By Thomas M. Burton 

WASHINGTON -- The Food and Drug Administration said it has learned of a probable human carcinogen found at low levels in some versions of the popular heartburn drug Zantac, sold over the counter and in various generic forms.

The FDA said it is evaluating whether the low amounts of the chemical, known as NDMA, pose a risk to patients. It said it would make that assessment available publicly as soon as it can.

Zantac is sold by Sanofi and generically under the name ranitidine. The agency said that while "NDMA may cause harm in large amounts," the levels it is finding in preliminary tests "barely exceed amounts you might expect to find in common foods."

The chemical is part of a class of compounds called nitrosamines that are found in water and in foods like meats, dairy products and vegetables.

Ranitidine, originally thought of as an ulcer drug, now is approved both for treatment and prevention of stomach ulcers and those of the intestines, as well as for gastroesophageal reflux disease, or heartburn.

A range of generic drugs for high blood pressure already had been found to be contaminated by low levels of NDMA and related carcinogenic chemicals. The FDA has been grappling with this issue for more than a year, principally in generic drugs including valsartan manufactured in China and India.

The FDA said it couldn't immediately say whether any of the generic Zantac products were made in China or India.

"Sanofi takes patient safety seriously, and we are committed to working with the FDA," Sanofi said. "Zantac OTC (over the counter) has been around for over a decade and meets all the specified safety requirements for use in the OTC market."

The FDA has previously acknowledged that two million or more people world-wide had already been exposed to the chemical in blood pressure drugs. These included generic drugs like valsartan, irbesartan and losartan.

Over the past year, there have been a series of recalls of various lots of those hypertension drugs made by various companies, largely from raw material facilities both in China and India. The contamination, while small, has raised questions about the safety of generic drugs, many of which come from raw materials in those countries.

Not all generic blood-pressure products are affected.

So far, the FDA has said about the blood-pressure drugs that the impurities in question resulted inadvertently from a manufacturing process. It has said that, regarding the issue with the blood-pressure drug valsartan, there may be one additional case of cancer among 8,000 people if they took the highest dose of the drug constantly for four years.

Write to Thomas M. Burton at


(END) Dow Jones Newswires

September 13, 2019 14:12 ET (18:12 GMT)

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