Olmesartan

Olmesartan is an angiotensin II receptor blocker that acts on the AT1 receptor, with relatively limited action on the AT2 receptor. Angiotensin II is the main effector molecule of the renin-angiotensin-aldosterone system (RAAS) and normally acts through AT1 receptors to cause vasoconstriction, increase blood pressure, promote adrenal aldosterone secretion leading to sodium and water retention, stimulate the sympathetic nervous system, and promote vascular and myocardial hypertrophy. When olmesartan competitively blocks AT1 receptors, angiotensin II can no longer exert these effects, resulting in vasodilation, reduced blood pressure, natriuresis and diuresis, and reduced AT1 receptor-mediated long-term adverse cardiovascular remodeling.