A double-blind study to compare the efficacy, tolerance and safety of two doses of the angiotensin converting enzyme inhibitor ramipril with placebo.

In a randomized, double-blind trial, 2 doses of ramipril (2.5 and 5 mg once daily) were compared with placebo in patients with mild to moderate essential hypertension. A 2-week placebo run-in phase was followed by 4 weeks of treatment. Eighty-six patients entered the study and 17 withdrew during the course of the study. Both doses of ramipril appeared to be more effective than placebo in reducing blood pressure, but significant differences between 2.5 mg of ramipril and placebo were not found in any statistical analyses. In the endpoint analyses (taking the last measurement from each patient), the patients receiving 5 mg of ramipril had significantly larger decreases in blood pressure than the patients receiving placebo (t tests: standing systolic, p less than 0.001; supine diastolic, p less than 0.05; standing diastolic, p less than 0.05) and also than the patients receiving 2.5 mg of ramipril (standing systolic, p less than 0.05). It appears from the results of this study that the minimum effective dosage of ramipril is 5 mg once daily. No clinically relevant side effects or clinically relevant changes in laboratory values were observed.