A Study of the Effectiveness and Safety of Topiramate for the Prevention of Migraine
Condition: Vascular Headaches; Migraine
MeSH terms: Migraine Disorders; Vascular Headaches; Headache
Study type: Interventional
Phase: Phase 3

Summary: 
      The primary purpose of this study is to evaluate the effectiveness and safety of topiramate
      (an epilepsy medication) compared with placebo in the prevention of migraine.
    

Detailed description: 
      Topiramate is a medication that is widely used for the treatment of adult and pediatric
      patients with seizures and has been shown in preliminary studies to be effective for migraine
      prevention in adults. This is an outpatient, randomized, double-blind, placebo-controlled
      study to confirm preliminary studies of the effectiveness of topiramate in the prevention of
      migraine attacks. The study is composed of 4 phases: pretreatment, double-blind treatment for
      20 weeks, a blinded transition, and an open-label extension. During the pretreatment phase
      patients discontinue all medication for migraine prevention and keep a daily record of
      headache information in a diary. Patients with 3 to 8 migraines, but not more than 15
      headache days, during the pretreatment phase continue in the double-blind treatment phase. In
      the 20-week double-blind treatment phase, oral topiramate tablets (or placebo) are taken
      daily beginning at 25 mg once daily for 1 week, increasing to twice daily doses of up to a
      maximum of 8 tablets (200 mg) per day during the 8-week titration period, and maintained at
      that dose during the 12-week maintenance period. Patients who successfully complete the
      double-blind therapy phase may continue in an open-label extension (32 weeks), during which
      the study medication (topiramate or placebo) will be decreased and simultaneously topiramate
      (open-label) will be administered at increasing doses. During the study, patients will
      maintain headache and medication records to document the following: occurrence and duration
      of headaches; severity of headache pain; associated symptoms, such as nausea, vomiting,
      photophobia (avoidance and dread of light), phonophobia (fear of sound); and medication taken
      to relieve headache pain or symptoms. The primary measure of effectiveness is the percent
      reduction in the frequency of monthly migraine episodes during the entire double-blind
      treatment phase compared with the pretreatment phase. Other assessments of effectiveness
      include the percent of patients responding to treatment (>= 50% reduction in average monthly
      migraine attacks) during the double-blind treatment phase compared with the pretreatment
      phase, the reduction in number of migraine days/month during treatment, and the reduction in
      severity and duration of migraines during treatment. Safety assessments include the incidence
      of adverse events throughout the study, and measurement of vital signs (pulse, blood
      pressure, body weight), physical examinations, and clinical laboratory tests (hematology,
      biochemistry, and urinalysis) at specified intervals. The study hypothesis is that the
      decrease in the mean monthly migraine rate is greater in the topiramate group than in the
      placebo group.

      Oral topiramate tablets 25 mg or placebo tablets, beginning at 25 mg once daily for 1 week,
      increasing to twice daily doses of up to a maximum of 8 tablets (200 mg) during the 8-week
      titration period, and maintained at that dose during the 12-week maintenance period (20 weeks
      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; migraine headache; migraine prevention; migraine