The effect of slow-release nicardipine on ambulatory and clinic blood pressure in mild hypertension.

1. The antihypertensive efficacy of a long acting formulation of the calcium channel blocking drug, nicardipine, was assessed using clinic and ambulatory (Remler M2,000) blood pressure measurements. 2. Eleven patients with essential hypertension (mean +/- s.e. mean; 173 +/- 6.6/103 +/- 1.9 mmHg) completed a randomised double-blind, placebo-controlled, cross-over study. The dose of nicardipine used was 60 mg twice daily for 4 weeks. 3. Mean ambulatory blood pressure was reduced from 164 +/- 5.3/97 +/- 2.9 to 151 +/- 5.2/88 +/- 2.4 mmHg (P less than 0.01); this effect was shown to be sustained for 8 h after the morning dose. Mean ambulatory heart rate was not significantly affected by treatment. 4. Clinic lying systolic blood pressure was reduced on treatment from 169 +/- 7.1 to 157 +/- 5.9 mmHg (P less than 0.2) and diastolic blood pressure from 99 +/- 3.6 to 89 +/- 3.9 mmHg (P less than 0.05). 5. One patient was withdrawn because of dizziness and flushing while on nicardipine; vasodilatory side effects such as headache, palpitations and flushing on nicardipine were noted by three patients. 6. We conclude that the long acting formulation of nicardipine studied in a dose of 60 mg twice daily is effective as monotherapy and is relatively well tolerated in mild hypertension. 7. This study highlights the importance of ambulatory blood pressure measurement in detecting significant changes in blood pressure, thereby permitting the study of small numbers of patients.