Zonisamide monotherapy in a multi-group clinic

OBJECTIVE Reports on zonisamide monotherapy are limited despite favourable preliminary data, and typically restricted to tertiary referral centres. The goal of this study is to report clinical experience with zonisamide monotherapy in a large, multi-group clinic setting. METHODS We reviewed the charts of patients treated with zonisamide monotherapy in the Neurology Department of the Kelsey-Seybold Clinic (Houston, Texas) during an 18-month period. We analysed subgroups of patients who were naive to antiepileptic drug (AED) therapy (Group 1) and those who had previous exposure to AEDs (Group 2). RESULTS The study included 54 paediatric and adult patients with a variety of seizure types: 15 patients in Group 1 and 39 patients in Group 2. Mean maintenance zonisamide dosages in the two groups were similar (193 mg/day in Group 1 vs. 218 mg/day in Group 2). Thirty-eight patients (70.4%) continued zonisamide monotherapy, with 7 patients (13.0%) adding a second AED and 9 patients (16.7%) switching to a different drug. Of the 24 patients who became seizure free on zonisamide monotherapy, 11 were on the 100-mg initial dosage. Zonisamide monotherapy was well tolerated. CONCLUSIONS Zonisamide monotherapy is safe and effective for a variety of seizure types and may be appropriate as first-line therapy in some cases.