FDA Warns of Cancer-Causing Substance in Heartburn Drug Zantac

With thousands of drugs available to consumers, both by prescription and over-the-counter, it should surprise no one that a large percentage pose safety risks. Many drugs present dangerous side effects or contain properties that can be hazardous to our health. But when unintended substances make their way into a drug, it can be difficult to detect and carry severe consequences. This has occurred more frequently over the past few years and has recently made headlines with the FDA warning that it has detected a cancer-causing contaminant in the heartburn drug Zantac.

The carcinogen in question, a nitrosamine impurity called N-nitrosodimethylamine (NDMA), was detected in samples of Zantac tested by the FDA. If NDMA sounds familiar, it may be because it was also found by the FDA in contaminated samples of the blood pressure medication Valsartan in July 2018.

NDMA is classified as a probable human carcinogen (a substance that could cause cancer) based on results from laboratory tests. NDMA is a known environmental contaminant and found in water and foods, including meats, dairy products, and vegetables.

A spokesman for Sanofi, the company which sells the brand-name version of Zantac, confirmed the company has no plans to recall the product at this time.

“Sanofi takes patient safety seriously, and we are committed to working with the F.D.A.,” the spokeswoman, Ashleigh Koss, said in a statement. The over-the-counter version of Zantac “has been around for over a decade and meets all the specified safety requirements for use in the O.T.C. market.”

An FDA spokesman announced that the agency is still investigating the source and severity of the contamination, stating that it is unclear how many companies’ products are affected. However, the spokesman did confirm that of the small number of products tested for the impurity, all have contained NDMA at low levels.

While it may be too early to confirm where the NDMA contamination originated from, industry experts are suggesting the issue lies in the lax oversight of drug manufacturing in countries like China that frequently make their way to the US.

“I think this is another good example of how our regulations need to change,” said Dinesh Thakur, a drug-safety advocate in an interview with the New York Times. “Things like this will never get caught, unless somebody is actually actively looking for stuff.”

As a result of the contamination, the FDA is advising concerned patients taking over-the-counter versions of Zantac to consider switching to another medication. The agency has not, however, recommended a recall of the drug.