Some heartburn medications sold under the brand-name Zantac contain a cancer-causing impurity, the U.S. Food and Drug Administration warned Friday.
The FDA said low levels of a nitrosamine impurity called N-nitrosodimethylamine (NDMA) were found in the medications. NDMA is classified as a "probable human carcinogen" (a substance that could cause cancer).
The FDA said NDMA is a known environmental contaminant found in water and foods, including meats, dairy products and vegetables.
The heartburn medicine ranitidine, commonly known as Zantac, is an over-the-counter and prescription drug that works as a histamine-2 blocker to decrease the amount of acid created by the stomach.
Despite the warning issued Friday, the FDA said patients do not need to stop taking Zantac yet.
"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," the agency said.
The FDA said patients who have been prescribed Zantac should talk to their physician if they want to stop taking the medication.
People taking OTC ranitidine could consider using other OTC medicines approved for their condition. There are multiple drugs on the market that are approved for the same or similar uses as ranitidine, the FDA said.
Consumers and health care professionals should report any adverse reactions with ranitidine to the FDA's MedWatch program to help the agency better understand the scope of the problem:
- Complete and submit the report online at www.fda.gov/medwatch/report.htm
- Download and complete the appropriate form, then submit it via fax at 1-800-FDA-0178