Long-term efficacy and safety of monotherapy and adjunctive therapy with zonisamide

The long-term effects of zonisamide as monotherapy or adjunctive therapy were investigated in patients with seizure disorders. One hundred twelve adult neurology patients treated with zonisamide were retrospectively identified through a chart review; 90 patients (n = 45 monotherapy, n = 45 adjunctive therapy) who received zonisamide for ⩾3 months were included in the efficacy-evaluable population, and all 112 patients were included in the safety population. The average duration of treatment was 24.3 months (range, 3–46 months), and the average zonisamide dosage was 324 mg/day (range, 100–1000 mg/day). Thirty-eight of 90 patients (42%; n = 25 monotherapy, n = 13 adjunctive therapy) were seizure-free, and an additional 26 patients (29%; n = 9 monotherapy, n = 17 adjunctive therapy) had ⩾50% seizure frequency reduction at the last follow-up visit. Thirty of 112 patients (27%) reported mild to moderate adverse events, such as weight loss (5.4%), fatigue (4.5%), and sedation (2.7%). Zonisamide, as monotherapy or adjunctive therapy, was a safe, effective, and well-tolerated long-term treatment option in patients with various seizure types.