Carbamazepine Side Effects
A few common side effects of carbamazepine include drowsiness, unsteadiness, and vomiting. Some of the less common side effects include hair loss, dry mouth, and blurred vision. While side effects of this drug are usually minor, certain ones are more serious and may need medical attention. Notify your healthcare provider immediately if you experience unusual bleeding or bruising, hallucinations, or an irregular heart rhythm.
As with any medicine, side effects are possible with carbamazepine (Carbatrol®, Epitol®, Equetro®, Tegretol®). However, not everyone who takes the medication will experience side effects. In fact, most people tolerate it quite well. If carbamazepine side effects do occur, in most cases, they are minor and either require no treatment or are easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with carbamazepine. Your healthcare provider can discuss a more complete list of carbamazepine side effects with you.)
Some side effects with carbamazepine, while occurring infrequently, are potentially serious and should be reported immediately to your healthcare provider. These include but are not limited to:
- Anemia or other blood disorders
- Unusual bruising or bleeding
- Worsening of seizures
- Suicidal thoughts or behaviors
- Increased infections or infections that do not go away
- Water retention, swelling, or difficulty breathing, which can be signs of congestive heart failure (CHF)
- High blood pressure (hypertension) or low blood pressure (hypotension)
- An irregular heart rhythm (arrhythmia)
- Yellowing of the whites of the eyes or skin (jaundice), which may be a sign of liver damage, including liver failure or hepatitis
- Difficulty passing urine or a sudden, unexplained decrease in urine production (which can be a sign of kidney damage)
- Low sodium levels in the blood (hyponatremia), which may cause symptoms such as:
- Loss of appetite
- Nausea or vomiting
- Excessive tiredness
- Muscle weakness
- Muscle spasms or cramps
- Signs of an allergic reaction, including:
- An unexplained rash
- Unexplained swelling
Suicidal thinking or behavior (see Seizure Medications and Suicide).
Rarely, carbamazepine can cause very dangerous skin reactions known as Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). These problems start out as skin rashes but can progress to permanent disfigurement or even loss of life. Not every skin rash in people taking carbamazepine will be related to SJS or TEN. However, because of the seriousness of such problems, it is recommended that people stop taking carbamazepine immediately at the first sign of a rash, unless it is very clear that the rash is not related to carbamazepine. In most (but not all) cases, SJS and TEN reactions occur within the first month of starting carbamazepine.
Interestingly, SJS and TEN reactions to carbamazepine are much more common in people of Asian descent, who are more likely to have a specific gene (known as HLA-B*1502) that appears to increase the risk of such problems. If you are of Asian descent, your healthcare provider may choose to test for the gene before recommending carbamazepine for you.