PHARMACOKINETIC INTERACTIONS OF THE NEW ANTIEPILEPTIC DRUGS

Therapy with traditional antiepileptic drugs is associated with a wide range of pharmacokinetic drug-drug interactions. In particular, enzym e induction, enzyme inhibition and displacement from protein binding m ay result in important changes in serum concentrations of antiepilepti cs. Relevant interactions have also been described for some new antiep ileptics. Felbamate increases serum concentrations of phenytoin, pheno barbital and valproic acid (sodium valproate). On the other hand, it r educes concentrations of carbamazepine and increases concentrations of its metabolite carbamazepine-10,11-epoxide. Concentrations of felbama te itself are reduced by phenytoin and carbamazepine. Concentrations o f lamotrigine are considerably increased by valproic acid and decrease d by phenytoin, carbamazepine and phenobarbital