Comparison of angiotensin II receptor antagonists.

Nonpeptide orally active angiotensin II type 1 (AT1) receptor antagonists are the most specific means presently available to block the renin-angiotensin enzymatic cascade. Six of these drugs have already been licensed in Europe and in the United States for the treatment of high blood pressure, and additional candidates are in the pipeline. The World Health Organisation has also recently endorsed their use for this condition. Inasmuch as AT1 receptor antagonists have proven themselves the equals of angiotensin converting enzyme inhibitors with respect to antihypertensive efficacy, but demonstrated better safety profiles, this class of drugs may be considered to be a qualitative improvement in the treatment of essential hypertension. Interestingly, the six agents now on the market diverge considerably with respect to their pharmacokinetic and pharmacodynamic properties, although it is not certain whether such differences are clinically relevant. A considerable number of large, multicentre trials are in progress to ascertain the possible longer-term organoprotective effects of these substances on cardiovascular morbidity and mortality. Because of their noteworthy safety record to date, and simple once-a-day dosage regimen, AT1 receptor antagonists have the potential to improve compliance in patients with chronic hypertension.