Recently in September 2019, the U.S. Food and Drug Administration (FDA) announced the discovery of a nitrosamine impurity called N-nitrosodimethylamine (NDMA) at low levels within certain ranitidine medications, commonly known as Zantac. NDMA is highly toxic to the liver and is classified as a probable human carcinogen. It is a known environmental contaminant that can be found in water, as well as foods such as cured meat products and smoked fish.
In the wake of this news, a large number of manufacturers and pharmacies have voluntarily recalled ranitidine. Initial claims of NDMA levels from third-party laboratories were inaccurately high secondary to introduction of NDMA during the testing protocol used. The FDA has since performed extensive testing of numerous ranitidine products on the market with a more reliable method, and have found levels of NDMA similar to that expected within common foods like grilled or smoked meats. They have simulated exposure of ranitidine to a stomach or small intestine environment, and have not seen formation of NDMA.
However, some NDMA levels detected still exceed what the FDA considers an acceptable limit (96 nanograms per day or 0.32 ppm). Additionally, NDMA has been identified in a similar medication called nizatidine, commonly known as Axid. The FDA is now asking manufacturers of ranitidine and nizatidine to voluntarily recall medications in which NDMA has been found to exceed the acceptable daily intake level. They have asked manufacturers to continue conducting independent testing and sending samples to the FDA. There is ongoing investigation into the true source of NDMA and the root cause of low levels of NDMA present in these drugs.
In the meantime, we recommend individual healthcare providers discuss these findings with patients taking either ranitidine or nizatidine medications and consider switching them to an alternative medication. Possible alternatives include famotidine (Pepcid), cimetidine (Tagamet), esomeprazole (Nexium), lansoprazole (Prevacid), and omeprazole (Prilosec), which were all negative for NDMA impurities on FDA testing thus far.