COMPARISON OF THE EFFICACY AND SAFETY OF DILTIAZEM AND CAPTOPRIL IN MILD-TO-MODERATE ESSENTIAL-HYPERTENSION

This 12-week, double-blind multicenter study was performed to compare the efficacy and safety of the calcium antagonist diltiazem and the ACE inhibitor captopril in patients with mild to moderate stable essential hypertension. Following a 2-week placebo-washout phase, 58 outpatients with diastolic blood pressure greater-than-or-equal-to 95 mmHg and < 115 mmHg were randomly assigned to a therapy with either diltiazem 180 mg once daily (n = 27) or captopril 50 mg once daily (n = 31). The average age was 57 years in both groups. If diastolic blood pressure was still higher than 90 mmHg after 2 weeks, the dose was to be titrated to diltiazem 270 mg daily or captopril 75 mg daily, respectively. 22 patients of the diltiazem and 30 patients of the captopril group completed the study. Efficacy was evaluated using 24-h ambulatory blood pressure monitoring (ABPM) measurements. The mean 24-h baseline value of diastolic blood pressure was 93 mmHg in both treatment groups, and was reduced by a mean of 6.8 mmHg with both forms of therapy. While for the average reduction of the 24-h blood pressure no differences between the treatment groups were found, the mean baseline value of day-time diastolic blood pressure of 97 mmHg in both groups was reduced by 7.7 mmHg in the diltiazem and by 4.0 mmHg in the captopril group, and the mean night-time diastolic blood pressure of 85 mmHg in both groups was reduced by 5.0 mmHg in the diltiazem and by 8.1 mmHg in the captopril group. A total of four patients in the diltiazem group reported seven adverse events, all resulting in withdrawal from the study. No adverse events were reported in the captopril group. In conclusion, diltiazem and captopril showed comparable reductions in mean 24-h blood pressure, but relatively marked differences for the day- and night-time values. Possibly, that may be an advantage of diltiazem. According to the results of this study, the tolerability of captopril seems to be somewhat better than that of diltiazem.