Atrial flutter/atrial fibrillation associated with lacosamide for partial seizures.

Lacosamide (LCM) is a novel antiepileptic drug that exerts a strong antiepileptic effect via slow inactivation of voltage-gated sodium channels. LCM has been approved by the Food and Drug Administration for treatment of partial seizures at doses up to 400mg/day. Clinical trials have employed doses up to 600mg/day. LCM has been associated with atrial fibrillation at high doses (600mg/day) in patients with diabetes who had risk factors for heart disease. To our knowledge, atrial flutter or atrial fibrillation has not been reported in people with epilepsy. We report atrial flutter/atrial fibrillation at high doses of LCM (600mg/day) in a patient with epilepsy who had no significant risk factors for heart disease, which resolved following discontinuation of LCM. The literature regarding LCM-related cardiac death and arrhythmia is discussed. Physicians should be aware of the potential cardiac effects of this novel antiepileptic drug.