Comparison of Captopril (Sq 14225) With Hydrochlorothiazide in the Treatment of Mild and Moderate Essential Hypertension

Captopril (C) and hydrochlorothiazide (H) were given alone or in combination to 20 patients with essential hypertension (WH O Stage I or Stage II). After a placebo period, patients were allocated at random to C (12 patients) or H (8 patients) for dose titration over four weeks. The alternative test drug was added later during an eight-week maintenance period if blood pressure was not controlled (that is, supine diastolic blood pressure did not fall to 90 mmHg or lower). Blood pressure was controlled in seven of 11 patients treated with C alone, and that of the remaining four patients was controlled with the addition of H. Only one of eight patients treated with H alone had the blood pressure controlled, but in the remaining seven it was controlled with the addition of C. One patient, who experienced gastrointestinal side effects with C, was withdrawn from the trial. Skin rash occurred in four other patients who were treated with C, but resolved after reduction of C dose and the administration of antihistamine. One patient whose blood pressure was controlled on C alone was lost to follow up. Thus, at the end of the maintenance period after three months of treatment, 18 patients had their blood pressures controlled, six with C, one with H, and 11 with a combination of C and H. Captopril is an effective and reasonably well-tolerated drug in the treatment of mild and moderate essential hypertension. The antihypertensive effects of C and H appear to be additive.