Efficacy and safety of adjunctive levetiracetam therapy in pediatric intractable epilepsy.

To investigate the efficacy and safety of levetiracetam adjunctive therapy in childhood intractable epilepsy, data were reviewed for 130 children who had >or=4 seizures per month, whose seizures were intractable to an initial >or=2 antiepileptic drugs, and who could be monitored for at least 6 months after levetiracetam add-on. Reduction in seizure frequency and related variables were investigated. Sixty-two of the 130 patients (48%) showed a seizure reduction of >or=50%, and 28 patients (22%) became seizure-free. A reduction in seizures by >or=50% was observed in 33/64 in children with partial seizures (52%) and in 29/66 children with generalized seizures (44%). Efficacy did not differ significantly among seizure types. Overall efficacy was unaffected by abnormalities evident from magnetic resonance imaging, by mental retardation, or by maintenance dose of levetiracetam. The mean maintenance dose of levetiracetam was 47.0mg/kg per day (S.D. = +/- 29.7), and mean follow-up duration was 13.4 months (S.D. =+/- 8.7). No demographic features differed significantly between patients with seizure freedom and without seizure remission. Levetiracetam was discontinued in 24 children at last visit (retention rate, 82%). The most common complaint was irritability (5%), and none of the adverse events were life threatening. In conclusion, levetiracetam adjunctive therapy is effective and safe for childhood intractable epilepsy.