Topiramate was assessed in an open-label trial as broad-spectrum antiepileptic monotherapy, independently from the epilepsy type or syndrome. Adults and children aged 2 years and older, who were diagnosed with epilepsy within the last 5 years, treatment-naive or failing prior treatment with one antiepileptic drug (AED), received individually adjusted doses of topiramate, after escalation to 100mg/day over 4 weeks (maximum 400mg/day) or 3mg/kg/day over 6 weeks (maximum 9 mg/kg/day), respectively. Patients were followed for >or=7 months and optionally up to a maximum of 13 months. Data were analysed for all patients (n=692), as well as for focal (n=421) and generalized epilepsies (n=148). The median topiramate dose used was 125 mg/day in adults and 3.3mg/kg/day in children (<or=12 years). Overall, 80% of patients completed the 7-month study. During this period, 44.3% were seizure-free, while 76.3% achieved >or=50% reduction in mean monthly seizure frequency. Patients with focal and generalized epilepsies alike responded to treatment (73.9 and 83.8% with at least 50% seizure reduction): 39.4% of patients with focal epilepsy and 61.5% of those with generalized epilepsy were seizure-free. The mean monthly seizure frequency was significantly reduced versus baseline at all visits (p<0.001). Similar response rates were obtained from the 237 patients completing the 1-year observation period. During the mandatory 7-month period of study, 8.8% of patients reported insufficient tolerability as a reason for dropout. The most frequent adverse event was paraesthesia. Our results support findings that emerge from controlled studies that topiramate is effective and well tolerated when used as initial or second monotherapy. They also suggest that in a naturalistic setting, overall good retention on treatment and seizure freedom are observed at low doses in a broad spectrum of epilepsies.
