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Vimpat

Vimpat (Lacosamide) Dosages: Your GoodRx Guide

Alex Evans, PharmD, MBAAlyssa Billingsley, PharmD
Written by Alex Evans, PharmD, MBA | Reviewed by Alyssa Billingsley, PharmD
Updated on September 24, 2025

Key takeaways:

  • Vimpat (lacosamide) is medication that treats seizures in adults and children ages 1 month and older.

  • The typical starting Vimpat dosage for adults is 50 mg to 100 mg twice daily. From there, your prescriber may slowly increase your dosage up to a maximum of 200 mg twice daily. The Vimpat dosage for children is based on their body weight.

  • In some cases, your prescriber may have you take a one-time dose of Vimpat that’s higher than your typical twice-daily dose. This helps Vimpat start working faster. But it can also cause more side effects, so it’s not recommended for everyone.

  • Vimpat is available as a lower-cost generic. GoodRx can help you save over 90% off the average retail price of generic Vimpat at certain pharmacies.

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Vimpat (lacosamide) is a prescription medication that treats certain types of seizures. It’s approved for both children and adults and can be taken alone or along with other anti-seizure medications.

The recommended Vimpat dosage depends on factors such as your age and why you’re taking it. We’ll look at the recommended dosages in detail below. Keep in mind that your prescriber may have you take a different Vimpat dosage than what’s described here. It’s best to follow their instructions and reach out with any questions.

What dosage forms does Vimpat come in?

Vimpat comes in two oral forms: tablets and a liquid solution. Vimpat also comes in an injectable form, but it’s typically given in a hospital setting. So we won’t cover it in this dosage guide.

Vimpat oral tablets come in four doses:

  • 50 mg

  • 100 mg

  • 150 mg

  • 200 mg

Vimpat also comes as a strawberry-flavored oral solution that contains 10 mg per 1 mL. The solution may be a better option for young children or adults who have trouble swallowing tablets.

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Be sure to measure the oral solution with a syringe or measuring device from your pharmacy. A household spoon won’t measure Vimpat accurately. You can keep the oral solution at room temperature, but you shouldn’t use it more than 6 months after you open the bottle.

You can take Vimpat with or without food. But taking it with a meal or snack may help prevent nausea, a known Vimpat side effect.

What’s the typical Vimpat dosage for adults?

The typical Vimpat dosage for adults (ages 17 and older) depends on why you’re taking it. It also depends on whether you’re taking it alone (monotherapy) or with another anti-seizure medication (adjunctive therapy).

Monotherapy for partial-onset seizures

The recommended Vimpat dosage as a solo treatment for partial-onset seizures in adults starts at 100 mg twice daily. Your prescriber will then slowly increase your dose to the recommended amount of 150 mg to 200 mg twice daily (300 mg to 400 mg per day). The maximum recommended Vimpat dosage is 400 mg per day.

There should be at least 1 week between each increase in your Vimpat dosage. And it’s not recommended to raise the dose by more than 50 mg per dose (100 mg per day) at a time.

In some cases, you’ll start with a single 200 mg dose of Vimpat, called a loading dose. You’ll then start the above dosage schedule 12 hours later. This helps Vimpat start working faster, but it can also raise your risk of side effects, such as headache, dizziness, and drowsiness. Your prescriber will determine if you need a loading dose based on your medical history.

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Adjunctive therapy for partial-onset or tonic-clonic seizures

If you’re taking Vimpat with other anti-seizure medication (adjunctive therapy), your recommended daily dose is lower than if you’re taking it alone. You’ll start with a Vimpat dosage of 50 mg twice daily, then slowly increase to the recommended dosage of 100 mg to 200 mg twice daily (200 mg to 400 mg daily).

There should be at least 1 week between each dosage increase. And it’s not recommended to raise the dose by more than 50 mg per dose (100 mg per day) at a time.

In some cases, your prescriber may recommend a 200 mg loading dose of Vimpat. Then, 12 hours later, you’ll start taking 100 mg twice daily. This can help Vimpat start working faster. If needed, your prescriber may increase your dosage from there to a maximum of 200 mg twice daily as described above.

What’s the typical Vimpat dosage for children?

Vimpat is approved as monotherapy and adjunctive therapy for partial-onset seizures in children ages 1 month and older. But adjunctive therapy for tonic-clonic seizures is only approved for children ages 4 and older.

The typical Vimpat dosage for children under age 17 is based on their body weight.

Children weighing 50 kg (110 lbs) or more will start with 50 mg twice a day, then increase to the same target dosages as adults (as described above).

The recommended oral Vimpat dosages for children weighing less than 50 kg are described in the chart below.

