The FDA is continuing to test ranitidine products from multiple manufacturers following the discovery of impurities in low levels in some medicines, including Zantac. The impurity, N-nitrosodimethylamine (NDMA), is classified as a probable human carcinogen, and is a known environmental contaminant found in water and foods, including meats, dairy products, and vegetables.1,2

Ranitidine is an H2 (histamine-2) blocker that decreases the amount of acid created by the stomach. It is available as an over-the-counter (OTC) and prescription drug. OTC ranitidine is approved to prevent and relieve heartburn associated with acid ingestion and sour stomach, while prescription ranitidine is approved for multiple indications, including treatment and prevention of ulcers of the stomach and intestines and treatment of gastroesophageal reflux disease.2

The agency has asked manufacturers to conduct their own laboratory testing to assess levels of NDMA in their ranitidine products. The samples should then be sent to the FDA to be tested by their team of scientists.1

The FDA recommends using an LC-HRMS testing protocol to test samples of ranitidine since this method does not use elevated temperatures. LC-HRMS testing has also shown the presence of much lower levels of NDMA in ranitidine medicines than reported by the third-party laboratory.1

Ranitidine oral solution products have been tested by the FDA, and other H2 blockers and proton-pump inhibitors are beginning to be tested. The agency will provide more information as it becomes available.1

  1. Update- FDA provides update on testing of ranitidine for NDMA impurities [press release]. Silver Spring, MD; October 2, 2019: FDA website. Accessed October 2, 2019.
  2. Probable carcinogen found in samples of ranitidine. Pharmacy Times website. Published September 13, 2019. Accessed October 2, 2019.