Tegretol Side Effects Increase Risk of Spina Bifida During Pregnancy: Study

According to a new study, European researchers have linked side effects of Tegretol, an epilepsy drug, to a risk of the serious birth defect spina bifida when the medication is taken by pregnant women.

The study, which was published online Friday by the British Medical Journal, looked at eight cohort studies of 2,680 pregnancies where the women were exposed to carbamazepine, which is marketed as Tegretol, Carbatrol, Epitol and Equetrol.

Overall, 3.3% of women who took the drug in the first trimester gave birth to children with birth defects. They determined that Tegretol side effects during pregnancy were associated with a 2.6 times risk of having a child with spina bifida than women who were not exposed to carbamazepine.

Spina bifida is a developmental birth malformation involving the spinal cord, where some vertebrae are not fully formed. The condition may allow portions of the spinal cord to protrude through the opening in the bones, leading to serious life-long injuries for the child

The use of valproate epilepsy drugs during pregnancy, such as Depakote, Depacon, Depakine and Stavzor, have also been associated with an increased risk of birth defects, including spina bifida, cleft palate, abnormal skull development, malformed limbs, holes in the heart and urinary tract problems.

Late last year, the FDA added more stringent warnings about the risk of birth defects from Depakote and other valproate-based anti-seizure drugs. The warnings came after the agency found that the risk of giving birth to a child with a neural tube defect was 1-in-20 for women who took valproate during the first 12 weeks of pregnancy, compared with a risk of only 1-in-1500 for women not taking the epilepsy drug.

In the new British Medical Journal study, researchers found that spina bifida from Tegretol and other carbamazepine drugs was the only major congenital malformation that could be significantly associated with these epilepsy drugs.

In an accompanying editorial, Irena Nulman, associate professor of paediatrics at the University of Toronto, cautioned that the links to birth defects should be carefully weighed against the benefits Tegretol, Depakote and other epilepsy drugs provide.

“For many pregnant women, discontinuing antiseizure drugs is not an option,” Nulman wrote. “Women should plan their pregnancy, receive evidence based prenatal counseling, and be given the safest antiepileptic drug.”

Tegretol (carbamazepine) was first approved in the U.S. in 1974 as an anticonvulsant. It is approved for the treatment of epilepsy, trigeminal neuralgia and bipolar disorder.