Angiotensin receptor blockers: pharmacology and clinical significance.

Several imidazole derivatives that bind specifically to the angiotensin II type 1 receptor (the angiotensin receptor blockers, or ARB), have been developed in recent years and made available to clinicians. Preclinical studies revealed some differences in pharmacokinetic parameters and in vitro effects. However, most of the reported physiologic effects associated with ARB administration are similar to those of angiotensin-converting enzyme inhibitors (ACEI). In short-term clinical studies, the efficacy of ARB in reducing BP (BP) was similar to that of the ACEI, whereas (with a few exceptions) the side-effect profile was comparable to that of placebo. Whether targeting antihypertensive treatment with such a high specificity within the renin cascade carries major clinical advantages over inhibiting angiotensin-converting enzyme remains to be demonstrated.