May 4, 2006

A German study presented at the annual meeting of the European Headache Federation demonstrated that chronic migraine sufferers treated preventively with Topamax (topiramate) experienced fewer migraine-related days per month than those treated with placebo.

The TOP-CHROME (TOPiramate in CHROnic MigrainE) study was a 16-week, multicenter, double-blind, randomized, placebo-controlled study involving 59 patients aged 18 to 65 who experienced chronic migraines -- defined as a total of 15 or more migraine days every four weeks. The study began with a four-week baseline observation period without trial medication followed by initiation of treatment with placebo or Topamax at a daily dose of 25 mg. The dose was then increased in weekly 25-mg increments to a target dose of 100 mg/day. Final doses ranged between 50 mg and 200 mg per day, according to patients' individual needs.

During the last 4 weeks of treatment with topiramate, the number of migraine days was reduced from a baseline of 15.5 days to just 12 days (-3.5), compared to patients on placebo who experienced a 0.2 day increase in their migraine frequency. Patients' rating of the impact of migraine on their quality of life, as assessed by MIDAS2 questionnaires, was also significantly better for TOPAMAX than placebo. Improvements in quality of life were found with the MSQ3 and HIT-64 questionnaires, but there were no statistically significant differences between the treatment groups.

Topamax was shown to be generally well-tolerated, the study found. There was a higher incidence of adverse events in the Topamax group (75 percent) compared to patients on placebo (37 percent). The most commonly reported side effects were paraesthesia (59 percent), vomiting (16 percent), dizziness (13 percent) and nausea (9 percent). There was no statistically significant difference in satisfaction reported in the tolerability of the treatments.

"This trial enhances our understanding of the role that topiramate may play in reducing the frequency of migraine attacks in chronic migraine sufferers and medication overuse patients," noted H.C. Diener, a professor at the University of Essen in Germany and one of the study's principal investigators.