Lamotrigine (Lamictal®)

This article provides a comprehensive overview of lamotrigine, including how it works, its indications, side effects, drug interactions, and other important information.

Key Takeaways:

• Lamotrigine is an anti-seizure medication approved to treat various types of seizures, as well as bipolar disorder. It works by calming excessive activity in the brain and nervous system.

• Lamotrigine has many possible side effects, such as sleepiness, headache, pain, and dizziness. Severe side effects are possible, including rare but potentially life-threatening rashes.

• Lamotrigine has several possible drug interactions and may be unsuitable for pregnant women, and individuals with various mental or physical conditions. Your doctor will determine if lamotrigine is safe and effective for you.

Understanding Lamotrigine

Lamotrigine is an anti-seizure medication. It was initially approved for use in the United States in 1994, and has been used to treat different types of seizures. It is only available as a prescription. ^[1]

More recently, lamotrigine has also shown effectiveness as a mood stabilizer, and may help treat various mood-related disorders, such as bipolar disorder. ^[2]

How it Works

Lamotrigine likely works through several mechanisms. For one, it seems to control excessive brain activity, in part by inhibiting glutamate and aspartate, which are excitatory neurotransmitters. This provides calming effects that help to control seizures and attenuate rapid mood swings within bipolar disorder. ^[1]

In addition, lamotrigine may also help balance levels of serotonin, dopamine, and noradrenaline, which may offer antidepressant effects for individuals with bipolar disorder. ^[2]

Lamotrigine Brand Names

The most common brand name of lamotrigine is Lamictal®, which is in tablet form. There are also other forms of this drug, including: ^[3]

• Lamictal® CD: Chewable dispersables

• Lamictal® ODT: Orally disintegrating tablets

• Lamictal® XR: Extended-release tablets

What is Lamotrigine Used For?

Lamotrigine is FDA-approved for the following conditions:

• Epilepsy

• Bipolar disorder

Within epilepsy, lamotrigine is approved as an adjunctive treatment for individuals aged 2 years and older for: ^[4]

• Partial seizures

• Primary generalized tonic-clonic seizures

• Generalized seizures of Lennox-Gestaut syndrome

Lamotrigine can also be used on its own for epilepsy in individuals aged 16 years and older who are transitioning off of another anti-epileptic drug, such as carbamazepine or phenytoin. ^[4]

Regarding lamotrigine for bipolar disorder, it is approved as a maintenance treatment for individuals aged 18 years and older. It is designed to help increase the time between major mood episodes within bipolar disorder, such as mania and depression. ^{[3] [4]}

There are also several off-label lamotrigine uses, including for: ^[1]

• Rapid-cycling bipolar depression

• Panic disorder

• Binge eating disorder

• Trigeminal neuralgia

• Migraines

• Schizoaffective disorder

• Schizophrenia

Lamotrigine Side Effects

There are many possible side effects of lamotrigine. Some may diminish or resolve completely as your body adjusts to the medication, while others may not get better over time. Always talk with your doctor if you notice any side effects when taking lamotrigine, especially when you first start taking it and if your dose is changed.

The most common side effects of lamotrigine are: ^[4]

• Dizziness

• Headache

• Nausea

• Blurred vision

• Sleepiness

• Rash

• Runny nose

• Diplopia (double vision)

• Ataxia (poor muscle control that causes clumsy movements)

• Insomnia

• Back pain

• Fatigue

• Stomach pain

• Dry mouth

Other relatively common lamotrigine side effects include: ^{[1] [3] [4] [5]}

• Vomiting

• Fever

• Tremors

• Edema

• Weight changes

• Constipation

• Weakness

• Anxiety

• Irritability

• Difficulty thinking or concentrating

• Hearburn

• Loss of appetite

• Abnormal dreams

• Sore throat

Dangerous and Rare Side Effects

There are also several rare, but potentially dangerous or life-threatening side effects with lamotrigine. For example, lamotrigine is documented to cause serious rashes that may require hospitalization, such as Stevens-Johnson syndrome and toxic epidermal necrosis. Severe cases have led to rash-related death. This risk is significantly higher in children than adults. ^{[1] [4]}

Other potential severe lamotrigine side effects include:

• Acute multiorgan failure (which can be fatal)

• Severe allergic reactions (anaphylaxis): Includes several symptoms, such as:

• Swelling of the face, throat, tongue, lips, or eyes

• Difficulty breathing or swallowing

• Seizures

• Unusual bleeding or bruising

• Blood dyscrasias (various disorders that affect the blood), such as:

• Neutropenia

• Thrombocytopenia

• Agranulocytosis

• Pancytopenia

• Suicidal behavior or ideation

• Infection, which has many signs, such as:

• Fever

• Chills

• Coughing

• Pink eye

• Ear pain

• Painful urination

• Aseptic meningitis: A serious condition involving inflammation of the meninges. Symptoms include:

• Headache

• Fever

• Stiff neck

• Light sensitivity

• Chills

• Confusion

• Muscle pain

• Impaired liver function

• Heart rhythm abnormalities (e.g. rapid heart rate, skipped heart beat)

This list may not contain all possible side effects. Contact your doctor as soon as possible if you notice signs of any of these more severe side effects.

