What is the recommended treatment regimen for partial-onset seizures using Vimpat (lacosamide)?

Recommended Treatment Regimen for Partial-Onset Seizures Using Vimpat (Lacosamide)

For partial-onset seizures, Vimpat (lacosamide) is recommended as an adjunctive therapy at doses of 200-400 mg/day, administered orally or intravenously, with 400 mg/day providing the optimal balance of efficacy and tolerability. 1, 2

Dosing and Administration

• Initial titration should begin at 100 mg/day (50 mg twice daily) with weekly increases of 100 mg/day until reaching the target dose 3
• The recommended maintenance dose is 200-400 mg/day, divided into two equal doses 2, 4
• The 600 mg/day dose may provide additional benefit for some patients with difficult-to-control seizures, particularly those with secondarily generalized tonic-clonic seizures, but has a higher incidence of adverse effects 3, 5
• Both oral (tablets or syrup) and intravenous formulations are available with similar bioavailability, allowing for flexibility in administration 2, 6

Efficacy

• Lacosamide significantly reduces seizure frequency compared to placebo, with median percent reductions of 37.3% at 400 mg/day and 37.8% at 600 mg/day 3
• Responder rates (≥50% reduction in seizure frequency) are approximately 38.3% for 400 mg/day and 41.2% for 600 mg/day 3
• Lacosamide shows particularly strong efficacy for secondarily generalized tonic-clonic seizures, with median reductions of 59.4% at 400 mg/day and 93.0% at 600 mg/day 3
• Onset of efficacy is evident within the first week of treatment 4

Safety and Tolerability

• Most common adverse effects include dizziness (30.6%), nausea (11.4%), and diplopia (10.5%) 5
• Adverse effects are generally dose-related, with most being mild to moderate in intensity 5
• Severe adverse effects are predominantly observed at the 600 mg/day dose 5
• Adverse effects are more common during the titration phase than during maintenance therapy 5
• The intravenous formulation has a similar tolerability profile to oral administration, with additional potential for injection site discomfort, pain, irritation, or erythema 2

Special Considerations

• Lacosamide works through a novel mechanism of action by selectively enhancing slow inactivation of voltage-gated sodium channels 2, 6
• Efficacy is maintained with long-term treatment (up to 8 years) 2
• Lacosamide is effective regardless of prior surgical intervention for epilepsy 4
• Lacosamide shows efficacy when combined with various concomitant antiepileptic drugs 4
• When used with carbamazepine, discontinuation rates due to adverse effects are 15.3% (vs 3.9% with placebo); with lamotrigine 19.2% (vs 4.3%); and with levetiracetam 10.1% (vs 3.9%) 5

Monitoring and Follow-up

• Patients should be monitored for adverse effects, particularly during the titration phase 5
• Regular assessment of seizure frequency and severity is recommended to evaluate treatment efficacy 3
• Patients and caregivers should be instructed on how to respond to breakthrough seizures 1

Lacosamide provides an effective adjunctive treatment option for patients with partial-onset seizures, with a manageable side effect profile when properly titrated to the appropriate dose.