Which of the following is an adverse effect commonly associated with calcium channel blockers?

• A. Nausea Only
• B. Hypoglycemia
• C. Hypertension
• D. Dizziness, flushing, headache, peripheral edema, and constipation

Answer: (D)

Calcium channel blockers cause vasodilation of vascular smooth muscle, which leads to several effects that show up as common adverse reactions. The most characteristic cluster includes dizziness, flushing, headache, peripheral edema, and constipation. Dizziness and headaches come from dilation of cerebral vessels and lower vascular resistance, which can make you feel lightheaded or-tension headaches. Flushing happens due to increased cutaneous blood flow. Edema, especially in the legs, results from arteriolar dilation raising capillary hydrostatic pressure and fluid leaking into tissues. Constipation is particularly noted with non-dihydropyridine agents like verapamil because of slowed GI motility. While other adverse effects like hypotension and bradycardia can occur, hypertension and hypoglycemia are not typical; nausea can happen but isn’t as characteristic as this specific set of symptoms.