Comparison of captopril (SQ 14225) with hydrochlorothiazide in the treatment of essential hypertension.

Captopril, a newly developed, orally active inhibitor of the angiotensin-converting enzyme, and hydrochlorothiazide were given alone or in combination to 39 patients with mild or moderate essential hypertension. After a placebo period the patients were randomly allocated in the proportion 3:2 to treatment with captopril (n = 23) or hydrochlorothiazide (n = 16) for dose titration over 4 weeks. The alternative test drug was added thereafter during an 8-week maintenance period if the supine diastolic blood pressure was more than 90 mmHg. The average supine BP reduction in the captopril group was 29/21 mmHg and in the hydrochlorothiazide group 18/15 mmHg. Only one patient who started on captopril had to have hydrochlorothiazide added. Four of those who started on hydrochlorothiazide had to have captopril added. The antihypertensive effects of captopril and hydrochlorothiazide appear to be additive. Among the side effects due to captopril, there were two patients with taste disturbances and another two with rashes.