ANGIOTENSIN-II RECEPTOR INHIBITION - A NEW THERAPEUTIC PRINCIPLE

Angiotensin II receptor antagonists represent a new class of drugs tha t provide a site-specific blockade of the effects of angiotensin II. L osartan potassium, he first compound of this drug class, has recently become available in the United States. The clinical experience with an giotensin II receptor antagonists has demonstrated that these drugs ar e safe and efficacious for the treatment of hypertension and, possibly , congestive heart failure. Unlike with angiotensin-converting enzyme inhibitors, the incidence of cough observed with angiotensin receptor antagonists is similar to that with placebo. Although several angioten sin receptors have been characterized, the effects of losartan and oth er angiotensin receptor antagonists under development are selective fo r the angiotensin II type 1 receptor. Unlike angiotensin-converting en zyme inhibitors, angiotensin receptor antagonists do not inhibit brady kinin metabolism or enhance prostaglandin synthesis. The antihypertens ive efficacy of the angiotensin receptor antagonists has been document ed to be similar to that of angiotensin-converting enzyme inhibitors. If the findings of clinical studies corroborate the initial reports on efficacy and safety, it seems likely that the angiotensin receptor an tagonists will be added to the list of drugs that have been deemed sui table for first-line therapy in the treatment of hypertension and cong estive heart failure.