Determination of the optimal dosage regimen of captopril + hydrochlorothiazide in the treatment of moderate arterial hypertension.

A multicentre controlled trial was carried out to determine the optimal dosage of a 2/1 combination of captopril plus hydrochlorothiazide (HCTZ) in mild hypertension at three doses against placebo in a 6 week double-blind trial. The number of patients was 111:27 received placebo; 26 were treated with captopril 25 mg plus HCTZ 12.5 mg (25/12.5); 25 with captopril 50 mg plus HCTZ 25 mg (50/25); and 33 with captopril 100 mg plus HCTZ 50 mg (100/50). A significant fall in blood pressure was seen in all four groups, but was greater with the active treatments. The percentage of patients who were normalized [diastolic blood pressure (DBP) less than or equal to 90 mm Hg] or good responders (10% fall in DBP) increased as a function of the dose. At Day 21, the antihypertensive effect of 50/25 was similar to that of 100/50, but greater than that of captopril 25-HCTZ 12.5. At Day 42, the antihypertensive effects of the three doses were similar. Tolerance data showed a higher incidence of side-effects with 100/50 than with the other dosages. Thus, 50/25 appeared to be the optimal dosage for the control of mild hypertension.