Zantac Study Finds Gastrointestinal Cancer Risk Three Times Higher Among Users of Recalled Heartburn Drug

The findings of a new study provides more evidence about the toxic side effects of Zantac, indicating users of the recalled heartburn drug may face a three-fold increased risk of developing gastrointestinal cancer due to the chemical byproduct N-nitrosodimethylamine (NDMA), which is produced by the active ingredient ranitidine.

In a report published last week in the medical journal Cancers, researchers from the University of Alabama evaluated the association between ranitidine in Zantac and gastrointestinal cancer.

Zantac and other generic ranitidine drugs have been used by millions of Americans for years to prevent and relieve heartburn. However, all versions of the medication were pulled from the market earlier this year, after it was discovered the pills commonly contained extremely high and dangerous levels of NDMA, which is a potent human carcinogen.

The problems were first identified by researchers at the independent pharmacy Valisure, which began testing all medications for NDMA after the chemical resulted in widespread recalls for valsartan, irbesartan, losartan and other widely used generic blood pressure drugs. However, unlike those recalls, where NDMA was created as a byproduct of changes in the generic drug making process, Valisure determined that Zantac problems involved the active ingredient ranitidine converting to NDMA over time when introduced to high heat during storage, or even as it is digested inside the human body.

In this latest study, researchers looked at adverse events reported to the FDA linked to the use of different types of medications used to prevent or treat heartburn, including proton pump inhibitors (PPIs), and H2 antagonists. Zantac is a member of the latter class. The researchers then compared the proportionate reporting rations (PPR) between the different medications.

According to the findings, overall rates of gastrointestinal cancer for ranitidine had a PPR of 3.66 when compared to all other heartburn drugs. This means the rate of gastrointestinal cancer with ranitidine use was more than triple the rate among users of other heartburn drugs.

Some specific types of cancer were even more strongly associated with Zantac side effects, according to the study. The highest association was with colorectal cancer, which was more than 16 times more likely for Zantac users than those who used other heartburn drugs. That was followed by pharyngeal cancer, which was more than nine times more likely with Zantac use; and anal and gallbladder cancer, which were both more than four times more likely with Zantac use.

“The results of the current study supported the interpretation that NDMA is carcinogenic in humans, specifically to the gastrointestinal system. This study was unique in that it compared cancer occurrence among ranitidine users to that of a population that uses medications to treat similar conditions, though not known to be contaminated with NDMA,” the researchers noted. “By comparing ranitidine users to users of PPIs and other H2 antagonists, the current study was better able to reduce the impact of confounding by indication and thereby isolate the role of NDMA.”

Zantac Cancer Lawsuits

The findings come as a growing number of former users are now pursuing Zantac lawsuits against makers of various ranitidine-containing drugs, indicating that years of exposure to NDMA in the pills caused the development of breast cancer, kidney cancer, stomach cancer, testicular cancer and other injuries as the chemical passed through their body.

Given common questions of fact and law raised in complaints filed in U.S. District Courts nationwide, a federal multidistrict litigation (MDL) was established earlier this year, centralizing all claims pending throughout the federal court system before U.S. District Judge Robin L. Rosenberg is presiding over the coordinated discovery and pretrial proceedings.

There are currently hundreds of lawsuits included in the litigation, with tens of thousands of additional cases registered on a census established by the court to allow the parties to gauge the size an scope of the litigation as Zantac cancer lawyers continue to review claims for individuals nationwide.

It is expected the litigation may become one of the largest active mass tort proceedings involving a pharmaceutical medication before the first cases reach trial.