any one of a class of drugs that block the action of the hormone angiotensin II, which constricts blood vessels; they are therefore useful in treating hypertension. These drugs include candesartan (Amias), irbesartan (Aprovel), losartan (Cozzar), telmisartan (Micardis), and valsartan (Diovan). They are taken by mouth and side-effects are usually mild.
Medical dictionary. 2011.