A 60-year-old man with an ejection fraction of 30% due to dilated cardiomyopathy is prescribed an antihypertensive. Which agent should be avoided because it causes direct negative inotropy and worsens heart failure?

• A Nifedipine
• B Minoxidil
• C Hydralazine
• D Verapamil ✓

Explanation

Verapamil blocks L-type calcium channels in cardiac muscle as well as vascular smooth muscle, producing marked negative inotropy, negative chronotropy and AV nodal suppression. In a failing ventricle this depresses contractility further and can precipitate decompensation, so non-dihydropyridine calcium channel blockers are contraindicated in HFrEF. Nifedipine acts almost entirely on vascular smooth muscle and does not depress contractility significantly, while hydralazine and minoxidil are pure arteriolar vasodilators with no direct cardiac depression.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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