The Food and Drug Administration is warning women of child-bearing age that the epilepsy drug Topamax can increase the risk of birth defects around the mouth.
Regulators said Friday that data collected from a registry of pregnant women showed a higher rate of cleft lip and cleft palate in babies whose mothers were taking the drug during the first trimester. Infants who were exposed to the drug had a 1.4 percent rate of mouth defects, which was more than three times greater than that seen with other seizure medications. The frequency of the defects in mothers not taking any epilepsy medication is .07 percent.
"Health care professionals should carefully consider the benefits and risks of topiramate when prescribing it to women of child-bearing age," said Dr. Russell Katz, director of the FDA's division of neurology products. "Alternative medications that have a lower risk of birth defects should be considered."
The FDA raised the drug's pregnancy category to D, which means there is evidence the drug can harm a human fetus, but there are situations where the drug's benefits to the mother could outweigh its risks. The FDA did not place the drug in category X, which means the drug should never be used by women who are or may become pregnant.
Topamax is marketed by Johnson & Johnson to control seizures caused by epilepsy, a neurological disorder that causes excessive nerve signals in the brain. The drug is also used to prevent migraine headaches. Roughly 4.3 million patients filled prescriptions for the drug between 2007 and 2010.
J&J and generic companies which market the drug, known as topiramate, will be required to add a stronger warning label about the drug's effect on pregnancies.
New Brunswick, N.J.-based J&J said in a statement that the drug's label already outlined the drug's risks to pregnant women.
"Today's FDA announcement strengthens this, and notes there is positive evidence of human fetal risk based on human data," the company states.
Women taking topiramate should talk to their doctor immediately if they are planning to or become pregnant, the FDA said.
Oral cleft defects occur when parts of the mouth do not completely fuse together, which can lead to difficulties eating and talking. The problem can usually be successfully treated with surgery that closes the lip or palate.
The FDA's announcement sank shares of Vivus Inc., which has been seeking approval for a weight loss drug combining topiramate with phentermine, an appetite suppressant. Last month the company said the FDA wanted more information on birth defects among women who use topiramate to treat migraines. The FDA denied approval of the drug.
Shares of the Mountain View, Calif.-based company fell 45 cents, or 6.4 percent, to $6.60.