lacosamide
Brand: Vimpat
Prototype Drug
Drug Class: antiepileptic drug
Drug Family: antiepileptic
Subclass: selective sodium channel slow inactivation enhancer
Organ Systems: cns
Mechanism of Action
Novel mechanism of sodium channel modulation: selectively enhances slow inactivation of voltage-gated Na+ channels (vs. fast inactivation targeted by phenytoin, carbamazepine) and binds CRMP-2 (collapsin response mediator protein-2), reducing neuronal hyperexcitability in a manner complementary to other Na+ channel blockers.
voltage-gated sodium channels (selective enhancement of slow inactivation)
Indications
- partial (focal) seizures (adjunctive or monotherapy in adults)
- primary generalized tonic-clonic seizures (adjunctive)
Contraindications
- hypersensitivity to lacosamide
Adverse Effects
Common
- diplopia
- headache
- dizziness
- nausea
- ataxia
Serious
- PR interval prolongation (cardiac conduction); monitor ECG
- cardiac arrhythmias (in patients with cardiac conduction disorders)
- suicidal ideation (class AED effect)
- drug reaction with eosinophilia and systemic symptoms (DRESS)
Pharmacokinetics (ADME)
| Absorption | oral or IV; bioavailability ~100% |
| Distribution | <15% protein bound |
| Metabolism | hepatic via CYP2C19 (minor); mainly excreted unchanged |
| Excretion | renal (95%) |
| Half-life | 13 hours |
| Onset | rapid |
| Peak | 1–4 hours |
| Duration | 12 hours (BID dosing) |
| Protein Binding | <15% |
| Vd | 0.6 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| drugs prolonging PR interval (carbamazepine, lidocaine, beta-blockers) | additive PR prolongation; risk of AV block | moderate |
Nursing Considerations
- Obtain baseline ECG; lacosamide prolongs PR interval; use with caution in patients with cardiac conduction disorders or on other PR-prolonging drugs.
- IV form available for patients unable to take oral medications (1:1 dose conversion); infuse over 30–60 minutes.
- Minimal drug interactions due to low protein binding and minimal CYP metabolism; good choice in complex polypharmacy patients.
- Monitor for dizziness and diplopia, especially with initiation; start at low doses and titrate slowly.
Clinical Pearls
- Lacosamide's unique mechanism targeting slow Na+ channel inactivation means it works via a different molecular mechanism than phenytoin and carbamazepine, making combination with these agents pharmacodynamically complementary rather than redundant.
- The IV formulation with 1:1 oral bioequivalence makes lacosamide practical for hospitalized patients who cannot take oral medications — an advantage over many other AEDs.
Safety Profile
Pregnancy use-with-caution
Lactation insufficient-data
Renal Adjustment Required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.