Potential Side Effects and Risks of Tegretol

Tegretol (carbamazepine) is an anticonvulsant sometimes prescribed as a mood stabilizer in bipolar disorder. Bipolar disorder is a mental health condition that involves extreme shifts in mood, thoughts, and behavior.

People with bipolar disorder experience mania or hypomania and periods of depression. Symptoms of mania can include elevated mood, grandiose behavior, impulsivity, and racing thoughts, while depression can involve symptoms such as fatigue, low mood, and loss of interest. Tegretol can treat manic, hypomanic, or mixed episodes of bipolar disorder. It lowers the excitability of nerve receptors that affect mood and motivation.

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.

This article discusses the most common Tegretol side effects and the more serious ones that may occur. It also covers tests you may need before you take this medication to prevent potential severe side effects.

Most Common Tegretol Side Effects

The most common side effects while taking Tegretol are:

• Dizziness
• Drowsiness
• Unsteadiness
• Nausea
• Vomiting

Such side effects tend to be more intense when you start taking the medication but may decrease with time as your body adjusts to the drug. Talk with your doctor if these side effects are persistent or bothersome.

Potential for Severe Skin Rash

One rare side effect of Tegretol described in case reports 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 for a person on Tegretol to follow up frequently with their doctor for periodic skin checks.

Potential for Bone Marrow Problems

Other potential rare but serious side effects of Tegretol are aplastic anemia and agranulocytosis. These reactions involve the 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 for include:

• Easy bruising
• Swollen lymph nodes
• 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. Your urine and a kidney blood test will be checked.

Heart problems, especially heart block, are other potential severe reactions. 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.

What to Tell Your Doctor

Be sure and tell your doctor all of your medical conditions and problems. Some may mean that you cannot take Tegretol or need to be monitored more closely.

It's important to provide your doctor with a list of all your medications, including prescriptions, over-the-counter medications, herbals, vitamins, and supplements. Some may interact with Tegretol and require your Tegretol dose to decrease or increase.

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.