Some ranitidine medicines, including Zantac, contain a carcinogenic impurity at low levels, according to a new FDA warning.
The impurity, N-nitrosodimethylamine (NDMA), was also found in Angiotensin II Receptor Blockers (ARBs) in 2018 and 2019.
However, in this case of ranitidine contamination, FDA “is evaluating whether the low levels of NDMA in ranitidine pose a risk to patients,” said Janet Woodcock, MD, director of FDA’s Center for Drug Evaluation and Research, in a statement.
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“Patients should be able to trust that their medicines are as safe as they can be and that the benefits of taking them outweigh any risk to their health. Although NDMA may cause harm in large amounts, the levels the FDA is finding in ranitidine from preliminary tests barely exceed amounts you might expect to find in common foods,” Woodcock said.
Ranitidine is an OTC and prescription H2 (histamine-2) blocker, which decreases the amount of acid created by the stomach. OTC ranitidine is approved to prevent and relieve heartburn associated with acid ingestion and sour stomach. Prescription ranitidine is approved for multiple indications, including treatment and prevention of ulcers of the stomach and intestines and treatment of gastroesophageal reflux disease.
FDA is working with international regulators and industry partners to determine the source of this impurity in ranitidine. “The agency is examining levels of NDMA in ranitidine and evaluating any possible risk to patients. The FDA will take appropriate measures based on the results of the ongoing investigation. The agency will provide more information as it becomes available,” FDA said.
The agency is not advising individuals to stop taking ranitidine at this time. “However, patients taking prescription ranitidine who wish to discontinue use should talk to their health care professional about other treatment options,” Woodcock said.
People taking OTC ranitidine could consider using other OTC medicines approved for their condition, Woodcock said. “There are multiple drugs on the market that are approved for the same or similar uses as ranitidine,” she said.
FDA has been investigating NDMA and other nitrosamine impurities in ARB drugs for blood pressure and heart failure and has recommended numerous recalls as it discovered “unacceptable levels of nitrosamines,” Woodcock said.
For example, Hetero Labs Ltd. in India recalled 87 lots of losartan potassium tablets in March because they contain NDMA.