypovolemia may also develop reversible renal insufficiency. When aliskiren is administered in combination with furosemide, the AUC and Cmax of furosemide are reduced by approximately 30% and 50%, respectively; the pharmacokinetics of aliskiren are not affected. Patients should be monitored for loss of effect of furosemide when aliskiren is initiated. Blood pressure and electrolytes should be routinely monitored. (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.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Aliskiren can enhance the effects of loop-diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Patients with hyponatremia or hypovolemia may also develop reversible renal insufficiency. When aliskiren is administered in combination with furosemide, the AUC and Cmax of furosemide are reduced by approximately 30% and 50%, respectively; the pharmacokinetics of aliskiren are not affected. Patients should be monitored for loss of effect of furosemide when aliskiren is initiated. Blood pressure and electrolytes should be routinely monitored. (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.
    Aliskiren; Valsartan: (Moderate) Aliskiren can enhance the effects of loop-diuretics on blood pressure if given concomitantly. This additive effect may be desirable, but dosages must be adjusted accordingly. Patients with hyponatremia or hypovolemia may also develop reversible renal insufficiency. When aliskiren is administered in combination with furosemide, the AUC and Cmax of furosemide are reduced by approximately 30% and 50%, respectively; the pharmacokinetics of aliskiren are not affected. Patients should be monitored for loss of effect of furosemide when aliskiren is initiated. Blood pressure and electrolytes should be routinely monitored. (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Alogliptin: (Minor) Although the incidence is low, hyperglycemia has been detected during torsemide therapy, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including alogliptin. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Alogliptin; Metformin: (Minor) Although the incidence is low, hyperglycemia has been detected during torsemide therapy, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including alogliptin. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Alogliptin; Pioglitazone: (Minor) Although the incidence is low, hyperglycemia has been detected during torsemide therapy, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including alogliptin. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Alpha-glucosidase Inhibitors: (Minor) Loop diuretics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Alprostadil: (Minor) The concomitant use of systemic alprostadil injection and antihypertensive agents, such as loop 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) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Amiloride; Hydrochlorothiazide, HCTZ: (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.
    Aminoglycosides: (Moderate) The risk of ototoxicity or nephrotoxicity secondary to aminoglycosides may be increased by the addition of concomitant therapies with similar side effects, including loop diuretics. If loop diuretics and aminoglycosides are used together, it would be prudent to monitor renal function parameters, serum electrolytes, and serum aminoglycoside concentrations during therapy. Audiologic monitoring may be advisable during high dose therapy or therapy of long duration, when hearing loss is suspected, or in selected risk groups (e.g., neonates).
    Amiodarone: (Major) Monitor serum electrolytes if coadministration of bumetanide and amiodarone is necessary. Bumetanide therapy may cause electrolyte abnormalities (i.e., hypokalemia, hypomagnesemia) which may exaggerate the degree of QTc prolongation and increase the potential for torsade de pointes. In addition, monitor the diuretic effect and blood pressure if torsemide and amiodarone are administered together. The torsemide dose may need to be reduced. The concomitant use of torsemide and amiodarone can decrease torsemide clearance and increase torsemide plasma concentrations. Torsemide is a substrate of CYP2C9; amiodarone inhibits CYP2C9.
    Amlodipine; Benazepril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Amlodipine; Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Amlodipine; Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Amlodipine; Olmesartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Amlodipine; Telmisartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Amlodipine; Valsartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    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; Lansoprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Amphetamine; Dextroamphetamine Salts: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Amphetamine; Dextroamphetamine: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Amphotericin B cholesteryl sulfate complex (ABCD): (Moderate) Amphotericin B-induced hypokalemia can result in interactions with other drugs. Concurrent use of amphotericin B with loop diuretics can cause additive hypokalemia or hypomagnesemia due to renal potassium and magnesium wasting. It is prudent to monitor renal function parameters and serum electrolyte concentrations during co-therapy with loop diuretics and drugs which induce hypokalemia.
    Amphotericin B lipid complex (ABLC): (Moderate) Amphotericin B-induced hypokalemia can result in interactions with other drugs. Concurrent use of amphotericin B with loop diuretics can cause additive hypokalemia or hypomagnesemia due to renal potassium and magnesium wasting. It is prudent to monitor renal function parameters and serum electrolyte concentrations during co-therapy with loop diuretics and drugs which induce hypokalemia.
    Amphotericin B liposomal (LAmB): (Moderate) Amphotericin B-induced hypokalemia can result in interactions with other drugs. Concurrent use of amphotericin B with loop diuretics can cause additive hypokalemia or hypomagnesemia due to renal potassium and magnesium wasting. It is prudent to monitor renal function parameters and serum electrolyte concentrations during co-therapy with loop diuretics and drugs which induce hypokalemia.
    Amphotericin B: (Moderate) Amphotericin B-induced hypokalemia can result in interactions with other drugs. Concurrent use of amphotericin B with loop diuretics can cause additive hypokalemia or hypomagnesemia due to renal potassium and magnesium wasting. It is prudent to monitor renal function parameters and serum electrolyte concentrations during co-therapy with loop diuretics and drugs which induce hypokalemia.
    Amyl Nitrite: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Angiotensin II receptor antagonists: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Angiotensin-converting enzyme inhibitors: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Apalutamide: (Moderate) Monitor diuretic effect and blood pressure if coadministration of torsemide with apalutamide is necessary. Torsemide is a CYP2C9 substrate and apalutamide is a CYP2C9 inducer. Concomitant use of CYP2C9 inducers increases torsemide clearance and decreases torsemide plasma concentrations.
    Apomorphine: (Moderate) Use of loop 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.
    Aprepitant, Fosaprepitant: (Minor) Use caution if torsemide and aprepitant are used concurrently and monitor for a possible decrease in the efficacy of torsemide. After administration, fosaprepitant is rapidly converted to aprepitant and shares the same drug interactions. Torsemide is a CYP2C9 substrate and aprepitant is a CYP2C9 inducer. Administration of a CYP2C9 substrate, tolbutamide, on days 1, 4, 8, and 15 with a 3-day regimen of oral aprepitant (125 mg/80 mg/80 mg) decreased the tolbutamide AUC by 23% on day 4, 28% on day 8, and 15% on day 15. The AUC of tolbutamide was decreased by 8% on day 2, 16% on day 4, 15% on day 8, and 10% on day 15 when given prior to oral administration of aprepitant 40 mg on day 1, and on days 2, 4, 8, and 15. The effects of aprepitant on tolbutamide were not considered significant. When a 3-day regimen of aprepitant (125 mg/80 mg/80 mg) given to healthy patients on stabilized chronic warfarin therapy (another CYP2C9 substrate), a 34% decrease in S-warfarin trough concentrations was noted, accompanied by a 14% decrease in the INR at five days after completion of aprepitant.
    Aripiprazole: (Minor) Aripiprazole may enhance the hypotensive effects of antihypertensive agents.
    Arsenic Trioxide: (Major) Because electrolyte abnormalities increase the risk of QT interval prolongation and serious arrhythmias, avoid the concomitant use of arsenic trioxide with drugs that may cause electrolyte abnormalities, particularly hypokalemia and hypomagnesemia. Examples of drugs that may cause electrolyte abnormalities includes loop diuretics. If concomitant drug use is unavoidable, frequently monitor serum electrolytes (and replace as necessary) and electrocardiograms.
