Switchability Study Between Brand and Generic Topiramate

Generic antiepileptic drugs (AED) achieve blood concentration similar to the brand AED. However, controversies exist about efficacy and safety of substituting generic AEDs. Because even minor absorption and kinetic differences can elicit a breakthrough seizure in patients who are changed to a generic AED from brand AED. Therefore, more ideal evaluation of interchangeability from the brand AEDs to generic formulation of the same drug is three-way or four-way crossover study, which can evaluate within-subject variability in pharmacokinetic and pharmacodynamic. Investigator designed four-way crossover study aimed to assess bioequivalence of brand and generic topiramate, to measure trough serum level , and to evaluate efficacy, tolerability and side effect of generic topiramate.