[A randomized double-blind therapeutic trial of enalapril versus timed-release nifedipine in mild to moderate essential hypertension]

Abstract

In a multicentre, randomized, double-blind, double-placebo therapeutic trial, the effectiveness and safety of enalapril and slow-release nifedipine were studied in two groups of ambulatory patients with mild to moderate essential hypertension. Following a 2-week placebo period, 136 patients were allocated at random to either enalapril 20 mg/day in one evening dose (group 1, n = 68) or to nifedipine 40 mg/day in two doses, one a.m. the other p.m. (group II). Each treatment was administered for 12 weeks. Patients in both groups whose diastolic arterial pressure remained above 90 mmHg were given hydrochlorothiazide 25 mg/day from the 4th week onward. When blood pressure did not return to normal, the dose of hydrochlorothiazide was increased to 50 mg/day in the 8th week. After 4 weeks of treatment, no significant difference in reduction of supine diastolic arterial pressure was observed between the two groups (- 12.1 +/- 9.9 mmHg in groups I vs - 10.3 +/- 9.0 mmHg in group II). At the end of the 12-week treatment the decrease of diastolic blood pressure was more pronounced in patients on enalapril than in those on nifedipine (- 16.3 +/- 8.0 mmHg vs - 13.9 +/- 7.1 mmHg), although the difference was not statistically significant (P = 0.06). The number of patients with undesirable side-effects was greater in the nifedipine group (33 patients; 48.5 per cent) than in the enalapril group (18 patients; 26.5 per cent). Treatment was discontinued on account of side-effects in 3 patients of the enalapril group and 10 patients of the nifedipine group.