title: Altered ratio of carbamazepine-10,11-epoxide/carbamazepine in plasma of children: evidence of anticonvulsant drug interaction.
abstract: A method of measuring carbamazepine-10,11-epoxide (CBZ-10,11-EPOX) has been developed and used to monitor plasma concentrations in children suffering from various forms of epilepsy. Children stabilised on standard doses of CBZ alone showed a ratio of CBZ-10,11-EPOX/CBZ of 18.92 +/- 8.08, expressed as a percentage of the CBZ concentration, while those on multiple-drug therapy (with the exception of benzodiazepines and phenobarbitone) showed both increased values of CBZ-10,11-EPOX/CBZ ratio and increased absolute concentrations of CBZ-10,11-EPOX in plasma. These changes correlated with clinical side-effects which could not be attributed to CBZ itself or to the other drugs administered concurrently.
mesh_terms: D000927:Anticonvulsants / Q000008:administration & dosage*; D002220:Carbamazepine / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood; D002648:Child; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D004827:Epilepsy / Q000188:drug therapy*; D006801:Humans; D014635:Valproic Acid / Q000008:administration & dosage
chemical_list: D000927:Anticonvulsants; D002220:Carbamazepine; D014635:Valproic Acid; C012227:carbamazepine epoxide