Class Explorer · Cardiovascular

Mineralocorticoid receptor antagonists

Competitive antagonists at the aldosterone receptor in the distal nephron: sodium out, potassium retained, and, in the heart, less fibrosis. The diuretic effect is modest; the outcome benefit is not.

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Members

SpironolactoneA weak diuretic with a strong survival benefit, and a potassium you must watch.EplerenoneSpironolactone without the gynecomastia, at a price.

Also in this class: Finerenone (non-steroidal, cardiorenal in diabetic kidney disease). Full pages arrive as the library grows.

Compare the members

Drug	Receptor selectivity	Endocrine effects	Where it wins
Spironolactone	Non-selective	Gynecomastia, breast tenderness	HFrEF, ascites, resistant hypertension, cheapest
Eplerenone	Selective	Minimal	When gynecomastia forces a switch; post-MI HF

Spironolactone

Receptor selectivity: Non-selective
Endocrine effects: Gynecomastia, breast tenderness
Where it wins: HFrEF, ascites, resistant hypertension, cheapest

Eplerenone

Receptor selectivity: Selective
Endocrine effects: Minimal
Where it wins: When gynecomastia forces a switch; post-MI HF

Shared across the class

Indications: Heart failure with reduced ejection fraction · Resistant hypertension · Ascites in cirrhosis (spironolactone) · Primary aldosteronism
Adverse effects: Hyperkalemia · Acute kidney injury when volume-deplete · Gynecomastia (spironolactone)
Contraindications: Hyperkalemia at baseline · Severe renal impairment · Addison disease
Monitoring: Potassium and creatinine at baseline, one week, one month, then quarterly · Sooner after any dose increase, illness, or added RAAS blocker

What makes each agent different

Spironolactone is non-selective and binds androgen and progesterone receptors too: gynecomastia, breast tenderness and menstrual irregularity are its own, not the class's.
Eplerenone is selective and largely free of those endocrine effects, at greater cost and with a shorter half-life.
Only spironolactone has the ascites evidence; only spironolactone is cheap enough to be the reflex first choice everywhere else.

The dose that helps the heart is far below the dose that produces a diuresis. A patient can be on a full 'heart-failure dose' and pass no extra urine at all.

The most dangerous day for an MRA patient is the day they get diarrhoea and keep taking it.

Last reviewed 2026-08-16 · Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed.