OBJECTIVE: To investigate the effect of grapefruit juice (GJ) on the pharmacokinetics of orally administered verapamil in hypertensive patients. METHODS: Ten hypertensive patients on chronic verapamil treatment participated in a two-day study. On day 1 200 ml of water was given 1 hour before, and together with the morning verapamil dose; on the day 2, water was replaced by GJ in the same order. Serial blood samples were collected and the concentrations of verapamil and its main dealkylated metabolite (D-617) were determined by high-performance liquid chromatography (HPLC). The area under the concentration versus time curve of verapamil (AUCv) and its metabolite D-617 (AUCM) were calculated before and after GJ ingestion. The peak serum concentration (Cmax) and the time until its appearance (tmax) were also determined. RESULTS: GJ did not affect Cmax, tmax, AUCv or AUVm. The AUCv/AUCm ratio (AUCR) was slightly, but significantly, increased after GJ (1.67 vs 1.92). CONCLUSIONS: A single administration of GJ with short-acting verapamil has no significant effect on the pharmacokinetics, of verapamil.
OBJECTIVE: To investigate the effect of grapefruit juice (GJ) on the pharmacokinetics of orally administered verapamil in hypertensivepatients. METHODS: Ten hypertensivepatients on chronic verapamil treatment participated in a two-day study. On day 1 200 ml of water was given 1 hour before, and together with the morning verapamil dose; on the day 2, water was replaced by GJ in the same order. Serial blood samples were collected and the concentrations of verapamil and its main dealkylated metabolite (D-617) were determined by high-performance liquid chromatography (HPLC). The area under the concentration versus time curve of verapamil (AUCv) and its metabolite D-617 (AUCM) were calculated before and after GJ ingestion. The peak serum concentration (Cmax) and the time until its appearance (tmax) were also determined. RESULTS: GJ did not affect Cmax, tmax, AUCv or AUVm. The AUCv/AUCm ratio (AUCR) was slightly, but significantly, increased after GJ (1.67 vs 1.92). CONCLUSIONS: A single administration of GJ with short-acting verapamil has no significant effect on the pharmacokinetics, of verapamil.
Authors: Michael J Hanley; Paul Cancalon; Wilbur W Widmer; David J Greenblatt Journal: Expert Opin Drug Metab Toxicol Date: 2011-01-22 Impact factor: 4.481