A 62-year-old man on spironolactone for heart failure develops painful bilateral gynecomastia. The cardiologist switches him to another mineralocorticoid receptor antagonist. The advantage of the replacement drug is:

• A It has greater selectivity for the mineralocorticoid receptor over sex steroid receptors ✓
• B It antagonizes progesterone receptors instead of androgen receptors
• C It has a longer half-life allowing once weekly dosing
• D It does not cause hyperkalemia

Explanation

Eplerenone is a selective mineralocorticoid receptor antagonist with much lower affinity for androgen and progesterone receptors than spironolactone, so it avoids gynecomastia, menstrual irregularity and libido changes. It still blocks aldosterone and still causes hyperkalemia, so potassium monitoring remains mandatory. Its half-life is shorter, not longer, requiring twice daily dosing in heart failure.

Reference: Katzung Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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