Sept. 30 (UPI) -- The maker of generic versions of the anti-heartburn drug Zantac is recalling the medicine due to concerns of a possible link to cancer.Drug maker Apotex has voluntarily recalled generic 75-milligram and 150-milligram ranitidine tablets sold at Walgreens, Walmart and Rite Aid, and CVS has pulled Zantac and its own generic version from its shelves.
The medication is used to treat heartburn, ulcers and other stomach issues.
The voluntary recall was issued after brand name and generic forms of ranitidine were found to contain low levels of N-nitrosodimethylamine, or NDMA.
"NDMA is classified as a probable human carcinogen (a substance that could cause cancer) based on results from laboratory tests," Apotex said in a statement. "NDMA is a known environmental contaminant and found in water and foods, including meats, diary products and vegetables."
Concerns were first raised earlier this month but patients were not encouraged to stop taking the drug.
David Light, CEO of online pharmacy Valisure, said the levels were high enough to warrant follow-up testing.
"All of this data put together is showing a very, very strong scientific story that the drug itself is very unstable," Light said. "This appears to be a fundamental problem with the molecule itself."
Sanofi, which manufactures Zantac, said it will continue shipping products in the United States.
"The FDA reported that the levels of N-nitrosodimethylamine in ranitidine in preliminary tests barely exceeded amounts found in common foods," Sanofi spokeswoman Ashleigh Koss said. "We are working closely with the FDA and are conducting our own robust investigation to ensure we continue to meet the highest quality safety and quality standards."
The FDA says users shouldn't panic, but suggests they switch to different heartburn drug during testing.