[Preventive treatment of chronic migraine with zonisamide: a study in patients who are refractory or intolerant to topiramate].

INTRODUCTION: About half of the patients with chronic migraine do not respond or do not tolerate the different migraine preventatives. AIM: To analyse the efficacy and tolerability of zonisamide in the treatment of migraine in patients who had not responded or tolerated topiramate, the current drug of choice for the treatment of this condition. PATIENTS AND METHODS: Those patients with no response or intolerance to topiramate received zonisamide. This drug was increased 25 mg per week up to a maximum of 200 mg/day. The efficacy of this drug 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 34 patients, most of them middle-aged women. All met chronic migraine criteria. Zonisamide showed efficacy (response) in 19 patients (56%), response being excellent in 6 (18%). Nine patients (26%) did not show response, whereas 6 (18%) did not tolerate the drug. CONCLUSIONS: The results, obtained in patients refractory to other preventatives and particularly to topiramate, suggest that zonisamide can be useful in the prevention of chronic migraine. Of course, controlled clinical trials are necessary to confirm these preliminary results.