title: Zonisamide for migraine prophylaxis in patients refractory to topiramate.
abstract: BACKGROUND
  Topiramate is a sulfamate-substituted monosaccharide that has proven efficacy in reducing migraine attacks frequency and severity and has similar mechanisms of action and side effects profile to zonisamide. Although there are some studies suggesting a potential role of this drug in migraine prophylaxis, data are still scarce. We evaluate the efficacy and safety of zonisamide for migraine prevention in patients refractory to topiramate.
  
  
  METHODS
  Sixty-three patients were initiated on 50 mg/d zonisamide dosage, which was titrated to 400 mg/d, as tolerated. Number of migraine attacks, headache severity (according to a 1- to 10-point visual analog scale), and use of acute medication were tested before and 2 and 6 months after the initiation of zonisamide. Demographic data, dose of the medication, duration of the treatment, and adverse events were also collected and analyzed.
  
  
  RESULTS
  Statistically significant improvement in number of migraine attacks, headache severity, and use of acute medication reduction was obtained after the second month of zonisamide therapy and carried through month 6 of treatment. Fifteen patients reported adverse events, the most common of which was concentration difficulties.
  
  
  CONCLUSIONS
  These results suggest that zonisamide is effective and well tolerated for migraine prevention in patients refractory to topiramate. With the exception of the inhibition of T-type calcium channels by zonisamide, its mechanisms of action seem to be very similar to topiramate's. We suggest the potential role of these channels in the pathophysiology of migraine.
authors.affiliation: Servicio de Neurologia, Hospital Universitario Puerta de Hierro, Hospital Ruber, Madrid Spain. pedro_bermejo@hotmail.com
authors.forename: Pedro Emilio
authors.initials: PE
authors.lastname: Bermejo
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Dorado
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005632:Fructose / Q000009:adverse effects / Q000031:analogs & derivatives*; D006801:Humans; D007555:Isoxazoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000188:drug therapy / Q000517:prevention & control*; D012720:Severity of Illness Index; D000077236:Topiramate; D016896:Treatment Outcome; D055815:Young Adult; D000078305:Zonisamide
chemical_list: D000927:Anticonvulsants; D007555:Isoxazoles; D000077236:Topiramate; D005632:Fructose; D000078305:Zonisamide