Discontinuing Therapy

Suddenly stopping lamotrigine increases the risk of worsening seizures. Stopping lamotrigine may also cause your mood symptoms to return or worsen. This may cause anxiety, irritability, depression, insomnia, agitation, and headache, among other symptoms.

If your doctor determines that you should stop taking lamotrigine, they will gradually taper you off the medication over a period of at least 2 weeks. ^[4]

Precautions

There are several important precautions to be aware of with lamotrigine. Always talk with your doctor before starting lamotrigine, especially if you have any of the following conditions or symptoms: ^{[3] [6]}

• Autoimmune disease

• Blood disorders

• Depression or other mood disorders

• Suicidal thoughts or actions

• Heart problems

• Kidney or liver disease

• Ascites (swelling of the stomach caused by liver disease)

In these situations, your doctor may prescribe a lower dose of lamotrigine or determine that it is not safe to use at all.

Lamotrigine is generally not recommended for nursing women. And while large studies show no clear increase in major birth defects, it should still only be used during pregnancy if the benefits outweigh the risks. ^{[3] [4]}

Lamotrigine should be used cautiously in children, since they have a greater risk of side effects. Lamotrigine is not approved for use in anyone under 18 for bipolar disorder. ^[4]

You should not use lamotrigine if you have an allergy or hypersensitivity to it.

Lamotrigine may cause dizziness or drowsiness, and may affect your ability to drive, operate machinery, or perform other mental or physical tasks. Do not engage in these activities until you know how lamotrigine affects you and you receive your doctor’s approval. ^[3]

Drug Interactions

Lamotrigine may interact with other drugs and medications. For example, it may interact significantly with other anti-seizure medications, such as: ^{[1] [4]}

• Valproate

• Carbamazepine

• Phenytoin

• Primidone

• Phenobarbital

Other possible drug interactions with lamotrigine include: ^{[1] [4] [5]}

• Oral estrogen-containing contraceptives

• Certain antibiotics (e.g. rifampin)

• Antipsychotics (e.g. aripiprazole, olanzapine)

• Certain antiviral medications (e.g. ritonavir, lopinavir)

This list does not contain all possible drug interactions with lamotrigine.

Other Interactions

Lamotrigine may interact with some herbs and supplements, especially those with a possibility of similar side effects, such as sleepiness, rash, or shaking.

You shouldn’t use alcohol or street drugs with lamotrigine, as this may increase sedation and other adverse effects, some of which may be serious or life-threatening.

Tell your doctor everything you take or have taken, including prescription and over-the-counter medicines, herbs, vitamins, and dietary supplements.

Lamotrigine Dosage

Lamotrigine is available in the following formulations: ^{[1] [5]}

• Oral tablets (25 mg, 100 mg, 150 mg, and 200 mg)

• Oral disintegrating tablets (25 mg, 50 mg, 100 mg, 200 mg)

• Chewable dispersables (2 mg, 5 mg ,and 25 mg)

• Extended-release tablets (25 mg, 50 mg, 100 mg, 200 mg, 250 mg, and 300 mg) .

All forms of lamotrigine are taken orally.

Common dosage recommendations for lamotrigine are as follows: ^[1]

• For seizures:

• Monotherapy

• Starting dose: 25 mg to 50 mg per day, which is gradually increased over several weeks

• Maintenance dose: 100 to 500 mg per day, in two divided doses

• For bipolar I disorder:

• Starting dose: 25 to 50 mg per day, which is gradually increased over several weeks

• Maintenance dose: 200 to 400 mg per day, in one or two doses

Risk of Overdose

Overdose on lamotrigine can lead to serious side effects, and it can be fatal in severe instances. Symptoms of lamotrigine overdose include: ^{[3] [4]}

• Increased seizures

• Irregular heartbeat

• Coma

• Loss of consciousness

• Loss of balance or coordination

• Double vision

• Uncontrollable eye movements

If an overdose is suspected, contact a poison control center or emergency medical line right away. Hospitalization is recommended to manage an overdose.

Lamotrigine FAQs

Listed below are frequently asked questions about the use of lamotrigine.

Does lamotrigine cause weight gain?

Lamotrigine may cause weight gain for some individuals. Some people may also experience weight loss, and others may have no weight changes.

Does lamotrigine make you tired?

Lamotrigine may make you tired or sleepy; this is a common side effect.

Is lamotrigine safe in pregnancy?

There are potential risks, though large studies show no clear increase in major birth defects. As always, caution should be exercised by the mother and the provider, but there may be certain circumstances where lamotrigine may be appropriate.