New York-based Pfizer reaped about $3.3 billion in Zoloft sales in 2005, making it the best-selling antidepressant on the market. (JB Reed/Bloomberg News)

Pfizer’s warnings about the risks of its Zoloft antidepressant were adequate to clear the drugmaker in a second trial over alleged links between the medication and birth defects.

A Philadelphia jury on Thursday rejected a woman’s claims that Pfizer officials hid the alleged risks. The verdict may dissuade other Zoloft users from suing over the birth-defect claims. Pfizer faces more than 1,000 such lawsuits.

“This verdict affirms that the Zoloft label contains adequate, science-based information on the benefits and risks of the medicine,” Neha Wadhwa, a Pfizer spokeswoman, said in an e- mailed statement.

It was Pfizer’s second win in as many trials after the drugmaker persuaded a St. Louis jury in April to reject a family’s arguments that the drug caused a boy’s cardiac abnormalities.

In the Philadelphia trial, 8-year-old Mia Robinson sought at least $2.4 million in compensation for her heart abnormalities.

The jury found the drug’s label, which already warns physicians to weigh the benefits of using the medication against its risks to pregnant women before prescribing it, was adequate. Some researchers say those risks include birth defects.

New York-based Pfizer reaped about $3.3 billion in Zoloft sales in 2005, making it the best-selling antidepressant on the market. The company lost patent protection on the drug the next year, and generic versions are now made by other drugmakers, including Roxane Laboratories.

Rachel Robinson, the girl’s mother, wept in the arms of Joe Zonies, one of her lawyers, after the jurors ruled Pfizer wasn’t liable for the damages.

During the two-week trial, the family’s lawyers produced internal Pfizer documents showing that a scientist warned executives last year about Zoloft’s potential link to birth defects and recommended changes to the medication’s safety warning.

The family’s attorneys also showed jurors a 1998 Pfizer review of Zoloft side-effect reports that found more than a dozen cases of birth defects for which the mothers’ Zoloft use couldn’t be ruled out as a cause.

“We will keep fighting until Pfizer tells doctors what it has concluded internally — that Zoloft is capable of causing birth defects,” Zonies said in an e-mailed statement. He also represented the plaintiffs in the St. Louis case.

Beth Wilkinson, Pfizer’s lead lawyer, said in the trial that no major medical group, such as the American Heart Association, has raised questions about Zoloft’s ties to cardiac abnormalities in newborns.

— Bloomberg News