A patient with heart failure and reduced ejection fraction develops gynecomastia on spironolactone. The physician switches to eplerenone. Eplerenone is preferred over spironolactone in this situation because it:

• A Lacks significant antiandrogen and progesterone receptor activity ✓
• B Has greater mineralocorticoid receptor affinity and potency
• C Inhibits aldosterone synthase rather than the mineralocorticoid receptor
• D Acts on the proximal tubule rather than the collecting duct

Explanation

Eplerenone is a more selective mineralocorticoid receptor antagonist with minimal affinity for androgen and progesterone receptors, causing fewer endocrine side effects like gynecomastia and menstrual irregularities. Spironolactone binds these steroid receptors, causing antiandrogen effects. Eplerenone has lower mineralocorticoid receptor affinity than spironolactone, not greater. Neither drug inhibits aldosterone synthase; they both act as competitive antagonists at the receptor.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 13th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.