Aldosterone antagonist

Aldosterone antagonist refers to diuretic drugs which antagonize the action of aldosterone at mineralocorticoid receptors. This group of drugs is often used as adjunctive therapy, in combination with other drugs, for the management of chronic heart failure. Spironolactone, the first member of the class, is also used in the management of hyperaldosteronism (including Conn's syndrome) and female hirsutism.

Mode of action
Aldosterone antagonists are, as the name suggests, receptor antagonists at the mineralocorticoid receptor. Antagonism of these receptors inhibits sodium resorption in the collecting duct of the nephron in the kidneys. This interferes with sodium/potassium exchange, reducing urinary potassium excretion and weakly increasing water excretion (diuresis).

In congestive heart failure, they are used in addition to other drugs for additive diuretic effect, which reduces edema and the cardiac workload.

Examples
Members of this class in clinical use include:
 * Spironolactone
 * Eplerenone - more specific than spironolactone on target, but also more expensive
 * Canrenone (canrenoate potassium)
 * Prorenone (prorenoate potassium)
 * Mexrenone (mexrenoate potassium)