Losartan potassium (Cozaar - Merck), the first angiotensin II receptor antagonist, has been approved for oral treatment of hypertension by the US Food and Drug Administration. It will be marketed both alone and in a fixed-dose combination with the diuretic hydrochlorothiazide (Hyzaar).

Valsartan (Diovan - Novartis), a non-peptide tetrazole, is the second angiotensin II receptor antagonist approved for oral treatment of hypertension by the US Food and Drug Administration. The first was losartan (Cozaar - Medical Letter, 37:57, 1995).

Angiotensin receptor blockers (ARBs) are widely used as an alternative to angiotensin converting enzyme (ACE) inhibitors for treatment of hypertension because they lower blood pressure without inducing a cough. It has not been established that they provide the same cardiac benefits as ACE inhibitors. Recently, an editorial in the British Medical Journal suggested that ARBs may increase the risk of myocardial infarction.

Olmesartan medoxomil (Benicar - Sankyo), a substituted imidazole, is the seventh oral angiotensin II receptor blocker (ARB) approved by the FDA for treatment of hypertension.

Irbesartan (Avapro - Sanofi/Bristol-Myers Squibb) is the third angiotensin II receptor antagonist to become available in the USA for oral treatment of hypertension. Losartan (Cozaar) and valsartan (Diovan) were marketed earlier. Eprosartan (Teveten - SmithKline Beecham) has been approved by the FDA but not marketed.

Candesartan cilexetil (Atacand - Astra) is the fourth angiotensin II receptor antagonist to become available in the USA for oral treatment of hypertension.

The angiotensin receptor blocker (ARB) azilsartan medoxomil (Edarbi – Takeda) was recently approved by the FDA for oral treatment of hypertension, either alone or combined with other drugs. It is the eighth ARB approved for this indication.

Eplerenone (e pler' en one; Inspra - Pharmacia), an aldosterone receptor antagonist similar to spironolactone (Aldactone, and others), has been approved by the FDA, but not yet marketed, for treatment of hypertension. It has also been tried for treatment of heart failure.

Many patients with hypertension require more than one drug to control their blood pressure. Tribenzor (Daiichi Sankyo), recently approved by the FDA for treatment of hypertension, combines the calcium channel blocker amlodipine (Norvasc, and others), the angiotensin receptor blocker (ARB) olmesartan (Benicar)and the most commonly prescribed diuretic, hydrochlorothiazide (HCTZ). Tribenzor is not approved for initial therapy, but is recommended for patients not adequately controlled on any 2-drug combination of a calcium channel blocker, an ARB or a diuretic.

The FDA has approved a fixed-dose combination of the angiotensin receptor blocker (ARB) azilsartan and the thiazide-like diuretic chlorthalidone as Edarbyclor (Takeda) for treatment of hypertension