Potential of the angiotensin II receptor 1 blocker eprosartan in the management of patients with hypertension or heart failure.

When angiotensin-converting enzyme (ACE) inhibition first became available to block the renin system, few could have predicted the evolution that would occur in this field. The advent of angiotensin II receptor 1 (AT(1)) blockers has created new opportunities. These agents, including eprosartan, are extraordinarily well tolerated, not only when compared with antihypertensive agents but also in comparison with the ACE inhibitors, which are rather well tolerated. The AT(1) blocker class is growing rapidly, at least in part because many believe that these drugs will share with the ACE inhibitors the special ability to reduce morbidity and mortality. Does eprosartan have a special role within this class? Eprosartan differs structurally from the other AT(1) blockers in that it is not a biphenyl tetrazole. It differs functionally in vitro in being a pure competitive antagonist, as opposed to the nonequilibrium, insurmountable characteristics of the other blockers. This feature may prove to be useful for titration in the fragile patient. The reduction in catecholamine release induced by eprosartan that has been observed in animal models may account for some special examples of increased efficacy. One such example pertains to the difference in the dose-response relationship for the action of eprosartan on the renal blood supply in comparison with other AT(1) blockers. Eprosartan doses well below those required for control of blood pressure have a pronounced effect on the kidney. If research already under way supports these early suggestions, then eprosartan will be an important addition to our therapeutic armamentarium.