Lamotrigine extended-release as adjunctive therapy with optional conversion to monotherapy in older adults with epilepsy

Purpose: To determine the tolerability and efficacy of lamotrigine extended-release (LTG XR) as adjunctive therapy with optional conversion to monotherapy in patients ages ≥65 years with epilepsy. Methods: This open-label study included the standard LTG XR dose escalation, an 8-week Adjunctive Maintenance Phase (AMP), a 13-week Adjunctive Optimization Phase or Conversion and Monotherapy Phase, and a Taper/Follow-Up Phase. At the end of the AMP, patients on a single concomitant antiepileptic drug (AED) were converted to LTG XR monotherapy over 5 weeks and then remained in the Monotherapy Maintenance Phase for 8 weeks. All other patients remained in the study on concomitant AEDs for an additional 13 weeks in the Adjunctive Optimization Phase. Key findings: The number of patients who took ≥1 dose of study medication was 121. Of the 92 patients completing the AMP, 68 patients (74%) were deemed by their treating physician to be eligible to proceed with monotherapy; the remaining 24 patients (26%) continued in the Adjunctive Optimization Phase. The types of adverse events reported with LTG XR were similar to those in studies of LTG XR in younger adult patients with epilepsy and studies of LTG immediate-release (IR) across age groups with epilepsy. No serious rashes were reported. For subjects who were not seizure free at baseline (n = 55), the median baseline seizure frequency was 0.5 seizures per week. During the entire treatment period, the median percent change from baseline was 90% (p<0.0001). Fifty-two (52) patients (76%) of the 68 who entered the monotherapy phase successfully converted to monotherapy. Significance: In this small open label study, LTG-XR was safe and effective when added to the AED regimen of older patients with epilepsy. Many patients were able to be converted to LTG-XR monotherapy.