Abstract
Steady state metabolite/parent drug plasma ratios were measured in 15 epileptic patients on carbamazepine (CBZ) monotherapy and in seven patients treated with CBZ and clobazam (CLB). CBZ plasma concentrations did not differ between the two groups but patients also treated with CLB exhibited higher concentrations of CBZ-10,11-epoxide (CBZ-E) and trans-10,11-dihydro-10,11-dihydroxy-CBZ (CBZ-T). Ratios between all of the metabolites of CBZ and the parent compound were higher in patients on polytherapy but the ratio between metabolites was not different. CLB comedication causes a moderate increase (about 1.5-fold) in CBZ metabolism, probably by inducing its epoxidation.
Full text
PDF


Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bertilsson L., Tomson T. Clinical pharmacokinetics and pharmacological effects of carbamazepine and carbamazepine-10,11-epoxide. An update. Clin Pharmacokinet. 1986 May-Jun;11(3):177–198. doi: 10.2165/00003088-198611030-00001. [DOI] [PubMed] [Google Scholar]
- Bourgeois B. F., Wad N. Carbamazepine-10,11-diol steady-state serum levels and renal excretion during carbamazepine therapy in adults and children. Ther Drug Monit. 1984;6(3):259–265. doi: 10.1097/00007691-198409000-00001. [DOI] [PubMed] [Google Scholar]
- Bourgeois B. F., Wad N. Individual and combined antiepileptic and neurotoxic activity of carbamazepine and carbamazepine-10,11-epoxide in mice. J Pharmacol Exp Ther. 1984 Nov;231(2):411–415. [PubMed] [Google Scholar]
- Brodie M. J., Forrest G., Rapeport W. G. Carbamazepine 10, 11 epoxide concentrations in epileptics on carbamazepine alone and in combination with other anticonvulsants. Br J Clin Pharmacol. 1983 Dec;16(6):747–749. doi: 10.1111/j.1365-2125.1983.tb02257.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Callaghan N., Goggin T. Adjunctive therapy in resistant epilepsy. Epilepsia. 1988;29 (Suppl 1):S29–S35. doi: 10.1111/j.1528-1157.1988.tb05789.x. [DOI] [PubMed] [Google Scholar]
- Greenblatt D. J., Divoll M., Puri S. K., Ho I., Zinny M. A., Shader R. I. Reduced single-dose clearance of clobazam in elderly men predicts increased multiple-dose accumulation. Clin Pharmacokinet. 1983 Jan-Feb;8(1):83–94. doi: 10.2165/00003088-198308010-00005. [DOI] [PubMed] [Google Scholar]
- Haigh J. R., Pullar T., Gent J. P., Dailley C., Feely M. N-desmethylclobazam: a possible alternative to clobazam in the treatment of refractory epilepsy? Br J Clin Pharmacol. 1987 Feb;23(2):213–218. doi: 10.1111/j.1365-2125.1987.tb03032.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jawad S., Richens A., Oxley J. Single dose pharmacokinetic study of clobazam in normal volunteers and epileptic patients. Br J Clin Pharmacol. 1984 Dec;18(6):873–877. doi: 10.1111/j.1365-2125.1984.tb02558.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Levy R. H., Lane E. A., Guyot M., Brachet-Liermain A., Cenraud B., Loiseau P. Analysis of parent drug-metabolite relationship in the presence of an inducer. Application to the carbamazepine-clobazam interaction in normal man. Drug Metab Dispos. 1983 Jul-Aug;11(4):286–292. [PubMed] [Google Scholar]
- Macphee G. J., McInnes G. T., Thompson G. G., Brodie M. J. Verapamil potentiates carbamazepine neurotoxicity: a clinically important inhibitory interaction. Lancet. 1986 Mar 29;1(8483):700–703. doi: 10.1016/s0140-6736(86)91099-8. [DOI] [PubMed] [Google Scholar]
- Macphee G. J., Thompson G. G., Scobie G., Agnew E., Park B. K., Murray T., McColl K. E., Brodie M. J. Effects of cimetidine on carbamazepine auto- and hetero-induction in man. Br J Clin Pharmacol. 1984 Sep;18(3):411–419. doi: 10.1111/j.1365-2125.1984.tb02483.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Patel I. H., Wedlund P., Levy R. H. Induction effect of phenobarbital on the carbamazepine to carbamazepine-10, 11-epoxide pathway in rhesus monkeys. J Pharmacol Exp Ther. 1981 Jun;217(3):555–558. [PubMed] [Google Scholar]
- Pisani F., Fazio A., Oteri G., Spina E., Perucca E., Bertilsson L. Effect of valpromide on the pharmacokinetics of carbamazepine-10, 11-epoxide. Br J Clin Pharmacol. 1988 May;25(5):611–613. doi: 10.1111/j.1365-2125.1988.tb03354.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pullar T., Edwards D., Haigh J. R., Peaker S., Feely M. P. The effect of cimetidine on the single dose pharmacokinetics of oral clobazam and N-desmethylclobazam. Br J Clin Pharmacol. 1987 Mar;23(3):317–321. doi: 10.1111/j.1365-2125.1987.tb03051.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robertson M. M. Current status of the 1,4- and 1,5-benzodiazepines in the treatment of epilepsy: the place of clobazam. Epilepsia. 1986;27 (Suppl 1):S27–S41. doi: 10.1111/j.1528-1157.1986.tb05730.x. [DOI] [PubMed] [Google Scholar]
- Tomson T. Interdosage fluctuations in plasma carbamazepine concentration determine intermittent side effects. Arch Neurol. 1984 Aug;41(8):830–834. doi: 10.1001/archneur.1984.04050190036011. [DOI] [PubMed] [Google Scholar]
- Tomson T., Tybring G., Bertilsson L. Single-dose kinetics and metabolism of carbamazepine-10,11-epoxide. Clin Pharmacol Ther. 1983 Jan;33(1):58–65. doi: 10.1038/clpt.1983.8. [DOI] [PubMed] [Google Scholar]
- van Belle G., Friel P. N. Problem of spurious correlation in the evaluation of steady-state carbamazepine levels using metabolite data. Ther Drug Monit. 1986;8(2):177–183. doi: 10.1097/00007691-198606000-00009. [DOI] [PubMed] [Google Scholar]
