Abstracts

RATIONALE: The purpose of this study was to assess the efficacy and tolerability of zonisamide (ZNS) as a broad-spectrum antiepilepsy drug (AED) in children, in a managed care plan with approximately 350,000 children.
METHODS: A retrospective analysis of difficult-to-treat pediatric epilepsy patients was undertaken at Kaiser Permanente N.W. with all follow-up encounters documented with an electronic comprehensive record (Epicare). Twenty-three pediatric patients participated in the study (14 male, 9 female) with 20 patients under 16 years of age; one each was 16, 17, and 18 years old. The average age was 10.24 years (range 1.5-18). Subjects ranged in weight from 10-105 kg, with a mean of 45.04 kg. Seizure types included: 65% (15 patients) complex partial seizures (CPS), 17% (4) tonic/clonic (T/C), 13% (3) with mixed seizure types, and 4% (1) with myoclonic seizures. Patients were treated with ZNS for an average of 14 weeks. Dosage ranged from 100-500 mg/day (mean 234.78 mg), an average of 5.2 mg/kg/day and a range of 1.75 [ndash] 11.1 mg/kg/day.
RESULTS: Zonisamide proved to be efficacious and well tolerated by the majority of study subjects. Seventeen patients (74%) experienced a reduction in seizure activity. Eight (35%) showed [gt] 50% improvement; 9 (39%) experienced seizure reduction up to 50%. Four patients (17%) demonstrated no reduction in seizure activity, and 1 (4%) had increased seizures.
Although all patients initially received zonisamide in tandem with other AEDs, five patients (22%) were able to convert to ZNS monotherapy by end of study. The average number of additional AEDs taken was 1.26. Ten patients (43%) took ZNS with only one other AED; 5 (22%) received 2 additional AEDs; 3 (13%) required 3 AEDs; and 5 (22%) had the vagal nerve stimulator.
Tolerability of zonisamide was excellent. Eighteen patients (78%) experienced no adverse events. A minor, transient side effect experienced by 4 patients (17%), was drowsiness. One patient (4%) showed poor toleration of ZNS and discontinued medication.
CONCLUSIONS: Findings suggest that zonisamide is effective and well tolerated as adjunctive therapy, or monotherapy, for multiple seizure types. Results of this study indicate that zonisamide[ssquote]s broad-spectrum activity may eliminate the need for excess AEDs. Inclusion of zonisamide in managed care formularies may prove to be an effective and possibly cost-efficient treatment option.