    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; Omeprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Atenolol; Chlorthalidone: (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.
    Atracurium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Azelastine; Fluticasone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Azilsartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Azilsartan; Chlorthalidone: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Bacitracin: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential. (Minor) Additive nephrotoxicity may occur with concurrent use of these medicines. When possible, avoid concomitant administration of systemic bacitracin and loop diuretics. Use of topically administrated preparations containing bacitracin, especially when applied to large surface areas, may have additive nephrotoxic potential with loop diuretics.
    Bacitracin; Hydrocortisone; Neomycin; Polymyxin B: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
    Bacitracin; Neomycin; Polymyxin B: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
    Bacitracin; Polymyxin B: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
    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.
    Beclomethasone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Benazepril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Bendroflumethiazide; Nadolol: (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.
    Benzhydrocodone; Acetaminophen: (Moderate) Benzhydrocodone may reduce the efficacy of diuretics due to induction of the release of antidiuretic hormone. Adjustments to diuretic therapy may be needed in some patients. In addition, opiate agonists may potentiate orthostatic hypotension when used concurrently with diuretics.
    Benzphetamine: (Major) Benzphetamine can increase both systolic and diastolic blood pressure and may counteract the activity of loop diuretics. This represents a pharmacodynamic, and not a pharmacokinetic, interaction. Close monitoring of blood pressure, especially in patients who are taking antihypertensive agents, may be needed.
    Beta-agonists: (Moderate) Loop diuretics may potentiate hypokalemia and ECG changes seen with beta agonists. Hypokalemia due to beta agonists appears to be dose related and is more likely with high dose therapy. Caution is advised when loop diuretics are coadministered with high doses of beta agonists; potassium levels may need to be monitored.
    Betamethasone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Bisacodyl: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (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.
    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; Hydrocodone; Pseudoephedrine: (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: (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: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Budesonide; Formoterol: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Cabergoline: (Minor) Cabergoline has minimal affinity for adrenergic receptors; however, it has been associated with hypotension in some instances. Cabergoline should be used cautiously in those receiving antihypertensive agents.
    Calcium Carbonate; Magnesium Hydroxide: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    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. In addition, loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Canagliflozin: (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, loop diuretics can also decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. 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: (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, loop diuretics can also decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving canagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Candesartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Cannabidiol: (Moderate) Consider a dose reduction of torsemide as clinically appropriate, if adverse reactions occur when administered with cannabidiol. Increased torsemide exposure is possible. Torsemide is a CYP2C9 substrate. In vitro data predicts inhibition of CYP2C9 by cannabidiol potentially resulting in clinically significant interactions.
    Capecitabine: (Moderate) Monitor diuretic effect and blood pressure if coadministration of torsemide with capecitabine is necessary; adjust the dose of torsemide if clinically appropriate. Torsemide is a CYP2C9 substrate and capecitabine is a weak CYP2C9 inhibitor. Concomitant use can decrease torsemide clearance and increase torsemide plasma concentrations.
    Capreomycin: (Moderate) The risk of ototoxicity or nephrotoxicity secondary to capreomycin may be increased by the addition of concomitant therapies with similar side effects, including loop diuretics. Ototoxicity from furosemide or other loop diuretics, while uncommon, can be a transient or permanent side effect of significance. Ototoxicity is best documented with the loop diuretics ethacrynic acid and furosemide, but may also occur with either bumetanide or torsemide. The exact mechanism by which furosemide or other loop diuretics produce ototoxicity is unknown. Usually, reports indicate that furosemide ototoxicity is associated with rapid injection, severe renal impairment, higher than recommended dosages or infusion rates, or concomitant therapy with aminoglycoside antibiotics, ethacrynic acid, or other ototoxic drugs. If loop diuretics and capreomycin are used together, it would be prudent to monitor renal function parameters, serum electrolytes, and serum aminoglycoside concentrations during therapy. Audiologic monitoring may be advisable during high dose therapy or therapy of long duration, when hearing loss is suspected, or in selected risk groups (e.g., neonates).
    Captopril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    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) 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) 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) 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) 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) 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.
    Cardiac glycosides: (Moderate) Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting drugs such as loop diuretics, increasing the risk of proarrhythmic effects of cardiac glycosides. Potassium levels should be monitored and normalized prior to and during concurrent diuretic administration and these agents.
    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.
    Casanthranol; Docusate Sodium: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Castor Oil: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Cefaclor: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefadroxil: (Severe) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefazolin: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefdinir: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefditoren: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefepime: (Minor) Cefepime's product label states that cephalosporins may potentiate the adverse renal effects of nephrotoxic agents, such as aminoglycosides and loop diuretics. Carefully monitor renal function, especially during prolonged therapy or use of high aminoglycoside doses. The majority of reported cases involve the combination of aminoglycosides and cephalothin or cephaloridine, which are associated with dose-related nephrotoxicity as singular agents. Limited but conflicting data with other cephalosporins have been noted.
    Cefixime: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefoperazone: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefotaxime: (Minor) Cefotaxime's product label states that cephalosporins may potentiate the adverse renal effects of nephrotoxic agents, such as aminoglycosides and loop diuretics. Carefully monitor renal function, especially during prolonged therapy or use of high aminoglycoside doses. The majority of reported cases involve the combination of aminoglycosides and cephalothin or cephaloridine, which are associated with dose-related nephrotoxicity as singular agents. Limited but conflicting data with other cephalosporins have been noted.
    Cefotetan: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefoxitin: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefpodoxime: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefprozil: (Minor) Cefprozil's product label states that cephalosporins may potentiate the adverse renal effects of nephrotoxic agents, such as aminoglycosides and loop diuretics. Carefully monitor renal function, especially during prolonged therapy or use of high aminoglycoside doses. The majority of reported cases involve the combination of aminoglycosides and cephalothin or cephaloridine, which are associated with dose-related nephrotoxicity as singular agents. Limited but conflicting data with other cephalosporins have been noted.
    Ceftaroline: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Ceftazidime: (Minor) Ceftazidime's product label states that cephalosporins may potentiate the adverse renal effects of nephrotoxic agents, such as aminoglycosides and loop diuretics. Carefully monitor renal function, especially during prolonged therapy or use of high aminoglycoside doses. The majority of reported cases involve the combination of aminoglycosides and cephalothin or cephaloridine, which are associated with dose-related nephrotoxicity as singular agents. Limited but conflicting data with other cephalosporins have been noted.
    Ceftazidime; Avibactam: (Minor) Ceftazidime's product label states that cephalosporins may potentiate the adverse renal effects of nephrotoxic agents, such as aminoglycosides and loop diuretics. Carefully monitor renal function, especially during prolonged therapy or use of high aminoglycoside doses. The majority of reported cases involve the combination of aminoglycosides and cephalothin or cephaloridine, which are associated with dose-related nephrotoxicity as singular agents. Limited but conflicting data with other cephalosporins have been noted.
    Ceftibuten: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Ceftizoxime: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Ceftriaxone: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cefuroxime: (Minor) Cefuroxime's product label states that cephalosporins may potentiate the adverse renal effects of nephrotoxic agents, such as aminoglycosides and loop diuretics. Carefully monitor renal function, especially during prolonged therapy or use of high aminoglycoside doses. The majority of reported cases involve the combination of aminoglycosides and cephalothin or cephaloridine, which are associated with dose-related nephrotoxicity as singular agents. Limited but conflicting data with other cephalosporins have been noted.
