On September 13, 2019, the U.S. Food and Drug Administration (FDA) reported the discovery of the carcinogenic contaminant N-nitrosodimethylamine (NDMA) in Zantac (ranitidine), a common heartburn medication available in both prescription and over-the-counter versions.
​
In April of 2020, the FDA announced that all Zantac brand heartburn drugs, prescription and over-the-counter, should be immediately pulled from the market because of potential NDMA contamination, a chemical linked to cancer.
​
The first Zantac lawsuit was filed in California in 2019. In that lawsuit, the plaintiffs accuse drugmakers Sanofi and Boerhringer Ingelheim of manufacturing, marketing, and selling a product they knew or should have known had been contaminated with an industrial chemical known to cause cancer.
​
The exact cause of the NDMA contamination is still under investigation. However, during the period in which Boerhinger Ingelheim and Sanofi manufactured and marketed Zantac, scientific research demonstrated a clear link between ranitidine, the active ingredient in Zantac, and NDMA. Specifically, when ranitidine comes in contact with water, it creates a chemical reaction that causes the formation of NDMA.
​
Despite the availability of this information, the drugmakers chose not to disclose this risk to the government or to consumers.
Lawsuits argue that as far back as 1981, drugmakers were aware of several studies pointing to the dangers of NDMA formation with Zantac. The studies found that the potential of forming NDMA increases when ranitidine makes contact with nitrite in the body, according to a lawsuit filed by Michael and Deborah Combs.
​
The Comb's complaint list other more recent studies that connect ranitidine to NDMA formation. One 2011 study by Ruquao Shen and Susan A. Andrews observed that ranitidine could form NDMA when exposed to drinking water disinfected with Chlorine.
​
Another cited study from 2016 by Teng Zend and William A. Mitch found evidence suggesting ranitidine could form NDMA when combined with nitrite in "stomach relevant pH conditions." They also found NDMA excreted in the urine over a 24-hour period after taking ranitidine "increased 400-folds from 110 to 47 600ng, while totla N-nitrosamines increased 5-folds."
​
Despite this information, lawsuits say drugmakers failed to warn the public.