A comparative study of captopril and enalapril in patients with severe hypertension

Twenty patients with moderate to severe essential hypertension were randomized in a paralleled, double-blind, 22-week study of captopril (ten) and enalapril (ten) following four weeks of hydrochlorothiazide (50 mg/d) baseline treatment. The captopril group was administered 25 mg tid and increased to 100 mg tid, while the enalapril group began with 5 mg bid and increased to 20 mg bid, depending on the patient's blood pressure (BP) response. Methyldopa, 250 mg to 500 mg bid and 1,000 mg bid, was administered to patients in both groups if BP was not adequately controlled. Patients were seen every two weeks for BP monitoring and metabolic evaluation. Each group showed a significant and equal decrease in BP, with the effect being the greatest on the diastolic pressure, supine and upright. Of the 20 patients, ten (four whites and six blacks) required methyldopa for adequate BP control. Four patients, two from each group, developed reversible prerenal azotemia (BUN [blood urea nitrogen] congruent to 50 mg/dL). No other clinical or metabolic side effects were noted. We concluded that captopril and enalapril were equally effective in lowering BP in the dosages given; no racial differences in BP response were noted, although more black patients required the addition of methyldopa for adequate BP control; and both drugs were safe and well tolerated.