Imidapril is a long-acting angiotensin converting enzyme inhibitor, which has been demons-trated to be effective in reducing blood pressure. The purpose of this study is to compare the antihypertensive efficacy, safety and tolerability of imidapril and enalapril in patients with stage 1 to 2 essential hypertension.

In this double-blind, double-dummy, randomized, parallel study, the efficacy, safety and tolerability of once-daily imidapril versus once-daily enalapril were evaluated in 84 patients with stage 1 - 2 hypertension during 8 weeks. If antihypertensive response was insufficient after 4 week treatment period, the dosage for both study drugs doubled until the end of study.

Data from 84 patients who completed the study were eligible for per-protocol analysis. An adequate antihypertensive effect was observed in 47.6% (20/42) in the imidapril group and in 23.8% (10/42) in enalapril group. There was statistically significant difference between the two treatments in the percentage of patients achieving a "reduced blood pressure". The pulse rate did not changed in both groups. Safety profiles were similar between treatments.

In patients with mild to moderate hypertension, the imidapril group showed better response with regard to antihypertensive effect. Both imidapril and enalapril were well tolerated with similar safety profiles.