Olmesartan, an AT1-selective antihypertensive agent

Olmesartan is an angiotensin II receptor antagonist indicated for the treatment of essential hypertension. Angiotensin II is an important hormonal effector and end-product of the renin-angiotensin system. When it binds to its endogenous receptor sites, it causes widespread vasoconstriction and a subsequent increase in blood pressure. Olmesartan works by selectively binding to AT(1) against the pathophysiologic events leading to diabetic nephropathy and cardiovascular morbidity/mortality. This end-organ protection is independent of olmesartan's blood pressure lowering properties and is therefore thought to be mediated by different mechanisms. In summary, olmesartan has an efficacy profile superior to other available antihypertensive agents, with a tolerability profile comparable to that of placebo. In addition, the convenience of its once-daily dosing means that olmesartan should be considered not only as an alternative, but also as a first-line treatment for patients with mild to severe essential hypertension. Thus, olmesartan appears to be a very promising new therapy for the treatment of hypertension.