Influence of food on the bioavailability of a sustained-release verapamil preparation.
The effects of food on the bioavailability of a sustained-release (SR) formulation of verapamil (SR-verapamil; Isoptin SR) were determined in an open, three-way single-dose study involving 12 volunteers receiving (in randomized order) the SR preparation (1 X 240 mg) either fasting or with food and a conventional formulation of verapamil (3 X 80 mg) fasting. Compared with the conventional formulation, SR-verapamil had a reduced Cmax, prolonged tmax, and unchanged t1/2, consistent with its SR formulation. The AUC was 80% of the conventional preparation. Concomitant food administration significantly prolonged the tmax of SR-verapamil from 7.3 +/- 3.4 to 11.7 +/- 6.3 h, but had little effect on Cmax, t1/2, or AUC. Similar results were obtained with the metabolite, norverapamil. Food administration also had little effect on the blood pressure and ECG effects of SR-verapamil. Cautions regarding taking this preparation with food therefore appear to be unnecessary.
Conway
E L
EL
University of Melbourne, Department of Medicine, Austin Hospital, Heidelberg, Victoria, Australia.
Phillips
P A
PA
Drummer
O H
OH
Louis
W J
WJ
D000328:Adult; D000368:Aged; D001682:Biological Availability; D001794:Blood Pressure / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations; D004562:Electrocardiography; D005260:Female; D005502:Food; D006207:Half-Life; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D014700:Verapamil / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics* / Q000494:pharmacology
D003692:Delayed-Action Preparations; C016904:norverapamil; D014700:Verapamil