An anti-mineralocorticoid, or an aldosterone antagonist, refers to a diuretic drug which antagonizes 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.
Mechanism 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). 
Members of this class in clinical use include:
- Eplerenone - more specific than spironolactone on target
- Canrenone (canrenoate potassium)
- Prorenone (prorenoate potassium)
- Mexrenone (mexrenoate potassium)
See also 
- Rossi S, editor. Australian Medicines Handbook 2006. Adelaide: Australian Medicines Handbook; 2006.
- Aldosterone Antagonists at the US National Library of Medicine Medical Subject Headings (MeSH)
- MeSH list of agents 82000451