More than a year after an independent pharmacy rang the alarm bell about the potential risk of cancer linked to Zantac (ranitidine), which has resulted in recalls for all versions of the popular heartburn drug, former users continue to discover new cancers diagnosed long after last taking the drug.

Zantac and generic ranitidine, including both prescription and over-the-counter versions, have been used by millions of Americans, as the medication has been one of the top selling drugs for decades. However, late last year, manufacturers started issuing Zantac recalls after confirming that high levels of the cancer-causing chemical Nitrosodimethylamine (NDMA) were present in the pills.

The problems are not linked to a manufacturing problem where the chemical contaminated the pills, but rather NDMA is believed to be a byproduct of ranitidine contained in Zantac pills, which can convert to the cancer-causing chemical during storage at high temperatures or inside the human body.

Since the problems were discovered last fall, thousands of individuals have contacted Zantac lawyers investigating claims for cancers diagnosed in prior years, including breast cancer, testicular cancer, kidney cancer, bladder cancer, stomach cancer and other injuries. However, included in the mounting litigation are a steady number of cancers diagnosed long after last use of Zantac, and the number of cases is likely to continue to increase for years to come.

Given common allegations raised in product liability complaints filed in U.S. District Courts nationwide, a multidistrict litigation (MDL) has been established in the federal court system, to centralize the cases for coordinated discovery and pretrial proceedings before U.S. District Judge Robin L. Rosenberg in the Southern District of Florida.

While there are currently about 500 lawsuits pending in the MDL, Judge Rosenberg has ordered the parties to conduct a census, which is gathering information on both filed and unfiled claims that are still under investigation by lawyers nationwide. It is believed that tens of thousands of cases are already registered, and the Zantac litigation may one day become the largest active mass tort litigation in the U.S.

Each of the complaints raise similar allegations, indicating that the drug makers knew or should have known that ranitidine contained in Zantac was inherently unstable, yet they continued to market and sell the drug for decades, exposing users throughout the U.S. to an increased risk of cancer that may continue for years. A number of Zantac class action lawsuits have also been filed seeking funds for medical monitoring of former users.

As part of the coordinated management of the litigation, if Zantac settlements are not reached, it is expected that Judge Rosenberg will establish a bellwether program, where small groups of representative cases will be prepared for early trial dates in the federal MDL, to help the parties gauge how juries are likely to respond to certain testimony and evidence that is repeated throughout the claims.