Abstracts

RATIONALE: Oxcarbazepine (OXCZ) already available in other countries since years is newly admitted for the treatment of children in Germany. The therapeutical spectrum is comparable to that of carbamazepine (CBZ). But especially in combination with other antiepileptic drugs (AED) its tolerability seems to be better than that of CBZ. Severe hyponatremia is reported to be more frequent in adults treated with OXCZ than with CBZ. There is no sufficient data about the incidence of hyponatremia in childhood during the treatment with OXCZ. METHODS: Our group consists of 89 patients (48 girls, 41 boys, mean age 9;5y, Range 4 mo-17 y)suffering from difficult to treat epilepsies (symptomatic focal 50, cryptogenic focal 19, symptomatic multifocal 7, Lennox-Gastaut-Syndrome 6, others 7). They were treated with OXCZ as inpatients in our hospital. We controlled serum levels of sodium and chloride without OXCZ and during the treatment with OXCZ. Dosage and serum levels of the antiepileptic medication were monitored. In the case of former treatment with CBZ electrolytes were even measured during that period. RESULTS: All 89 patients had normal sodium serum levels at the onset of OXCZ-treatment. Severe clinically relevant hyponatremia during treatment with OXCZ occured in one girl only (1.1%). In 20 patients (22,5%) we found hyponatremia (Na+ < 135 mmol/l) without any clinical symptoms. There was neither statistically significant correlation between sodium and chloride levels and serum levels of 10-OH-carbazepine (the clinically relevant metabolite of OXCZ) nor to the AED comedication. CONCLUSIONS: In children electrolytes should be measured before establishing OXCZ and if clinically relevant side effects as somnolence, listlessness and loss of fine motor skills occur. Routine monitoring of electrolytes during the treatment with OXCZ is not necessary in children without relevant symptoms.