Which of the following is an example of a non-dihydropyridine calcium channel blocker?

• A. Amlodipine
• B. Nifedipine
• C. Verapamil
• D. Felodipine

Answer: (C)

Non-dihydropyridine calcium channel blockers primarily affect the heart, slowing AV nodal conduction and reducing heart rate and contractility. Verapamil is in this class, so it decreases AV nodal conduction and myocardial contractility, making it useful for rate control in tachyarrhythmias and for certain angina. The other three drugs are dihydropyridines, whose main action is arterial vasodilation with less impact on the heart’s conduction system or rate. This difference in primary effect explains why verapamil is the non-dihydropyridine example among the options.