Lamotrigine extended-release as adjunctive therapy for partial seizures

Objective: To evaluate the efficacy and tolerability of once-daily adjunctive lamotrigine extendedrelease (XR) for partial seizures in epilepsy. Methods: Patients more than 12 years old diagnosed with epilepsy with partial seizures and taking one to two baseline antiepileptic drugs were randomized to adjunctive once-daily lamotrigine XR or placebo in a double-blind, parallel-group trial. The study comprised a baseline phase, a 7-week double-blind escalation phase, and a 12-week double-blind maintenance phase during which doses of study medication and concomitant antiepileptic drugs were maintained. escalation phase and received study medication. Lamotrigine XR was more effective than placebo with respect to median percent reduction from baseline in weekly partial seizure frequency ( primary endpoint-entire 19-week treatment phase: 46.1% vs 24.2%, p=0.0004 via Wilcoxon test; escalation phase: 28.0% vs 16.3%, p=0.028; maintenance phase: 58.0% vs 26.7%, p < 0.0001). The percentage of patients with >= 50% reduction in partial seizure frequency (42.2% vs 24.2%, p=0.0037) and time to >= 50% reduction in partial seizure frequency (p=0.0007) also favored lamotrigine XR over placebo. A similar pattern of results was observed for secondarily generalized seizures. The most common adverse events were headache ( lamotrigine XR 17%, placebo 15%) and dizziness ( lamotrigine XR 18%, placebo 5%). Differences between lamotrigine XR and placebo on health outcomes measures were not significant. Conclusions: Once-daily adjunctive lamotrigine extended-release compared with placebo effectively reduced partial seizure frequency and was well tolerated in this double-blind study. Results support the clinical utility of this new once-daily formulation.