Zantac.

A federal judicial panel sent more than 140 lawsuits filed over heartburn medication Zantac to the Southern District of Florida, where U.S. District Judge Robin Rosenberg will preside over them.

In a Thursday order, the U.S. Judicial Panel on Multidistrict Litigation cited the convenience and resources of the Southern District of Florida, adding that Rosenberg, a 2014 appointee of President Obama, has not handled an MDL before.

"A large number of Zantac actions are pending in the Southern District of Florida, which is supported by the majority of responding plaintiffs," wrote MDL Panel Chairwoman Karen Caldwell. "The district is a relatively convenient and accessible forum, with the resources and the capacity to efficiently handle what could be a large litigation."

The lawsuits, both individual cases alleging personal injuries and class actions brought for economic damages, allege that the companies that made and sold Zantac knew its active ingredient, ranitidine, metabolized in the human body to form a carcinogen known as N-nitrosodimethylamine, or NDMA.

Sanofi-Aventis U.S., which recalled over-the-counter Zantac on Oct. 18 after the U.S. Food and Drug Administration found unacceptable levels of NDMA in ranitidine samples, is one of several defendants named in the cases, which have brought in top defense attorneys. The others are GlaxoSmithKline, which first received FDA approval to sell the drug and recalled prescription Zantac on Oct. 8, and Boehringer Ingelheim Pharmaceuticals Inc. and Pfizer Inc., which both sold Zantac.

Plaintiffs attorneys have predicted large numbers of cases over Zantac, which has been on the market since 1983.

They initially sought an MDL in several venues in addition to Florida, such as New Jersey, California and New York. "At oral argument, however, most plaintiffs appeared to have coalesced around the Southern District of Florida as their first choice for transferee district," the panel wrote in its order.

In an email, plaintiffs attorney Steve Berman of Seattle's Hagens Berman Sobol Shapiro, who initially sought a Zantac MDL in New Jersey, said Florida had "more judicial resources," while judges in New Jersey were "slammed due to judicial shortages."

The defendants supported the District of New Jersey, where Sanofi has its U.S. headquarters, or the Southern District of New York, home to Pfizer. GlaxoSmithKline's U.S. unit is based in Philadelphia, and Boehringer Ingelheim has a U.S. unit in Connecticut.

The lawsuits follow the FDA's investigation of NDMA in some blood pressure and heart failure medicines. Last year, the FDA found a carcinogen in those medications, such as generic valsartan, prompting the filing of more than 140 lawsuits now coordinated in multidistrict litigation in New Jersey. Lawyers suing over Zantac sought to distinguish the valsartan cases, which focus on an alleged manufacturing defect.