Dose dependency of captopril effects in severely hypertensive patients.

In a double-blind randomized study, the dose response to captopril was studied in 12 severely hypertensive patients whose blood pressure had been previously controlled by this converting enzyme inhibitor, either in association with a diuretic (seven patients), or with a diuretic and a beta-blocker (five patients). All patients received in random sequence 32.5, 75, and 150 mg/day of captopril in three divided doses. Significant correlations were revealed between the dose administered and the levels of arterial blood pressure, plasma renin, plasma aldosterone and plasma potassium. Under the conditions of this study, dose-response curves were obtained for concentrations of captopril between 0.5 and 4 mg/day/kg body weight.