Hydrochlorothiazideinteractions

ACE inhibitors, Angiotensin II receptor antagonists, aldosterone blockers, potassium supplements, heparin, low molecular weight heparin, and other drugs known to cause hyperkalemia Concomitant administration may lead to severe hyperkalemia. Alcohol, barbiturates, or narcotics Potentiation of orthostatic hypotension may occur. Antidiabetic drugs (e.g., oral agents, insulin) Dosage adjustment of the antidiabetic drug may be required (see Precautions ). Corticosteroids, ACTH Intensified electrolyte depletion, particularly hypokalemia, may occur. Pressor amines (e.g., norepinephrine) Both spironolactone and hydrochlorothiazide reduce the vascular responsiveness to norepinephrine. Therefore, caution should be exercised in the management of patients subjected to regional or general anesthesia while they are being treated with spironolactone and hydrochlorothiazide. Skeletal muscle relaxants, nondepolarizing (e.g., tubocurarine) Possible increased responsiveness to the muscle relaxant may result. Lithium Lithium generally should not be given with diuretics. Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity. Nonsteroidal anti-inflammatory drugs (NSAIDs) In some patients, the administration of an NSAID can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing, and thiazide diuretics. Combination of NSAIDs, e.g., indomethacin, with potassium-sparing diuretics has been associated with severe hyperkalemia. Therefore, when spironolactone and hydrochlorothiazide tablets and NSAIDs are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained. Acetylsalicylic acid Acetylsalicylic acid may reduce the efficacy of spironolactone. Therefore, when spironolactone and hydrochlorothiazide tablets and acetylsalicylic acid are used concomitantly, spironolactone and hydrochlorothiazide tablets may need to be titrated to higher maintenance dose and the patient should be observed closely to determine if the desired effect is obtained. Digoxin Spironolactone has been shown to increase the half-life of digoxin. This may result in increased serum digoxin levels and subsequent digitalis toxicity. Monitor serum digoxin levels and adjust dose accordingly. Thiazide-induced electrolyte disturbances, i.e. hypokalemia, hypomagnesemia, increase the risk of digoxin toxicity, which may lead to fatal arrhythmic events (see Precautions ) Cholestyramine Hyperkalemic metabolic acidosis has been reported in patients given spironolactone concurrently with cholestyramine. Abiraterone Spironolactone binds to the androgen receptor and may increase prostate-specific antigen (PSA) levels in abiraterone-treated prostate cancer patients. Concomitant use of spironolactone is not recommended. Mitotane Avoid concomitant use of spironolactone and hydrochlorothiazide tablets and mitotane. Spironolactone reduces mitotane plasma levels. The effect of concomitant spironolactone on the pharmacokinetics of mitotane has not been studied; however, patients exhibited significantly lower mitotane levels compared to those who did not receive concomitant spironolactone despite receiving higher mitotane doses.