The newer antiepileptic drugs: Their collective role and defining characteristics

The utility of long-established antiepileptic drugs (AEDs) has been restric ted by lack of efficacy in some patients, neurotoxicity, teratogenicity, id iosyncratic reactions, and complex pharmacokinetics. Eight new AEDs have be en introduced in the United States since 1993 (felbamate, gabapentin, lamot rigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, zonisamide). T hese newer AEDs offer both options for improved efficacy in the treatment o f refractory seizures and the possibility of reducing or eliminating the ad verse effects of older AEDs, Some of the newer AEDs are associated with les s sedation, less weight gain, and possibly fewer endocrine effects. Moreove r, the newer agents' fewer drug interactions offer greater ease of use. Whi le the current role of the newer AEDs generally remains limited to second-l ine therapy, the many new options they have afforded clinicians are of cons iderable value, given the great variability of patient response to AED ther apy. Because of this variability and the lack of data directly comparing th e newer AEDs with one another, all of the newer AEDs should be available to patients.