Abstracts

Rationale: When compared to the younger population, the elderly population often requires lower doses of medications and, potentially, an extended dose escalation schedule to achieve maintenance doses due to altered pharmacokinetic/pharmacodynamic properties in this age group. Although the elderly are the fastest growing segment of the population, there are little data on the use of antiepileptic drugs in this group. Lacosamide, FDA approved in 2008, has little to no data on its use in people ? 60 years old. We will study the safety, tolerability, and effectiveness of lacosamide in this population.Methods: Patients ? 60 years of age treated with lacosamide were retrospectively identified at 4 sites. Data was collected then sent to the primary site for aggregation. 23 patients met inclusion criteria; 10 had incomplete data and were excluded. 13 patients were included in this analysis. As a primary endpoint, 3, 6, and 12 month retention rates (RR) were calculated. As secondary endpoints, mean and median final total daily dose, mean days to achieve final maintenance dose, and seizure freedom at final maintenance dose were calculated. Frequency of adverse effects (AEs) during the titration and maintenance phases were also analyzed.Results: The 3 month RR of lacosamide was 100% (n=13). The 6 month RR was 92.3% (12/13) with one patient discontinuing due to hostility and lack of effectiveness. The 12 month RR was 91.7% (11/12). One patient was started on lacosamide less than one year from the date of data analysis. The mean effective total daily dose in our population was 303.85 mg/day (range: 150-600 mg/day) and the median effective total daily dose was 300 mg/day. The average time to achieve final maintenance dose was 209.2 days (range: 0-612 days). In our population, 38.5% (5/13) of patients achieved seizure freedom. During the titration phase, 8 of 13 (61.5%) patients reported adverse events. The most commonly reported adverse effects during the titration phase were dizziness (30.8% - 4/13), cognitive difficulties including word finding problems and cognitive slowness (23.1% - 3/13), tremor/shakiness (15.4% - 2/13), and somnolence/fatigue (15.4% - 2/13). During the maintenance phase 10 of 13 (76.9%) patients reported no adverse effects. Balance problems, decreased dexterity in the hands, memory problems, and nasal congestion were each reported in 1 patient.Conclusions: Our data suggests that lacosamide is highly effective and well tolerated in the elderly population. The small size of our data set is, admittedly, a limitation; however, the rates of retention we found imply that lacosamide is a viable option in the elderly. Once patients achieved their final maintenance dose, the agent was well tolerated. Adverse events were common during the titration phase with approximately 30% of patients reporting dizziness, a number that is consistent with what has been reported in the package insert at 400 mg/day. Based on these findings, we recommend that patients ? 60 years of age should be dose escalated slowly to the smallest effective dose or a target maintenance dose of 300 mg/day.