Update [10/2/19] FDA is continuing to test ranitidine products from multiple manufacturers and is assessing the potential impact on patients who have been taking ranitidine. In addition, the agency has asked manufacturers of ranitidine to conduct their own laboratory testing to assess levels of NDMA in their ranitidine products and to send samples of ranitidine products to FDA to be tested by our scientists.

FDA observed the testing method used by a third-party laboratory uses higher temperatures. The higher temperatures generated very high levels of NDMA from ranitidine products because of the test procedure. FDA published the method for testing angiotensin II receptor blockers (ARBs) for nitrosamine impurities. That method is not suitable for testing ranitidine because heating the sample generates NDMA.

FDA recommends using an LC-HRMS testing protocol to test samples of ranitidine. FDA’s LC-HRMS testing method does not use elevated temperatures and has shown the presence of much lower levels of NDMA in ranitidine medicines than reported by the third-party laboratory. International regulators using similar LC-MS testing methods have also shown the presence of low levels of NDMA in ranitidine samples.

FDA will test ranitidine oral solution products and has begun testing samples of other H2 blockers and proton-pump inhibitors to help inform this ongoing investigation. To date, the agency’s early, limited testing has found unacceptable levels of NDMA in samples of ranitidine. The agency will provide more information as it becomes available.