Irbesartan is a nonpeptide tetrazole acquired and an angiotensin II adversary that selectively blocks the bounden of angiotensin II to the AT1 receptor. In the renin-angiotensin system, angiotensin I is adapted by angiotensin-converting agitator (ACE) to anatomy angiotensin II. Angiotensin II stimulates the adrenal case to amalgamate and bury aldosterone, which decreases the elimination of sodium and increases the elimination of potassium. Angiotensin II aswell acts as a vasoconstrictor in vascular bland muscle.

Irbesartan, by blocking the bounden of angiotensin II to the AT1 receptor, promotes vasodilation and decreases the furnishings of aldosterone. The abrogating acknowledgment adjustment of angiotensin II on renin beard is aswell inhibited, but the consistent acceleration in claret renin concentrations and consistent acceleration in angiotensin II claret concentrations do not annul the claret pressure–lowering aftereffect that occurs. The activity of ARBs is altered from ACE inhibitors, which block the about-face of angiotensin I to angiotensin II, acceptation that the assembly of angiotensin II is not absolutely inhibited, as the hormone can be formed via added enzymes. Also, clashing ACE inhibitors, irbesartan and added ARBs do not baffle with acknowledgment to bradykinins and actuality P, which allows for the absence of adverse furnishings that are present in ACE inhibitors (eg. dry cough).