Topiramate as add-on therapy in drug-resistant localization-related epilepsies: efficacy and tolerability

RATIONALE: The aim of this study is to investigate efficacy and tolerability of topiramate (TPM) add-on therapy in Drug resistant (DR) Localization Related Epilepsies. METHODS: Forty-two patients (22 M and 20 F) affected by DR Localization Related Epilepsies entered the study after informed consent. Mean age was 32.3 years (range 17-59). Twenty four patients (57.1%) were affected by Symptomatic Localization Related Epilepsies and 18 (42.9%) by Cryptogenic Localization Related Epilepsies. All patients were already treated with 14 antiepileptic drugs (AEDs) with plasma levels within therapeutic ranges. TPM was given as add-on treatment with doses ranging from 150 to 600 mg/day. After TPM titration all patients entered a follow-up period lasting at least 6 months (mean 9.8 months). Patients were considered responders when seizures showed a 2 50% reduction with respect to the 6-month period preceding TPM add-on. RESULTS: In the whole group responders were 26 (61.9%) with 3 patients (7.1%) completely seizure free. No significant differences in seizure response were observed between Symptomatic and Cryptogenic Epilepsies. Side effects were reported in 13 patients (31.0%), consisting mainly of weight reduction. This phenomenon was generally transient and did not lead to discontinuation of TPM therapy. CONCLUSIONS: TPM add-on treatment showed a good efficacy and tolerability in DR Localization Related Epilepsies. The most frequent side effect was weight reduction.