What are the side effects of taking oxcarbazepine?

October 11, 2025 •

3 min read

As an effective medication for controlling partial seizures, oxcarbazepine is prescribed to many patients, but it's important to understand what are the side effects of taking oxcarbazepine, as these can range from mild to severe. While many individuals experience only minor issues, vigilance for serious reactions is crucial.

Quick Summary

Oxcarbazepine can cause side effects ranging from common issues like dizziness and nausea to rare but severe reactions such as low sodium, severe skin rashes, and mood changes, requiring close medical supervision.

Key Points

Common Side Effects: Oxcarbazepine frequently causes mild-to-moderate side effects such as dizziness, drowsiness, headache, nausea, and double vision, particularly at the start of treatment.
Severe Skin Reactions: Rarely, oxcarbazepine can trigger severe skin conditions like Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), a risk that is higher in individuals with the HLA-B*1502 gene, particularly those of Asian descent.
Hyponatremia Risk: The medication can lead to low sodium levels in the blood (hyponatremia), with serious cases potentially causing confusion, increased seizures, or severe weakness.
Suicidal Thoughts: There is a documented risk of suicidal thoughts and behaviors with antiepileptic medications like oxcarbazepine, and any changes in mood or behavior should be reported immediately.
Drug Interactions: Oxcarbazepine can reduce the effectiveness of hormonal birth control and increase drowsiness when combined with other CNS depressants.
Population-Specific Effects: Children may experience more significant weight gain, while older adults face a higher risk of side effects like low sodium and falls.

Common Side Effects

Many common side effects affect the central nervous system, often improving with time. Caution is advised with activities requiring alertness until you know how the medication affects you.

Dizziness and Drowsiness: Frequent side effects that can impact balance.
Vision Problems: Double or blurred vision and uncontrolled eye movements can occur.
Gastrointestinal Issues: Nausea, vomiting, and stomach pain are common. Taking with food may help.
Headaches: A commonly reported effect.
Difficulty with Concentration: Issues with focus and language may arise.
Tremor: Involuntary shaking can occur.

Serious and Potentially Life-Threatening Side Effects

Serious side effects are less common but require immediate medical attention.

Hyponatremia (Low Sodium)

Oxcarbazepine can cause low blood sodium, which can be severe. Risk may be higher in older adults or those taking diuretics. Symptoms include headache, confusion, nausea, vomiting, weakness, and increased seizures.

Severe Skin Reactions

Rare but serious reactions like Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) can occur. These start with flu-like symptoms followed by a severe rash. A genetic factor (HLA-B*1502 allele), more common in people of Asian descent, increases this risk.

Multi-Organ Hypersensitivity (DRESS)

This rare allergic reaction can affect organs like the liver and kidneys. Symptoms may include fever, rash, swollen glands, and organ damage signs.

Suicidal Thoughts and Behaviors

Oxcarbazepine, like other antiepileptics, may increase suicidal thoughts risk. Report any new or worsening mood changes immediately.

Blood Disorders

Rarely, serious blood disorders can occur. Report unexplained bruising, bleeding, signs of infection, or unusual fatigue.

Oxcarbazepine Side Effects by Population

Children

Children may experience more significant weight gain and somnolence.

Older Adults

Older adults may be more sensitive to side effects like hyponatremia and dizziness due to reduced kidney function, increasing fall risk.

Comparison of Oxcarbazepine Side Effects


Feature	Common Side Effects	Serious Side Effects
Frequency	Very common (e.g., dizziness, somnolence)	Rare (e.g., severe rash, blood disorders)
Onset	Often occur early in treatment	Can be delayed, occurring weeks or months after starting
Severity	Generally mild to moderate	Potentially life-threatening; require immediate medical intervention
Symptoms	Dizziness, fatigue, double vision, nausea, headache, unsteadiness	Severe rash, fever, blisters, low sodium (confusion, headache), suicidal thoughts, multi-organ reactions

Managing and Monitoring Side Effects

Follow Dosage Instructions: Stick to your prescribed dose. Dosages may need adjustment for certain populations.
Do Not Stop Abruptly: Sudden discontinuation can increase seizure risk. Consult your doctor before making changes.
Stay Alert for Symptoms: Report any unusual symptoms, especially rash or signs of low sodium, to your doctor immediately.
Use Caution with Other Substances: Avoid alcohol. Inform your doctor of all other medications.
Consider Genetic Testing: For individuals of Asian descent, testing for the HLA-B*1502 allele may be recommended to assess severe skin reaction risk.

Conclusion

Understanding what are the side effects of taking oxcarbazepine is crucial. While common effects are usually manageable, vigilance for serious reactions like severe skin rashes and hyponatremia is necessary. Communicate openly with your healthcare provider to manage risks and ensure safe treatment. For additional information on oxcarbazepine, consult the official FDA product label.

Frequently Asked Questions

While oxcarbazepine can be associated with weight gain in a minority of patients, it appears to be a more significant concern in children than in adults, where it is less common.

Yes, oxcarbazepine can cause a rash. While some rashes may be mild, others can be symptoms of rare but life-threatening conditions like Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Any new rash should be reported to a doctor immediately.

Symptoms of low sodium (hyponatremia) can include headache, confusion, nausea, vomiting, unusual fatigue, or a worsening of seizures. These symptoms should be reported to your doctor.

No, you should not stop taking oxcarbazepine abruptly. Doing so can increase the risk of more frequent or severe seizures. Any discontinuation of the medication should be done gradually under a doctor's supervision.

If you experience dizziness, avoid activities that require alertness, like driving or operating machinery, until you know how the medication affects you. If the dizziness is severe or persistent, contact your healthcare provider, as a dosage adjustment may be necessary.

Yes, oxcarbazepine can make hormonal contraceptives, including birth control pills, less effective. If you use hormonal birth control, you should discuss alternative or additional contraception methods with your doctor.

Serious side effects like Stevens-Johnson syndrome (SJS) are rare, but their potential severity means they should not be ignored. The risk can be higher in individuals with the HLA-B*1502 gene allele, more common in some Asian populations.