The Pharmaco-Chronological Effects of Levo-amlodipine on Abnormal BP Circadian Rhythm in Hypertensive Patients in Elderly

Objective To investigate the pharmco-chronological effect of levo-amlodipine on BP and circadian rhythm in elderly hypertensive patients. Methods Fifty-five elderly patients with non-dipper pattern of night BP were treated with amlodipine (2.5 mg/d) with morning dose (n=28) and evening dose program(n=26) for 48 weeks. Results 1) Both programs decreased office SBP with no differences between them. ABPM showed that both programs effectively decreased night SBP, while evening program reduced night SBP more pronouncedly. Although the target day time SBP(135 mm Hg) was of no differences between the 2 programs (39.3% vs 30.8%, P0.05), the target night-time SBP(125 mm Hg) was achieved by evening program in 61.5% patients which was greatly higher than that by morning program(28.6%, P0.01). Circadian rhythm transformed from non-dipper to dipper was found in 17.9% in morning program versus 46.2% in the evening program(P0.01). Conclusion Both morning and evening programs of levo-amlodipine administration were effective in decreasing night BP. Compared with morning program, evening program might be more effective in decreasing the high night BP load and alteration from non-dipper to dipper pattern.