Efficacy and safety of delapril plus manidipine compared with enalapril plus hydrochlorothiazide in mild to moderate essential hypertension: results of a randomized trial

Abstract

Background: The use of combination therapy is required to achieve blood pressure targets in 40% to 75% of patients with hypertension. There have been few studies comparing the efficacy and tolerability of the new fixed combination of the angiotensin-converting enzyme (ACE) inhibitor delapril 30 mg and the calcium channel antagonist manidipine 10 mg with those of a standard combination of another ACE inhibitor and a diuretic.

Objective: The aim of this study was to compare the antihypertensive efficacy and tolerability of delapril 30 mg given alone or with manidipine 10 mg with those of enalapril 20 mg given alone or with hydrochlorothiazide (HCTZ) 12.5 mg in patients with mild to moderate essential hypertension.

Methods: This was a multicenter, active-controlled, parallel-group trial. After an initial 2-week placebo run-in period, patients aged 18 to 75 years with diastolic blood pressure (DBP) > or =90 and < or =109 mm Hg were randomized in a 2:1 ratio to receive delapril or enalapril for 8 weeks. After the initial 8 weeks, nonresponders (DBP > or =85 mm Hg) received an additional 8 weeks of treatment with a fixed combination of delapril + manidipine or enalapril + HCTZ; patients whose DBP was normalized continued their initial monotherapy through the end of the study. The primary efficacy variable was the change in sitting DBP at the end of treatment. Secondary efficacy variables were the percentage of patients whose DBP was normalized (DBP Z:85 mm Hg) and the percentage of responders (> or =10-mm Hg reduction in DBP or DBP <85 mm Hg).

Results: One hundred sixty patients (84 men, 76 women) were randomized to receive delapril (n = 106) or enalapril (n = 54). After 16 weeks of treatment, the mean (SD) reduction in DBP was similar with the 2 treatments (delapril, -14 [8] mm Hg; enalapril, -15 [8] mm Hg). In the delapril and enalapril groups, DBP was normalized in a respective 55 (51.9%) and 29 (53.7%) patients, and 77 (72.6%) and 38 (70.4%) were responders; there was no significant difference between groups. Tolerability was also similar in both groups--10 (9.4%) patients in the delapril group and 5 (9.3%) in the enalapril group experienced adverse events that were judged related to treatment.

Conclusions: The results of this study suggest that delapril alone or combined with manidipine is well tolerated and as effective as enalapril alone or combined with HCTZ in lowering blood pressure in patients with mild to moderate essential hypertension.