What is the dosage and administration of injectable (IV) lacosamide for partial-onset seizures?

Injectable Lacosamide Dosing and Administration

For adults with partial-onset seizures, initiate IV lacosamide at 50 mg twice daily (100 mg/day) for adjunctive therapy or 100 mg twice daily (200 mg/day) for monotherapy, titrating to a maintenance dose of 200-400 mg/day (100-200 mg twice daily) based on response and tolerability. 1

Standard Dosing Protocol

Initial Dosing

• Adjunctive therapy: Start at 50 mg IV twice daily 1
• Monotherapy: Start at 100 mg IV twice daily 1
• Maximum recommended dose: 200 mg twice daily (400 mg/day) 1

Titration Strategy

• Increase dosage no more frequently than once per week based on clinical response and tolerability 2
• The American College of Neurology recommends weekly titration in 100 mg/day increments to target dose of 200-400 mg/day 3
• Loading doses have not been studied and are not recommended for routine use 2

Administration Guidelines

Infusion Parameters

• Bioequivalence: IV and oral formulations are bioequivalent and can be used interchangeably without dose adjustment or retitration 2
• Infusion duration: 15 minutes is safe and well-tolerated for short-term replacement (2-5 days) 4
• Infusions as short as 10 minutes, or as long as 30-60 minutes, have been evaluated and found safe 4, 5
• The tolerability profile of IV lacosamide is consistent with oral administration 2

Duration of IV Therapy

• IV lacosamide is intended for short-term replacement (2-5 days) when patients are temporarily unable to take oral medication 4
• Transition back to oral formulation when feasible without dose adjustment 2

Critical Safety Monitoring

Cardiac Considerations

• Monitor for PR interval prolongation: Lacosamide causes small dose-related increases in cardiac conduction time 2
• Exercise caution in patients with pre-existing cardiac conduction abnormalities 2
• Obtain baseline ECG and monitor during therapy, particularly at higher doses 2

Common Adverse Events

• Most frequent: dizziness, headache, somnolence, nausea, and injection site pain or discomfort 6
• Most adverse events are mild to moderate in severity 6
• Injection-site events are rare and not linked to infusion doses or rates 4
• Higher doses (≥400 mg/day) are associated with more frequent adverse events 4

Special Populations and Dose Adjustments

Renal Impairment

• Dose adjustment recommended for severe renal impairment 1

Hepatic Impairment

• Dose adjustment recommended for mild or moderate hepatic impairment 1
• Use in patients with severe hepatic impairment is not recommended 1

Pediatric Patients (1 month to <17 years)

• Dosing is based on body weight and administered twice daily 1
• Lacosamide has shown efficacy in pediatric refractory epilepsy, with 50% of patients achieving >50% seizure reduction 7

Critical Pitfalls to Avoid

Discontinuation Protocol

• Never abruptly discontinue lacosamide: Withdrawal seizures can occur with sudden cessation 2, 6
• Gradual tapering is required when discontinuation is necessary 6

Drug Interaction Advantages

• Lacosamide has minimal drug-drug interactions as a non-enzyme-inducing antiepileptic drug 3
• Preferred over enzyme-inducing agents (phenytoin, carbamazepine, phenobarbital) in patients taking multiple concomitant medications, steroids, or cytotoxic agents 2, 3

Inappropriate Use

• Do not use for primary seizure prophylaxis in seizure-free patients (e.g., brain tumor patients without seizure history) 2, 3