    Celecoxib: (Moderate) If celecoxib (an NSAID) and torsemide (a diuretic) are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy; side effects from celecoxib may also increase. The concomitant use of celecoxib, a sensitive substrate of CYP2C9, and torsemide, a CYP2C9 inhibitor, may result in increased plasma concentrations of celecoxib. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Cephalexin: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Cephradine: (Moderate) Nephrotoxicity associated with cephalosporins may be potentiated by concomitant furosemide therapy. Clinicans should be aware that this may occur even in patients with minor or transient renal impairment.
    Ceritinib: (Moderate) Monitor diuretic effect and blood pressure if torsemide is used in combination with ceritinib; adjust the dose of torsemide if necessary. Ceritinib is a weak CYP2C9 inhibitor and torsemide is primarily metabolized by CYP2C9.
    Cetirizine; Pseudoephedrine: (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) 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.
    Chloroprocaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Chlorothiazide: (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.
    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; Dihydrocodeine; 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; Dihydrocodeine; Pseudoephedrine: (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) 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; 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; Hydrocodone; Pseudoephedrine: (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) 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.
    Chlorthalidone: (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.
    Chlorthalidone; Clonidine: (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.
    Cholestyramine: (Minor) Cholestyramine inhibits the oral bioavailability of torsemide. Simultaneous use of torsemide and cholestyramine is not recommended. Stagger the administration times of cholestyramine and oral torsemide by several hours to avoid the possibility of this interaction.
    Ciclesonide: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Cidofovir: (Severe) 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 potassium-wasting diuretic therapies, such as loop diuretics. Drugs that are associated with depletion of electrolytes may cause cisapride-induced cardiac arrhythmias.
    Cisatracurium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Cisplatin: (Moderate) Concurrent use of cisplatin and other agents known to be ototoxic (e.g., loop diuretics) may increase the risk of drug-induced ototoxicity, but confirmatory data are not available. Usually, reports indicate that furosemide ototoxicity is associated with rapid injection, severe renal impairment, higher than recommended furosemide dosages or infusion rates, hypoproteinemia, or concomitant therapy with other ototoxic drugs. Additive effects of cisplatin and loop diuretics on renal parameters and electrolyte balance should also be considered. Saline hydration and diuretic use are common during cisplatin therapy to manage hydration status. If furosemide and cisplatin are used together, it is prudent to monitor renal function parameters and serum electrolyte concentrations during co-therapy. Audiologic monitoring may be advisable during high dose therapy or therapy of long duration, when hearing loss is suspected, or in selected risk groups.
    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.
    Clozapine: (Major) Caution is advisable during concurrent use of clozapine and loop diuretics. Treatment with clozapine has been associated with QT prolongation, torsade de pointes (TdP), cardiac arrest, and sudden death. Concurrent use of clozapine and medications known to cause electrolyte imbalance may increase the risk of QT prolongation.
    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; Phenylephrine; Promethazine: (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.
    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.
    Conivaptan: (Moderate) There is potential for additive hypotensive effects when conivaptan is coadministered with antihypertensive agents.
    Corticosteroids: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Corticotropin, ACTH: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Cortisone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Cosyntropin: (Moderate) Use cosyntropin cautiously in patients receiving diuretics. Cosyntropin may accentuate the electrolyte loss associated with diuretic therapy.
    Dapagliflozin: (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving dapagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Dapagliflozin; Metformin: (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving dapagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Dapagliflozin; Saxagliptin: (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving dapagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Darifenacin: (Minor) Diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Deflazacort: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Desloratadine; Pseudoephedrine: (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.
    Desmopressin: (Major) Desmopressin, when used in the treatment of nocturia is contraindicated with loop diuretics because of the risk of severe hyponatremia.
    Desvenlafaxine: (Moderate) Patients receiving a diuretic during treatment with venlafaxine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs, including venlafaxine. Cases involving serum sodium levels lower than 110 mmol/l have been reported. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Dexamethasone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (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 loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Dexmethylphenidate: (Moderate) Dexmethylphenidate can reduce the hypotensive effect of antihypertensive agents, including loop diuretics. Periodic evaluation of blood pressure is advisable during concurrent use of dexmethylphenidate and antihypertensive agents, particularly during initial coadministration and after dosage increases of dexmethylphenidate.
    Dextroamphetamine: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    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) 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.
    Diazoxide: (Moderate) Additive hypotensive effects can occur with the concomitant administration of diazoxide with loop diuretics. 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.
    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.
    Diclofenac: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Diclofenac; Misoprostol: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Diethylpropion: (Major) Diethylpropion has vasopressor effects and may limit the benefit of loop 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) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Digitoxin: (Moderate) Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting drugs such as loop diuretics, increasing the risk of proarrhythmic effects of cardiac glycosides. Potassium levels should be monitored and normalized prior to and during concurrent diuretic administration and these agents.
    Digoxin: (Moderate) Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting drugs such as loop diuretics, increasing the risk of proarrhythmic effects of cardiac glycosides. Potassium levels should be monitored and normalized prior to and during concurrent diuretic administration and these agents.
    Dihydrocodeine; Guaifenesin; Pseudoephedrine: (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) 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) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Diphenhydramine; Naproxen: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    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.
    Docusate Sodium; Senna: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Docusate: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Dofetilide: (Major) Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting drugs such as loop diuretics increasing the potential for dofetilide-induced torsade de pointes. Potassium levels should be within the normal range prior and during administration of dofetilide.
    Dolasetron: (Major) The manufacturer warns that the coadministration of dolasetron with diuretics associated with hypokalemia could increase the risk of QT prolongation. 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 increasing the potential for cardiac arrhythmias. Potassium levels should be within the normal range prior to and during therapy with dolasetron.
    Doxacurium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Droperidol: (Moderate) Caution is advised when using droperidol in combination with loop diuretics which may lead to electrolyte abnormalities, especially hypokalemia or hypomagnesemia, as such abnormalities may increase the risk for QT prolongation or cardiac arrhythmias.
    Dulaglutide: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Duloxetine: (Moderate) Patients receiving a diuretic during treatment with venlafaxine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs, including venlafaxine. Cases involving serum sodium levels lower than 110 mmol/l have been reported. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Empagliflozin: (Moderate) When empagliflozin is initiated in patients already receiving loop 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, volume status should be assessed and corrected. Monitor for signs and symptoms after initiating therapy. Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving empagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Empagliflozin; Linagliptin: (Moderate) When empagliflozin is initiated in patients already receiving loop 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, volume status should be assessed and corrected. Monitor for signs and symptoms after initiating therapy. Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving empagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Loop diurectics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, such as linagliptin. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Empagliflozin; Metformin: (Moderate) When empagliflozin is initiated in patients already receiving loop 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, volume status should be assessed and corrected. Monitor for signs and symptoms after initiating therapy. Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving empagliflozin should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Enalapril, Enalaprilat: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Enalapril; Felodipine: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Enflurane: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Enzalutamide: (Moderate) Monitor diuretic effect and blood pressure if coadministration of torsemide with enzalutamide is necessary. Torsemide is a CYP2C9 substrate and enzalutamide is a moderate CYP2C9 inducer. Concomitant use of CYP2C9 inducers increases torsemide clearance and decreases torsemide plasma concentrations.
