Topiramate for migraine prevention.

Migraine is a costly, recurrent condition that affects 28 million individuals in the United States yet remains underdiagnosed and undertreated. In 2004, the U.S. Food and Drug Administration approved topiramate for the prevention of migraine in adults, joining three other agents with this indication: divalproex sodium, propranolol, and timolol. We evaluated the role of topiramate in the treatment of migraine based on published literature and our clinical experiences. A qualitative systematic search of the literature from January 1966-December 2004 was conducted by using MEDLINE, and other pertinent literature was reviewed. Three large, randomized, placebo-controlled trials of topiramate for migraine prevention in individuals experiencing 3-12 attacks/month have been published, as have several small studies and a comparator trial with propranolol. Based on the results of these studies, 100 mg/day is the optimum topiramate dosage in terms of efficacy and tolerability. Using that dosage, the number of migraine attacks/month decreased by approximately two. Several other secondary outcome measures were also significantly reduced including the number of days/month with migraine and the use of acute treatment/attack. Suboptimal efficacy was shown with 50 mg/day, whereas 200 mg/day caused considerably more tolerability issues. Paresthesia was dose related and the most common cause of attrition. Cognitive dysfunction and weight loss were also commonly reported. The reduction by two migraines/month demonstrated with topiramate in clinical trials is similar to the published results for other preventive agents, though most of those studies were small, antiquated, and poorly designed. In contrast, the topiramate trials enrolled a larger number of patients and closely adhered to the International Headache Society research recommendations, strengthening the quality of results. Topiramate 100 mg/day is an effective option in adults who require migraine prophylaxis. Although the published efficacy results of the various migraine preventive agents are comparable, the superior study design of the topiramate trials warrants consideration of topiramate as an agent of choice for migraine prevention. Future studies of any preventive agent should include more refined quality-of-life outcomes.