Vimpat side effects and how to avoid them

Vimpat is a brand-name medication manufactured by UCB, Inc. It is classed as an anticonvulsant used to treat partial-onset seizures in adults and children aged four years and older. While Vimpat is generally well tolerated, there are some potential side effects that people should be aware of. The most common side effects of Vimpat include dizziness and drowsiness. Less common, but more serious side effects, can include serious allergic reactions.

Learn more about the side effects of Vimpat and what you can do to avoid them.

What is Vimpat (lacosamide)?

The active ingredient in Vimpat is called lacosamide. It’s an antiepileptic drug (AED) that reduces your chances of having seizures. Lacosamide works by stopping certain circuits in your brain cells (neurons), called voltage-gated sodium channels, from activating in a repetitive way.

Lacosamide still allows your neurons to send signals, so doesn’t stop them from working and doesn’t affect your brain function. But it does stop neurons that have been active for long periods from sending repeating signals over and over, which is what is thought to trigger epilepsy. Rather than affecting your whole brain, you can think of Vimpat as targeting and calming those brain cells which are most likely to give you a seizure.

Always check with your doctor or pharmacist before taking any medication, including Vimpat, to make sure it is safe for you.

Vimpat dosage

Vimpat is available in tablet form in the following doses: 50 mg, 100 mg, 150 mg, and 200 mg tablets, 200 mg/20 mL single-dose vial for intravenous use, and 10 mg/mL oral solution.

You usually take Vimpat twice a day, in the morning and evening, to keep your seizures at bay. Vimpat can be taken as a tablet or oral solution that’s swallowed, or by injection into a vein (intravenous injection). Adults can take Vimpat in any of these ways, and this will be decided upon by your doctor. Children aged between four and 17 should only take Vimpat orally either as a tablet or an oral solution.

If you miss a dose of Vimpat take it as soon as you remember, but skip the missed dose if it is almost time for your next dose.

Read the complete medication guide provided with this medicine for the full drug information and patient information, and always speak with your healthcare provider for medical advice about any changes to your dose so they can monitor and evaluate your condition.

Vimpat side effects

The most common side effects of lacosamide in clinical trials compared to placebo include:

  • Headaches
  • Dizziness
  • Drowsiness
  • Double vision
  • Nausea

Vimpat can cause more serious side effects, including:

  • An increased risk of suicidal thoughts and actions
  • Drug reaction with eosinophilia and systemic symptoms (DRESS) – serious allergic reaction symptoms include fever, dark urine, headache, hives, stomach pain, tender lymph glands in the neck, groin, or armpit, unusual tiredness, or yellowing of eyes or skin (jaundice)
  • Serious heart symptoms – fast or irregular heartbeats, fluttering in your chest, chest pain, shortness of breath, sudden dizziness, feeling lightheaded, or faint
  • Hypoesthesia
  • Cerebellar syndrome
  • New or worsening seizures
  • Dyskinesia

If you experience any of these serious side effects, stop taking Vimpat and seek medical attention immediately. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit, or call 1-800-FDA-1088.

What are the long term side effects of taking Vimpat?

Antiepileptic drugs such as Vimpat may increase the risk of suicidal thoughts and behavior. Patients may also experience forgetfulness, itching skin. lack of appetite, and a loss of interest or pleasure.

Is weight gain a side effect of Vimpat?

Weight gain is not a common side effect of Vimpat, but it may cause weight loss. Get medical advice from your doctor if you experience weight loss with Vimpat.

Side effects of Vimpat and Keppra

Common side effects of Vimpat and Keppra include dizziness, drowsiness, and tiredness. Other side effects of Vimpat only include blurred vision, nausea, vomiting, loss of balance, shakiness, and headaches. Other side effects of Keppra only include loss of appetite, stuffy nose, hostility, nervousness, and weakness.

Vimpat side effects in elderly

Certain side effects may be more common in the elderly. These may include dizziness, a loss of balance, drowsiness, blurred vision, nausea, feeling tired, or memory problems may occur. Speak to your doctor for medical advice if you have these side effects.

Vimpat drug interactions

Vimpat can interact with other medications including:

  • Any other medications to treat seizures or epilepsy
  • Any medications taken for heart conditions
  • Any medications that can affect your heartbeat – carbamazepine, lamotrigine, or pregabalin
  • Any medications taken to treat fungal infections – fluconazole, itraconazole, or ketoconazole
  • Treatments for HIV infections – ritonavir
  • Antibiotics – clarithromycin or rifampicin
  • St. John’s wort

Before taking Vimpat, be sure to tell your doctor about all of the medications you are taking to ensure they are safe to take at the same time.

