Effects of the chronotherapeutic delivery of verapamil on circadian blood pressure in African-American patients with hypertension.

Objective: To evaluate the effects of COER-verapamil on circadian blood pressure (BP) and heart rate in African-American patients with hypertension.

Design: Retrospective pooled analyses of efficacy and tolerability data from three prospective, randomized, double-blind, placebo-controlled trials with COER-verapamil in hypertension.

Patients/participants: Sixty-eight African-American patients with stages I-III hypertension (seated diastolic BP, 95-114 mm Hg) were randomized to receive placebo or treatment with 180-540 mg of COER-verapamil once daily at bedtime for 4 to 8 weeks.

Methods: Using ambulatory monitoring, efficacy was assessed by measuring change from baseline in systolic and diastolic BP, heart rate, and the heart rate-systolic pressure product during three time intervals: early morning (0600 to 1000), daytime (0800 to 2200), and nighttime (2200 to 0800). Changes also were compared to data from the non-African-American population. Adverse effects were tabulated at each visit.

Results: Mean changes from baseline in early-morning BP, heart rate, and rate-pressure product for patients treated with COER-verapamil were -13.8/-11.2 mm Hg, -6.2 beats/minute, and -1960 mm Hg-beats/min, respectively (P<0.01 for all parameters compared to placebo). Significant and similar reductions also were observed for daytime and nighttime BP, heart rate, and the rate-pressure product. The incidence of side effects in the COER-verapamil-treated patients was similar to placebo and the African-American patients had similar incidences to the non-African-American patients.

Conclusions: The chronotherapeutic delivery of verapamil significantly reduced circadian BP, heart rate, and the rate-pressure product. The side effect profile of COER-verapamil was similar to that of placebo. Thus, this therapy for delivery of a heart-rate lowering calcium channel blocker is a useful antihypertensive strategy for African-American patients with hypertension.