Switchability Study Between Brand and Generic Topiramate

Study Overview
=================
Brief Summary
-----------------
The purpose of the study is to prove the bioequivalence of brand and generic topiramate.

Detailed Description
-----------------
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.

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

Conditions
-----------------
Epilepsy

Intervention / Treatment
-----------------
* Procedure: Pharmacokinetic study


Participation Criteria
=================
Eligibility Criteria
-----------------
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.)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Pharmacokinetic study, topamed<br>For pharmacokinetics, blood samples was taken after receiving Topamax 100mg twice a day in first visit day. For pharmacokinetics, blood samples was taken after receiving Topamed 100mg twice a day in second visit day. For pharmacokinetics, blood samples was taken after receiving Topamax 100mg twice a day in third visit day. For pharmacokinetics, blood samples was taken after receiving Topamed 100mg twice a day in third visit day. | Procedure: Pharmacokinetic study<br>* Patients who are examen pharmacokinetic study after taking Topamax or Topiramate during 7 days<br>|
| Active Comparator: Pharmacokinetic study, topamax<br>For pharmacokinetics, blood samples was taken after receiving Topamed 100mg twice a day in first visit day. For pharmacokinetics, blood samples was taken after receiving Topamax 100mg twice a day in second visit day. For pharmacokinetics, blood samples was taken after receiving Topamed 100mg twice a day in third visit day. For pharmacokinetics, blood samples was taken after receiving Topamax 100mg twice a day in third visit day. | Procedure: Pharmacokinetic study<br>* Patients who are examen pharmacokinetic study after taking Topamax or Topiramate during 7 days<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To Measure the Area under the plasma concentration versus time curve, serum trough drug level of generic and brand topiramate through pharmacokinetics study. | All comparisons of the drug formulations fulfill the bioequivalence criteria, with all 90% Confidential intervals(CIs) for Cmax, AUC, and Ctrough being within the 80-125% acceptance range. Scaling average bioequivalence that the acceptable bioequivalence limits of 90% CI of generic to brand topiramate will be those limits that are within and/or similar to the bioequivalence limits of the 90% CI of Brand to Brand topiramate | [ Time Frame: 0.5, 1, 1.5, 2, 3, 4, 6, 8, and 12 hours after taking the brand or generic topiramate during 7 days] | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants with Adverse Events as a Measure of Safety and Tolerability of generic topiramate in subjects with epilepsy |  | 4weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
epilepsy, anticonvulsants, generic drugs