Zonisamide monotherapy in newly diagnosed infantile spasms.
OBJECTIVE
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.
Suzuki
Y
Y
Department of Pediatrics, Osaka University Medical School, Suita, Japan.
Nagai
T
T
Ono
J
J
Imai
K
K
Otani
K
K
Tagawa
T
T
Abe
J
J
Shiomi
M
M
Okada
S
S
D000324:Adrenocorticotropic Hormone / Q000627:therapeutic use; D000927:Anticonvulsants / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D004569:Electroencephalography; D006801:Humans; D007223:Infant; D007555:Isoxazoles / Q000627:therapeutic use*; D011446:Prospective Studies; D013036:Spasms, Infantile / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome; D000078305:Zonisamide
D000927:Anticonvulsants; D007555:Isoxazoles; D000078305:Zonisamide; D000324:Adrenocorticotropic Hormone