INTERACTIONS INVOLVING NEW ANTIEPILEPTIC DRUGS

The advent of new antiepileptic drugs (AED) has increased the opportun ities for interaction. Clinicians seek therapeutic interactions in whi ch two AED together have greater efficacy than either drug alone; ther e are case reports of such, but few prospective studies. Interactions must also be suspected when the adverse effects of a new AED differ ac cording to the co-medication. The basis can be pharmacodynamic, but mo re frequently it is pharmacokinetic. Inhibition of cytochrome P450 enz ymes by the new drugs is more common than induction. There are importa nt implications for the design of clinical trials and the planning of treatment changes in patients.