Topiramate Linked to Birth Defects
Robert Lowes
Medscape

March 4, 2011 ? Pregnant women taking topiramate (Topamax, Ortho-McNeil Janssen) to treat epileptic seizures or prevent migraine headaches have an increased risk of bearing children with a cleft lip or palate, the US Food and Drug Administration (FDA) announced today.

Consequently, clinicians should warn women of childbearing age about the possibility of these birth defects if they become pregnant while taking the medication.

"Health care professionals should carefully consider the benefits and risks of topiramate when prescribing it to women of childbearing age," said Russell Katz, MD, director of the Division of Neurology Products in the FDA's Center for Drug Evaluation and Research, in a statement from the FDA. "Alternative medications that have a lower risk of birth defects should be considered."

Pregnant women prescribed the medication should continue to take it unless advised not to by a clinician.

Topiramate, an anticonvulsant, is approved for treating certain seizures in patients with epilepsy and preventing migraine headaches. However, it is not indicated for treating the pain of such headaches when they occur. The drug also is used on an off-label basis to treat weight loss, alcohol dependence, and psychiatric illnesses such as bipolar disorder.

According to new data from the North American Antiepileptic Drug Pregnancy Registry, infants exposed to topiramate as a single therapy in the first trimester of pregnancy had a 1.4% prevalence of oral clefts compared with 0.38% to 0.55% for infants exposed to other antiepileptic drugs. The prevalence rate was even lower ? 0.07% ? for infants of mothers who did not have epilepsy and were not being treated with other AEDs.

These findings have prompted the agency to strengthen the label warning for topiramate by changing its pregnancy classification to category D. This category means that there are human data showing positive evidence of human fetal risk, but that the drug's benefits in pregnant women may outweigh the risks in some situations. The drug's pregnancy category previously had been a lower category C because of the absence of human data.

The FDA also will update the patient medication guide and prescribing information for the brand name and generic versions of topiramate.

More information about today's announcement is available on the FDA Web site.