Lacosamide
Class: Antiepileptic (functionalized amino acid derivative)
Indications
- Adjunctive or monotherapy for focal (partial-onset) seizures
- Adjunctive therapy for primary generalized tonic-clonic seizures (adults & ≥4 years children)
- Off-label: Neuropathic pain
Mechanism of Action
- Enhances slow inactivation of voltage-gated sodium channels
- Stabilizes hyperexcitable neuronal membranes
- Modulates collapsin response mediator protein-2 (CRMP-2)
Dosage
- Adults: Start 50 mg twice daily; titrate to 200–400 mg/day in 2 doses
- IV formulation: Equivalent to oral dosing, infused over 30–60 minutes
- Children ≥4 years: 1–2 mg/kg/day in 2 doses, titrate to 8–12 mg/kg/day (max 400 mg/day)
Major Side Effects
- Dizziness, headache, diplopia
- Nausea, vomiting
- Ataxia, fatigue
- Prolonged PR interval, atrioventricular block (rare)
Contraindications
- Hypersensitivity to lacosamide
- Second- or third-degree AV block
Compatible Solvent / Administration
- Oral tablets, oral solution, and IV injection
- IV can be given undiluted or diluted with 0.9% NaCl, D5W, or Ringer’s lactate
Special Precautions
- Monitor ECG in patients with cardiac conduction disorders
- Use caution with other drugs that prolong PR interval
- Gradual tapering recommended to avoid rebound seizures
- Pregnancy Category C – use only if benefits outweigh risks
Key Point: Lacosamide is a newer AED effective for focal and generalized seizures, generally well tolerated but requires cardiac monitoring due to risk of PR interval prolongation.