A 68-year-old man with diastolic heart failure and atrial fibrillation is treated with a rate-control drug. Which drug is CONTRAINDICATED in hypertrophic obstructive cardiomyopathy (HOCM)?

• A Digoxin ✓
• B Metoprolol
• C Verapamil in the presence of severe outflow obstruction and high left ventricular filling pressure
• D Diltiazem

Explanation

Digoxin is contraindicated in HOCM because its positive inotropic effect increases left ventricular contractility, worsening the dynamic outflow tract obstruction (LVOT gradient). In HOCM, the obstruction increases when the heart contracts more vigorously. Beta-blockers and verapamil are first-line for HOCM by reducing heart rate and contractility. Verapamil requires caution in severe obstruction with elevated filling pressures (risk of pulmonary edema), but digoxin is the clearest contraindication.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.