Which drug class prevents the conversion of angiotensin I to angiotensin II?

• A. ACE inhibitors
• B. ARBs
• C. Calcium channel blockers
• D. Diuretics

Answer: (A)

Blocking the formation of angiotensin II reduces vasoconstriction and aldosterone-driven sodium and water retention, leading to lower blood pressure. The drug class that does this is ACE inhibitors, which inhibit angiotensin-converting enzyme and prevent angiotensin I from becoming angiotensin II. With less angiotensin II, there’s less vasoconstriction and less aldosterone release, so vessels can relax and more salt and water are excreted.

ACE inhibitors also increase bradykinin levels because ACE normally degrades bradykinin, which can contribute to side effects like cough or angioedema in some patients.

In contrast, ARBs block the angiotensin II type 1 receptor rather than preventing its production, so they don’t stop formation of angiotensin II. Calcium channel blockers affect calcium influx in vascular smooth muscle and the heart, not the RAAS conversion process. Diuretics lower blood pressure by reducing fluid volume, not by inhibiting angiotensin II formation. Examples of the drug class described are ACE inhibitors such as captopril and enalapril.