FDA is telling Pfizer to change the safety warnings for the antidepressant Zoloft. It also wants the drug maker to acknowledge for the first time ever that some clinical studies link the drug to heat defects in infants. The evidence to date does not find any tie to birth defects, however.

FDA asked Pfizer last month to change the warnings on Zoloft to show that some research has shown a higher risk of congenital heart defects in babies whose mothers were taking the drug.

This request is part of a larger FDA effort to make improvements to drug labels across the pharmaceutical industry.

Pfizer has been fighting hundreds of lawsuits from mothers who have claimed that the drug maker did not warn them enough that the drug could cause heart problems with their babies. Some legal experts think that changing Zoloft’s label could help Pfizer to reduce future lawsuits.

However, those same experts also note that changing the label could help the claims of those who have already started suits against Pfizer and Zoloft, which was once the most popular antidepressant in the US.

Some experts argue that because FDA is making the company admit that there are credible studies that show Zoloft could cause heart problems in infants, a jury could decide that the company was ignoring that data and selling the product anyway.

Drug regulators have noted that most of the Zoloft research found no difference in birth defect risk for most users of the drug. The current label on the bottle says that there is not any well controlled study on pregnant women who take the drug.

Lawyers for Pfizer first hinted about the label changes at a hearing in federal court in September in Philadelphia. The company continues to claim that the drug does not cause heart defects, and that it did warn women about risks of the drug.

Pfizer has a lot at stake with Zoloft. The company made about $3.3 billion in sales off of Zoloft in 2005, making it the most popular antidepressant. The company lost its patent protection in 2006 and generic versions of the drug are now made by other companies, such as Mylan NV. US law requires that the drug label on generic versions has to have the identical warnings as what is on the Pfizer label.

While it is true that the change on the label could help old Zoloft customers sue the drug giant, it also will allow the company to defend itself better against future lawsuits. One expert says that it puts a limit on the number of cases in the future that could be brought that accuses Pfizer or not warning people about heart defect risks.

Earlier in 2015, officials from Pfizer were able to persuade juries in MO and PA that the current Zoloft label does urge doctors to look closely at the risks of the drug before doing a prescription for a pregnant woman. Panels in both states ruled in favor of Pfizer in the two Zoloft cases that have gone on trial.

A reviewer for Pfizer’s Worldwide Safety Strategy unit has recently revealed studies that do indicate an association between Zoloft and cardiac deformities in infants, which could be causal. That same reviewer in 2014 warned the company that doing an update  on the label could be necessary because of the higher risk of cardiac defects, which could include defects in the septum.

FDA has suggested that new parts of the warning label should include a reference to links between Zoloft and defects in the septum. This is where a hole develops in the infant heart

Overall, FDA has been working on improving the labeling of many prescription drugs, especially drugs that are used during pregnancy and breastfeeding. It produced a final rule on this subject in December 2014.

About Birth Injuries

Birth injuries can happen in newborns for many reasons and the severity can vary greatly. In some cases, the issue can make itself known right away, and other times, the problem may become apparent as the child grows older. In the case of heart defects, the problem may not always be obvious at birth, but could become clear in the days after birth, or in the first year of life.

A birth defect that involves the heart can be potentially life threatening. They can develop in the chambers of the heart, in the valves, blood vessels or in the septum. A baby could be born with just one defect in the heart or many. Some heart defects do not need medical treatment, even into the adult years. However, some heart defects will need surgical correction.

There is precedent for antidepressants causing birth defects. Paxil was a very popular antidepressant in the 1990s. However, the drug was found in some cases to lead to heart defects and physical deformities in newborns. Many lawsuits have been filed against GSK for legal fees, damages and punitive damages.