    Ephedrine: (Major) The cardiovascular effects of sympathomimetics, such as ephedrine, may reduce the antihypertensive effects produced by loop diuretics. Blood pressure and heart rates should be monitored closely to confirm that the desired antihypertensive effect is achieved.
    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: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Ertugliflozin; Metformin: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Ertugliflozin; Sitagliptin: (Minor) Torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    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 loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Esomeprazole; Naproxen: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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. (Moderate) Proton pump inhibitors, such as esomeprazole, have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Etodolac: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Etomidate: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Exenatide: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Famotidine; Ibuprofen: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Fenofibric Acid: (Minor) At therapeutic concentrations, fenofibric acid is a mild-to-moderate inhibitor of CYP2C9. Concomitant use of fenofibric acid with CYP2C9 substrates, such as torsemide, has not been formally studied. Fenofibric acid may theoretically increase plasma concentrations of CYP2C9 substrates and could lead to toxicity for drugs that have a narrow therapeutic range. Monitor the therapeutic effect of torsemide during coadministration with fenofibric acid.
    Fenoprofen: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Fentanyl: (Moderate) Fentanyl may reduce the efficacy of diuretics due to induction of the release of antidiuretic hormone. Adjustments to diuretic therapy may be needed in some patients. In addition, opiate agonists may potentiate orthostatic hypotension when used concurrently with diuretics.
    Fexofenadine; Pseudoephedrine: (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.
    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.
    Fluconazole: (Moderate) Monitor the diuretic effect and blood pressure if torsemide and fluconazole are administered together. The torsemide dose may need to be reduced. Concomitant use of torsemide and fluconazole can decrease torsemide clearance and increase torsemide plasma concentrations. Torsemide is a substrate of CYP2C9; fluconazole inhibits CYP2C9.
    Fludrocortisone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Flunisolide: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    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.
    Fluoxetine; Olanzapine: (Moderate) Olanzapine may induce orthostatic hypotension and thus enhance the effects of antihypertensive agents. (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) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Fluticasone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Fluticasone; Salmeterol: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Fluticasone; Umeclidinium; Vilanterol: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Fluticasone; Vilanterol: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    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.
    Formoterol; Mometasone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Foscarnet: (Moderate) Avoid concurrent use of loop diuretics with foscarnet. Coadministration may impair the renal tubular secretion of foscarnet, thereby increasing the possibility for toxicity. When use of a diuretic is indicated in patients being treated with foscarnet, consider a thiazide diuretic.
    Fosinopril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Fospropofol: (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.
    Ginseng, Panax ginseng: (Major) Ginseng may decrease the effectiveness of loop diuretics. One case report described a temporal relationship between the use of ginseng and resistance to furosemide therapy, resulting in edema, hypertension, and hospitalization on 2 separate occasions. Other nutritional products were taken concurrently by the patient were not specified in the report. A mechanism of action or causal relationship has not been definitively established.
    Glimepiride; Pioglitazone: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Glimepiride; Rosiglitazone: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Glipizide; Metformin: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Glyburide; Metformin: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    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; Pseudoephedrine: (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) 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.
    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 potassium-wasting diuretic therapies such as loop diuretics.
    Haloperidol: (Major) QT prolongation has been observed during haloperidol treatment. Use of haloperidol and medications known to cause electrolyte imbalance may increase the risk of QT prolongation. Therefore, caution is advisable during concurrent use of haloperidol and loop diuretics. In general, haloperidol should also 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.
    Hawthorn, Crataegus laevigata: (Moderate) Hawthorn, Crataegus laevigata may lower peripheral vascular resistance. Hawthorn use in combination with antihypertensive agents may lead to additional reductions in blood pressure in some individuals. Patients receiving hawthorn concurrently with antihypertensive medications should receive periodic blood pressure monitoring.
    Hydralazine; Hydrochlorothiazide, HCTZ: (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.
    Hydralazine; Isosorbide Dinitrate, ISDN: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Hydrochlorothiazide, HCTZ: (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.
    Hydrochlorothiazide, HCTZ; Irbesartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrochlorothiazide, HCTZ; Lisinopril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrochlorothiazide, HCTZ; Losartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrochlorothiazide, HCTZ; Methyldopa: (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.
    Hydrochlorothiazide, HCTZ; Metoprolol: (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.
    Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrochlorothiazide, HCTZ; Propranolol: (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.
    Hydrochlorothiazide, HCTZ; Quinapril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrochlorothiazide, HCTZ; Spironolactone: (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.
    Hydrochlorothiazide, HCTZ; Telmisartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrochlorothiazide, HCTZ; Triamterene: (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.
    Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative. (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.
    Hydrocodone; Ibuprofen: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Hydrocodone; 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.
    Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (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) 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: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Ibandronate: (Moderate) When the intravenous formulation of ibandronate is used for the treatment of hypercalcemia of malignancy, combination therapy with loop diuretics should be used with caution in order to avoid hypocalcemia. In patients with hypercalcemia of malignancy, the initial treatment typically includes the use of loop diuretics, in combination with saline hydration, however, diuretic therapy should not be employed prior to correction of hypovolemia and dehydration.
    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) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Ibuprofen; Oxycodone: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Ibuprofen; Pseudoephedrine: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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. (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.
    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) Further reductions in blood pressure may occur when inhaled iloprost is administered to patients receiving other antihypertensive agents.
    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.
    Incretin Mimetics: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Indomethacin: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Inotersen: (Moderate) Use caution with concomitant use of inotersen and diuretics due to the risk of glomerulonephritis and nephrotoxicity.
    Insulin Degludec; Liraglutide: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Insulin Glargine; Lixisenatide: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Insulins: (Minor) Monitor patients receiving insulin closely for worsening glycemic control when bumetanide, furosemide, and torsemide are instituted. Bumetanide, furosemide, and torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents.
    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.
    Irbesartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    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.
    Isoflurane: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Moderate) Monitor the diuretic effect and blood pressure if torsemide and rifampin are administered together. The torsemide dose may need to be increased. Concomitant use of torsemide and rifampin can increase torsemide clearance and decrease torsemide plasma concentrations. Torsemide is a substrate of CYP2C9; rifampin induces CYP2C9.
    Isoniazid, INH; Rifampin: (Moderate) Monitor the diuretic effect and blood pressure if torsemide and rifampin are administered together. The torsemide dose may need to be increased. Concomitant use of torsemide and rifampin can increase torsemide clearance and decrease torsemide plasma concentrations. Torsemide is a substrate of CYP2C9; rifampin induces CYP2C9.
    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.
    Isosorbide Dinitrate, ISDN: (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.
    Ivacaftor: (Minor) Increased monitoring is recommended if ivacaftor is administered concurrently with CYP2C9 substrates, such as torsemide. In vitro studies showed ivacaftor to be a weak inhibitor of CYP2C9. Co-administration may lead to increased exposure to CYP2C9 substrates; however, the clinical impact of this has not yet been determined.
    Ketamine: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Ketoprofen: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Ketorolac: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Lactulose: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Lansoprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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. (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Levodopa: (Moderate) Concomitant use of antihypertensive agents with levodopa can result in additive hypotensive effects.
    Levomethadyl: (Moderate) Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting drugs such as loop diuretics, increasing the risk of proarrhythmic effects of levomethadyl. Potassium levels should be monitored and normalized prior to and during concurrent diuretic administration and these agents.
