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Lamotrigine side effects and how to avoid them

Lamotrigine is a generic prescription drug used to prevent certain types of seizures as well as treat bipolar I disorder and migraines

Lamotrigine side effects | Serious side effects of lamotrigine | How long do side effects last? | Warnings | Interactions | How to avoid side effects

Lamotrigine is a generic prescription drug primarily used to prevent certain types of seizures in people with epilepsy (including Lennox-Gastaut syndrome) as well as to help stabilize moods in people with bipolar I disorder. For both types of conditions, lamotrigine is used alone or combined with other antiepileptic or bipolar medications. 

Lamotrigine is sometimes used off-label to prevent migraines. Available also under the brand names Lamictal and Lamictal XR (an extended-release form of lamotrigine), lamotrigine works by slowing down nerve activity, making seizures and brain excitement less likely. Lamotrigine does have risks, however, so a careful review of side effects, drug interactions, restrictions, and other warnings will help people taking lamotrigine to manage these risks.

RELATED: Learn more about lamotrigine

Common side effects of lamotrigine

Because lamotrigine affects the nervous system, it can affect the entire body. The most common side effects of lamotrigine are:

  • Dizziness
  • Headache
  • Double vision
  • Loss of coordination
  • Blurred vision
  • Nausea
  • Sleepiness or insomnia
  • Weakness
  • Nasal congestion and runny nose
  • Sore throat
  • Skin rash
  • Vomiting
  • Back or abdominal pain
  • Fatigue
  • Dry mouth

Serious side effects of lamotrigine

Lamotrigine can cause serious side effects such as:

  • Seizure lasting longer than 5 minutes (status epilepticus)
  • Withdrawal seizures if the medication is stopped abruptly
  • Suicidal thoughts and behaviors
  • Worsening of depression
  • Aseptic meningitis (swelling of the membranes surrounding the brain)
  • Liver failure
  • Irregular heartbeat
  • Blood problems
  • Kidney problems
  • Immune system problems such as hemophagocytic lymphohistiocytosis and vasculitis
  • Severe or life-threatening hypersensitivity reactions including serious skin rash, Stevens-Johnson syndrome, angioedema, and toxic epidermal necrolysis

How long do side effects last?

Lamotrigine has a half-life of about 25 hours in healthy people, meaning it takes about 25 hours to clear half of the medication dose from the body. It takes about 4 to 5 half-lives to clear most of a drug from the body. Most temporary side effects, such as headache, dizziness, drowsiness, nausea, rash, and vision problems, then, will take about 4 to 5 days to fade after taking the last dose of lamotrigine. Some side effects may get better as the body adjusts to the medicine. The prescribing information states that lamotrigine should be discontinued at the first sign of rash unless the rash is definitely not related to the medication. This is because a rash caused by lamotrigine could be anywhere from mild to serious or life-threatening.

More severe side effects may require medical treatment to resolve, particularly meningitis, blood problems, immune system problems, severe allergic reactions, and status epilepticus. Many of these are life-threatening conditions that require immediate emergency medical care. Some conditions may have lifelong consequences.

Lamotrigine contraindications & warnings

Several red flags may prompt a healthcare provider to either avoid prescribing lamotrigine or doing so only cautiously. 

Abuse and dependence

The U.S. Food and Drug Administration (FDA) does not classify lamotrigine as a controlled substance. Although it has sedative effects, it is rarely used recreationally because of its high rate of side effects. 

Lamotrigine does not cause physical dependence, but sudden discontinuation of the drug may cause seizures even in patients taking lamotrigine for conditions other than epilepsy. When it’s time to stop lamotrigine, a healthcare provider will use a steadily tapering dose (over about 2 weeks) to prevent seizures.

Lamotrigine overdose

Depending on how much medicine is taken, an overdose of lamotrigine is a medical emergency and could be fatal. Symptoms of an overdose include:

  • Impaired coordination
  • Repetitive uncontrolled eye movements (nystagmus)
  • Blurred vision
  • Abnormal heartbeat
  • Seizures and convulsions
  • Reduced consciousness, fainting, or loss of consciousness
  • Coma

If there’s any sign or suspicion that too much lamotrigine has been taken, seek emergency medical care. 

Contraindications

Lamotrigine should never be taken by people who are allergic to the drug or any of its inactive ingredients. Any severe allergic or immunological reaction while taking lamotrigine will result in the drug being immediately discontinued.

Kidney or liver disease

People with significant renal or moderate to severe hepatic impairment may require a lower dose. People with mild liver impairment should be able to receive a normal dose. The prescribing information advises using lamotrigine with caution in patients with severe kidney impairment.

Heart problems

Because lamotrigine can change the heart’s rhythm, lamotrigine is used cautiously in people with heart failure, heart disease, heart rhythm problems, ischemic heart disease, heart conduction problems such as Brugada syndrome, ischemic heart disease, or who have risk factors such as coronary artery disease. Medically serious and potentially fatal changes in the heart’s rhythm are possible, so healthcare providers are very careful about using lamotrigine in these patients.

Depression

Lamotrigine can worsen depression and even provoke suicidality. Anyone taking lamotrigine, especially people with depression or a history of suicidality, will need to be monitored carefully by both healthcare professionals and caregivers for signs of increased depression, behavior changes, suicidal thoughts, and suicidal or risk-taking behaviors.

Pregnancy and breastfeeding

There is no evidence that taking lamotrigine during pregnancy will harm a fetus, but there is conflicting data between human and animal studies. Your healthcare provider can determine if lamotrigine is safe for you during pregnancy. Lamotrigine may decrease folate levels, so healthcare providers will suggest taking folic acid supplements.

