Section 01 · Monograph

Lacosamide

Reviewed Nov 2026FDA label

VimpatNa+ channel modulator

Indications

Treatment of partial-onset seizures, age 1 month and older (monotherapy or adjunctive)FDA-labeled
Adjunctive therapy for primary generalized tonic-clonic seizures, age 4 years and olderFDA-labeled

Selectively enhances slow inactivation of voltage-gated sodium channels (distinct from the fast inactivation targeted by traditional sodium channel blockers), stabilizing hyperexcitable neuronal membranes and reducing repetitive neuronal firing without affecting fast inactivation

Adults, monotherapy: initiate 100mg BID; may titrate by 50mg BID at weekly intervals to a usual maintenance dose of 150-200mg BID (max 400mg/day)
Adults, adjunctive therapy: initiate 50mg BID; titrate by 50mg BID weekly to a usual maintenance range of 100-200mg BID (max 400mg/day)
Available as oral tablet, oral solution, and IV injection at equivalent doses — IV is a substitute when oral administration is temporarily not feasible; infuse over 15-60 minutes
Obtain baseline ECG before initiation and consider a follow-up ECG after titration to steady-state maintenance dose, especially in patients with cardiac conduction risk factors

Renal impairment: reduce maximum dose by ~25% if CrCl <30 mL/min; supplemental dose after hemodialysis session should be considered

Hepatic impairment: reduce maximum dose by ~25%; not recommended in severe hepatic impairment

Strong CYP3A4 or CYP2C9 inhibitors/inducers may alter lacosamide exposure — dose adjustment may be warranted
Additive PR-interval prolongation/cardiac conduction effects with other drugs affecting cardiac conduction (beta-blockers, calcium channel blockers, other sodium channel blocking antiseizure drugs) — use caution and consider ECG monitoring
Relatively few clinically significant pharmacokinetic interactions with other AEDs compared to older agents

Common: diplopia, dizziness, headache, nausea, somnolence, ataxia
PR interval prolongation (dose-dependent); atrioventricular block, bradycardia, and rare cases of ventricular tachyarrhythmia including fatal events have been reported
Caution and baseline/follow-up ECG advised in patients with known conduction abnormalities, severe cardiac disease, or those on concomitant PR-prolonging drugs
Dizziness/ataxia may increase fall risk
Suicidal ideation/behavior (class effect); rash and DRESS (drug reaction with eosinophilia and systemic symptoms) reported
Multiorgan hypersensitivity reactions reported postmarketing

Baseline ECG before initiation and at steady-state maintenance dose in patients with cardiac conduction risk factors or those on concurrent PR-prolonging medications
Signs/symptoms of syncope, bradycardia, or AV block, particularly during up-titration
Mental status for mood changes or suicidal ideation

Animal studies showed developmental toxicity at clinically relevant exposures; human data are limited and insufficient to establish drug-associated risk
Encourage enrollment in the North American Antiepileptic Drug (NAAED) Pregnancy Registry (1-888-233-2334)
Lacosamide is present in breast milk; monitor breastfed infants for excess sedation or feeding difficulty