Abstracts

A longitudinal examination of up to 4 years[rsquo] experience with oxcarbazepine monotherapy in adult and pediatric patients with newly diagnosed partial seizures or generalized tonic-clonic seizures. Data collected during three multicenter, double-blind, randomized, flexible-dose, 1-year, active-controlled clinical trials of similar design were included in this analysis. The studies compared the efficacy and safety of oxcarbazepine and valproate in patients aged 15-65 years (Christe et al. Epilepsy Res 1997;26:451-460) or compared oxcarbazepine and phenytoin in either adult (16-65 years old) (Bill et al. Epilepsy Res 1997;27:195-204) or pediatric patients (5-18 years old) (Guerreiro et al. Epilepsy Res 1997;27:205-213). The trials were extended to include a 1-year open-label follow-up (OF) phase and a subsequent open-label extension (OLE) phase. Data were integrated into a combined database to include up to 4 years[rsquo] experience with oxcarbazepine. Long-term outcomes were evaluated in patients exposed to oxcarbazepine from initiation of the double-blind treatment phase, through the OF phase, and continuing into the OLE phase. A total of 362 patients received oxcarbazepine for a mean duration of 622 days (range: 1-1666 days). In adults ([gt]18-65 years; n=217) and pediatric patients (5-18 years; n=145), the median daily dose of oxcarbazepine was 900 mg (range: 300-2400 mg) and 17.8 mg/kg (range: 6.38-43.5 mg/kg), respectively.Estimated Kaplan-Meier retention rates were 71%, 61%, and 59% after 1, 2, and 4 years of treatment with oxcarbazepine, respectively. Patient discontinuations due to adverse events (AEs) were [le]6% for up to 4 years of oxcarbazepine treatment. Analysis of the intent-to-treat population from initiation of oxcarbazepine over the first year of therapy estimated that 51.9% of patients remained seizure free. Seizure freedom improved over the second year of oxcarbazepine therapy (73.8% of patients were seizure free for the enrollment period [gt]1 year-[le]2 years), and reached 74.5% after [gt]2 years of oxcarbazepine therapy. Over 4 years of oxcarbazepine treatment, the probability of experiencing at least 1 year of seizure freedom was 78%. The most frequent AEs ([gt]20%) occurring over the entire period were headache, somnolence, dizziness, and viral infection. The seizure-free data reported in this combined analysis compare well with reported rates in newly diagnosed patients successfully treated with the first antiepileptic drug chosen (Kwan and Brodie. NEJM 2000;342:314-319). The clinical utility of long-term oxcarbazepine therapy was demonstrated by good tolerability combined with sustained long-term seizure control in patients with newly diagnosed epilepsy. (Supported by Novartis Pharmaceuticals)