Topiramate: the evidence for its therapeutic value in the prevention of migraine

INTRODUCTION Preventive therapy is recommended in patients with migraines frequent and/or severe enough to interfere with daily life, and/or with an inadequate response to acute therapy (26-43% of patients with migraine in a recent US survey). Preventive treatments include beta blockers, amitriptyline, and antiepileptics (sodium valproate, gabapentin), but these may have significant adverse effects and are contraindicated in some patients. Topiramate is an antiepileptic recently approved for prevention of migraine. AIMS To assess the evidence on the therapeutic value of topiramate as preventive treatment for migraine in adults. EVIDENCE REVIEW All identified outcomes were patient-oriented. Strong evidence shows that topiramate 100 or 200 mg/day is more effective than placebo in reducing mean monthly migraine frequency, and further evidence shows better effectiveness than placebo on responder rate, rescue medication use, migraine severity, and migraine duration. The 100 mg/day dose appears generally better tolerated than 200 mg/day. Evidence shows that topiramate is associated with weight loss rather than weight gain. Limited evidence suggests that topiramate can improve health-related quality of life and reduce days with disability. Uncontrolled studies indicate effectiveness in refractory migraine. Limited evidence indicates broadly similar efficacy and tolerability for topiramate 100 mg/day and propranolol 160 mg/day, though more comparative trials are required. There is insufficient economic evidence to assess the cost effectiveness of topiramate. PLACE IN THERAPY Topiramate 100 mg/day is the dose with the best balance between efficacy and tolerability, and offers therapeutic value in patients in whom propranolol or other preventive migraine therapies are contraindicated, poorly tolerated, or ineffective.