Carcinogen scare sets off global race to contain tainted Zantac

The FDA has learned that some medicines to reduce acid and treat heartburn, including Zantac, contain low levels of a cancer-causing impurity.
(SOPA Images / LightRocket via Getty Images)

Drugmakers and global public health regulators are taking steps to remove supplies of Zantac, a popular heartburn medication, from the market because it may have become tainted with a cancer-causing agent.

Novartis’ Sandoz unit said Wednesday that it was halting worldwide distribution of generic versions of the stomach drug, just days after regulators in the U.S. and Europe began investigating the discovery of a likely human carcinogen called NDMA, or N-Nitrosodimethylamine, in the medication. Some versions of Zantac, which is also known by the generic name ranitidine, have also been recalled in Europe and Canada.

The moves are the latest in a series of actions aimed at getting drugs tainted with potentially deadly contaminants off pharmacy shelves. Since last year, the U.S. Food and Drug administration has been overseeing a recall of a type of generic blood pressure pills that originated in China and India and were contaminated with NDMA.


Until last week, concerns had mostly been limited to that class of hypertension drugs, known as angiotensin II receptor blockers. But Friday, the FDA and Europe’s top drug regulator said they were examining NDMA levels in Zantac and its generic forms and whether they posed any risk to patients.

Ranitidine is taken by millions of people worldwide to treat gastrointestinal disorders and discomfort. Sandoz is one of several generic-drug makers that distribute it. French drugmaker Sanofi makes branded Zantac, sold without a prescription.

“A precautionary distribution stop of all Sandoz ranitidine-containing medicines in all our markets will remain in place under further clarification; this includes capsules in the USA,” said Eric Althoff, a spokesman for Novartis. “Our internal investigation is ongoing to determine further details.”

Sandoz is also recalling its prescription oral version of ranitidine after testing found it contained NDMA levels “above what is considered acceptable,” Health Canada said in a statement Tuesday. The company didn’t disclose any details concerning the levels of NDMA that might have been found in its drugs.

Some countries in the European Union are recalling ranitidine containing an active ingredient made by an India-based manufacturer, Saraca Laboratories Ltd., Germany’s Federal Institute for Drugs and Medical Devices said in a statement. German health officials didn’t specify which countries were recalling the products or what drugmakers purchased the ingredients from Saraca.

There are indications other drug manufacturers could be affected by the contamination as well, according to the statement.


Saraca Labs is registered with the FDA to make active ingredients for medicines taken by American consumers. Since pharmaceutical companies don’t have to disclose where they buy drug materials, it’s unclear whether any use the company as their active-ingredient supplier for Zantac or its generics sold in the U.S.

The FDA didn’t immediately respond to a request for comment about Saraca.

Health officials in Canada have asked all companies that make brand-name and generic versions of Zantac to stop distribution of the heartburn treatment in that country. The request means existing stocks of ranitidine products in pharmacies or at retail stores may continue to be sold.

“Current evidence suggests that NDMA may be present in ranitidine, regardless of the manufacturer,” Canadian health officials said in a statement.

Brand-name Zantac maker Sanofi isn’t halting distribution of the drug or any of its other ranitidine products outside of Canada, Ashleigh Koss, a spokeswoman for the company, said.

“We are working closely with the FDA and are conducting our own robust investigations to ensure we continue to meet the highest-quality safety and manufacturing standards,” Koss said.

NDMA is commonly found in cured or cooked meats such as bacon and is a common industrial byproduct. The FDA has said it’s reasonably safe to consume as much as one microgram of NDMA a day.


Some tainted pills have been found to contain much higher levels. The FDA found NDMA levels as high as 17 micrograms in blood pressure pills recalled starting in July 2018. Online pharmacy Valisure, which tests all the drugs it distributes, detected NDMA levels as high as 3,000 micrograms in Zantac pills and its generics. Valisure testing that sought to re-create the conditions of the stomach detected NDMA levels as high as 300 micrograms in the Zantac drugs.

The blood-pressure-pill recall that started in 2018 was linked to NDMA that formed during the manufacturing process used by some active-ingredient suppliers in China and India that then sold the medication components to makers of generic drugs who finished the pills.

Public health officials haven’t said whether they have determined how the contaminant may have ended up in ranitidine medications.

Valisure detected the NDMA levels in Zantac and its generics and petitioned the FDA to recall the drugs. NDMA may be inherent in the ranitidine molecule, said Valisure Chief Executive David Light.

Other global regulators didn’t immediately say whether they planned to follow Canada’s decision to halt distribution of ranitidine.

“The FDA will take appropriate measures based on the results of the ongoing investigation,” Jeremy Kahn, a spokesman for the U.S. Food and Drug Administration, said in an email.


The FDA didn’t recommend people who take Zantac or its generics stop taking it but advised that other medications were available.