lacosamide and Infant--Newborn--Diseases

Lacosamide is an antiepileptic drug with US Food and Drug Administration approval for the treatment of partial-onset seizures in patients older than one month. Lacosamide works by selective enhancement of proteins that induce preferential slow promotion of sodium channels to the hyperpolarized inactive state. Lacosamide is generally well-tolerated; however, clinical and nonclinical studies have linked its use with cardiac side effects including PR prolongation and atrioventricular (AV) block.. We present the case of a three-week-old female neonatal patient born at 25 weeks' gestation who developed second-degree AV heart block and cardiac arrest after initiating lacosamide therapy. The patient was being treated for neonatal seizure complicated by intraventricular hemorrhage (grade II) and electrolyte disturbances with phenobarbital, levetiracetam, and phenytoin. Before addition of lacosamide therapy, the patient had an unremarkable electrocardiogram and no known cardiac risk factors for lacosamide. After medication discontinuation, the patient experienced no reoccurring episodes or other cardiac events.. Use of lacosamide for neonatal populations is currently under evaluation. This is the first report of adverse cardiac event (AV block) in the setting of neonatal lacosamide use. Risk of future adverse cardiac events should be evaluated when determining the safety and efficacy of lacosamide in the neonatal population.

Topics: Anticonvulsants; Atrioventricular Block; Female; Heart Arrest; Humans; Infant, Newborn; Infant, Newborn, Diseases; Lacosamide; United States

Voltage-gated sodium channel alpha subunit 2 (SCN2A) gene mutations are associated with neonatal seizures and a wide range of epilepsy syndromes. Previous reports suggest that traditional sodium channel blockers (SCBs) such as phenytoin, carbamazepine, and lamotrigine have a beneficial effect on SCN2A-related neonatal seizures, as they counteract the gain-of-function effect of mutated Nav1.2 channels. Additionally, SCBs are beneficial against other sodium and potassium channel-related neonatal seizures. There are, however, few reports describing the effect of the new SCB lacosamide against neonatal and infantile epileptic seizures. We report herein two neonates with intractable neonatal seizures with SCN2A pathogenic missense variants. Both infants showed temporary seizure relief following IV administrations of phenytoin, but were resistant to a combination of antiepileptic drugs, while complete seizure control was achieved following lacosamide administration. We suggest that SCBs, e.g. phenytoin, should be introduced early for refractory neonatal seizures of non-lesional and presumably genetic origin. If any beneficial response to a SCB is noted, this should prompt an initiation of additional SCBs. New clinical trials will provide data on the efficacy and safety of the new SCB lacosamide for genetic neonatal seizures and perhaps neonatal seizures in general.

Topics: Drug Resistant Epilepsy; Electroencephalography; Epilepsy; Female; Humans; Infant, Newborn; Infant, Newborn, Diseases; Lacosamide; Male; Mutation, Missense; NAV1.2 Voltage-Gated Sodium Channel; Spasms, Infantile; Voltage-Gated Sodium Channel Blockers