Child’s body weight

Starting dosage

Goal dosage

(same for monotherapy and adjunctive therapy)

30 kg - less than 50 kg 

(66 lbs -110 lbs)

1 mg/kg twice daily
or
4 mg/kg loading dose
then 2 mg/kg twice daily

2 mg/kg - 4 mg/kg

twice daily

6 kg - less than 30 kg

(13 lbs - 66 lbs)

1 mg/kg twice daily
or
4.5 mg/kg loading dose
then 3 mg/kg twice daily

3 mg/kg - 6 mg/kg

twice daily

Less than 6 kg (13 lbs)

1 mg/kg twice daily
or
3.5 mg/kg twice daily (no loading dose)

3.75 mg/kg - 7.5 mg/kg

twice daily

The Vimpat dosage for children who weigh under 50 kg should be increased by no more than 1 mg/kg per dose (2 mg/kg per day) each week.

If your child receives a loading dose of Vimpat, they’ll start their twice daily dosage 12 hours afterward.

Are there any dosage adjustments for medical conditions?

If you have other medical conditions, such as kidney or liver problems, your recommended Vimpat dosage may change.

Dosage for people with kidney problems

If you have kidney problems, it may be harder for your body to clear Vimpat. This can increase Vimpat levels and make side effects more likely. If you have severe kidney problems, your prescriber may lower your Vimpat dosage by 25%. They’ll decide if you need a lower dose of Vimpat based on your kidney function.

Dosage for people with liver problems

A 25% lower Vimpat dosage is also recommended if you have mild or moderate liver problems. But if your liver problems are severe, Vimpat isn’t recommended. Your prescriber will help determine if you need a lower Vimpat dosage based on your liver function.

What happens if you miss a dose of Vimpat?

If you realize you've missed a dose of Vimpat, take it as soon as you remember. But if it's almost time for your next dose, skip the missed dose and take the next one as scheduled. Don’t try to make up for the missed dose by taking two doses at once.

Remember, consistency is key when it comes to Vimpat. Taking your doses at the same time each day helps maintain a steady level of the medication in your body. This helps it work effectively. Missing multiple doses of Vimpat could cause a return of your seizure activity and other withdrawal symptoms.

If you're having trouble remembering to take Vimpat, try setting a reminder on your phone or using a pillbox. You can also talk to your pharmacist or prescriber. They may be able to suggest strategies to help you remember.

What should you do if you take too much Vimpat?

If you take an extra dose of Vimpat by mistake, it’s not likely to cause a problem. You may have more side effects than usual, such as dizziness or blurry vision. They should go away as your dose wears off.

But taking a large amount of Vimpat can be dangerous and even life-threatening in some cases. Symptoms can include confusion, heart problems, or even a coma in severe cases.

If you or your child takes too much Vimpat, seek emergency medical attention or call Poison Control at 1-800-222-1222. Do not wait for symptoms to appear.

How to save on Vimpat

There are ways to save on the cost of Vimpat, which is available as both a brand-name and generic medication. 

  • Save with GoodRx. GoodRx can help you save over 90% off the average retail price of the generic version. Generic Vimpat’s price at certain pharmacies is as low as $27.11 per month with a free GoodRx discount.

  • Manufacturer savings program. You can pay as little as $84.99 (without insurance) for a month’s supply of brand-name Vimpat tablets through the manufacturer’s direct-to-patient program.

Frequently asked questions

It takes about 3 days to clear Vimpat from your system after you stop taking it. But it can be dangerous to stop taking Vimpat abruptly on your own. If you’re interested in stopping Vimpat, talk to your prescriber first. They can help you stop taking it safely or switch you to a different seizure medication, if needed.

In most cases, Vimpat doesn’t require frequent blood tests in the way some other antiseizure medications do. So in most cases, your prescriber will determine your dosage based on how well you tolerate side effects and how well Vimpat is managing your seizure activity. Let them know about any changes or concerns that arise during treatment.

No, you shouldn’t cut or crush Vimpat tablets — you should swallow them whole. If you have trouble swallowing pills, let your prescriber know. They can switch you to the Vimpat oral liquid instead.

The bottom line

Vimpat (lacosamide) is a prescription medication that treats certain types of seizures in adults and children. The usual starting Vimpat dosage for adults is 50 mg to 100 mg twice daily, depending on whether you’re taking it alone or with other seizure medications. From there, it can be increased up to a maximum of 200 mg twice daily if needed. The Vimpat dosage for children ages 16 and under is based on their body weight.

In some cases, your prescriber may have you start with a single loading dose of Vimpat that’s higher than your twice daily dosage. This can help Vimpat start working faster, but it may cause more side effects. Your healthcare team will determine the best Vimpat dosage for you based on your medical history.

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Why trust our experts?

Alex Evans, PharmD, MBA, has been a pharmacist for 12 years. His first job was floating in a community chain pharmacy.
Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.
Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

References

GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.

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