LAMOTRIGINE PHARMACOKINETICS IN PATIENTS RECEIVING FELBAMATE

Drug interactions can significantly complicate the management of patie nts receiving multiple medications. It is essential therefore that pot ential pharmacokinetic interactions be evaluated as new antiepileptic medications are introduced. Lamotrigine (LTG) is a recently marketed m edication whose pharmacokinetics are significantly influenced by conco mitant drugs. Felbamate (FBM), another relatively new antiepileptic ag ent has been associated with multiple interactions including both enzy me induction and inhibition. The purpose of the present pilot study wa s to evaluate potential differences in lamotrigine kinetics in six pat ients concomitantly receiving FBM compared to five patients receiving lamotrigine as monotherapy. There was no statistically significant dif ferences in either apparent LTG oral clearance (0.026 +/- 0.005 vs. 0. 024 +/- 0.01 l/kg per h, respectively), or in mean elimination half-li fe (33.7 +/- 7.5 vs. 40.2 +/- 15.05 h, respectively). Oral clearance v alues in our patients are also consistent with data reported previousl y in the literature. Data from this pilot study suggest that a marked effect of FBM upon lamotrigine pharmacokinetics is unlikely. (C) 1997 Elsevier Science B.V.