Abstracts

RATIONALE: Zonisamide (Zonegran[reg]) is a novel antiepilepsy drug (AED) approved for use in the United States as adjunctive treatment of partial seizures in adults with epilepsy. Zonisamide[ssquote]s antiseizure properties appear to stem from its ability to block both sodium and T-type calcium channels. Zonisamide[ssquote]s broad spectrum suggests that it may be effective against multiple seizure types. However, little information exists to date regarding the use of zonisamide in patients with frontal lobe or progressive myoclonic epilepsy. The objective of this study was to assess the efficacy of zonisamide in patients with frontal lobe or progressive myoclonic epilepsy.
METHODS: In this case review, 9 patients (4 males and 5 females) with frontal lobe or progressive myoclonic epilepsy were placed on zonisamide therapy after failing to adequately respond to other AEDs. The patients ranged in age from 5 to 50 years (mean=26 years). Zonisamide was used as adjunctive therapy and administered either once (n=1) or twice (n=8) daily in dosages ranging from 300 to 500 mg/d (mean=422 mg/d). Efficacy was assessed via reduction in seizure frequency, type, and duration following initiation of zonisamide treatment.
RESULTS: Multiple seizure types were observed in this small group of patients, and none of the patients experienced adequate seizure control with previously administered AEDs. Several patients had failed treatment with newer AEDs; 1 child failed treatment with a ketogenic diet, and a vagus nerve stimulator was tried without success in another pediatric patient. All patients experienced a decrease in seizure frequency following initiation of zonisamide treatment. One 50-year-old male with a brain tumor and focal seizures with rapid secondary generalization experienced no further seizures after beginning zonisamide treatment. Improvements in alertness, social interaction, cognition and behavior were noted in some pediatric patients after beginning zonisamide treatment.
CONCLUSIONS: All 9 patients in this study demonstrated improvement in seizure frequency when zonisamide was added to their therapeutic regimen. These results suggest that zonisamide may be effective against a variety of seizure types experienced in patients with frontal lobe or progressive myoclonic epilepsy. These preliminary findings warrant further investigation of zonisamide in these patient populations.
(Disclosure: Consulting - Elan Pharmaceuticals UCB Abbott Laboratories Ortho-McNeil GlaxoSmithKline, Honoraria - Elan Pharmaceuticals UCB Abbott Laboratories Ortho-McNeil GlaxoSmithKline)