Potential Side Effects and Risks of Tegretol

Woman reading the label on a medication bottle

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Tegretol, generic name carbamazepine, is an anticonvulsant that is sometimes prescribed as a mood stabilizer in bipolar disorder. In addition to seizures and bipolar disorder, it's also prescribed for pain relief in trigeminal neuralgia.

Most Common Tegretol Side Effects

The most common side effects that occur while taking Tegretol, especially when a person initiates it, are dizziness, drowsiness, unsteadiness, nausea, and vomiting. Talk with your doctor if these side effects are persistent or bothersome. Also, if you experience drowsiness, it's important to discuss driving with your doctor or other activities that could be dangerous if you are not fully alert.

Potential for Severe Skin Rash

One rare side effect of Tegretol is a serious and potentially fatal skin reaction called Stevens-Johnson syndrome and/or toxic epidermal necrolysis. This serious skin rash usually occurs within the first few months of taking Tegretol.

People of Asian ancestry who carry a certain gene called the HLA-B*1502 allele may be at an increased risk for developing this skin rash. This is why before taking Tegretol, certain patients (those with ancestry in populations where the gene may be present) will need to undergo a screening genetic blood test.

That being said, an absence of the gene doesn't mean a person cannot develop a serious rash. Likewise, having the gene doesn't mean a person will absolutely develop a severe rash. This is why it's critical a person on Tegretol to follow-up frequently with their doctor for periodic skin checks.

Potential for Bone Marrow Problems

Another two potential rare but serious side effects of Tegretol are aplastic anemia and agranulocytosis. These reactions involve depression of a person's bone marrow, which is where infection-fighting cells (white blood cells), blood-making cells (red blood cells) and blood-clotting cells (platelets) are produced.

Some signs of bone marrow depression to watch out include easy bruising, swollen lymph nodes, or the presence of tiny red dots (petechiae) on your body—a sign that you are bleeding into your skin. To monitor for bone marrow problems, your doctor will check your blood cell counts before and during treatment with Tegretol.

Other Health Concerns

Liver dysfunction may also occur on Tegretol so a blood test of your liver function will be drawn prior to starting Tegretol and at regular intervals. Signs of liver dysfunction that a person on Tegretol should watch out for include yellowing of the skin, nausea or vomiting, or a loss of appetite. Kidney problems can also occur with Tegretol. So like your liver, your urine and a kidney blood test will be checked.

Heart problems, especially heart block, is another potential severe reaction—it's important to tell your doctor if you have ever had an abnormal electrocardiogram (ECG). Finally, eye changes may occur with Tegretol, so an eye exam is warranted before starting Tegretol and periodically when on it.

Like other anticonvulsants, Tegretol may increase a person's risk of suicidal thinking and behavior. Be sure to seek emergent medical attention if you or a loved one's mood or behavior is changing and concerning while on Tegretol.

What to Tell Your Doctor

Be sure and tell your doctor all of your medical problems, as some may mean that you cannot take Tegretol or need to be monitored more closely while taking it. In addition, it's important to provide your doctor with a list of all your medications—this includes prescriptions, over-the-counter medications, herbals, vitamins, and any supplements. Some may interact with Tegretol and require that your Tegretol dose is decreased or increased.

It's also wise to inform your doctor if you drink alcohol and be candid about the amount and frequency. You will need to be more careful about alcohol intake while taking Tegretol and may need to cut down.

Bottom Line

In addition to seizures and trigeminal neuralgia, Tegretol is sometimes prescribed for people who are bipolar, either alone or in combination with other medications.

While there are some risks and side effects to watch out for when taking Tegretol, the good news is that studies show this medication to be effective and generally well-tolerated in people with bipolar disorder. So if you are prescribed Tegretol, you are already doing the right thing by being informed. Remain an advocate for your health safety.​​​

6 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.
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  3. Ferrell PB, Mcleod HL. Carbamazepine, HLA-B*1502 and risk of Stevens-Johnson syndrome and toxic epidermal necrolysis: US FDA recommendations. Pharmacogenomics. 2008;9(10):1543-6. doi:10.2217/14622416.9.10.1543

  4. Daughton JM, Padala PR, Gabel TL. Careful monitoring for agranulocytosis during carbamazepine treatment. Prim Care Companion J Clin Psychiatry. 2006;8(5):310-1. doi:10.4088/pcc.v08n0510a

  5. Koutsampasopoulos K, Zotos A, Papamichalis M, Papaioannou K. Carbamazepine induced atrial tachycardia with complete AV block. Hippokratia. 2014;18(2):185-6.

  6. Chen CH, Lin SK. Carbamazepine treatment of bipolar disorder: a retrospective evaluation of naturalistic long-term outcomes. BMC Psychiatry. 2012;12:47. doi:10.1186/1471-244X-12-47

Additional Reading
  • Chen C-H & Lin S-K. Carbamazepine treatment of bipolar disorder: a retrospective evaluation of naturalistic long-term outcomes. BMC Psychiatry. 2012;12:47.
  • Novartis (2009). Tegretol
  • Weisler RH. Carbamazepine extended-release capsules in bipolar disorder. Neuropsychiatr Dis Treat. 2006 Mar;2(1):3-11. 

By Marcia Purse
Marcia Purse is a mental health writer and bipolar disorder advocate who brings strong research skills and personal experiences to her writing.