The angiotensin II type 1 receptor blocker losartan in clinical practice: a review.

Blockade of angiotensin II receptors was first achieved in the 1970s using a peptide, saralasin acetate. Although it was effective in lowering blood pressure, it required parenteral administration and had a short duration of action and partial agonist activity. These disadvantages are absent with losartan, a selective, orally administered, nonpeptide blocker of the angiotensin II type 1 receptor that recently became available for clinical use. Losartan has a sustained duration of action, permitting once-daily dosing in many patients, and lacks partial agonist activity. More than 3300 hypertensive patients have received losartan in Phase III, controlled clinical trials. Losartan given concomitantly with a low dose (12.5 mg) of hydrochlorothiazide further reduces blood pressure. Its overall incidence of adverse experiences is similar to that of placebo. Because of its efficacy, specificity, duration of action, and safety profile, losartan should be considered as first-line therapy for the treatment of patients with hypertension.