About Irbesartan Angiotensin II Receptor Blocker, a non-peptide compound, Antihypertensive. Mechanism of Action of Irbesartan It is a competitive antagonist of angiotensin-2 at AT-1 receptor. It decreases peripheral resistance and lowers BP in hypertensive individuals. It blocks all overt actions of angiotensin-2 such as: - 1. Vasoconstriction, 2. Central & Peripheral sympathetic stimulus, 3. Release of aldosterone and adrenaline, 4. Salt and water reabsorption, 5. Central actions like thirst, vasopressin release, and growth promoting actions on heart and blood vessels. Indications for Irbesartan 1. Hypertension Interactions for Irbesartan No significant interactions have been found in concomitant use with hydrochlorothiazide, digoxin, warfarin and nifedipine.