Lacosamide Dosing for Partial-Onset Seizures in Adults
For adults with partial-onset seizures, initiate lacosamide at 100 mg/day with weekly titration in 100 mg/day increments to a target maintenance dose of 200-400 mg/day, administered twice daily. 1
Standard Dosing Algorithm
Initial Dosing
- Start at 100 mg/day divided into twice-daily dosing 1
- Titrate upward by 100 mg/day increments on a weekly basis 1
- Target maintenance dose: 200-400 mg/day 1, 2
- Maximum studied dose: 600 mg/day in clinical trials, though doses up to 800 mg/day have been evaluated in long-term studies 3, 4
Maintenance Therapy
- The median effective dose in long-term monotherapy studies was 500 mg/day 4
- Doses of 200 mg/day and 400 mg/day demonstrated significantly greater seizure reduction (34% and 40% responder rates, respectively) compared to placebo (23%) 5
- Both oral and intravenous formulations are bioequivalent and can be used interchangeably 5, 2
Critical Dosing Considerations
Loading Doses
- No loading dose protocol has been established or studied for lacosamide 6
- For non-emergent situations, standard maintenance dosing should be initiated without loading 6
Formulation Options
- Oral tablets and oral syrup are bioequivalent 5
- IV formulations (15-, 30-, or 60-minute infusions) provide similar bioavailability to oral dosing and can be used for temporary conversion 5, 2
- IV lacosamide is well-tolerated but is indicated only for short-term replacement of oral therapy, not for loading 7
Safety and Tolerability Profile
Common Adverse Effects (Dose-Related)
- Dizziness (30.6% vs 8.2% placebo), nausea (11.4% vs 4.4% placebo), and diplopia (10.5% vs 1.9% placebo) are the most common adverse events 3
- Most adverse events occur during titration phase and decrease during maintenance 3
- Adverse events are predominantly mild to moderate in severity; severe events are mainly observed at 600 mg/day 3
Discontinuation Rates
- Treatment discontinuation due to adverse events: 8.1% at 200 mg/day, 17.2% at 400 mg/day, and 28.6% at 600 mg/day (vs 4.9% placebo) 3
- When combined with carbamazepine, discontinuation rates were higher (15.3%) compared to combinations with lamotrigine (19.2%) or levetiracetam (10.1%) 3
Key Advantages Over Older Antiepileptic Drugs
Drug Interaction Profile
- Lacosamide is a non-enzyme-inducing antiepileptic drug with minimal drug-drug interactions 1
- No significant interactions with cytochrome P450 enzymes 2
- Preferred in patients taking multiple concomitant medications 1
Safety in Special Populations
- In women of childbearing potential, lacosamide is preferred over valproate due to valproate's significant teratogenicity risks 1
- For pregnant women with well-controlled seizures on lacosamide, continuation is recommended as seizure control takes priority 8
Critical Pitfalls to Avoid
Withdrawal Seizures
- Abrupt discontinuation of lacosamide can precipitate withdrawal seizures 1, 6
- Maintain consistent dosing to avoid breakthrough seizures 6
- If discontinuation is necessary, taper gradually rather than stopping abruptly 8
Inappropriate Use
- Lacosamide is not effective for seizure prophylaxis in seizure-free patients (e.g., brain tumor patients without seizure history) 1
- Do not use as prophylactic therapy in patients who have never had seizures 1
Pregnancy Management
- Do not discontinue lacosamide in pregnant women with well-controlled seizures, as breakthrough seizures pose greater risks than medication continuation 8
- Changing to another antiepileptic during pregnancy introduces unnecessary risks if seizures are already controlled 8
Long-Term Efficacy Data
- In long-term extension studies with up to 2 years of exposure, 74.2% of patients achieved ≥50% seizure reduction at 24 months 4
- The majority of patients (69.4%) achieved lacosamide monotherapy for at least 12 months during long-term follow-up 4
- Median duration of monotherapy was 587 days, demonstrating sustained tolerability 4