Felbamate pharmacokinetics

Richens A, Banfield CR, Salfi M, Nomeir A, Lin CC, Jensen P, Affrime MB, Glue P. Single and multiple dose pharmacokinetics of felbamate in the elderly. Br J Qin Pharmacol 1997 44(2) 129-34. 

Palmer KJ, McTavish D. Felbamate. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in epilepsy. Drugs 1993 45(6) 1041-65. 

Colucci R, Glue P, Banfield C, Reidenberg P, Meehan J, Radwanski E, Korduba C, Lin C, Dogterom P, Ebels T, Hendriks G, Jonkman J, Affrime M. Effect of felbamate on the pharmacokinetics of clonazepam. Am J Ther 1996 3(4) 294-7. 

Sachdeo R, Wagner ML, Sachdeo S, Shumaker RC, Lyness WH, Rosenberg A, Ward D, Perhach JL. Coadministration of phenytoin and felbamate evidence of additional phenytoin dose-reduction requirements based on pharmacokinetics and tolerabihty with increasing doses of felbamate. Epilepsia 1999 40(8) 1122-8. 

Pharmacokinetics. Felbamate is rapidly and well absorbed. The absorption is unaffected by food or antacids. About 40% to 50% of a dose of felbamate is metabolized by hydroxylation and conjngation pathways in the liver, with the remainder being excreted imchanged in the mine. Felbamate displays linear pharmacokinetics. ... 

Battino D, Estienne M, Avanzini G. Clinical pharmacokinetics of antiseizure drugs in pediatric patients. Part II. Phenytoin, carbamazepine, sulthiame, lamotrigine, vigabatrin, oxcarbazepine, and felbamate. Clin Pharmacokinet 1995 29 341-369. 

Battino, D., Estienne, M., and Avanzini, G., Chnical pharmacokinetics of antiepUeptic drugs in paediatric patients. Part II. Phenytoin, carhamazepine, sulthiame, lamotrig-ine, vigabatrin, oxcarbazepine and felbamate, Clin. Pharmacokinet., 29 341-369,... 

Glue, P. et al.. Pharmacokinetic interactions with felbamate in vitro-in vivo correlation, Clin. Pharmacokinet., 33 214-224, 1997. 

In a randomised, crossover study, 12 epileptic patients were given felbamate 3 g or 3.6 g daily, either alone or with erythromycin 333 mg every 8 hours for 10 days. The pharmacokinetics of felbamate were unchanged by erythromycin. There would therefore seem no reason for avoiding erythromycin in patients taking felbamate. 

Felbamate has no clinically relevant effect on the pharmacokinetics of oxcarbazepine, but concurrent use appears to increase the incidence of adverse effects. 

Hulsman JARJ, Rentmeester TW, Banfield CR, Reidenberg P, Colucci RD, Meehan JW, Rad-wanskiE, MojaverianP, LinC-C, Nezamis J, Affrime MB, Glue P. Effects of felbamate on the pharmacokinetics of the monohydroxy and dihydroxy metabolites of oxcarbazepine. Clin Pharmacol Ther( 995) 58,383-9. 

Any changes in the pharmacokinetics of oxcarbazepine brought about by other antiepileptics seem to be of minimal clinical relevance. However, the clinical relevance of the increase in the active metabolite monohydroxyoxcarbazepine with lamotrigine requires further study. In addition, there is the theoretical risk that monohydroxyoxcarbazepine levels might rise to toxic levels if carbamazepine or phenytoin were withdrawn. For mention that there may be an increase in adverse effects if oxcarbazepine is used with felbamate, see Oxcarbazepine +Felbamate , p.545. 

Gidal BE, Zupanc ML. Potential pharmacokinetic interaction between felbamate and phenobarbital. Arm Pharmacother (1994) 28,455-8. 

Kelley MT, Walson PD, Cox S, Dusci LJ. Population pharmacokinetics of felbamate in children. Ther Drug Monit ( 99T) 19,29-36. 

Glue P, Banfield CR, Perhach JL, Mather GG, Racha JK, Levy RH Pharmacdcinetic interactions with felbamate. Clin Pharmacokinet (1997) 33,214-24. 

It was noted that felbamate levels were lower in patients taking phenobarbital than in historical control patients who were not taking phenobarbital. However, in a modelling study, phenobarbital apparently had little or no effect on the pharmacokinetics of felbamate. ... 

Established interactions. The phenytoin dosage may need to be reduced (a 20 to 40% reduction seems to be about right / ) if felbamate is added, and to increase it if felbamate is withdrawn. However, note that as phenytoin pharmacokinetics are non-linear any dosage adjustments will need to be assessed in individual patients. The importance of the reduced felbamate levels is uncertain, but is probably less important because felbamate has a wide therapeutic range. ... 

No clinically relevant pharmacokinetic interactions appear to occur between vigabatrin and felbamate. 

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