A 62-year-old man on ranitidine-like therapy for peptic ulcer disease develops gynaecomastia and impotence. Switching him to which agent will abolish this adverse effect?
- A Pantoprazole
- B Famotidine ✓
- C Sucralfate
- D Misoprostol
Correct answer: B. Famotidine
Explanation
Cimetidine binds androgen receptors and causes antiandrogenic effects including gynaecomastia, impotence and loss of libido, especially in elderly men on high doses; it also inhibits several cytochrome P450 enzymes causing many drug interactions. Famotidine is another H2 blocker with equal acid suppression but negligible affinity for androgen receptors and no clinically important CYP inhibition, making the switch curative. Pantoprazole, sucralfate and misoprostol would also work, but the item asks for the alternative agent of the same class.
Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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