24-hour blood pressure control with ramipril: comparison of once-daily morning and evening administration

The antihypertensive efficacy of ramipril administered once daily, either in the morning or in the evening, was compared in an open, randomized, crossover trial in 33 patients with mild-to-moderate essential hypertension. A 24-hour ambulatory blood pressure monitoring device was used. A significant (P < 0.05) decrease from baseline blood pressure values was observed with both dosing regimens. A slight, but discernible difference in the effectiveness of the two regimens was observed in the mean daytime (10 am to 8 pm) blood pressure for both diastolic and systolic values. The mean daytime blood pressure decreased from 145.8/95.4 mm Hg to 139.7/89.7 mm Hg following morning administration and to 142.3/91.8 mm Hg following evening administration. The mean nighttime (midnight to 6 am) blood pressure was slightly lower in patients receiving ramipril in the evening than in those receiving the drug in the morning. The mean blood pressure during the critical time (4 am to 8 am) was similar for the two dosing regimens. Ramipril proved to be an efficacious antihypertensive treatment with once-daily dosing and provided as good, or slightly better, blood pressure control when administered in the morning than in the evening.