The Safety of Lacosamide for Treatment of Seizures and Seizure Prophylaxis in Adult Hospitalized Patients

Background: Lacosamide (LCM) is a newer antiepileptic drug (AED) with favorable properties for hospitalized patients including intravenous formulation, minimal hepatic metabolism, and no adverse respiratory effects. We sought to determine the safety profile of LCM in hospitalized patients. Methods: We performed a retrospective medical record review of patients who received LCM between July 1, 2009, and January 31, 2010, at Mayo Clinic Hospital. Data included demographics, LCM dosing, concomitant AED therapy, documented seizure activity, hemodynamic variables, electrocardiogram (ECG), and laboratory data. Adverse drug reaction and drug–drug interactions were reviewed. Results: Thirty-two patients were identified. No major hypotension or serious cardiac arrhythmias occurred. Heart rate increased, however, in seizure group compared with the prophylaxis group 2 hours postdrug infusion (median heart rate = 86 vs 164). The ECGs demonstrated a mean PR interval prolongation of about 6 milliseconds (ms) after LCM initiation (mean PR 185.5 ms, compared with baseline ECG mean of 179.3 ms). Laboratory data revealed no clinically significant changes 24 hours after LCM initiation. Three patients developed adverse events (9.4%): One with altered mental state and exceptionally prolonged ECG PR interval (212 vs 178 ms baseline); One with unexplained thrombocytopenia; and a third patient with dizziness, all of which resolved after drug discontinuation. Conclusion: The LCM demonstrated ECG PR prolongation as previously reported without systemic hypotension, with no discernable drug–drug interactions in hospitalized patients. About 9% of patients had transient adverse drug reactions after LCM, namely alteration in mental state, unexplained thrombocytopenia, and dizziness, which stopped after discontinuation of the drug.