ABSTRACT
The present study was aimed at evaluating the antihypertensive efficacy of sustained-release diltiazem 180 mg vs. sustained-release nicardipine 40 mg both given twice daily. To this end 20 patients with mild to moderate hypertension were studied. After a two-week placebo period diltiazem and nicardipine were administered for 4 weeks according to a crossover design. To assess the antihypertensive efficacy of the two drugs all patients underwent Twenty-four-hour non-invasive blood pressure (BP) monitoring and a submaximal bicycle ergometric test. Ambulatory BP monitoring showed a tendency for systolic BP to be lower with nicardipine than with diltiazem during waking hours, while diastolic BP was lowered to the same extent by the two drugs. During sleep a slightly greater BP fall was observed with diltiazem. 24-hour spontaneous BP variability was slightly reduced with diltiazem and unchanged with nicardipine. Mean 24-hour heart rate was also unchanged with nicardipine and slightly reduced with diltiazem. Peripheral resistance measured by plethysmography significantly decreased with the former but not with the latter. BP and heart rate response to exercise was left unchanged by nicardipine and was slightly decreased by diltiazem. This study demonstrates that both sustained-release diltiazem and nicardipine are effective in controlling BP throughout the 24 hours without increasing BP variability. While the antihypertensive action of nicardipine was associated with a decrease of peripheral resistance, this was not the case with diltiazem.
