Abstracts

Rationale: Lacosamide (LCS) is a relatively new antiepileptic drug available for intravenous administration which has been reported last year to be a fast, effective and safe alternative in emergency situations. This warrants further investigation to better understand the safety and doses which can be used in this situation. Methods: With IRB approval, patients were identified that received IV LCS in the ICU for acute treatment of seizures in the past 12 months. Selected were those who were give an initial infusion of 400 mg or more. Data collected were age, gender, weight, duration of infusion, change or termination of infusion for side effects (primarily drop in blood pressure), initiation of pressor agents during or up to 2 hrs after infusion completed. On a subset of 9 patients, LCS level was collected about 10 minutes after completion of infusion. Results: Sixty three patients were identified. Demographics were male/female 32/31, average weight 83.0 kg (range 43.68 - 181.81), and average age was 56.1 yrs (24 - 83). Doses given were 400 mg (24 pts), 500 (4 pts), 600 mg (31 pts) and 800 mg (4 pts). Weight base dosing ranged from 2.68 to 13.60 mg/kg (ave 6.51 mg/kg). No patient had a change in (1) BP resulting in reduction in or discontinuation of infusion or starting of pressors or (2) chemistries. LCS levels were obtained in 9 patients post infusion. Blood levels were related to weight based dosing. Doses above 7 mg/kg produced levels of 10 ug/ml. Volume of distribution was calculated to be 0.64 L/Kg. Conclusions: Loading doses of IV LCS can be safely given up to 800 mg and 13 mg/kg. Vd found in ICU patients (0.65) is similar to previous reported value of 0.6 L/K in healthy volunteers. Weight based dosing should be used to achieve a target plasma level. Steady state LCS levels reported in clinical trials with 200, 400 and 600 mg per day are 4.99, 9.35 and 12.46 ug/ml. To achieve high "therapeutic" level post IV load, doses of 7-10 mg/kg should be used which we found to be safe to use.