Regulators in the U.S. and Europe are investigating why traces of a possible carcinogen were found in certain heartburn drugs, including Zantac, more than a year after the same impurity was found in some blood pressure pills, a revelation that has raised questions about the safety of the pharmaceutical supply chain.

At issue is NDMA, an organic chemical that was once used to make rocket fuel and is an unintended by-product of certain chemical reactions. Last year, the substance was detected in a class of medicines known as angiotensin II receptor blockers, notably, valsartan, prompting an increasing spate of product recalls even as regulators have attempted to reassure consumers that cancer risks are low.

On Friday, both the Food and Drug Administration and the European Medicines Agency released statements disclosing that NDMA was found in certain ranitidine medicines, which are histamine-2 blockers that decrease the amount of acid created by the stomach. The medication is sold both over-the-counter and by prescription.


“The agency is examining levels of NDMA in ranitidine and evaluating any possible risk to patients,” the FDA said in its statement. The agency is not telling consumers to stop taking ranitidine medications, “at this time,” but did say consumers “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 EMA, by the way, separately noted that traces of the impurity were also found in a diabetes medicine but were found to be within acceptably safe limits.

A spokesperson for Sanofi (SNY), which manufactures Zantac, said the company “takes patient safety seriously, and we are committed to working with the FDA,” and that Zantac “has been around for over a decade and meets all the specified safety requirements for use in the [over-the-counter] market.”

The FDA acted after an online pharmacy called Valisure discovered NDMA while testing the quality of batches of medications that it sells. The pharmacy then filed a citizen’s petition with the FDA, asking the agency to recall rantidine heartburn medicines. The pharmacy claimed its analysis “using an FDA-recommended protocol for the detection of NDMA reveals the ability of the ranitidine molecule to form NDMA at high efficiency.”

The presence of NDMA in the heartburn medicines is certain to heighten anxiety.

Over the past year, the number of companies recalling the blood pressure pills has expanded as evidence indicated, in some cases, that supplies dated back several years. Meanwhile, potentially tainted drugs have been sold to millions of people in more than two dozen countries.

On a larger scale, the episode has raised questions about regulatory oversight, especially since some of the suppliers are located in India and China, where quality control problems are a regular — and growing — problem. The FDA, in particular, has been on the defensive after reports that earlier inspections found troubling laboratory procedures at Chinese and Indian companies that supplied a key ingredient.

Earlier this year, the House Committee on Energy and Commerce wrote the FDA to express concern about the ability to oversee foreign suppliers. They cited a 2016 Government Accountability Office report that found the FDA significantly increased the number of inspections of overseas facilities, but failed to assess the extent to which its efforts were improving the quality of drugs entering the country.

Meanwhile, at least one law firm has filed a class action lawsuit against manufacturers.

This post was updated to note that Valisure alerted the FDA to the contaminant.

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  • I have been taking large quantities of Zantac over the last year (as prescribed by my physician). Is there a specific cancer risk, like say colon cancer? Or is it more general?

  • All that i will say on this and other health issues with regards to The .F.D.A . and other Federal Health Care Regulatory Institutions . I have no confidence ,nor trust with them . Too much have taken place over time to trust them all .Once again ,Merck years ago is only one of where The F.D.A failed completely resulting in The Deaths of more than five hundred thousands deaths from Vioxx depending on which News Organization you read . i thank you . Trevor . A. Merchant . today . Tuesday . September, 17. 2019 at 4.51 p.m daylight savings time . New York City ,

    • The 500,000 Vioxx deaths stat is fake, sees this Science magazine piece.

      Deaths of this magnitude show up in overall mortality rates – a la the opioid crisis which has resulted in a noticeable bump in mortality. There was no such bump in heart attack deaths during the years Vioxx was prescribed; in fact, heart attack deaths continued to decline.

      There were about four million Vioxx users. In order for that 500K stat to be correct, the drug would have had to kill one in every nine patients!

  • This is an important issue that has to be considered for all drugs.
    Since this impurity was also reported for some antihypertensive drugs, it may come from the inactive ingredients (such as fillers, bonding chemicals etc) that are a part of the pharmaceutical forms such as tablets or capsules.In this case this carcinogen chemical can be avoided by changing the formulation of the pills. On the other hand, from this report it is not clear whether NDMA is formed during the synthesis of ranitidin (or the antihypertensive drug) and thus contamination comes as a byproduct of drug synthesis. In this case source of the active ingradient should be questioned.

  • I’ve taken Zantac for many, many years to protect my stomach from another medicine I have to take that is very hard on the stomach. Can I stop it cold turkey? Is their an equivalent to Zantac that is known not to have this carcinogenic chemical in it?

  • Ed, thanks for reply. Yes patients should get MDs advice on whether to switch meds, but the worry is that the new med may have quality issues as well, but not yet discovered. The other option is to take the brand name vs. generic product, but at the moment, Diovan is 11 times the cost of generic valsartan and if you are within deductible, that comes out of pocket.

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