[Effectiveness of topiramate in migraine prophylaxis, an observational study in a consecutive case-serie]

Open-label studies and three large and controlled trials had demostrated the efficacy of topiramate in migraine prophylaxis.

The objective of this study was to assess the effectiveness and tolerability of topiramate in patients not previously treated with any prophylactic drug.

Patients selection was made on sequential patients attending our outpatient clinic. Patients were adults diagnosed of either transformed migraine or migraine with a frequency of more than four migraine attacks per month. Topiramate was started at 25 mg and titrated in 4 weeks by weekly increments of 25 mg, up to 100 mg/day. Patients were then followed up for a 12-week maintenance phase. Efficacy was assessed by change in mean monthly migraine attack frequency from baseline. Additional assessments included responder rates, mean number of migraine days and global impression by a seven-point improvement scale.

Mean monthly migraine attacks decreased significantly from baseline (from 5.2 +/- 2.6 to 2.1 +/- 2.2; p < 0.0001). Sixty-nine percent of patients were considered responders and mean reduction rate in migraine was 55.6 %. Topiramare was overall well tolerated. Twentyfive (28.4 %) patients stopped treatment due to adverse events. The most common adverse events were paresthesia, weight loss and cognitive effects. Some grade of satisfaction was reported by 55 % of patients at the end of the study.

This naturalistic study confirms clinical trial data that 100 mg/day is an effective target dose for patients with migraine and presents the possible beneficial effect in transformed migraine.