Amiloride

DEA Class; Rx

Common Brand Names; Midamor

Oral potassium-sparing diuretic similar in action to triamterene; not a thiazide; used in the treatment or prevention of hypokalemia; also for edema and as an adjunct in HTN; has little antihypertensive or diuretic activity compared with other diuretics, some additive effects noted when used concurrently with thiazides or loop diuretics; useful for those not tolerating or not unresponsive to potassium supplements.

Indicated for the adjunctive treatment of heart failure edema, hypertension, or hypokalemia.

Hypersensitivity to amiloride

Hyperkalemia (K+ >5.5 mEq/L [5.5 mmol/L])

Concomitant use with K+-sparing diuretic, or K supplementation

Impaired renal function (Scr >1.5 mg/dL [132.6 umol/L], or BUN >30 mg/dL [10.7 mmol/L]) diabetes

Hyperkalemia

• The risk of hyperkalemia may be increased when potassium-conserving agents, including amiloride hydrochloride are administered concomitantly with an angiotensin-converting enzyme inhibitor, an angiotensin II receptor antagonist, cyclosporine or tacrolimus

Diabetes Mellitus

• In diabetic patients, hyperkalemia has been reported with the use of all potassium-conserving diuretics, including amiloride hydrochloride, even in patients without evidence of diabetic nephropathy; therefore, amiloride should be avoided, if possible, in diabetic patients and, if it is used, serum electrolytes and renal function must be monitored frequently; amiloride should be discontinued at least 3 days before glucose tolerance testing

Metabolic or Respiratory Acidosis

• Antikaliuretic therapy should be instituted only with caution in severely ill patients in whom respiratory or metabolic acidosis may occur, such as patients with cardiopulmonary disease or poorly controlled diabetes

Drug interaction overview

• In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop and potassium-sparing diuretics

Teratogenicity studies in rabbits and mice given 20 and 25 times maximum human dose, respectively, revealed no evidence of harm to fetus, although studies showed that the drug crossed the placenta in modest amounts

Studies in rats have shown that amiloride is excreted in milk in concentrations higher than those found in blood, but it is not known whether amiloride hydrochloride is excreted in human milk