Amiloride in primary hyperaldosteronism

Abstract

Amiloride is a potassium-sparing diuretic used in spontaneous and diuretic-induced hypokalemia. The effect of amiloride was studied prospectively in 12 patients with primary hyperaldosteronism. Four patients had unilateral adrenal adenomas and eight had bilateral adrenal hyperplasia. All patients were hypertensive and their mean plasma potassium levels were low. Amiloride, 10 to 40 mg daily, was given for 6 mo. Mean plasma potassium levels rose (0.96 mEq/l, P less than 0.001) and remained normal throughout the study without potassium supplementation. Mean blood pressure was lowered by amiloride (22/10 mm Hg, P less than 0.001) but normotension required concomitant antihypertensive therapy in most patients. No significant adverse clinical or laboratory experiences could be directly attributed to amiloride therapy. There was no correlation between the response to therapy and the plasma aldosterone levels, aldosterone secretion rate, or presence of a unilateral adrenal adenoma. Our study demonstrates the efficacy of amiloride in the correction of hypokalemia and amelioration of hypertension in primary hyperaldosteronism.

Pharmacological treatment of aldosterone excess

“…The ENaC-blockers that have been reported to have anti-aldosterone activity are amiloride and triamterene (Ferriss et al, 1978;Griffing et al, 1982;Kremer et al, 1977;Lim et al, 2001). Typically these drugs are used as potassium sparing diuretics for treatment of hypertension or heart failure, although in those conditions they are usually combined with a thiazide or loop diuretic.…”

Primary aldosteronism: from bench to bedside

“…Amiloride can correct or improve both hypertension and hypokalemia. Amiloride administered for between 6 weeks to 6 months resulted in 20-30 mmHg fall in systolic and 10-15 mmHg diastolic blood pressure [82,83]. Unlike spironolactone where nearly 50% of patients can be maintained on monotherapy, about 75% of patients on amiloride needed additional antihypertensive agents to control blood pressure.…”

Treatment of primary aldosteronism: Where are we now?

“…In patients with PA, the antihypertensive efficacy of epithelial sodium channel blockers, such as amiloride and triamterene, is suboptimal. Spironolactone is effective as monotherapy in approximately 50% of patients with PA, whereas 75% of patients on amiloride need additional antihypertensive drugs to achieve BP control [63,64]. Calcium channel blockers (CCBs) may reduce aldosterone secretion and BP by blocking the influx of calcium into the adrenal glomerulosa cells.…”