An elderly man on spironolactone 50 mg daily after myocardial infarction develops painful bilateral gynecomastia. His physician wishes to continue mineralocorticoid receptor blockade. The best alternative is:
- A Amiloride
- B Eplerenone ✓
- C Triamterene
- D Chlorthalidone
Correct answer: B. Eplerenone
Explanation
Gynecomastia and menstrual irregularities occur with spironolactone because it binds progesterone and androgen receptors in addition to the mineralocorticoid receptor. Eplerenone is a selective mineralocorticoid antagonist with minimal affinity for sex steroid receptors, providing equivalent blockade without endocrine side effects. Amiloride and triamterene block sodium channels rather than the receptor and do not confer the same mortality benefit data.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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