A Study of the Efficacy and Safety of Topiramate as add-on Therapy in the Treatment of Epilepsy Patients With Difficult to Treat, Partial-onset Seizures.
Condition: Epilepsy; Epilepsies, Partial; Seizures
MeSH terms: Epilepsy; Seizures; Epilepsies, Partial
Study type: Interventional
Phase: Phase 2

Summary: 
      The purpose of this study is to evaluate the efficacy and safety of topiramate as add-on
      therapy in patients with difficult to control partial onset seizures who are taking one or
      two standard antiepileptic drugs.
    

Detailed description: 
      Epilepsy is characterized by seizures, which are abnormal electrical discharges in the brain
      that temporarily disrupt normal brain function. Seizures are classified as "generalized,"
      originating in both sides of the brain simultaneously, or "partial-onset," starting in one
      area of the brain. Antiepilepsy medications, such as topiramate, are selected based on
      seizure type. This is a double-blind, placebo-controlled study to evaluate the efficacy and
      safety of topiramate as add-on therapy in patients with refractory partial epilepsy, that
      includes a baseline phase and a treatment phase in difficult to treat patients with partial
      epilepsy. During the baseline phase (12 weeks duration), patients receive one or two of the
      following standard antiepileptic drugs (AEDs): phenytoin, carbamazepine, phenobarbital,
      primidone, or valproic acid. Patients who continue to have seizures during treatment with
      standard AEDs proceed into the double-blind treatment phase. Patients then receive placebo or
      topiramate at a dosage of 100-milligrams (mg) twice daily, increasing to twice daily dosing
      at a maximum dose 600 mg/day, 800 mg/day, or 1000 mg/day, or maximum tolerated dose
      (depending on treatment group), through Week 18 (total duration of the double-blind phase),
      while continuing on their standard AED regimen. Assessments of effectiveness include the
      percent reduction in the average monthly seizure rate, percent of patients responding to
      treatment (having equal to or greater than 50% reduction in seizure rate), and the patient's
      and investigator's global assessments of medication at end of study. Safety assessments
      include the incidence of adverse events throughout the study, clinical laboratory tests
      (hematology, serum chemistry, urinalysis), neurologic examinations, and vital sign
      measurements (blood pressure, pulse, temperature) weekly during the treatment phase. The
      study hypothesis is that topiramate, taken as add-on therapy to treatment with AEDs, will
      significantly reduce seizure frequency, compared with placebo, in patients with refractory
      partial epilepsy. In addition, it is hypothesized that topiramate is well-tolerated.
      Topiramate, 100 mg oral tablets, or matching placebo. Dosage begins at 100-mg twice daily and
      increases gradually to twice daily dosing at a maximum dose of 600, 800, or 1000 mg/day, and
      continues through Week 18 (total duration).
    

Intervention name(s): topiramate
Intervention type(s): Drug
Intervention MeSH terms: Topiramate
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double
Primary purpose: Treatment
Keywords: topiramate; epilepsy; partial epilepsies; partial epilepsy; seizures; epileptic seizures; partial seizure disorder; brain diseases