The U.S. Food and Drug Administration announced Friday that it found a potentially cancer-causing carcinogen in some versions of the popular over-the-counter heartburn medication, Zantac.
Zantac is sold by drug-maker Sanofi, as well as generically, under the name ranitidine.
In a press statement, the FDA said that the chemical, N-nitrosodimethylamine, or NDMA, is “classified as a probable human carcinogen … based on results from laboratory tests,” but cautioned those who may be affected not to panic since it was only found at low levels.
“The FDA is not calling for individuals to stop taking ranitidine at this time,” the statement read. “However, patients taking prescription ranitidine who wish to discontinue should talk to their health care professional about other treatment options. People taking [over-the-counter] ranitidine could consider using other medicines approved for their condition.”
While NDMA could cause harm in high amounts, the levels found in some medications are not much more than what’s commonly found in foods and dairy, according to the FDA.
Still, several blood-pressure drugs have been recalled after strains of NDMA were found.
The FDA said it has been investigating NDMA since last year and will continue to assess whether low amounts of the chemical could pose a real threat to patients.
And in a statement, Sanofi said it plans to work closely alongside the agency: “Zantac has been around for over a decade and meets all the specified safety requirements for use in the [over-the-counter] market.”
Shares of Sanofi were down 21 percent as of press time.