Ambulatory Blood Pressure Monitoring in Patients with Essential Hypertension Treated with a New Calcium Antagonist, Cilnidipine

Cilnidipine (FRC-8653), a new dihydropyridine calcium antagonist, was given to 14 hospitalized patients with essential hypertension, and 24-hour ambulatory blood pressure (BP) monitoring was performed. Once-daily administration of cilnidipine (5–20 mg) for 1–3 weeks decreased the 24-hour average BP significantly from 149 ± 4/88 ± 2 mmHg to 141 ± 3/82 ± 2 mmHg without any change in the pulse rate. The decrease in ambulatory BP by cilnidipine was evident during the daytime (156 ± 4/93 ± 2 mmHg to 143 ± 5/84 ± 2 mmHg, p > 0.01 for systolic BP and p > 0.01 for diastolic BP), while it was mild during nighttime (141 ± 4/80 ± 2 mmHg to 133 ± 4/76 ± 3 mmHg, p > 0.05 for systolic and ns for diastolic BP). The decrease in the ambulatory BP over the whole day and during the nighttime was significantly correlated with the basal ambulatory BP levels. When the subjects were divided into the high ambulatory BP (n = 7) and low ambulatory BP (n = 7) groups, the BP reduction by cilnidipine was evident throughout 24 hours in the high ambulatory BP group, while it was mild and significant only during daytime in the low ambulatory BP group. In summary, once-daily cilnidipine exerts a sufficient and prolonged reduction of BP without an increase in the pulse rate in patients with hypertension. The potency of cilnidipine to decrease ambulatory BP may depend on the basal ambulatory BP level. Cilnidipine is thus a useful antihypertensive drug that may not cause an excessive decrease in BP or a reflex tachycardia.