RESUMO
INTRODUCTION: Chronic migraine refractory to preventive treatment is a common clinical situation in general neurology clinics. The aim is to analyse our experience with zonisamide in the preventive treatment of patients with frequent refractory migraine. PATIENTS AND METHODS: Those patients with no response or intolerance to topiramate and at least one more preventative received zonisamide. This drug was increased 25 mg per week up to 200 mg/day. The efficacy of zonisamide was evaluated in terms of 'response' (reduction in attack frequency below 50%) at the third month of treatment. RESULTS: Our series comprises a total of 172 patients, with ages ranging from 22 to 69 years. 85% were women. The final dosage of zonisamide was 50-200 mg/day, with the 100 mg/day being the most frequently administered dose. Zonisamide was efficacious (response) in 76 (44%) patients; response being excellent in 22 (13%). MIDAS score was reduced by 43.2%. Zonisamide was not tolerated by 27% of the patients, mainly due to subjective mental slowness or digestive symptoms. CONCLUSIONS: These results, obtained in a big sample of patients refractory or intolerant to topiramate and other preventatives, indicate that, at least in conditions of daily clinical practice, zonisamide, at relatively low dosages, is an option to be considered for the preventive treatment of patients with frequent migraine.