Abstracts

Rationale: Lacosamide (Vimpat ) is the newest generation anti-epileptic drug that acts on voltage-gated sodium channels to enhance slow inactivation. It is currently FDA approved for adults ?17 years of age for partial-onset seizures. Given its favorable efficacy, pharmacokinetic, and safety profile in adults, we believe it may be a useful anti-epileptic drug for children with refractory epilepsy. Methods: This is a single-center, prospective, ongoing, open-label study. Hospital IRB approval was obtained. Pediatric patients that were started on lacosamide after June 2009 as an adjunct for refractory epilepsy with various seizures types were followed. Inclusion criteria were children under the age of 18 and those who were refractory to multiple other anti-epileptic agents. Seizure type and frequency, drug dosage, duration, and adverse events were documented at baseline and at routine follow-up visits. Results: The age range of eleven patients was 20 months to 17 years (mean age 10.6 years). There were 7 males and 4 females. Diagnoses included localization-related epilepsy, Lennox-Gastaut Syndrome, and cryptogenic generalized epilepsy. The average number of seizure types per patient was 1.36. These included generalized-tonic clonic, atonic, tonic, and complex-partial seizures with or without secondary generalization. The average number of anti-epileptic agents that patients were on was 2.2. On average, patients had failed 6.4 other anti-epileptic agents, including the ketogenic diet and the vagus nerve stimulator. Patients were started on a moderate dose of lacosamide and generally titrated up weekly to an average dose of 7.3/mg/kg/day (range 3.2 to 12.8 mg/kg/day). Average length of initial follow-up was three months. Preliminary results of this prospective on-going trial showed lacosamide was effective in six of 8 patients with complex partial seizures. Two patients remain seizure-free. Two patients resulted in seizure reduction greater than 90%. Two patients had seizure reduction greater than 50%. Lacosamide was not found to be effective in the three remaining patients with generalized seizures (tonic-clonic, tonic and atonic seizures). Three patients were discontinued for lack of efficacy and/or adverse events, which included headache and increased seizure frequency. Conclusions: Lacosamide is generally effective and well tolerated in pediatric patients with refractory partial-onset epilepsy, usually as an adjunctive therapy. In this prospective, on-going study, six of eight pediatric patients with refractory complex-partial seizures responded well to the addition of lacosamide. Its efficacy in other seizure types remains to be determined.