lacosamide

Lacosamide is an anticonvulsant medication used as adjunctive therapy for partial-onset seizures in adults and in children aged 4 years and older. It is marketed under the brand name Vimpat and is available in oral tablet form and as an intravenous formulation for short-term use or when oral administration is not feasible.

Lacosamide enhances slow inactivation of voltage-gated sodium channels, which stabilizes hyperexcitable neuronal membranes and reduces repetitive neuronal firing. This mechanism is distinct from most other sodium-channel–blocking anticonvulsants that primarily affect fast inactivation.

Oral lacosamide has high bioavailability and reaches peak plasma levels within a few hours. The elimination half-life is about 13 hours, allowing twice-daily dosing. It is largely eliminated as metabolites through renal excretion after hepatic metabolism; only a small fraction remains unmetabolized. Dosing must be adjusted in patients with significant renal impairment.

Dosing is individualized and titrated based on response and tolerability. In adults, typical maintenance is 200-400 mg per day given in two divided doses; the maximum recommended daily dose is 400 mg. The intravenous form allows short-term administration and can be converted to oral when possible.

Common adverse effects include dizziness, headache, fatigue, diplopia, and nausea; some patients experience ataxia or somnolence. Lacosamide can prolong the PR interval on ECG and may cause arrhythmias, especially in patients with underlying conduction disease or when given with other drugs affecting AV conduction. There is a risk of hypersensitivity, including rash; like other antiepileptic drugs, there is a potential for suicidality.

Pregnancy category C; contraindicated in second- or third-degree AV block; caution with conduction disorders; monitor for drug interactions with other anticonvulsants and CNS depressants.