Lamotrigine does pass into breast milk, so infants who are nursing may experience lamotrigine side effects such as rash, drowsiness, trouble breathing, reduced feeding, and poor weight gain. Infants may need to be monitored for side effects. Alternatively, nursing women may be asked to stop nursing while taking lamotrigine.

Children

Lamotrigine is FDA-approved as an add-on drug in children as young as 2 years old in treating partial-onset seizures, generalized seizures of Lennox-Gastaut syndrome, and primary generalized tonic-clonic seizures. It is not approved as a single therapy or as a treatment for any other condition in children or teens. Children taking lamotrigine are more likely to experience infections than adults. In addition, children taking lamotrigine experience a high rate (14%) of accidental injury, though accidental injury is not a common side effect among adults.

Seniors

People aged 65 years and older can be prescribed lamotrigine, but healthcare providers will typically start older patients with a low dose and monitor them carefully for side effects.

Lamotrigine interactions

Several drugs can affect lamotrigine or increase the risk of side effects.

Contraindications

Some drugs are never combined with lamotrigine because they significantly raise the risk of seizures. These contraindicated drugs include amifampridine, dalfampridine, Wellbutrin (bupropion), and metoclopramide.

Other drug interactions

Other drugs can be taken with lamotrigine, but the combination will be avoided if possible or the patient will need dosage adjustments or careful monitoring. These include:

  • Drugs such as birth control pills, female hormone replacements, ritonavir, and rifampin
  • Anticonvulsant drugs such as phenobarbital, phenytoin, primidone, and carbamazepine may be prescribed along with lamotrigine but careful dosage adjustments are needed by healthcare providers.
  • Antiepileptic drug Depakote (divalproex sodium). One or both medication dosages should be adjusted by a trained healthcare professional.
  • Central nervous system depressants such as alcohol, opioids, barbiturates, benzodiazepines, sedatives, migraine medications, antihistamines, muscle relaxants, SSRIs, and MAO inhibitors. While these drugs don’t have to be avoided outright, increased drowsiness and impairment may significantly affect day-to-day life.

How to avoid lamotrigine side effects

Unfortunately, most people taking lamotrigine will experience one or more side effects. Many of these side effects are minor and will improve as the body adjusts to the drug. Still, there are ways to minimize side effects or increase the benefits of taking lamotrigine.

1. Tell the healthcare provider about all medical conditions and medications

The first step in preventing side effects is to tell the healthcare provider prescribing lamotrigine about all medical conditions, especially:

  • Any history of a rash or skin reactions to other epilepsy medications
  • Any history of depression, mood problems, or suicidality
  • Any heart problems or heart rhythm problems
  • Any history of aseptic meningitis while taking lamotrigine
  • Kidney or liver disease
  • Pregnancy or pregnancy plans
  • Breastfeeding or plans to breastfeed

Some side effects are caused or worsened by combining lamotrigine with other prescription or over-the-counter drugs. Keep a list of all medications being taken and share it with the healthcare provider prescribing lamotrigine. They will especially need to know about oral contraceptives or female hormone replacement therapy.

2. Take lamotrigine as directed

Take lamotrigine exactly as instructed. The dose will vary depending on the condition being treated, underlying medical conditions, and other medications prescribed. For lamotrigine to work, doses must be taken every day. Don’t skip a dose. If prescribed orally disintegrating tablets, chewable tablets, or dispersible tablets, follow the instructions carefully. They are not taken in the same way as tablets. If there are any questions about these instructions, consult with a pharmacist or other healthcare provider.

3. Avoid alcohol

Lamotrigine makes many people sleepy and can cause other impairments such as loss of coordination, double vision, or other problems. Drinking and lamotrigine don’t mix well. Alcohol will worsen the impairment caused by lamotrigine and put people at an increased risk of injury or accident.

4. Be careful about driving and other risky activities

In many people, lamotrigine can cause drowsiness and vision problems. Side effects like sleepiness and double vision can make simple daily activities such as driving or operating machinery hazardous. In many cases, these side effects will lessen as the body adjusts to lamotrigine. Avoid driving or other risky activities until lamotrigine’s impairment effects are well-understood or have faded.

5. Drink fluids

If diarrhea is experienced, drink plenty of fluids to avoid dehydration.

6. Talk to a healthcare provider

You should immediately call a healthcare provider if you notice side effects such a:

  • Skin rash
  • Blistering
  • Hives
  • Mouth or eyesores
  • Fever
  • Stiff neck
  • Muscle pain

Some other side effects such as shaking or tremors may be a sign that the dose is too high. Talk to the doctor or other healthcare provider if you have these side effects or others such as sleep disruption or irritability. Dosing may need to be adjusted.

7. Watch for signs of heart problems

Lamotrigine can cause irregular heartbeats, so people taking lamotrigine should immediately contact a healthcare provider or seek emergency medical treatment at any sign of heart problems such as:

  • Fast or slow heartbeat
  • Chest pain
  • Shortness of breath
  • Lightheadedness

8. Do not stop taking lamotrigine

Going cold turkey with lamotrigine may cause seizures even if the drug is prescribed for another condition. If the drug does not seem to be working or, worse, the side effects are too hard to take, see a healthcare professional for medical advice. The safest way to stop taking lamotrigine is with a steadily tapering dose—over several weeks—supervised by a healthcare provider.

9. Inspect your medication each time you fill your prescription.

Although mixups are very rare, due to multiple formulations as well as other drugs that are sometimes confused with lamotrigine (due to look-alike or sound-alike drug names), it is a good idea to check your medication each time you fill your prescription. If the medication looks different than the previous refill, check with your pharmacist to make sure you received the correct drug. 

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