LOSARTAN - FIRST OF A NEW CLASS OF ANGIOTENSIN ANTAGONISTS FOR THE MANAGEMENT OF HYPERTENSION

Angiotensin receptor antagonists represent a new class of drugs for th e treatment of patients with hypertension. Reduction of blood pressure in patients with essential hypertension requires increased activity o f the renin-angiotensin system. Losartan, the first orally active, non peptide angiotensin antagonist, specifically competes with angiotensin II (Ang II) for the AT(1) receptor and reversibly alters the receptor . Maximum blood pressure reductions occur after doses of approximately 50 mg, although some patients will require 100 mg; the parent compoun d and a metabolite are responsible for a smooth 24-hour effect on bloo d pressure. Once-daily dosing with losartan has been documented to be safe. The drug's safety has been evaluated in 4,058 patients; of these patients, more than 1,200 were treated for longer than 6 months and m ore than 800 were treated for longer than 1 year with doses of 10 mg t o 150 mg. Overall, no hypertensive patients were withdrawn from treatm ent because of elevated serum creatinine or potassium levels, and ther e were no reports of angioedema. In addition, some reductions in plasm a uric acid levels were noted. Cough occurred significantly less often in patients treated with losartan than in those treated with hydrochl orothiazide or lisinopril. In contrast to angiotensin-converting enzym e (ACE) inhibitors, losartan does not activate bradykinin-nitric oxide -prostanoid vasodilation.