Comparison of response rates to the angiotensin-converting enzyme inhibitor ramipril in mild-to-moderate hypertension in a double-blind, parallel-group study and an open single-blind study.

Appropriate clinical trial methodologies in general practice and suitable end points for dose-finding studies are discussed with reference to antihypertensive drugs in general and angiotensin-converting enzyme (ACE) inhibitors in particular. Two clinical studies were conducted with ramipril, a new nonsulfhydryl ACE inhibitor, to identify the minimum effective dose for the management of mild-to-moderate hypertension. Study 1 was a double-blind, parallel-group, randomized design with three treatment groups (placebo and 2.5 and 5 mg of ramipril), and study 2 was an open, single-blind design with individual dose titration from 2.5 to 5 mg of ramipril if the diastolic blood pressure (DBP) was greater than 90 mm Hg after 3 weeks. Response rates and DBP reductions with 2.5 mg of ramipril were similar in both studies, although overall response rates, DBP reductions, and side effect incidence appeared to be greater in the open, single-blind, dose-titration study. It is concluded that study methodology apparently influences efficacy and tolerability.

RCT Entities:   Population Interventions Outcomes