WASHINGTON An epilepsy drug also used to help prevent migraines can increase the risk for oral birth defects in babies born to women taking the medication, U.S. health officials said on Friday.
The Food and Drug Administration said new data shows expecting mothers taking the drug, sold generically and as Johnson & Johnson's Topamax, are about 20 times more likely to have their infants develop cleft lips or cleft palate deformities than those who are not treated.
Officials called on doctors to warn their female patients of childbearing age who are taking the medicine about its risks since the defects occur in the first three months of pregnancy, before women may know they are expecting.
FDA's Russell Katz, who heads the agency's Division of Neurology Products, said doctors should think carefully before prescribing the drug to women of childbearing age and "alternative medications that have a lower risk of birth defects should be considered."
Cleft lips and cleft palates are very rare in the United Stated but can occur when the mouth does not fully form, causing a "split lip" or a hole in the roof of the mouth.
The conditions can lead to multiple development issues because they can make it nearly impossible for babies to get adequate nutrition. They can be corrected with surgery, although sometimes several operations are needed.
In a statement, J&J said Topamax's label already notes the risks with pregnancy and "recommended cautious use in pregnant patients." It said it would work with the FDA to clarify the drug's use during pregnancy.
Topamax is expected to bring $569 million in worldwide revenue for the diversified drugmaker in 2010, according to Thomson Reuters data. At its peak, the drug took in more than $2.7 billion in 2008, before rivals arrived in 2009.
Teva Pharmaceutical Industries Ltd, Watson Pharmaceuticals Inc, Mylan Inc and other generic drug makers also sell the drug under its chemical name topiramate.
FDA issued the warning based on data collected from the North American Antiepileptic Drug Pregnancy Registry.
The data showed cleft lips or palates occurred in 1.4 percent of babies exposed to Topamax or generic rivals compared to between 0.38 percent and 0.55 percent in infants whose mothers took other drugs for epilepsy, FDA said. The defect occurs in about 0.07 percent of infants whose mothers are not on any such medication.
Separately, Vivus Inc said the warning does not impact the FDA's pending review of its experimental prescription weight-loss pill, Qnexa, which combines topiramate with the appetite suppressant phentermine.
A representative for the agency could not be immediately reached for comment.
In January, Vivus said FDA wanted the company to assess how feasible it would be to analyze available data to determine the risk of cleft lip and cleft palate in infants from women taking topiramate. Some analysts have said U.S. approval of Qnexa is unlikely this year.
The delay from that additional FDA request has hit the company's share price, and on Friday, Vivus shares closed down another 9.4 percent at $6.39.
(Reporting by Susan Heavey; Editing by Gerald E. McCormick, Tim Dobbyn, Gary Hill)