The angiotensin II receptor antagonist losartan: a new advance in the treatment of hypertension.

Losartan is the first of a new class of antihypertensive agents called 'angiotensin II antagonists'. It selectively and completely blocks the binding of angiotensin II at the angiotensin type 1 receptor-a unique mechanism of action different from all the other classes of antihypertensive agents. Losartan is as effective as other commonly used antihypertensive agents, but it permits convenient dosing and is better tolerated. On the strength of current data on its safety and efficacy, losartan should be considered a valuable option for many hypertension patients in whom angiotensin-converting enzyme inhibitors or calcium antagonists would be used. Although the administration of losartan produces beneficial effects and may be cost effective, long term data regarding morbidity and mortality in hypertension are needed.