Efficacy of felbamate in therapy for partial epilepsy in children.

Thirty children (2 to 17 years of age) with refractory partial seizures received open-label felbamate as an add-on medication to their background antiepileptic drugs. The dose was increased up to a maximum of 45 mg/kg. Compared with baseline seizure activity, there was a 53% decrease in seizure frequency during felbamate therapy; 50% of the patients had more than a 50% decrease in seizure frequency. Patients older than 10 years of age were more likely to have a favorable response. Age correlated positively with felbamate concentrations and negatively with apparent felbamate clearance. Transient weight loss occurred in 57% of the patients; the weight loss was maximal after 12 weeks of initiation of felbamate, and subsided after the twentieth week of treatment. Anorexia and insomnia were reported in 20% and 16% of the patients, respectively. Adverse effects were generally tolerable; felbamate therapy was discontinued because of side effects in only one patient, because of a rash. We conclude that felbamate can be a useful and well-tolerated medication in the treatment of refractory partial epilepsy in children. However, increased apparent clearance of this drug in younger children should be considered in treatment of this age group.