Comparison of amlodipine and captopril in hypertension based on 24-hour ambulatory monitoring.

The efficacy and toleration of once-daily amlodipine (5-10 mg o.d.) and captopril (25-50 mg b.i.d.) were compared in 45 patients with mild-to-moderate essential hypertension. Twenty-four-hour ambulatory blood pressure monitoring was performed at baseline and at the end of the 8-week study period. Clinic blood pressure, heart rate, and adverse events were assessed during a placebo run-in and after 2, 4, and 8 weeks of treatment. Both amlodipine and captopril significantly reduced clinic blood pressure without affecting heart rate. Between-treatment comparisons showed that amlodipine produced a significantly greater reduction in sitting diastolic blood pressure than captopril. Ambulatory blood pressure monitoring revealed a sustained reduction in both systolic and diastolic blood pressure throughout a full 24-h period in patients taking amlodipine. In contrast, however, the effects of captopril were no longer evident during the final 3 h of the dosing interval. Both drugs were generally well tolerated, and the incidence of adverse events was similar in each group. This study demonstrates that amlodipine is more effective as a once-daily antihypertensive agent than captopril administered twice daily.