Zonisamide for the treatment of myoclonic seizures in progressive myoclonic epilepsy: an open-label study.
OBJECTIVE
To examine the safety and efficacy of zonisamide in treating myoclonic seizures associated with progressive myoclonic epilepsy (PME), in an open-label setting.


METHODS
Thirty patients with refractory PME (aged > or = 5 years), who were taking up to three antiepileptic drugs, received adjunctive zonisamide (< or = 6 mg/kg/day) therapy for 16 weeks. Myoclonic seizures were recorded daily over a 24-hour period or in 10-minute epochs in the morning, afternoon, and evening. Safety was assessed via adverse events (AEs); efficacy was measured by the percentage of patients experiencing a > or = 50% decrease in myoclonic seizure frequency from baseline.


RESULTS
Treatment-related AEs, experienced by 53% (n = 16/30) of patients, led to five patients discontinuing zonisamide. The most common AEs were decreased appetite, somnolence, and asthenia. Overall, 36% of patients (n = 10/28) had a > or = 50% reduction in myoclonic seizure frequency.


CONCLUSIONS
These results suggest that zonisamide may be useful in the treatment of patients with PME. However, due to the size and open-label character of this study, further research is required.
Vossler
David G
DG
Epilepsy Center, Washington Neuroscience Institute, Renton, Washington 98055, USA. david_vossler@valleymed.org
Conry
Joan A
JA
Murphy
Jerome V
JV
D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007555:Isoxazoles / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D020191:Myoclonic Epilepsies, Progressive / Q000188:drug therapy*; D012640:Seizures / Q000188:drug therapy; D000078305:Zonisamide
D000927:Anticonvulsants; D007555:Isoxazoles; D000078305:Zonisamide