Eplerenone side effects

ACE inhibitors do not completely block aldosterone synthesis. Since this steroid hormone is a potent inducer of fibrosis in the heart, specific antagonists, such as spironolactone and eplerenone, have recently been very successfully used in clinical trials in addition to ACE inhibitors to treat congestive heart failure [5]. Formerly, these drugs have only been applied as potassium-saving diuretics in oedematous diseases, hypertension, and hypokalemia as well as in primary hyperaldosteronism. Possible side effects of aldosterone antagonists include hyperkalemia and, in case of spironolactone, which is less specific for the mineralocorticoid receptor than eplerenone, also antiandrogenic and progestational actions. 

Spironolactone is poorly absorbed after oral administration and has a delayed onset of action it may take several days until a peak effect is produced. It has a somewhat slower onset of action than triamterene and amiloride (discussed later), but its natriuretic effect is modestly more pronounced, especially during long-term therapy. Spironolactone is rapidly and extensively metabolized, largely to the active metabohte canrenone. Canrenone and potassium canrenoate, its K+ salt, are available for clinical use in some countries outside the United States. Canrenone has a half-life of approximately 10 to 35 hours. The metabolites of spironolactone are excreted in both the urine and feces. New selective aldosterone receptor antagonists (SARA), such as eplerenone, have been developed but have not yet been introduced into clinical practice. Eplerenone and canrenone exhibit fewer steroidlike side effects (gynecomastia, hirsutism). 

Like other diuretics, spironolactone should be initiated at a low dose and increased to treat symptoms. Spironolactone may be initiated at doses of 12.5 to 25 mg/day. Spironolactone shonld be avoided in severe renal failnre. Hyperkalemia and gynecomastia are the most common side effects. Eplerenone is a viable alternative to... 

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