eplerenone + spironolactone

Eplerenone + spironolactone is a combination of two mineralocorticoid receptor antagonists, both classified as aldosterone antagonists. These agents competitively inhibit the binding of aldosterone to the mineralocorticoid receptor in epithelial (e.g., kidney) and non-epithelial tissues (e.g., heart, blood vessels), thereby reducing sodium reabsorption and promoting diuresis. Both drugs are used primarily for the management of hypertension and heart failure with reduced ejection fraction, where they exert anti-inflammatory and anti-fibrotic effects that improve cardiovascular outcomes[2][3][6]. Eplerenone is more selective for the mineralocorticoid receptor than spironolactone, resulting in fewer endocrine-related side effects such as gynecomastia[3][8]. Spironolactone has active metabolites with longer half-lives, while eplerenone is metabolized mainly by CYP3A4 to inactive metabolites[4][8]. The combination of these two drugs is not standard clinical practice due to overlapping mechanisms and an increased risk of hyperkalemia; their concurrent use should generally be avoided unless under special circumstances with close monitoring[5].