11 Lamotrigine Side Effects You Should Know About

Lamotrigine is a medication that treats certain types of seizures. It’s available in many forms. This includes an immediate-release (IR) tablet (Lamictal) and extended-release (XR) tablet (Lamictal XR). IR lamotrigine is also FDA approved to treat bipolar 1 disorder.

Like all medications, lamotrigine has some risks and side effects. Some lamotrigine side effects are more common and mild. Others are more rare but can be severe.

Lamotrigine side effects at a glance

Some of the more mild lamotrigine side effects include:

• Dizziness

• Headache

• Blurry or double vision

• Nausea

• Sleepiness or trouble sleeping

• Stomach pain

• Diarrhea

• Clumsiness

• Tremor

• Nasal congestion

• Weight loss

• Anxiety

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However, some lamotrigine side effects are considered more serious and warrant a call to your doctor’s office. In severe cases, you may need to seek emergency care. Some serious lamotrigine side effects include:

• Severe rashes

• Heart rhythm abnormalities (arrhythmias)

• Abnormal blood cell levels that can lead to infection, bleeding, and bruising

• Suicidal thoughts or behavior

• Aseptic meningitis

• Withdrawal seizures

Life-threatening allergic reactions to lamotrigine can also occur. Below, we’ll discuss 11 of the most important lamotrigine side effects to know about. But keep in mind, this is not an exhaustive list.

1. Dizziness and clumsiness

Dizziness and clumsiness are two of the most common side effects of lamotrigine. They’re more common with higher doses. Dizziness is less likely with lamotrigine XR, but it's still possible.

If you’re experiencing dizziness or clumsiness from lamotrigine, take your time when moving from a lying or sitting position to standing. This will help you avoid falls, which can be dangerous — especially in older adults. You should also avoid alcohol. Alcohol can make dizziness worse. Additionally, if you have bipolar disorder or seizures, alcohol can make these conditions worse.

It’s also a good idea to avoid other medications that worsen dizziness or increase the risk of falls. Examples include opioids, such as oxycodone (Oxycontin, Roxicodone) and benzodiazepines, such as alprazolam (Xanax). Talk to your healthcare team about whether your other medications can worsen dizziness.

When you first start lamotrigine, avoid doing activities or tasks that require alertness, like driving. Wait to see how lamotrigine affects you first. If your dizziness or clumsiness is severe or causing falls, let your prescriber know.

2. Blurry or double vision

Lamotrigine and lamotrigine XR may cause eye problems like double vision or blurry vision. Abnormal eye movements can happen as well. Eye problems are less likely to happen with lamotrigine XR, but it’s still one of the most common side effects.

Lamotrigine is one of the most common seizure medications to cause eye problems. So your prescriber may switch you to another seizure medication if you’re having eye issues. However, don’t stop taking lamotrigine without speaking to your prescriber first. Stopping lamotrigine abruptly can be dangerous.

3. Headache

Headaches are another common lamotrigine side effect. They’re less common with lamotrigine XR. But interestingly enough, lamotrigine may help some people who experience migraines with aura. 

If you’re experiencing headaches, you might find relief from an over-the-counter (OTC) pain reliever. Examples include acetaminophen (Tylenol) and ibuprofen (Advil, Motrin). Talk to your healthcare team about whether these OTC pain relievers are a good option for you. If your headache continues, your prescriber may recommend an alternative medication to lamotrigine.

4. Nausea and vomiting

Some people report nausea and vomiting while using lamotrigine. It’s more likely to happen with higher doses. It’s not as common with lamotrigine XR, but it still can happen.

You can take lamotrigine and lamotrigine XR with or without food. If you experience nausea, try taking it with food and eating smaller but more frequent meals throughout the day. Eating bland foods, like bananas, rice, and applesauce, may also help.

If your nausea continues beyond a few days after starting lamotrigine, talk to your prescriber. They may recommend medication to help with nausea. Or they may recommend an alternative to lamotrigine.

5. Sleepiness

Sleepiness can occur with lamotrigine products. But it’s less common with lamotrigine XR.

Like dizziness, combining alcohol and certain medications can worsen sleepiness. It’s best to avoid combining lamotrigine with other medications and substances that cause drowsiness. This includes:

• Opioids like hydrocodone / acetaminophen

• Benzodiazepines like lorazepam (Ativan)

• Muscle relaxers like cyclobenzaprine (Amrix)

• Some OTC antihistamines like diphenhydramine (Benadryl)

If you’re taking lamotrigine XR, you can try taking your dose at night if you experience sleepiness. But since lamotrigine is usually taken twice a day, taking it in the morning may be unavoidable. If lamotrigine is causing extreme drowsiness, talk to your healthcare team. 

Good to know: Some people who take lamotrigine and lamotrigine XR may also experience trouble sleeping (insomnia). If that’s the case, try to avoid taking your lamotrigine product within a few hours of your bedtime.

6. Rash

Lamotrigine and lamotrigine XR can cause rashes. Often, these aren’t serious. But in rare cases, rashes from lamotrigine products can be life-threatening. And it’s hard to tell when a lamotrigine rash is serious, since mild rashes can become severe very quickly.

