Trileptal Side Effects in Bipolar Disorder

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Trileptal (oxcarbazepine) is an anti-seizure medication that is sometimes used as a mood stabilizer to treat bipolar disorder—although its effectiveness for this is still somewhat unclear. Trileptal is in a category of drugs known as anticonvulsants. Mood stabilizers work by reducing abnormal activity in the brain, according to the National Institute of Mental Health.

Like any medication, there are potential side effects. Let's review them so you feel prepared if you're starting Trileptal.

Trileptal Side Effects

Common Side Effects

According to the Food and Drug Administration (FDA), common side effects of Trileptal include:

  • Dizziness
  • Sleepiness
  • Double vision or other problems with vision
  • Feeling tired
  • Nausea and/or vomiting
  • Problems with walking or coordination
  • Trembling
  • Rash

In a 2011 review study in the Cochrane Database of Systematic Reviews on the use of Trileptal in people with bipolar disorder, the most frequent side effects reported were dizziness, sedation, and blurry vision.

Serious Side Effects

There are some serious side effects of Trileptal you should know about if you are taking or considering taking the medication.

Tell your doctor or seek urgent care immediately if you experience any of these serious side effects of Trileptal.

Trileptal can cause the sodium in your blood to be low, which is a condition called hyponatremia. It seems that people are most at risk of developing low sodium in their blood in the first 12 weeks of taking Trileptal. According to the FDA, symptoms of hyponatremia include:

  • Nausea
  • Low energy
  • Headache
  • Confusion
  • Seizures

Another potential serious side effect is an allergic reaction. Serious and potentially fatal rashes can occur as a result of taking Trileptal, like Stevens-Johnson syndrome and toxic epidermal necrolysis. Symptoms of an allergic reaction may include:

  • Rash
  • Swelling of the face, eyes, lips, or tongue
  • Problems breathing

Trileptal can also affect the liver and blood cells. Symptoms or signs of these side effects may include:

  • Yellowing of the skin or eyes
  • Unusual bruising or bleeding
  • Severe fatigue or weakness
  • Severe muscle pain
  • Frequent infections or infections that don't go away

Finally, similar to other anti-seizure medications, Trileptal may lead to thoughts or actions of suicide. This side effect is rare, occurring in about 1 in 500 people, according to the FDA. If you notice any changes in your mental health, mood, or thoughts, reach out to your healthcare provider.

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 1-800-273-8255 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

Oxcarbazepine vs. Carbamazepine

Trileptal (oxcarbazepine) is an analog to Tegretol (carbamazepine), meaning they share a similar chemical structure. Both are anti-seizure medications and Tegretol (carbamazepine) is also used sometimes to treat bipolar disorder.

Many people who are allergic to carbamazepine have reactions to oxcarbazepine as well, so be sure to tell your doctor if you're allergic to carbamazepine.

While they have similar side effect profiles, there are some subtle differences, according to the 2011 Cochrane review. For instance, a rash is less common with oxcarbazepine than with carbamazepine. Also, hyponatremia may be more common in people who take oxcarbazepine versus carbamazepine, especially if that person is older and has a low blood sodium level at baseline.

Notably, a 2020 study published in Yonsei Medical Journal found a lower incidence of more severe adverse side effects in those who took oxcarbazepine versus carbamazepine.


There are some important warnings you should know about before and while taking Trileptal. Remember to speak with your doctor about how to approach each of these situations so you can take the medication as safely as possible.

  • Stopping the medication: Don't suddenly stop taking Trileptal without consulting a physician as that could worsen seizures in those with epilepsy. Also, missing doses may result in a relapse of symptoms in bipolar disorder.
  • Birth control: Hormonal contraceptives may not be as effective while you're taking Trileptal.
  • Pregnancy: If you are pregnant or become pregnant, it's important to speak to your doctor as Trileptal could be harmful to an unborn baby. It can also end up in breast milk, so you and your doctor will need to weigh the risks and benefits of nursing and taking Trileptal.
  • Driving: Since Trileptal can cause drowsiness, dizziness, and other side effects that could be dangerous, be cautious about driving. Refrain from doing so until you're familiar with how the medication affects you.
  • Alcohol and other drugs: Similarly, using alcohol and other depressant drugs while taking Trileptal may exacerbate side effects such as drowsiness.
  • Other medications: Trileptal can interact with other medications, so always be sure to tell your doctor what else you're taking. Trileptal may decrease levels of certain blood pressure medications, medications to prevent organ transplant rejection, and oral contraceptives, and may increase the levels of certain seizure medications.
  • Mental health: If you notice changes in your mood and mental health while taking Trileptal—such as depression, anxiety, or irritability—reach out to your healthcare provider. A potential serious side effect of taking the medication is suicidal thoughts or actions.

A Word From VeryWell

First and foremost, never start or stop a medication without discussing the risks and benefits with your physician. Also, be sure to follow up with your physician once you are prescribed a medication to talk about any side effects and how well the medication is working for you.

It's also important to know that other side effects not listed above may occur in some people. This is not intended to be an all-inclusive list or to replace information provided by your personal doctor. If you notice any other side effects or have any concerns when taking Trileptal, please check in with your doctor.

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4 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute of Mental Health. Mental health medication: Mood stabilizers. Revised October 2016.

  2. Vasudev A, Macritchie K, Vasudev K, Watson S, Geddes J, Young AH. Oxcarbazepine for acute affective episodes in bipolar disorder. Cochrane Database Syst Rev. 2011;(12):CD004857. doi:10.1002/14651858.CD004857.pub2

  3. Lee JE, Min KR, Kim SH, Kim AH, Kim ST. Analysis of adverse drug reactions with carbamazepine and oxcarbazepine at a tertiary care hospital. Yonsei Med J. 2020;61(10):875-879. doi:10.3349/ymj.2020.61.10.875

  4. National Alliance on Mental Illness. Oxcarbezapine. Updated June 2019.

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