Zonisamide monotherapy in newly diagnosed infantile spasms

Epilepsia. 1997 Sep;38(9):1035-8. doi: 10.1111/j.1528-1157.1997.tb01488.x.


Purpose: We determined the short-term efficacy of zonisamide (ZNS) monotherapy in newly diagnosed patients with infantile spasms (IS).

Methods: Eleven hospitals participated in this open, prospective trial. ZNS 3-10 mg/kg/day was administered as the second-choice drug to 11 newly diagnosed patients with IS (cryptogenic 3, symptomatic 8) who failed to respond to high-dose vitamin B6.

Results: Four infants with symptomatic IS had cessation of spasms and disappearance of the hypsarrhythmia. In these responders, the spasms ceased after a few days (1-5 days) of treatment at a dose of ZNS 4-5 mg/kg/day which produced plasma ZNS concentrations ranging from 5.2 to 16.3 microg/ml (mean 9.8 microg/ml). There were two relapses (50%) 4-6 weeks after cessation of seizures, however. Relapse was predicted by effects of ZNS on EEG; the 2 infants in whom an abnormal EEG persisted had relapses, whereas the 2 whose EEG normalized remained seizure-free (follow-up 20 and 26 months). No adverse reactions were noted.

Conclusions: ZNS may be effective in the initial treatment of selected patients with IS.

Publication types

  • Clinical Trial
  • Multicenter Study

MeSH terms

  • Adrenocorticotropic Hormone / therapeutic use
  • Anticonvulsants / therapeutic use*
  • Drug Administration Schedule
  • Drug Therapy, Combination
  • Electroencephalography
  • Humans
  • Infant
  • Isoxazoles / therapeutic use*
  • Prospective Studies
  • Spasms, Infantile / diagnosis
  • Spasms, Infantile / drug therapy*
  • Treatment Outcome
  • Zonisamide


  • Anticonvulsants
  • Isoxazoles
  • Zonisamide
  • Adrenocorticotropic Hormone