title: Effect of phenobarbital on the pharmacokinetics of carbamazepine-10,11-epoxide, an active metabolite of carbamazepine.
abstract: The single oral dose kinetics of carbamazepine-10,11-epoxide (CBZ-E), the active metabolite of carbamazepine, were studied in six epileptic patients, stabilized on phenobarbital (PB) monotherapy, and in six drug-free health volunteers. The epoxide metabolite was administered as an enteric-coated tablet at the dose of 200 mg to the patients and at the dose of 100 mg to the volunteers. Patients had a significantly higher plasma clearance of CBZ-E than the control group (mean values +/- SD = 220.2 +/- 63.5 versus 112.5 +/- 46.0 ml/h/kg, p less than 0.007) and a significantly shorter plasma half-life (mean values +/- SD = 4.3 +/- 1.0 versus 6.7 +/- 0.8 h, p less than 0.0015). These results suggest that PB induces CBZ-E metabolism.
authors.affiliation: Psychiatric Hospital, Institute of Pharmacology, Messina, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Spina
authors.forename: C
authors.initials: C
authors.lastname: Martines
authors.forename: A
authors.initials: A
authors.lastname: Fazio
authors.forename: R
authors.initials: R
authors.lastname: Trio
authors.forename: F
authors.initials: F
authors.lastname: Pisani
authors.forename: T
authors.initials: T
authors.lastname: Tomson
mesh_terms: D000328:Adult; D001682:Biological Availability; D002220:Carbamazepine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004347:Drug Interactions; D004827:Epilepsy / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010634:Phenobarbital / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D002220:Carbamazepine; C012227:carbamazepine epoxide; D010634:Phenobarbital