Eplerenone is an aldosterone antagonist, but selective, used as an adjunct in the management of chronic heart failure. It is similar to the diuretic spironolactone, though it is much more selective for the mineralocorticoid receptor in comparison. Eplerenone is a potassium-sparing diuretic. It appears equivalent to spironolactone but is much more expensive.  Eplerenone is a new selective aldosterone receptor antagonist with decreased progestational and antiandrogenic side effects compared with spironolactone. Eplerenone effectively reduces blood pressure compared with agents such as spironolactone, enalapril, losartan, and amlodipine.  Eplerenone reduces mortality in patients with left ventricular dysfunction. 

Both agents effectively treat hypertension and heart failure but comparisons are complicated by the deficiency of head-to-head trials and differences between patient populations.

Pharmacological differences between spironolactone and eplerenone include lower affinity of eplerenone for progesterone, androgen, and glucocorticoid receptors; more consistently demonstrated nongenomic properties for eplerenone; and the presence of long-acting metabolites for spironolactone. There are differences in the tolerability profiles; spironolactone is associated with dose-dependent sexual side effects. Both agents produce dose-dependent increases in potassium concentrations, although the effect with spironolactone appears to be greater when both agents are administered at recommended doses. Choice of a specific agent should be based on individual patient issues, such as the nature of heart failure and patient concerns about adverse events.