Which of the following is an ARB?

• A. Losartan
• B. Amlodipine
• C. Captopril
• D. Metoprolol

Answer: (C)

Angiotensin II receptor blockers work by blocking the AT1 receptor, preventing angiotensin II from causing vasoconstriction and aldosterone release. This leads to vasodilation and lower blood pressure. An example of this class is Losartan.

The other drugs belong to different antihypertensive families: Amlodipine is a calcium channel blocker that relaxes vascular smooth muscle; Captopril is an ACE inhibitor that prevents the formation of angiotensin II (and can raise bradykinin, sometimes causing a cough); Metoprolol is a beta-blocker that lowers heart rate and contractility.

ARBs are often chosen when patients cannot take ACE inhibitors due to cough or angioedema, since ARBs don’t increase bradykinin levels.