    Levomilnacipran: (Moderate) Patients receiving a diuretic during treatment with venlafaxine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs, including venlafaxine. Cases involving serum sodium levels lower than 110 mmol/l have been reported. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Linagliptin: (Minor) Loop diurectics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, such as linagliptin. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Linagliptin; Metformin: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose. (Minor) Loop diurectics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, such as linagliptin. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Liraglutide: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Lisdexamfetamine: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Lisinopril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Lithium: (Moderate) Loop diuretics may increase serum lithium concentrations by increasing lithium reabsorption in the proximal tubule, and possibly by decreasing lithium reabsorption in the loop of Henle with an increase in lithium delivery to the distal tubule with minor compensatory reabsorption. However, the effect of loop diuretics on lithium clearance relative to thiazide diuretics is generally minor. In one small study evaluating the pharmacokinetic effects of several different medications on a single 600 mg dose of lithium carbonate, administration of furosemide resulted in an 11% decrease in lithium clearance. According to the Beers Criteria, concurrent use of lithium and loop diuretics may result in a clinically important drug interaction, particularly in older adults. The Beers expert panel recommends avoiding concurrent use due to an increased risk of lithium toxicity. If the combination is necessary, monitoring of lithium concentrations is recommended.
    Lixisenatide: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Loratadine; Pseudoephedrine: (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: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    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.
    Lubiprostone: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Lumacaftor; Ivacaftor: (Minor) Although the clinical significance of this interaction is unknown, concurrent use of torsemide and lumacaftor; ivacaftor may alter torsemide exposure; caution and monitoring are advised if these drugs are used together. Torsemide is a substrate of CYP2C9. In vitro data suggest that lumacaftor; ivacaftor may induce and/or inhibit CYP2C9. The net effect of lumacaftor; ivacaftor on CYP2C9-mediated metabolism is not clear, but CYP2C9 substrate exposure may be affected leading to decreased efficacy or increased or prolonged therapeutic effects and adverse events.
    Lumacaftor; Ivacaftor: (Minor) Increased monitoring is recommended if ivacaftor is administered concurrently with CYP2C9 substrates, such as torsemide. In vitro studies showed ivacaftor to be a weak inhibitor of CYP2C9. Co-administration may lead to increased exposure to CYP2C9 substrates; however, the clinical impact of this has not yet been determined.
    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) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Magnesium Hydroxide: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Magnesium Salts: (Moderate) Diuretics may interfere with the kidneys ability to regulate magnesium concentrations. Long-term use of diuretics may impair the magnesium-conserving ability of the kidneys and lead to hypomagnesemia. (Moderate) Diuretics may interfere with the kidneys ability to regulate magnesium concentrations. Long-term use of loop diuretics may impair the magnesium-conserving ability of the kidneys and lead to hypomagnesemia. In addition, use caution when prescribing sulfate salt bowel preparation in patients taking concomitant 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) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Mefenamic Acid: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Meglitinides: (Minor) Loop diuretics have been associated with hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between loop diuretics and all antidiabetic agents. Monitor for a loss of diabetic control.
    Meloxicam: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    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.
    Metformin: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose.
    Metformin; Pioglitazone: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Metformin; Repaglinide: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose. (Minor) Loop diuretics have been associated with hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between loop diuretics and all antidiabetic agents. Monitor for a loss of diabetic control.
    Metformin; Rosiglitazone: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Metformin; Saxagliptin: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose. (Minor) Torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Metformin; Sitagliptin: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose. (Minor) Torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Methadone: (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.
    Methamphetamine: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Methazolamide: (Moderate) Loop 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.
    Methohexital: (Moderate) Concurrent use of methohexital and antihypertensive agents increases the risk of developing hypotension.
    Methyclothiazide: (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.
    Methylcellulose: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Methylphenidate: (Moderate) Methylphenidate can reduce the hypotensive effect of antihypertensive agents such as loop diuretics. Periodic evaluation of blood pressure is advisable during concurrent use of methylphenidate and antihypertensive agents, particularly during initial coadministration and after dosage increases of methylphenidate.
    Methylprednisolone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Metolazone: (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.
    Miconazole: (Minor) No formal drug interaction studies have been performed with buccal miconazole. Systemic absorption of miconazole following buccal administration is minimal. Vaginal and topical preparations are not likely to interact. However, the diuretic effect and blood pressure response may be affected if torsemide is administered with a CYP2C9 inhibitor. Torsemide is a substrate of CYP2C9; miconazole inhibits CYP2C9. Concomitant use of torsemide and miconazole can theoretically decrease torsemide clearance and increase torsemide plasma concentrations.
    Miglitol: (Minor) Loop diuretics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Milnacipran: (Moderate) Patients receiving a diuretic during treatment with venlafaxine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs, including venlafaxine. Cases involving serum sodium levels lower than 110 mmol/l have been reported. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. 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.
    Mineral Oil: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    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.
    Mivacurium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Moexipril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Mometasone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Morphine: (Moderate) Morphine may reduce the efficacy of diuretics due to induction of the 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) Morphine may reduce the efficacy of diuretics due to induction of the 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) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Naproxen: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Naproxen; Pseudoephedrine: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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. (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.
    Naproxen; Sumatriptan: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Nateglinide: (Minor) Loop diuretics have been associated with hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between loop diuretics and all antidiabetic agents. Monitor for a loss of diabetic control.
    Nebivolol; Valsartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Nefazodone: (Minor) Although relatively infrequent, nefazodone may cause orthostatic hypotension in some patients; this effect may be additive with antihypertensive agents. Blood pressure monitoring and dosage adjustments of either drug may be necessary.
    Nesiritide, BNP: (Major) The potential for hypotension may be increased when coadministering nesiritide with antihypertensive agents.
    Neuromuscular blockers: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Niacin, Niacinamide: (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.
    Niacin; Simvastatin: (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.
    Nitrates: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Nitroglycerin: (Moderate) Concomitant use of nitrates with other antihypertensive agents can cause additive hypotensive effects. Dosage adjustments may be necessary.
    Nitroprusside: (Moderate) Additive hypotensive effects may occur when nitroprusside is used concomitantly with other antihypertensive agents. Dosages should be adjusted carefully, according to blood pressure.
    Non-Ionic Contrast Media: (Moderate) Because patients should be well-hydrated prior to the administration of contrast media, loop diuretics such as furosemide that cause intravascular volume depletion might increase the risk of nephrotoxicity when using radiopaque contrast agents. In addition, furosemide plus normal saline have been evaluated for the prevention of contrast induced nephropathy; in one retrospective review, the incidence of contrast-induced nephropathy in the furosemide plus saline group was almost four times that of the saline only group (40% versus 11%, respectively). Other studies have shown no benefit with combination therapy.
    Norepinephrine: (Moderate) Diuretics can cause decreased arterial responsiveness to norepinephrine, but the effect is not sufficient to preclude their coadministration.
    Octreotide: (Moderate) Patients receiving diuretics or other agents to control fluid and electrolyte balance may require dosage adjustments while receiving octreotide due to additive effects.
    Olanzapine: (Moderate) Olanzapine may induce orthostatic hypotension and thus enhance the effects of antihypertensive agents.
    Olmesartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Omeprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Omeprazole; Sodium Bicarbonate: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Ondansetron: (Moderate) The coadministration of ondansetron with diuretics associated with hypokalemia could increase the risk of QT prolongation. Potassium levels should be within the normal range prior to and during therapy with ondansetron.
