Abstracts

Rationale: Levetiracetam (LEV) has been approved as adjunctive therapy for partial seizures in adults and children aged four years or more. It has also been used as adjunctive therapy in those younger. An intravenous (IV) preparation has recently become available. We review our experience with IV high-dose LEV as adjunctive therapy for acute seizure exacerbations, mainly acute repetitive seizures in young children with medically intractable epilepsy. Methods: Medical records of nine children (2 boys, 7 girls, ages 3 months to 3 years 8 months, mean 2.0±1.2 years) treated with IV high-dose LEV were retrospectively reviewed. The study was approved by the institutional review board at Children’s Hospital Boston. All children had medically intractable epilepsy with a seizure exacerbation that either lead to hospitalization (eight) or occurred during hospitalization (one), and received a dose of IV LEV of 150 mg/kg/day or greater. Two of the nine were taking oral LEV when they received IV LEV. Children who received lower doses of LEV were not included in the study. Seizure exacerbation in this study was defined by having multiple seizure per day, with a greater than a two-fold increase in seizure frequency compared to baseline. One child had refractory status epilepticus, while three had multiple seizures per hour, although not continuous seizures. Results: The mean dose of LEV was 228±48 mg/kg/day. All were taking other antiepileptic drugs at the time of LEV treatment. Various seizure types were seen (complex partial seizures in six, tonic seizures in three, tonic-clonic seizures in one, atypical absence seizures in one, and drop seizures in one). Etiology of the epilepsy was symptomatic in eight: malformations of cortical development (four), genetic abnormality (two), other syndromes (one), mitochondrial disorder (one). Eight out of nine children had resolution of the acute repetitive seizures, with reduced seizure frequency compared to baseline in seven (seizure freedom in two, 80% or more in four, and 50% in one). One child only had resolution of acute repetitive seizures and returned to the baseline seizure frequency. In one child, seizures increased with the higher LEV doses. Except for this one child with a seizure increase, all others tolerated IV LEV well without complications, such as agitation or somnolence, and were later converted to an equivalent oral dose of LEV. Conclusions: High–dose IV LEV is effective and well tolerated for treating acute seizure exacerbations. Our data demonstrate the benefit of high-dose LEV in children with intractable epilepsy. LEV has a favorable side-effect profile with no life-threatening side-effects. However, the long-term effect of this high-dose LEV needs to be carefully evaluated in future studies.