Abstracts

Rationale: FDA approval of Lacosamide (LAC) for adjunctive therapy in patients > 17 years occurred in USA mid-2009. A new AED had not been available since 2000 and many patients were candidates for LAC. We reviewed our early experience with LAC as used in our Level 4 epilepsy center practice. Methods: Charts of adult patients who were started on LAC from June 2009 to May 2010 were reviewed retrospectively, including clinic notes and laboratory results. Data abstracted included: age, seizure type, IQ, concomitant AEDs, titration schedule, final dose, serum AED levels, seizure control, adverse events. Results: The first sixty patients were included in this early review; 3 had been in phase 3 trial with LAC. Patients were between ages 18-63. IQs were >90 in 17 (N), between 70-90 (LN) in 19; and <70 in 24 (LIQ). Seizure types were partial with or without secondary generalization in 55, primary generalized in 3 and mixed in 2. Doses were 100-800 mg/day. Co-medications were 1-4 other AEDs. Typically titration began at 25-50 mg per day, response assessed at 200 mg per/day, and increases made by response to therapy. Five (8%) discontinued treatment: 1 for non-efficacy and 4 for adverse events (AEs). AEs included dizziness, nausea, vomiting, confusion, diplopia or blurred vision. These occurred in 15 patients. Eleven were on an AED with purported Na channel mechanism of action and 4 were on FBM. Two experienced weight increase. One reported depression, paranoia and panic. LAC blood levels ranged from 1.8-18.2 ug/ml, when available. There was no clear correlation between AE occurence and serum LAC level. Three patients (5%) were seizure-free; 31 (52%) reported improved seizure control of at least 50% (responder group), 13 (27%) reported they were worse but only 4(7%)of these patients were worse due to seizures being worse, the other 9 having AEs. No notable change in seizures was reported in 13 (21%). In LIQ group of 24, 17 were responders (72%). In the responder group as a whole, doses were 200-700 mg/day with levels between 2.7-14.2 ug/ml. In the responder group, the median level was 9 ug/ml with median dose of 400, mean 380 mg/day. Side effects were reported at doses between 200-500 mg/day and LAC levels of 1.8-14.1 ug/ml. Conclusions: LAC is added easily to most AED regimens. AEDs which act at the sodium channel may need to be down-titrated as LAC is added in order to reduce AEs and improve tolerability. Therapeutic efficacy in the group as a whole surpassed the phase 3 trial results with cognitively challenged individuals having an even greater response than the RR 40-46% at 400 mg/day in the trials.