What is the shared primary mechanism of action for ACE inhibitors and ARBs in blood pressure management?

• A. Inhibit HMG-CoA reductase
• B. Block the RAAS
• C. Block the beta-adrenergic receptors
• D. Activate PPAR gamma

Answer: (B)

Both ACE inhibitors and ARBs lower blood pressure by interrupting the renin-angiotensin-aldosterone system. ACE inhibitors block the conversion of angiotensin I to angiotensin II, reducing angiotensin II–mediated vasoconstriction and aldosterone release. ARBs block the angiotensin II type 1 receptor, preventing angiotensin II from producing its usual effects. Either way, there is less vasoconstriction and less aldosterone-driven sodium and water retention, leading to lower blood pressure. The other options involve different drug classes—statins affect cholesterol synthesis, beta-blockers blunt sympathetic stimulation, and PPAR gamma activators are used for insulin sensitivity—so they don’t share the same primary mechanism as ACE inhibitors and ARBs.