    Oprelvekin, rh-IL-11: (Major) Patients receiving loop diuretics during oprelvekin, rh-IL-11 therapy are at increased risk for developing severe hypokalemia; close monitoring of fluid and electrolyte status is warranted during concurrent diuretic and oprelvekin therapy.
    Oritavancin: (Moderate) Torsemide is metabolized by CYP2C9; oritavancin is a weak CYP2C9 inhibitor. Coadministration may result in elevated torsemide plasma concentrations. If these drugs are administered concurrently, monitor patients for signs of torsemide toxicity, such as dehydration, hypokalemia, or hypomagnesemia.
    Oxandrolone: (Moderate) Monitor the diuretic effect and blood pressure if torsemide and oxandrolone are administered together. The torsemide dose may need to be reduced. Concomitant use of torsemide and oxandrolone can decrease torsemide clearance and increase torsemide plasma concentrations. Torsemide is a substrate of CYP2C9; oxandrolone inhibits CYP2C9.
    Oxaprozin: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Oxybutynin: (Minor) Diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Oxymetazoline: (Major) The vasoconstricting actions of oxymetazoline, an alpha adrenergic agonist, may reduce the antihypertensive effects produced by diuretics. If these drugs are used together, closely monitor for changes in blood pressure.
    Paliperidone: (Moderate) Paliperidone may cause orthostatic hypotension, thereby enhancing the hypotensive effects of antihypertensive agents. Orthostatic vital signs should be monitored in patients receiving paliperidone and loop diuretics who are susceptible to hypotension.
    Pamidronate: (Moderate) Because both loop diuretics and intravenously administered bisphosphonates (i.e., alendronate, ibandronate, pamidronate, and zoledronic acid) can cause a decrease in serum calcium, caution is advised when used concomitantly in the treatment of hypercalcemia of malignancy in order to avoid hypocalcemia. In patients with hypercalcemia of malignancy, the initial treatment typically includes the use of loop diuretics, in combination with saline hydration, however, diuretic therapy should not be employed prior to correction of hypovolemia and dehydration.
    Pancuronium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Pantoprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Paroxetine: (Moderate) Patients receiving a diuretic during treatment with paroxetine 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 paroxetine should be considered in patients who develop symptomatic hyponatremia.
    Pasireotide: (Major) Cautious use of pasireotide and medicines that can affect potassium or magnesium concentrations such as diuretics is advised. Pasireotide may prolong the QT interval, and hypokalemia and/or hypomagnesemia are risk factors for QT prolongation. Assess the patient's potassium and magnesium concentration before and periodically during pasireotide receipt. Correct hypokalemia and hypomagnesemia before pasireotide receipt.
    Pentamidine: (Major) Drugs that are associated with hypokalemia and/or hypomagnesemia such as loop diuretics should be used with caution in patients also receiving pentamidine. Since pentamidine may cause QT prolongation independently of electrolyte imbalances, the risk for cardiac arrhythmias is potentiated by the concomitant use of agents associated with electrolyte loss. .
    Pentoxifylline: (Moderate) Pentoxifylline has been used concurrently with antihypertensive drugs (beta blockers, diuretics) without observed problems. Small decreases in blood pressure have been observed in some patients treated with pentoxifylline; periodic systemic blood pressure monitoring is recommended for patients receiving concomitant antihypertensives. If indicated, dosage of the antihypertensive agents should be reduced.
    Perindopril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Perindopril; Amlodipine: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Phenelzine: (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.
    Phentermine; Topiramate: (Moderate) Topiramate is a carbonic anhydrase inhibitor. Concurrent use of topiramate with non-potassium sparing diuretics (e.g., loop diuretics) may potentiate the potassium-wasting action of these diuretics. Monitor baseline and periodic potassium concentrations during coadministration.
    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.
    Phenylephrine; Promethazine: (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.
    Phenytoin: (Moderate) The concomitant use of phenytoin, a substrate of CYP2C9 with a narrow therapeutic range, and torsemide, a CYP2C9 inhibitor, may result in increased plasma concentrations of phenytoin. If these drugs are coadministered, monitor patients for signs of phenytoin toxicity. Monitoring phenytoin concentrations may be necessary.
    Pimozide: (Major) Pimozide is associated with a well-established risk of QT prolongation and torsade de pointes (TdP). Use of pimozide and medications known to cause electrolyte imbalance may increase the risk of QT prolongation. Therefore, caution is advisable during concurrent use of pimozide and loop diuretics. According to the manufacturer, potassium deficiencies should be correctly prior to treatment with pimozide and normalized potassium levels should be maintained during treatment.
    Pioglitazone: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Piroxicam: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Polycarbophil: (Moderate) Loop diuretics may increase the risk of hypokalemia, especially in patients receiving prolonged therapy with laxatives such as calcium polycarbophil. Monitor serum potassium to determine the need for potassium supplementation and/or alteration in drug therapy.
    Polyethylene Glycol: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics.
    Polyethylene Glycol; Electrolytes: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics. (Moderate) Use caution when prescribing sulfate salt bowel preparation in patients taking concomitant medications that may affect renal function such as diuretics.
    Polyethylene Glycol; Electrolytes; Ascorbic Acid: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics. (Moderate) Use caution when prescribing sulfate salt bowel preparation in patients taking concomitant medications that may affect renal function such as diuretics.
    Polyethylene Glycol; Electrolytes; Bisacodyl: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy. (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics.
    Polymyxin B: (Moderate) Systemic polymyxin B is nephrotoxic and should be used cautiously with loop diuretics, which may cause azotemia and may increase the risk for renal toxicity when coadministered. Close monitoring of renal status and for drug toxicity is recommended. Diminishing urine output and a rising BUN are indications to discontinue systemic polymyxin B therapy.
    Pramlintide: (Minor) Loop diuretics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. Monitor patient for diabetic control.
    Prazosin: (Moderate) The first dose response (acute postural hypotension) of prazosin may be exaggerated in patients who are receiving loop diuretics. This effect can be minimized by reducing the prazosin dose to 1 to 2 mg three times a day, by introducing the loop diuretic cautiously, and then by retitrating prazosin to clinical response.
    Prednisolone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Prednisone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Procainamide: (Moderate) Procainamide can decrease blood pressure and should be used cautiously in patients receiving antihypertensive agents. Intravenous administration of procainamide is more likely to cause hypotensive effects.
    Procaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Propofol: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Pseudoephedrine: (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.
    Psyllium: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Quetiapine: (Major) QT prolongation has occurred during concurrent use of quetiapine and medications known to cause electrolyte imbalance. Therefore, caution is advisable during concurrent use of quetiapine and loop diuretics.
    Quinapril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Quinidine: (Moderate) Quinidine can decrease blood pressure and should be used cautiously in patients receiving antihypertensive agents due to the potential for additive hypotension.
    Rabeprazole: (Moderate) Proton pump inhibitors have been associated with hypomagnesemia. Hypomagnesemia occurs with loop diuretics (furosemide, bumetanide, torsemide, and ethacrynic acid). 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.
    Ramipril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Rapacuronium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Rasagiline: (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.
    Repaglinide: (Minor) Loop diuretics have been associated with hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between loop diuretics and all antidiabetic agents. Monitor for a loss of diabetic control.
