Carbatrol

What is carbamazepine?

Carbamazepine is an anticonvulsant medication that is available in extended release capsule and tablet, tablet, chewable tablet, and oral suspension and is taken once or more daily. It is only available by prescription from your doctor.

What is carbamazepine used to treat?

Carbamazepine is used to treat epilepsy, bipolar disorder, and trigeminal or glossopharyngeal neuralgia (nerve pain in the throat or tongue) as well as many off-label uses in infants, children, and adults. Epilepsy is a brain disorder characterized by abnormal brain activity that can cause seizures. 

How does carbamazepine work?

Carbamazepine works by decreasing activity and stimulation of excessive neural impulses in the brain. In addition to anticonvulsant effects, carbamazepine also has muscle relaxant, pain relief, and antidepressive effects. 

If I am taking carbamazepine, can it harm my baby?

The treatment of serious medical conditions such as epilepsy is recommended during pregnancy. Carbamazepine is not recommended during pregnancy unless it is needed. There have been human studies and case reports that have looked at the safety of this medication in pregnancy, finding the potential for an increased risk of birth defects such as spina bifida..

Evidence from animal studies with carbamazepine:

When given to pregnant rats at doses 10-25 the recommended human doses, there were reports of cleft palate, rib defects, clubfoot, and eye defects in the offspring. 

Evidence for the risks of carbamazepine in human babies:

One study including 220,000 babies exposed to carbamazepine during the first trimester found an increased risk of birth defects with exposure to this medication. Reported birth defects included heart and spinal defects. Other reports have noted brain, facial, abdominal, genital, and skeletal defects as well as poor growth, hip dislocation, esophageal or anal atresia (narrowing), underdeveloped fingernails, small head size, and abnormal neurologic development with first trimester exposure to carbamazepine and/or other anticonvulsants. A 2002 review of 21 studies found that while in utero carbamazepine exposure was associated with an increased risk of neural tube defects (defects of the spine and/or brain), heart defects, urinary tract defects, and cleft palate, the risk of birth defects was greater with combination anticonvulsant therapy. One study found a strong association between use of carbamazepine alone and spina bifida in developing babies. Combined anticonvulsant therapy during pregnancy is expected to raise the risk of birth defects in babies by 3-4 times the normal risk associated with single anticonvulsant use and 10 times the risk of the normal population. It is recommended to use only a single anticonvulsant medication to treat bipolar disorder or epilepsy during pregnancy. Increasing carbamazepine dose has also been associated with an increased risk of birth defects.

A study in 72 women (54 delivered babies) who took carbamazepine and/or another anticonvulsant medication in early pregnancy found the risk of having a baby with two birth defects was similar to the risk in a control group of pregnant women not on carbamazepine therapy. The risk of having a baby with three birth defects was greater in pregnant women exposed to carbamazepine. The authors of this study noted birth defects associated with carbamazepine exposure may occur in a triad of craniofacial defects, underdeveloped fingernails, and neurodevelopmental delay known as fetal carbamazepine syndrome). The association between carbamazepine and neurobehavioral delay or intelligence (IQ) has been challenged, with some studies finding no difference in intelligence scores in children exposed to carbamazepine in utero versus children without exposure. One study found a direct link between carbamazepine dose during pregnancy and verbal/non-verbal development in babies at 4 ½  years old. 

A study done in 2000 found that folic acid supplementation during pregnancy did not decrease the risk of birth defects in babies exposed to carbamazepine, a known antagonist of folic acid absorption. However, the American Academy of Neurology recommends 2.5 mg/day to 5 mg/day of folic acid supplementation in women on carbamazepine therapy. A 2001 cohort study of pregnant women exposed to single or multiple anticonvulsants found the risk of birth defects associated with these medications was due to the medication themselves and not the diagnosis of epilepsy in the pregnant women. The Lamotrigine Pregnancy Registry collected data on women exposed to lamotrigine or carbamazepine during pregnancy from 1997 to 2010. Of 180 babies exposed to either of these medications, researchers found that 157 babies had no birth defects, 10 miscarriages happened, 9 elective abortions, 1 fetal death, and 3 birth defects. 

Babies whose moms have taken carbamazepine during pregnancy have developed health problems, similar to neonatal withdrawal syndrome, upon delivery. The following is a list of some health problems that have been reported in babies exposed to carbamazepine. 

• Slowed breathing
• Seizures
• Nausea
• Vomiting
• Diarrhea
• Difficulty feeding

Carbamazepine use during the third trimester of pregnancy has also been associated with bleeding conditions requiring Vitamin K therapy. 

Bottom line: Carbamazepine should not be used during pregnancy unless it is required. Human studies that have looked at the safety of carbamazepine during pregnancy have found an increased risk of birth defects, particularly with first trimester use.

If I am taking carbamazepine and become pregnant, what should I do?

If you are taking carbamazepine and become pregnant, you should contact your doctor immediately. Your doctor will determine if your medication is medically necessary, or if it should be discontinued until after the birth of your baby.

If I am taking carbamazepine, can I safely breastfeed my baby?

The American Academy of Pediatrics and the World Health Organization consider carbamazepine to be compatible with breastfeeding. Infants should be monitored for side effects such as jaundice, drowsiness, vomiting, difficulty breastfeeding or suckling, poor weight gain, and poor neurobehavioral development. One study evaluated neurobehavioral outcomes in 181 6-year-olds exposed to carbamazepine in utero, finding a beneficial effect of breastfeeding on IQ in these children. Transient adverse events including liver dysfunction have been reported in nursing infants exposed to carbamazepine through breast milk. If adverse events develop in nursing infants, breastfeeding should be discontinued. Women should be advised to weigh the benefits of continuing carbamazepine treatment and the risks of infant carbamazepine exposure before deciding to continue or discontinue breastfeeding while on this medication.

Bottom line: In breastfeeding moms who are taking carbamazepine, breastfeeding is considered compatible with therapy. Breastfeeding has been shown to have positive effects on IQ in infants. If breastfeeding while on carbamazepine, monitor your infant for any adverse side effects.

If I am taking carbamazepine, will it be more difficult to get pregnant?

There is limited evidence on the impact of carbamazepine on male or female fertility. Some studies suggest male sperm development and motility may be negatively affected by carbamazepine. Carbamazepine may decrease the efficacy of oral contraceptives. Women on carbamazepine therapy should use a backup form of contraception.

If I am taking carbamazepine, what
should I know?

Carbamazepine should not be used during pregnancy unless it is required. Human studies that have looked at the safety of carbamazepine during pregnancy have found an increased risk of birth defects such as spina bifida, particularly with first trimester use.

Breastfeeding is considered compatible with carbamazepine therapy. Breastfeeding has been shown to have positive effects on neurobehavioral development in infants. If breastfeeding while on carbamazepine, monitor your infant for any adverse side effects caused by medication exposure in breastmilk.

If I am taking any medication, what should I know?

This report provides a summary of available information about the use of carbamazepine during pregnancy and breastfeeding. Content is from the product label unless otherwise indicated.

You may find Pregistry's expert report about epilepsy here, reports about bipolar disorder here, and reports about the individual medications used to treat seizure disorders here.   Additional information can also be found in the resources below. 

For more information about carbamazepine during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links:

National Institutes of Health:  Epilepsy Information Page

U.S. Food and Drug Administration: Carbamazepine Prescribing Information