Abstracts

Zonisamide, one of the newer antiepilepsy drugs, is approved in the United States for the adjunctive treatment of partial seizures in adults with epilepsy. The drug has been available in Japan since 1989, where it has been used to treat a wide spectrum of seizure types in adults and children. This chart review was conducted to expand the current knowledge base regarding the safety of zonisamide in treating pediatric and young adult patients with a variety of seizure types. Charts of zonisamide-treated patients from a pediatric neurology clinic were reviewed. Data regarding the safety, efficacy, and tolerability of zonisamide were summarized for patients in each of the following age groups: [lt]7 years, 7 to [lt]10 years, 10 to [lt]12 years, 12 to 18 years, and [gt]18 years. A total of 171 zonisamide-treated patients (92 female, 79 male) were identified. Overall, the mean zonisamide dosage was highest in the 12-to 18-year age group (337.2 mg/d) and lowest in the [lt]7-year age group (218.8 mg/d). However, on a mg/kg per day basis, the mean zonisamide dosage was highest in the [lt]7-year age group (16.2 mg/kg per day) and lowest in the 12- to 18-year age group (6.8 mg/kg per day). The proportion of patients using zonisamide as monotherapy and the mean duration of zonisamide therapy were similar across age groups. Twelve patients (7.0%) discontinued zonisamide, 6 for adverse events. The [gt]18-year age group had the highest discontinuation rate (22.2%). A total of 48 patients (28.1%) reported adverse events. The only adverse events that were reported in [gt]10% of patients in any single age group were decreased/poor appetite (15.8% in the 10- to [lt]12-year age group), sedation/sleepiness (10.5% in the 10- to [lt]12-year age group), and weight loss (22.2% in the [gt]18-year age group). Seizure response data (based on subjective reports) were available for 116 patients; of these, 101 patients (87.1%) had at least a moderate response to zonisamide, including at least 80% of patients in each age group. This chart review expands the existing body of knowledge, which suggests that zonisamide is safe, effective, and well tolerated in pediatric and young adult patients across a variety of age groups. (Supported by Eisai Inc.)