    Rifampin: (Moderate) Monitor the diuretic effect and blood pressure if torsemide and rifampin are administered together. The torsemide dose may need to be increased. Concomitant use of torsemide and rifampin can increase torsemide clearance and decrease torsemide plasma concentrations. Torsemide is a substrate of CYP2C9; rifampin induces CYP2C9.
    Risperidone: (Moderate) Risperidone may induce orthostatic hypotension and thus enhance the hypotensive effects of antihypertensive agents. Lower initial doses or slower dose titration of risperidone may be necessary in patients receiving antihypertensive agents concomitantly.
    Rocuronium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Rofecoxib: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Rosiglitazone: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Rucaparib: (Moderate) Monitor diuretic effect and blood pressure if coadministration of torsemide with rucaparib is necessary; adjust the dose of torsemide if clinically appropriate. Torsemide is a CYP2C9 substrate and rucaparib is a weak CYP2C9 inhibitor. Concomitant use may increase plasma concentrations of torsemide.
    Sacubitril; Valsartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Salicylates: (Moderate) Salicylates may decrease the diuretic, natriuretic, and antihypertensive actions of diuretics, possibly through inhibition of renal prostaglandin synthesis. Patients receiving loop diuretics and salicylates should be monitored for changes in the effectiveness of their diuretic therapy.
    Saxagliptin: (Minor) Torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Selegiline: (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.
    Semaglutide: (Minor) Loop diuretics, such as bumetanide, furosemide, and torsemide, may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents, including incretin mimetics. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Senna: (Minor) The risk of hypokalemia due to loop diuretics may be increased in patients receiving prolonged therapy with certain laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy in patients receiving loop diuretics. Senna rarely causes hypokalemia with proper use.
    Serotonin norepinephrine reuptake inhibitors: (Moderate) Patients receiving a diuretic during treatment with venlafaxine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs, including venlafaxine. Cases involving serum sodium levels lower than 110 mmol/l have been reported. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Sertraline: (Moderate) Patients receiving a diuretic during treatment with sertraline 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 sertraline should be considered in patients who develop symptomatic hyponatremia.
    Sevoflurane: (Moderate) General anesthetics can potentiate the hypotensive effects of antihypertensive agents.
    Silodosin: (Moderate) During clinical trials with silodosin, the incidence of dizziness and orthostatic hypotension was higher in patients receiving concomitant antihypertensive treatment. Thus, caution is advisable when silodosin is administered with antihypertensive agents.
    Simvastatin; Sitagliptin: (Minor) Torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    Sitagliptin: (Minor) Torsemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between these drugs and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely if these drugs are initiated.
    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 receiving sodium phosphate monobasic monohydrate; sodium phosphate dibasic anhydrous. In addition, loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Sodium picosulfate; Magnesium oxide; Anhydrous citric acid: (Moderate) Use caution when prescribing sodium picosulfate; magnesium oxide; anhydrous citric acid in patients taking concomitant medications that may affect renal function such as diuretics. In addition, use caution in patients receiving drugs where hypokalemia is a particular risk.
    Sodium Polystyrene Sulfonate: (Moderate) Sodium polystyrene sulfonate should be used cautiously with other agents that can induce hypokalemia such as loop diuretics, insulins, or intravenous sodium bicarbonate. Because of differences in onset of action, sodium polystyrene sulfonate is often used with these agents. With appropriate monitoring, hypokalemia can be avoided.
    Solifenacin: (Minor) Diuretics can increase urinary frequency, which may aggravate bladder symptoms. Risk versus benefit should be addressed in patients receiving diuretics and solifenacin.
    Sorbitol: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
    Streptozocin: (Minor) Because streptozocin is nephrotoxic, concurrent or subsequent administration of other nephrotoxic agents (e.g,. aminoglycosides, amphotericin B, cisplatin, foscarnet, or diuretics) could exacerbate the renal insult.
    Succinylcholine: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Sulfonylureas: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents. Monitor blood glucose.
    Sulindac: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Telavancin: (Moderate) Concurrent or sequential use of telavancin with other potentially nephrotoxic drugs such as loop diuretics may lead to additive nephrotoxicity. Closely monitor renal function and adjust telavancin doses based on calculated creatinine clearance.
    Telmisartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Tetracaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Use extreme caution with the concomitant use of tetracaine and antihypertensive agents.
    Tezacaftor; Ivacaftor: (Minor) Increased monitoring is recommended if ivacaftor is administered concurrently with CYP2C9 substrates, such as torsemide. In vitro studies showed ivacaftor to be a weak inhibitor of CYP2C9. Co-administration may lead to increased exposure to CYP2C9 substrates; however, the clinical impact of this has not yet been determined.
    Thiazide 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.
    Thiazolidinediones: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Thiopental: (Moderate) Concurrent use of thiopental and alpha-blockers or antihypertensive agents increases the risk of developing hypotension.
    Thiothixene: (Moderate) Thiothixene should be used cautiously in patients receiving antihypertensive agents. Additive hypotensive effects are possible.
    Tizanidine: (Moderate) Concurrent use of tizanidine with antihypertensive agents can result in significant hypotension. Caution is advised when tizanidine is to be used in patients receiving concurrent antihypertensive therapy.
    Tolmetin: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Tolterodine: (Minor) Diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Tolvaptan: (Moderate) Monitor serum sodium closely if torsemide and tolvaptan are used together. Coadministration increases the risk of too rapid correction of serum sodium.
    Topiramate: (Moderate) Topiramate is a carbonic anhydrase inhibitor. Concurrent use of topiramate with non-potassium sparing diuretics (e.g., loop diuretics) may potentiate the potassium-wasting action of these diuretics. Monitor baseline and periodic potassium concentrations during coadministration.
    Toremifene: (Moderate) Monitor for an increase in torsemide-related adverse reactions including diuretic effect and blood pressure if coadministration with toremifene is necessary; adjust the dose of torsemide if necessary. Torsemide is a CYP2C9 substrate and toremifene is a weak CYP2C9 inhibitor.
    Trandolapril: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Trandolapril; Verapamil: (Moderate) Coadministration of loop diuretics and Angiotensin-converting enzyme inhibitors (ACE inhibitors) may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Tranylcypromine: (Severe) The use of hypotensive agents and tranylcypromine is contraindicated by the manufacturer of tranylcypromine because the effects of hypotensive agents may be markedly potentiated.
    Trazodone: (Minor) Due to additive hypotensive effects, patients receiving antihypertensive agents concurrently with trazodone may have excessive hypotension. Decreased dosage of the antihypertensive agent may be required when given with trazodone.
    Triamcinolone: (Moderate) Corticosteroids may accentuate the electrolyte loss associated with diuretic therapy resulting in hypokalemia and/or hypomagnesemia. While glucocorticoids with mineralocorticoid activity (e.g., cortisone, hydrocortisone) can cause sodium and fluid retention. Close monitoring of electrolytes should occur in patients receiving these drugs concomitantly.
    Trospium: (Minor) Diuretics can increase urinary frequency, which may aggravate bladder symptoms.
    Tubocurarine: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Valdecoxib: (Moderate) If a nonsteroidal anti-inflammatory drug (NSAID) and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy. Patients taking diuretics and NSAIDs concurrently are at higher risk of developing renal insufficiency. 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.
