Abstracts

Although the majority of childhood absence seizures can be well controlled with available antiepileptic drugs (AEDs), optimal choices for satisfactory treatment are limited. Seizure exacerbation and adverse reactions requiring discontinuation often contribute to the inadequacy of certain AEDs in this population. Therefore, patients may benefit from AEDs with potentially less toxic adverse reactions. Levetiracetam (LEV, Keppra[reg]) is a novel, broad-spectrum AED with a unique mechanism of action and proven efficacy as adjunctive therapy for refractory partial onset seizures in adults. Its lack of extensive hepatic metabolism and minimal protein binding ([lt]10%) minimizes the potential for drug-drug interactions. It is also generally well tolerated. The objective of this study was to characterize the use of LEV in pediatric patients with childhood absence seizures. The study included 11 children (mean age 8.2 years, range 4-11) diagnosed with absence seizures. Seven females and four males were represented. Mean age at seizure onset was 6.3 years. Baseline seizures ranged from 2-20 per day. All patients showed 3-4 Hz spike/wave complexes on EEG. Family history was significant in seven patients. LEV was introduced at a dose of 250 mg/day and titrated over at least one week to a maintenance dose of 500-1500 mg/day. Nine patients were treated with LEV monotherapy or converted to monotherapy, while two were administered LEV with a concomitant AED. In four patients, baseline AED therapy was discontinued due to breakthrough seizures, worsening behavior, or rash. The mean duration of LEV therapy was 1.2 years. An 88.6% reduction in seizure frequency was noted overall. Eight patients became seizure free, and the three remaining patients showed seizure reduction [ge]50%. The post-LEV clinical impression was excellent in eight patients, fair in two and poor in one. Two patients had histories of attention deficit hyperactivity disorder or pervasive development disorder which were exacerbated by LEV and required discontinuation. No other adverse events were reported. LEV was beneficial in this small sample of children with absence seizures. The high incidence of seizure freedom and relative lack of adverse events make LEV monotherapy or conversion to monotherapy promising in this population. Larger, well-controlled studies are needed to confirm these findings. (Supported by UCB Pharma.)