Low Dose Lacosamide-Induced Atrial Fibrillation: Case Analysis with Literature Review (P03.135)

OBJECTIVE: Dose-dependent lacosamide (LCM)-induced cardiac dysrhythmias have been reported in recent literature. This case represents the first instance of low dose (200 mg) LCM-induced atrial fibrillation. BACKGROUND: Lacosamide (LCM) is a novel anti-epileptic drug (AED) approved by the FDA for adjunct treatment of partial onset epilepsy with and without secondary generalization. LCM selectively modulates voltage-gated sodium channels. AED selection is related to both efficacy and adverse effect profile. DESIGN/METHODS: Case analysis with literature review. RESULTS: A 67 year-old woman with a history of complex partial seizures, migraines, and multiple myeloma was admitted for autologous bone marrow transplant. This patient had no known prior cardiac disease. Admission medications included methylprednisolone, clotrimazole, fluconazole, acyclovir, neupogen, ondansetron, pantoprazole, loperamide, calcium phospate, and primidone. Renal and hepatic function as well as serum electrolytes were normal. During her admission, episodes of staring with oral/facial automatisms increased in frequency and duration (multiple events/hour). The patient did not respond to addition of levetiracetam (1500 mg bid) and continuous video-EEG was initiated to characterize her seizure activities and to monitor response to treatment. Multiple epileptic events were recorded within four hours on video-EEG. LCM was initiated with 200 mg intravenous infusion, at the end of which an irregularly irregular rhythm was noted on telemetry. Asymptomatic atrial fibrillation lasted for two hours with spontaneous resolution. Atrial fibrillation onset correlated to the theoretical time of maximum LCM plasma concentration. LCM was discontinued. CONCLUSIONS: Low dose LCM may provoke atrial fibrillation in at risk patients. Neurologists and internists need to be cognizant of this potential adverse effect. Cardiac monitoring may be required with LCM dose rapid titration, especially if given intravenously. Disclosure: Dr. Velez has nothing to disclose. Dr. Kaufman has nothing to disclose. Dr. Wong has nothing to disclose. Dr. Mani has nothing to disclose.