Captopril and oxprenolol in a fixed combination with thiazide diuretics: comparison of their antihypertensive efficacy and metabolic effects.

After receiving placebo for two weeks, 20 patients with essential hypertension were randomly divided into two groups. Those in group 1 received a combination of 25 mg of captopril (CPT) and 25 mg of hydrochlorothiazide (HCT) BID. Those in group 2 received a combination of 80 mg of oxprenolol (OXP) and 10 mg of chlorthalidone (CHLT) BID. Patients whose recumbent diastolic blood pressure was less than 95 mmHg after four weeks of treatment continued with the same regimen for six more weeks, while the dosages were doubled for nonresponders. All the patients in group 1 had satisfactory blood pressure readings after the first four weeks of therapy; six patients in group 2 required double dosages to control their blood pressure. Both drug combinations reduced patients' recumbent systolic blood pressure, but CPT + HCT reduced their diastolic and standing systolic blood pressure more effectively. Doubling the dosages of OXP + CHLT was only slightly more effective in controlling patients' blood pressure. In addition, patients who received CPT + HCT showed a significant decrease in serum sodium level, whereas patients who received the double dosages of OXP + CHLT showed a significant increase in serum cholesterol and creatinine levels. The data suggest that low dosages of CPT + HCT control blood pressure more effectively than high dosages of OXP + CHLT and, in addition, do not have any negative metabolic effects.

RCT Entities:   Population Interventions Outcomes