A randomized, double-blind, active-controlled, parallel-group comparison of valsartan and amlodipine in the treatment of isolated systolic hypertension in elderly patients: the Val-Syst study.

Background: Some antihypertensive therapies are limited by dose-dependent adverse effects (AEs). The angiotensin II receptor blocker valsartan has been shown to reduce blood pressure (BP) in a dose-related manner with minimal dose-limiting AEs. Amlodipine besylate is a potent dihydropyridine calcium channel blocker also with dose-related antihypertensive efficacy, but with possible dose-limiting AEs, particularly peripheral edema.