What is the mechanism of action for Irbesartan?

Irbesartan is classified as an angiotensin II receptor blocker (ARB). Its mechanism of action involves antagonizing the angiotensin II receptors, specifically the type 1 (AT1) receptors. By blocking these receptors, Irbesartan prevents angiotensin II from exerting its effects, which include vasoconstriction, increased blood pressure, and stimulation of aldosterone secretion. As a result, the inhibition leads to vasodilation, reduced peripheral resistance, and ultimately lower blood pressure.

In contrast, inhibiting angiotensin converting enzyme would be characteristic of ACE inhibitors, which are a different class of medications. Blocking calcium channels pertains to calcium channel blockers, which function by preventing calcium from entering the cells of the heart and blood vessels, thus leading to muscle relaxation and vasodilation. Stimulating diuresis is a process typically associated with diuretics, which promote the excretion of water and sodium from the body, rather than targeting the renin-angiotensin system directly as Irbesartan does. Therefore, the choice that accurately describes the mechanism of Irbesartan is its action as an antagonist to angiotensin II receptors.