About olmesartanan angiotensin ii receptor antagonist, imidazole derivative, antihypertensive.mechanism of action of olmesartanolmesartan is a competitive antagonist of angiotensin-ii at at-1 receptor. it decreases peripheral resistance and lowers bp in hypertensive individuals. it blocks all overt actions of angiotensin-ii such as: - vasoconstriction, central & peripheral sympathetic stimulus, release of aldosterone and adrenaline, salt and water reabsorption and central actions like thirst, vasopressin release, and growth promoting actions on heart and blood vessels and at last produces lowering of blood pressure.indications for olmesartanhypertensiontypical dosage for olmesartanadult: 20mg/day and if needed dose can be increased to 40mg/day