The FDA has asked manufacturers to withdraw all prescription and over-the-counter (OTC) ranitidine products from the market immediately because of the presence of N-nitrosodimethylamine (NDMA), a probable human carcinogen, in these products.
An investigation by the agency determined that in some ranitidine products the impurity increases over time and when stored above room temperature, which could result in patient exposure to unacceptable levels of this compound.