title: Azelnidipine and amlodipine: a comparison of their pharmacokinetics and effects on ambulatory blood pressure.
abstract: We objected: 1) To compare the effects of azelnidipine and amlodipine on 24-h blood pressure; 2) To monitor the plasma concentration vs. the time profile in order to assess the association between pharmacokinetics and hypotensive activity after administration of either drug for 6 weeks. Blood pressure and pulse rate were measured by 24-h monitoring with a portable automatic monitor in a randomized double-blind study of 46 patients with essential hypertension. Azelnidipine 16 mg (23 patients) or amlodipine 5 mg (23 patients) was administered once daily for 6 weeks. Pharmacokinetics were analyzed after the last dose was taken. Both drugs showed similar effects on the office blood pressure and pulse rate. During 24-h monitoring, both drugs caused a decrease in systolic blood pressure of 13 mmHg and had a similar hypotensive profile during the daytime period (07:00-21:30). The pulse rate decreased by 2 beats/min in the azelnidipine group, whereas it significantly increased by 4 beats/min in the amlodipine group. Similar trends in the blood pressure and pulse rate were observed during the nighttime (22:00-6:30) and over 24 h. Excessive blood pressure reduction during the nighttime was not seen in either group. The pharmacokinetic results indicated that the plasma half-life (t1/2) of amlodipine was 38.5 +/- 19.8 h and that of azelnidipine was 8.68 +/- 1.33 h. Despite this difference in pharmacokinetics, the hypotensive effects of amlodipine and azelnidipine were similar throughout the 24-h administration period.
authors.affiliation: Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan. kuramoto@tmgh.metro.tokyo.jp
authors.forename: Kizuku
authors.initials: K
authors.lastname: Kuramoto
authors.forename: Shuichi
authors.initials: S
authors.lastname: Ichikawa
authors.forename: Aizan
authors.initials: A
authors.lastname: Hirai
authors.forename: Shigeto
authors.initials: S
authors.lastname: Kanada
authors.forename: Tetsu
authors.initials: T
authors.lastname: Nakachi
authors.forename: Toshio
authors.initials: T
authors.lastname: Ogihara
mesh_terms: D017311:Amlodipine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001383:Azetidinecarboxylic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D004095:Dihydropyridines / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010824:Physicians' Offices
chemical_list: D000959:Antihypertensive Agents; D004095:Dihydropyridines; D017311:Amlodipine; D001383:Azetidinecarboxylic Acid; C061679:azelnidipine