Lamotrigine has a black box warning for severe rashes. Rashes may be associated with various reactions to lamotrigine, including:

• Angioedema, which may present as a swollen face, lips, and tongue

• Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome may involve high fever, swollen lymph nodes, and organ damage

• Stevens-Johnson syndrome (SJS) may appear as a blistering, painful rash with flu-like symptoms

• Toxic epidermal necrolysis (TEN) appears as flu-like symptoms and a rash that covers more than 30% of your body’s surface

These rashes usually occur within 2 to 8 weeks of starting lamotrigine. But a rash can even occur after you’ve been taking lamotrigine for many months. They're more common in children than adults. They’re also more common if you:

• Take lamotrigine with Depakene (valproic acid) or Depakote (divalproex sodium) 

• Take a dose of lamotrigine that’s too high

• Increase your lamotrigine dose too quickly

If you experience a rash (even if it seems mild), contact your prescriber immediately. You may need to stop taking lamotrigine. If you experience any serious symptoms, like a painful rash, blisters, or trouble breathing, seek immediate medical attention.

7. Suicidal thoughts or behavior

In 2008, the FDA conducted a study on 11 seizure medications (including lamotrigine). The study showed that seizure medications may increase the risk of suicidal thoughts and behavior. However, this study grouped all seizure medications together. So it’s difficult to know the true risk of lamotrigine specifically.

Still, all seizure medications carry a warning for increased suicidal thoughts and behaviors. So it’s important to watch out for this. If you have unusual mood changes, or you feel more depressed after starting lamotrigine, let your prescriber know immediately.

If you or someone you know is having thoughts of suicide, you’re not alone, and help is available. Call the 988 Suicide & Crisis Lifeline at 988, or text HOME to 741-741 to reach the Crisis Text Line.

8. Irregular heart rhythm

Lamotrigine products can cause irregular heart rhythms (arrhythmias). If you have a history of heart problems, like an existing arrhythmia, heart failure, or heart disease, lamotrigine may not be the best medication for you. However if your healthcare team thinks you need it, they’ll likely monitor your heart function more closely.

Taking certain medications with lamotrigine can also make arrhythmias more likely. Examples include other seizure medications like phenytoin (Dilantin, Phenytek) and carbamazepine (Tegretol, Carbatrol). Heart medications can also cause this interaction. Examples include flecainide and propafenone.

Let your prescriber know if you have a heart condition before starting lamotrigine. And make sure they know what other medications you take. They can let you know whether it's safe to take lamotrigine.

9. Low blood cell levels

Lamiotrigine can lower the levels of certain blood cells. This includes white blood cells, which are part of the body’s immune system. It also includes platelets, which help your blood clot after an injury. This could lead to unexpected bruising or bleeding.

Sometimes, low blood cell levels may be associated with DRESS syndrome. Along with abnormal blood tests, it’s often characterized by fever, rash, and swollen lymph nodes.

Your healthcare team will likely monitor your blood cell levels recurrently throughout treatment with lamotrigine. If you experience a fever that won’t go away or unusual bleeding or bruising, let your prescriber know.

10. Aseptic meningitis

Aseptic meningitis is a rare condition where the layers around your brain (meninges) become inflamed. Possible symptoms include fever, nausea, and headache. You may also have a stiff neck, rash, and sensitivity to light. It can occur right when you start taking lamotrigine, but it could also occur 1 to 2 months afterwards. 

Usually, stopping lamotrigine resolves aseptic meningitis symptoms. If you’re experiencing symptoms of aseptic meningitis, let your prescriber know immediately. If the symptoms seem severe, call 911 or go to the nearest ER.

11. Withdrawal seizures

Abruptly stopping lamotrigine can increase your risk of seizures. These are called withdrawal seizures. This can happen even if you’re taking lamotrigine for something other than seizures (like bipolar 1 disorder).

If your prescriber recommends stopping lamotrigine at any point, they’ll usually lower your dose slowly over a couple of weeks. Don’t reduce your dose more quickly than recommended. And don’t stop taking it on your own.

Good to know: There are some reports of lamotrigine causing new or worsening seizures in some people — but this is rare. Talk to your prescriber if you experience worsening seizures while taking lamotrigine.

When should you contact your healthcare team about lamotrigine side effects?

If you experience any lamotrigine side effects that don’t improve within a few weeks, contact your doctor’s office. They’ll evaluate your symptoms to determine whether they’re likely caused by lamotrigine or something else. They may lower your dose or switch you to another medication altogether, if necessary. But don’t make any changes to your lamotrigine dosage without talking to your prescriber first. Stopping lamotrigine abruptly can lead to withdrawal seizures, especially if you’ve been taking it for a while.

If you experience symptoms that may be severe, like a rash, high fever, or trouble breathing, seek emergency care.

Good to know: Lamotrigine interacts with several medications. This can increase your risk of experiencing side effects. Give your prescriber and pharmacist a complete list of the medications and OTC products you take so they can check for interactions.

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Written by:

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP, has over a decade of experience as a pharmacist, professor, and researcher. She was a full-time clinical professor in the pharmacy practice department at D’Youville School of Pharmacy before subsequently joining the faculty of the pharmacy practice department at the University at Buffalo School of Pharmacy and Pharmaceutical Sciences.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Stacia Woodcock, PharmD

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.

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