Which adverse effect is commonly associated with verapamil, a non-dihydropyridine calcium channel blocker?

• A. Bradycardia
• B. Hypertension
• C. Hypoglycemia
• D. Constipation

Answer: (D)

Verapamil, a non-dihydropyridine calcium channel blocker, slows conduction through the heart and relaxes smooth muscle, including in the gastrointestinal tract. The most commonly reported adverse effect is constipation, caused by reduced motility of the intestinal smooth muscle. While slowed AV nodal conduction can lead to bradycardia, constipation stands out as the characteristic side effect of verapamil. Advise patients to increase fluids and dietary fiber, stay active, and monitor for persistent constipation or other GI symptoms, as needed.