    Valsartan: (Moderate) Coadministration of furosemide and Angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin II receptor antagonists may result in severe hypotension and deterioration in renal function, including renal failure. Hyponatremia or hypovolemia predisposes patients to acute hypotensive episodes following initiation of ACE inhibitor therapy. While ACE inhibitors and loop diuretics are routinely administered together in the treatment of heart failure, if an ACE inhibitor is to be administered to a patient receiving furosemide, initial doses should be conservative.
    Vecuronium: (Moderate) Furosemide-induced hypokalemia can potentiate neuromuscular blockade with nondepolarizing neuromuscular blockers. In addition, furosemide may antagonize the skeletal muscle relaxing effect of tubocurarine and can potentiate neuromuscular blockade following succinylcholine administration.
    Vemurafenib: (Moderate) Concomitant use of vemurafenib and torsemide may result in increased torsemide concentrations. Vemurafenib is a CYP2C9 inhibitor and torsemide is a CYP2C9 substrate. Patients should be monitored for toxicity.
    Venlafaxine: (Moderate) Patients receiving a diuretic during treatment with venlafaxine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hyponatremia due to SIADH may occur during therapy with SNRIs, including venlafaxine. Cases involving serum sodium levels lower than 110 mmol/l have been reported. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of the SNRI should be considered in patients who develop symptomatic hyponatremia.
    Vilazodone: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. 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 vilazodone, as well as implementation of the appropriate medical interventions.
    Vorinostat: (Moderate) Use vorinostat and loop diuretics together with caution; the risk of QT prolongation and arrhythmias may be increased if electrolyte abnormalities occur. Loop diuretics may cause electrolyte imbalances including low potassium; hypomagnesemia, hypokalemia, or hypocalcemia may increase the risk of QT prolongation with vorinostat. Frequently monitor serum electrolytes if concomitant use of these drugs is necessary.
    Vortioxetine: (Moderate) Patients receiving a diuretic during treatment with vortioxetine may be at greater risk of developing syndrome of inappropriate antidiuretic hormone secretion (SIADH). Clinically significant hyponatremia has been reported during therapy with vortioxetine. One case involving serum sodium levels lower than 110 mmol/l has occurred. Hyponatremia may be potentiated by agents which can cause sodium depletion such as diuretics. Discontinuation of vortioxetine should be considered in patients who develop symptomatic hyponatremia.
    Warfarin: (Moderate) Use caution and frequently monitor the PT/INR of patients receiving concomitant therapy with warfarin and torsemide; adjust the dose of warfarin as appropriate. S-warfarin is a CYP2C9 substrate; torsemide is a CYP2C9 inhibitor. Coadministration may result in increases in PT/INR response.
    Yohimbine: (Moderate) Yohimbine can increase blood pressure and therefore can antagonize the therapeutic action of antihypertensive agents. Use with particular caution in hypertensive patients with high or uncontrolled BP.
    Ziconotide: (Moderate) Patients taking diuretics with ziconotide may be at higher risk of depressed levels of consciousness. If altered consciousness occurs, consideration of diuretic cessation is warranted in addition to ziconotide discontinuation.
    Ziprasidone: (Minor) Monitor of potassium and magnesium levels when loop diuretics are used during ziprasidone therapy. The risk of QT prolongation from ziprasidone is increased in the presence of hypokalemia or hypomagnesemia.
    Zoledronic Acid: (Moderate) Loop diuretics should be used with caution in combination with zoledronic acid in order to avoid hypocalcemia. In patients with hypercalcemia of malignancy, the initial treatment typically includes the use of loop diuretics, in combination with saline hydration, however, diuretic therapy should not be employed prior to correction of hypovolemia and dehydration.

    PREGNANCY AND LACTATION

    Pregnancy

    There are no data on the use of torsemide in human pregnancy and the risk of major birth defects or miscarriage. Fetal toxicity (decrease in average body weight, increase in fetal resorption, and delayed fetal ossification) occurred in pregnant rats and rabbits administered 50 and 6.8 times the human dose, respectively.

    There are no data regarding the presence of torsemide in human milk or the effects of torsemide on the breast-feeding infant. Diuretics, such as torsemide, may suppress lactation as a result of intense diuresis. Previous American Academy of Pediatrics recommendations considered bendroflumethiazide, chlorthalidone, chlorothiazide, and hydrochlorothiazide as usually compatible with breast-feeding due to lack of noted adverse effects on the breast-feeding infant.

    MECHANISM OF ACTION

    Mechanism of Action: The actions of loop diuretics can be mediated by several mechanisms operating within the thick, medullary segment of the ascending loop of Henle. These include (a) interference with Na+/K+/2Cl- cotransport at the luminal surface, (b) Na-K pump, and (c) anion exchange. Similar to bumetanide, torsemide selectively blocks active sodium and chloride reabsorption in the thick ascending loop of Henle (mechanism (a) above) promoting rapid excretion of water, sodium and chloride. This action is a result of binding of the diuretic to a chloride ion binding site of the transport molecule. Torsemide also interferes with chloride channels, however, this appears to be a minor mechanism. Effects on potassium, calcium, or bicarbonate reabsorption are variable. Torsemide does not have a significant effect on glomerular filtration rate or renal blood flow. In general, diuretics worsen glucose tolerance. In addition, loop diuretics have been associated with hypercholesterolemia and hypertriglyceridemia.
     
    Torsemide has a significant hemodynamic effect in patients with essential hypertension; it lowers systolic and diastolic blood pressure in patients with acute heart failure or chronic renal failure. Torsemide reduces both preload and afterload in patients with heart failure. Loop diuretics are known to induce a rise in plasma renin and this response is thought to be mediated by renal prostaglandins. A study of the effects of torsemide in 6 healthy adults on a low sodium diet indicated that up to 50% of the diuretic effect may be secondary to increased production of renal prostaglandins resulting in renal vasodilation. Before the onset of diuresis, there is a short term increase in systemic venous capacitance, an added benefit in the treatment of pulmonary edema. Patients with liver disease have high levels of aldosterone which allows accumulation of sodium in the distal convoluted tubules and collecting ducts. More efficient diuresis can be achieved in these patients by combining torsemide therapy with an aldosterone antagonist or potassium-sparing diuretic.

    PHARMACOKINETICS

    Torsemide is administered orally and intravenously. It is metabolized by the hepatic cytochrome P450 enzyme system and is a substrate for CYP2C9. In humans, three metabolites, one of which is active, are produced. The active metabolite does not contribute significantly to clinical activity. In normal adults, about 80% is cleared through hepatic metabolism and 20% is cleared in the urine as unchanged drug. In healthy adults, the elimination half-life is about 3.5 hours.
     
    Affected cytochrome P450 isoenzymes and drug transporters: CYP2C9
    Torsemide is a substrate for CYP2C9.[] Theoretically, metabolism may be affected by drugs that are inhibitors of inducers of CYP2C9.

    Oral Route

    Following oral administration torsemide is rapidly absorbed with about 80% bioavailability. First-pass metabolism is insignificant. Peak plasma concentration is achieved in about one hour after oral administration and is proportional to the dose. Onset of diuresis occurs within the hour and a peak diuretic effect occurs within 1—2 hours.

    Intravenous Route

    Following IV administration, diuresis begins within 10 minutes and is maximal within one hour. The duration of diuresis is independent of the route of administration and lasts 6—8 hours. The volume of distribution is approximately doubled in patients with hepatic cirrhosis, compared to healthy adults and those with mild to moderate renal failure or congestive heart failure. Plasma protein binding is 97—99%.