title: Morning versus evening amlodipine treatment: effect on circadian blood pressure profile in essential hypertensive patients.
abstract: OBJECTIVE: To determine the antihypertensive efficacy and the potential impact on circadian blood pressure pattern of morning versus evening administration of amlodipine to essential hypertensive patients. METHODS: Twelve mild-to-moderate essential hypertensives were investigated in this open, randomized cross-over study. Blood pressure and heart rate were measured by use of ambulatory blood pressure monitoring after a wash-out period of 1 week and after treatment schedules with 5 mg amlodipine once a day either at 0800 h or at 2000 h for 3 weeks. Effects were evaluated by linear and rhythm analysis using the ABPM-FIT program. RESULTS: Both morning and evening administrations of amlodipine significantly (P < 0.01) reduced the elevated systolic and diastolic blood pressures during daytime. However, due to baseline values being lower during night-time, a significant (P < 0.05) reduction was observed only in systolic, not in diastolic, blood pressure. Maximal blood pressure values were significantly (P </= 0.01) decreased by both treatment regimens, whereas nightly minimum values remained unchanged. The early morning rise in blood pressure was decreaseed after morning and slightly more pronounced aftger evening dosing of amlodipine. Though both amlodipine treatments more effectively reduced daytime blood pressure levels, the circadian profile was not greatly affected. Amlodipine treatment had no effect on heart rate. CONCLUSION: The results demonstrate that, independently from the dosing time, the long-acting calcium antagonist amlodipine sufficiently reduced blood pressure in essential hypertensive patients without increasing the nightly drop. The drug-induced decrase in the early morning rise in blood pressure may be advantageous in reducing the early morning cardiovascular risk.
authors.affiliation: Institute of Pharmacology and Toxicology, Faculty of Clinical Medicine, Ruprecht Karls-Universität Heidelberg, Germany.
authors.initials: G
authors.lastname: Nold
authors.initials: G
authors.lastname: Strobel
authors.initials: B
authors.lastname: Lemmer