Inhibition of aldosterone production in diuretic-induced hyperaldosteronism by aldosterone antagonist canrenone in man.

Abstract

Healthy male subjects orally received the diuretic thiabutazide (15 mg/day) over 3 days. Thiabutazide caused a considerable loss in sodium and fluid and thereby induced a marked secondary hyperaldosteronism. On the third day of thiabutazide treatment one half of the subjects additionally received 5 mg/kg micronized canrenone. During the experiment a moderate dietary sodium restriction and a constant fluid intake were prescribed. Canrenone caused a significant decrease in aldosterone excretion in thiabutazide-induced hyperaldosteronism. The plasma aldosterone concentration was highly significantly reduced over more than 12 hrs after the administration of canrenone, although a marked increase in sodium and fluid excretion occurred. It is concluded that the spirolactone canrenone is not only a competitive antagonist of aldosterone in the kidney but obviously also an inhibitor of aldosterone synthesis in man.