Is lamotrigine safe when used for seizures and bipolar disorder?

What is lamotrigine (Lamictal®) prescribed for?

Lamotrigine is prescribed for the treatment of epilepsy. It treats several types of seizures including tonic-clonic and partial seizures. It is prescribed for bipolar disorder where it acts to stabilize mood and prevent depression. It is more effective in preventing depression than acute manic episodes.

How does lamotrigine work?

During seizures, there is abnormal electrical activity in the brain. Lamotrigine reduces abnormal electrical activity by stabilizing nerve cell membranes and blocking sodium channels. Its effect on sodium channels decreases release of glutamate (an excitatory neurotransmitter) and stabilizes neuronal membranes so that it stabilizes mood in bipolar disorder.

What are the side effects of lamotrigine?

Common side effects include drowsiness, dizziness, headache, incoordination, tremor, tiredness, and blurred or double vision. Lamotrigine can also cause insomnia, irritability, agitation, vomiting, diarrhea, constipation, abdominal pain and decreased appetite. Some people report difficulty with speech and word recall, which is often temporary; this is sometimes called “lamotrigine brain” or “Lamictal fog”.

In 2020, a safety warning was placed on lamotrigine’s label regarding possible cardiac toxicity, especially in people with pre-existing heart disease. Serious allergic reactions include severe skin reactions and swelling of face, throat, and lymph nodes. Lamotrigine can cause serious overactive immune system reaction called hemophagocytic lymphohistiocytosis (HLH). Symptoms of this reaction include persistent fever, rash, fatigue, swollen glands, bleeding and possible damage to liver, kidneys, spleen, and lungs. Lamotrigine can also worsen depression, which can lead to thoughts of suicide.

Is lamotrigine a controlled substance?

No, lamotrigine is not a controlled substance. It is a prescription drug available as immediate release and extended-release tablets, chewable/dispersible tablets (chew or disperse in water or juice), orally disintegrating tablets, and an oral suspension. The brand name is Lamictal and it is also available in generic versions.  

What should I avoid while taking lamotrigine?

You should avoid alcohol and other CNS depressants because of the increased risk of drowsiness and dizziness. Also avoid driving or doing anything dangerous until you determine how this medication affects your coordination. There are potential drug and supplement interactions that can significantly lower  or raise lamotrigine levels in your blood. Examples of drugs that may interact with lamotrigine to lower lamotrigine blood levels include birth control pills, other anticonvulsants, guarana, and garcinia cambogia. Valproic acid and ginseng are examples of substances that interact to raise lamotrigine blood levels. Talk to your doctor or pharmacist, or use an online drug interaction checker such as this one before taking a new drug.

Although rare, lamotrigine can cause orthostatic hypotension, which means your blood pressure drops if you stand up quickly. Therefore, it is recommended to stand up slowly, so you don’t feel dizzy. You should also avoid stopping lamotrigine abruptly since this may cause seizures to return.

What should I do if someone accidentally takes lamotrigine or takes too much lamotrigine?

If someone unintentionally takes a dose of someone else’s lamotrigine or takes a double dose, severe toxicity is unlikely although there is increased risk of nausea, drowsiness, dizziness, and headache. Use the webPOISONCONTROL^® online tool to be sure the dose taken is safe. Overdoses of lamotrigine can cause more serious toxicity including drowsiness, abnormal gait, seizures, coma, decreased blood pressure, increased heart rate, abnormal electrocardiogram (prolonged QRS or QT interval, AV block), and abnormal eye movements (nystagmus). Immediate medical attention is needed.

If someone swallows lamotrigine or if you have a question about using lamotrigine safely, use the webPOISONCONTROL^® online tool to get help, or call your poison center at 1-800-222-1222. Whether online or by phone, expert guidance is always free, confidential, and available 24 hours a day.