Lacosamide injection: uses, dosing, and side effects
Last updated September 7, 2026.
**Lacosamide injection is an anticonvulsant medicine given into a vein to control seizures.** It reduces abnormal electrical activity in your brain. It can disturb your heart rhythm, so report faintness or a slow or irregular heartbeat immediately.
What does it treat?
You may receive it for focal seizures, which start in one brain area and can cause unusual sensations, jerking, or impaired awareness. It also treats primary generalized tonic-clonic seizures, with stiffening and shaking, alongside other seizure medicines. Injection temporarily replaces oral treatment when you cannot take it.
How do you take it?
You receive an IV infusion, usually over 30 to 60 minutes. Adult starting doses are 100 mg twice daily when used alone or 50 mg twice daily as added treatment. Weekly increases lead to 150 to 200 mg twice daily alone or 100 to 200 mg twice daily as added treatment; the ceiling is 400 mg daily. Meals do not affect injections. Contact your infusion team about missed doses; never double up. For a serious allergic reaction, stop the infusion and get help. Otherwise, do not stop abruptly because seizures can worsen.
Side effects to know
- Common: You may experience dizziness, sleepiness, nausea, headache, double vision, poor balance, or injection site discomfort.
- Serious: Stop the infusion and get immediate help for facial swelling, breathing trouble, or a blistering rash. Fever with swollen glands or yellow skin can signal a serious immune reaction; suicidal thoughts or new heart symptoms also require immediate assessment.
Who should not take it?
Tell your clinician about medication allergies, heart rhythm problems, fainting, kidney or liver disease, depression, and every medicine you use. Severe liver disease makes use inadvisable. Discuss pregnancy or breastfeeding before treatment changes. Avoid alcohol until your prescriber advises you.
When is it an emergency?
For suspected overdose, call Poison Control at 1-800-222-1222 immediately. Signs include severe dizziness, confusion, seizures, or an abnormal heartbeat. Call 911 for collapse, breathing trouble, inability to wake, or throat swelling. Chest pain with fainting also needs emergency help.
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Common questions
What is the maximum adult dose?
The usual ceiling is 200 mg twice daily. Kidney or liver impairment can lower your limit. Never increase your dose yourself.
Can I drink alcohol?
Ask your prescriber before drinking. Alcohol can worsen dizziness and sleepiness. Tell your clinician about heavy drinking.
What if I am pregnant or breastfeeding?
Human pregnancy data cannot establish the risk; animal studies found developmental harm. Do not stop treatment yourself. Lacosamide enters breast milk, so monitor your baby for excessive sleepiness.
Do I need food with treatment?
Injections do not depend on meals. Oral tablets and solution can also be taken with or without food. Follow any fasting instructions for other procedures.
Which medicines interact?
Beta blockers and other medicines affecting heart conduction need review. Your clinician may order an ECG. Bring your complete medication list.