In a patient with suspected Prinzmetal (variant) angina and normal coronary arteries, which medication is inappropriate to use?

• A. Amlodipine
• B. Isosorbide dinitrate
• C. Lisinopril
• D. Propranolol

Answer: (D)

In Prinzmetal (variant) angina the chest pain comes from transient coronary artery vasospasm. The goal is to prevent and relieve that vasospasm with vasodilators. Calcium channel blockers and nitrates do this effectively by relaxing vascular smooth muscle and reducing spasm episodes. Propranolol, a nonselective beta-blocker, is inappropriate here because blocking beta-2–mediated vasodilation can remove a protective mechanism that helps keep coronary arteries relaxed. With unopposed alpha-adrenergic vasoconstriction, vasospasm can worsen, making chest pain more likely or severe.

Amlodipine and isosorbide dinitrate directly promote vasodilation and help prevent or abort spasm, which is why they’re appropriate. Lisinopril isn’t a primary treatment for vasospasm but doesn’t worsen it and can be used for blood pressure control or other indications.