Comparative Efficacy and Safety of Enalapril and Sustained-Release Nifedipine in Patients with Mild to Moderate Hypertension

The long acting angiotensin-converting enzyme inhibitor enalapril was compared with the calcium channel blocker nifedipine as sustained-release formulation in 136 patients with mild to moderate hypertension. This multicentre study was carried out in a double-blind, double-dummy fashion by 28 cardiologists in private practice. After a 2-week placebo period, patients were randomly allocated to 2 treatment groups; the first group received enalapril 20mg daily (n=68), and the second group received sustained-release nifedipine 20mg twice daily (n=68). The duration of treatment was 12 weeks. In both groups, hydrochlorothiazide 25mg was added at week 4 if diastolic blood pressure remained > 90mm Hg. At week 8, if the target diastolic pressure of < 90mm Hg was not achieved, the dosage of hydrochlorothiazide was increased to 50mg. The clinical characteristics of the patients in each group were comparable.