Angiotensin II receptor blocker

Angiotensin II receptor blockers (ARBs), formally angiotensin II receptor type 1 (AT₁) antagonists, also known as angiotensin receptor blockers, angiotensin II receptor antagonists, or AT₁ receptor antagonists, are a group of pharmaceuticals that bind to and inhibit the angiotensin II receptor type 1 (AT₁) and thereby block the arteriolar contraction and sodium retention effects of renin–angiotensin system.

Their main uses are in the treatment of hypertension (high blood pressure), diabetic nephropathy (kidney damage due to diabetes) and congestive heart failure. They selectively block the activation of the AT₁ receptor, preventing the binding of angiotensin II compared to ACE inhibitors.

ARBs and the similar-attributed ACE inhibitors are both indicated as the first-line antihypertensives in patients developing hypertension along with left-sided heart failure. However, ARBs appear to produce fewer adverse effects compared to ACE inhibitors.

Angiotensin II receptor blockers are used primarily for the treatment of hypertension where the patient is intolerant of ACE inhibitor therapy primarily because of persistent and/or dry cough. They do not inhibit the breakdown of bradykinin or other kinins, and are thus only rarely associated with the persistent dry cough and/or angioedema that limit ACE inhibitor therapy.^{[citation needed]} More recently, they have been used for the treatment of heart failure in patients intolerant of ACE inhibitor therapy, in particular candesartan. Irbesartan and losartan have trial data showing benefit in hypertensive patients with type 2 diabetes,^{[citation needed]} and may delay the progression of diabetic nephropathy.^{[citation needed]} A 1998 double-blind study found "that lisinopril improved insulin sensitivity whereas losartan did not affect it." Candesartan is used experimentally in preventive treatment of migraine. Lisinopril has been found less often effective than candesartan at preventing migraine.

The angiotensin II receptor blockers have differing potencies in relation to blood pressure control, with statistically differing effects at the maximal doses. When used in clinical practice, the particular agent used may vary based on the degree of response required.^{[citation needed]}

Some of these drugs have a uricosuric effect.

Angiotensin II, through AT₁ receptor stimulation, is a major stress hormone and, because (ARBs) block these receptors, in addition to their eliciting anti-hypertensive effects, may be considered for the treatment of stress-related disorders.

In 2008, they were reported to have a remarkable negative association with Alzheimer's disease (AD). A retrospective analysis of five million patient records with the US Department of Veterans Affairs system found different types of commonly used antihypertensive medications had very different AD outcomes. Those patients taking angiotensin receptor blockers (ARBs) were 35 to 40% less likely to develop AD than those using other antihypertensives.