Vimpat warnings & precautions

Don’t take Vimpat if you:

  • Are allergic to the active ingredient lacosamide
  • Have a known hypersensitivity to any of the other ingredients in Vimpat
  • Have a heart problem called second- or third-degree AV block

Talk to your doctor before taking Vimpat if you:

  • Are taking any of the medications that could interact with Vimpat
  • Have or have had depression, other mood disorders, suicidal thoughts, or suicidal behaviors
  • Have any heart problem (such as heart failure or myocardial ischemia)
  • Have any liver problems
  • Have any kidney problems
  • Have phenylketonuria (PKU) – The oral solution contains aspartame (a source of phenylalanine), which can make this condition worse
  • Have ever abused prescription medications, alcohol, or illegal drugs
  • Are pregnant or are planning to become pregnant
  • Are breastfeeding or are planning to breastfeed – It is unknown if this drug passes into breast milk

You should always check with your doctor or pharmacist before taking any medication, including Vimpat, to make sure it is safe for you.

Other warnings you should know about

Antiepileptic drugs like Vimpat can increase the risk of suicidal thoughts and actions in some people. Seek urgent medical attention if you feel, or someone you care for who is taking Vimpat, feels they are at risk of suicide.

Vimpat is a federally controlled substance because it can be abused and can lead to drug dependence. Keep your Vimpat in a safe place and protect it from theft. Never give or sell your Vimpat to anyone else, it may harm them and is against the law.

Vimpat can cause side effects, like dizziness, sleepiness, and blurred vision, that can affect your ability to drive, operate machinery, or perform other dangerous tasks. Avoid these activities when taking Vimpat until you’re confident it doesn’t give you side effects that put you or others in danger.

Vimpat should not be given to children under four years of age and should not be given through intravenous injection to children aged four to 17.

How to avoid Vimpat side effects

The best way to avoid side effects is to take Vimpat as directed by your doctor. Follow your doctor’s instructions carefully and do not take more or less than prescribed.

If you experience any side effects, talk to your doctor or pharmacist. They may be able to recommend ways to help reduce or prevent some of the side effects.

1. Stick to the recommended dosage

Take your prescribed dose of Vimpat that has been recommended by your healthcare professional. Do not take more or less than prescribed.

2. Monitor your blood sugar levels

If you have diabetes, it is important to monitor your blood sugar levels closely while taking Vimpat. Check your blood sugar levels as directed by your doctor and report any changes to your doctor immediately.

3. Drink plenty of fluids

Drink eight to 10 glasses of water or fluids every day to help prevent dehydration, which can make side effects worse.

4. Avoid alcohol

Avoid drinking alcohol while taking Vimpat as it can increase your risk of side effects such as dizziness, drowsiness, and confusion.

5. Don’t skip meals

Eating regular meals and snacks will help to prevent low blood sugar levels (hypoglycemia).

6. Check your feet

If you have diabetes, check your feet for any cuts, sores, or redness regularly. Tell your caregiver if you experience any problems with your feet while taking Vimpat.

7. Know the signs and symptoms of Vimpat side effects

Signs and symptoms of side effects include dizziness and drowsiness. If you experience any of these symptoms speak to your doctor for medical advice.

8. Monitor your weight

Weight gain is not a common side effect of Vimpat, but it may cause weight loss. If you experience weight loss while taking Vimpat, get medical advice from your doctor.

9. Tell your doctor about all medications you’re taking

Be sure to tell your doctor about all other medications you’re taking, including over-the-counter drugs, vitamins, and herbal supplements, as they can interact with Vimpat.

10. Get regular medical check ups

It is important to get regular medical check ups and monitor your medical conditions. Your doctor will monitor your side effects and may adjust your dose of Vimpat as needed.

Medically reviewed

A medical professional has reviewed this article.

Jamie Winn, PharmD
Jamie Winn, PharmD

Jamie Winn, PharmD

Medical Writer & Reviewer

Jamie Winn, PharmD

Medical Writer & Reviewer

Dr. Jamie Winn received his Doctor of Pharmacy in 2002 from the University of South Carolina College of Pharmacy, Columbia, SC. Jamie is a medical reviewer for NiceRx.

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The content on this website is intended for information purposes only. It does not constitute medical advice. The information on this website should not be relied upon and is not a substitute for professional medical advice. You should always speak to your doctor regarding the risks and benefits of any treatment.