Abstract and Introduction
Angiotensin II (AT-II)-Receptor Antagonists are Reviewed.
Research focused on blocking the renin- angiotensin system (RAS) led to the discovery of angiotensin-converting-enzyme (ACE) inhibitors, which are effective in the treatment of hypertension but are associated with a high frequency of cough and other adverse effects. AT-II-receptor antagonists were developed as agents that would more completely block the RAS and thus decrease the adverse effects seen with ACE inhibitors. AT-II-receptor antagonists include losartan, valsartan, irbesartan, candesartan, eprosartan, telmisartan, and tasosartan. Several clinical trials have demonstrated that AT-II-receptor antagonists are as effective as calcium-channel blockers, b-blockers, and ACE inhibitors in the treatment of hypertension and induce fewer adverse effects. The adverse effects of AT-II-receptor antagonists dizziness, headache, upper-respiratory- tract infection, cough, and gastrointestinal disturbances occur at about the same rate as with placebo. Of the AT-II-receptor antagonists, only candesartan has any clinically important interactions with digoxin, warfarin, and hydrochlorothiazide. All available AT-II-receptor antagonists seem to be equally effective in reducing both systolic and diastolic blood pressure, and they are comparable in cost. Currently, AT-II-receptor antagonists are used either as monotherapy in patients who cannot tolerate ACE inhibitors or in combination with other antihypertensive agents.
Angiotensin II-receptor antagonists are well tolerated and are as effective as ACE inhibitors in decreasing blood pressure.
High blood pressure affects over 50 million Americans, but 14.8% of this population is untreated and 26.2% is inadequately treated; in another 31.6%, the condition remains undiagnosed. Hypertension is adequately controlled in only one patient out of four. Life-style modifications and drug therapy can prevent most of the morbidity and mortality associated with this disease. When used properly, drug therapy can control the progression of end-organ damage. The sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VI) recommended diuretics and b-blockers for the initial treatment of hypertension. These agents are considered first line because of their proven ability to reduce cardiovascular-associated morbidity and mortality. JNC-VI also acknowledged that angiotensin-converting- enzyme (ACE) inhibitors, calcium-channel blockers, a 1 -receptor blockers, a/b-blockers, and angiotensin-receptor antagonists are as efficacious as b-blockers and diuretics in reducing blood pressure.
This article provides an overview of the angiotensin II (AT-II)-receptor antagonists.
Am J Health Syst Pharm. 2000;57(13) © 2000 American Society of Health-System Pharmacists
Cite this: Angiotensin II-Receptor Antagonists: An Overview - Medscape - Jul 01, 2000.