Switchability Study Between Brand and Generic Topiramate

A Clinical Pharmacokinetics Comparing Brand and Generic Topiramate in Epilepsy Patients : A Open-label,Randomised, Three-period Crossover Study

The purpose of the study is to prove the bioequivalence of 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.

Inclusion Criteria:

• aged 18-65 years
• Patients with epilepsy who take by topamax 100mg bid or who need to take topamax 100mg bid

Exclusion Criteria:

• poor compliance
• subjects whose dose of antiepileptic drug are changed during the study
• subjects whose seizure is not well-controlled judged by neurologist
• history of any kind of drug allergy
• pregnancy or nursing
• existing or recent significant disease (cardiac, hepatic, or renal disease, severe diabetes mellitus, sepsis, etc.)