The Food and Drug Administration is taking a drastic step over a common drug used to treat allergies and acid reflux, following an investigation that confirmed the persistent presence of a likely carcinogen in products containing it. On Wednesday, the agency announced that it’s requesting all manufacturers of ranitidine to immediately pull any remaining products off the market; it’s also telling any users of ranitidine to throw out their bottles and switch to other medications.
Last June, the independent testing lab and pharmacy company Valisure flagged a potential concern to the FDA via a citizen petition to the agency. Its tests had found a chemical known as N-nitrosodimethylamine, or NDMA, in products containing ranitidine, which include the popular brand name heartburn drug Zantac. They theorized that ranitidine itself was an unstable chemical capable of easily breaking down into NDMA under certain conditions, including high heat.
NDMA is used to induce cancer in lab animals and is considered a probable human carcinogen. A year earlier, it was found in products containing the drug valsartan, which prompted a series of widespread recalls. In that case, though, the NDMA was traced back to contamination at manufacturing facilities.
By September, the FDA announced its own investigation of the link between ranitidine products and NDMA, though the agency didn’t jump on board with Valisure’s theory. NDMA is found in trace amounts practically everywhere in the environment, and it can be accidentally produced in all sorts of ways. Initially, the FDA stated the NDMA it had found in products “barely exceeded” the trace levels sometimes found in food and didn’t seem to pose any cancer risk.
Nevertheless, the agency began recommending recalls of ranitidine products by drug manufacturers and chain pharmacies like CVS. Recalls and outright bans were similarly encouraged by health agencies in other countries as well. Companies complied, and by March 2020, many products with ranitidine were temporarily taken off the market.
The FDA’s investigation has seemingly now agreed with Valisure’s conclusions. The agency determined that levels of NDMA can build up in ranitidine products over time, especially when these products are stored at higher than room temperature. And because of the potential that people can be exposed to much higher amounts of NDMA than the initial FDA tests showed, the agency has decided to effectively shelve any and all ranitidine products in the U.S. for the foreseeable future.
“The FDA is sending letters to all manufacturers of ranitidine requesting they withdraw their products from the market. The FDA is also advising consumers taking OTC ranitidine to stop taking any tablets or liquid they currently have, dispose of them properly and not buy more,” the agency said in its announcement Wednesday.
Valisure CEO David Light applauded the FDA’s decision, through he argues that the link between NDMA and ranitidine could and should have been discovered earlier by relevant health agencies or drug companies.
“Ranitidine actually has both of the primary components of NDMA, the N and the DMA, on the drug itself. So it’s actually quite straightforward that this could have happened. And there’s decades of academic research that has talked about the potential for this to happen,” Light told Gizmodo over the phone, referencing studies that date back to the 1980s when the first ranitidine drugs hit the market. “I think it speaks to a really fundamental problem here, which is just the complete disconnect between the regulatory and pharmaceutical bubble and everything else that goes on in the academic world.”
Thankfully, ranitidine is only one of many similar antihistamines and antacids available to people, so switching medications shouldn’t be too much of a worry. According to the FDA, products containing famotidine (Pepcid), cimetidine (Tagamet), esomeprazole (Nexium), lansoprazole (Prevacid) or omeprazole (Prilosec) do not appear to contain NDMA. Those with a prescription ranitidine product should talk with doctors about which drug is the best replacement.
Even with this latest move, however, Light believes there’s still the potential for long term dangers from ranitidine-containing products for the public.
Valisure’s work and others has suggested that NDMA isn’t just created from the manufacturing and storage of ranitidine but when people ingest it, thanks to the stomach’s gastric acid. So some people may have gotten exposed to much more NDMA than anyone has realized—enough possibly to significantly raise their risk of cancer. Light said that his lab has started to collaborate with other researchers for epidemiological studies that will try to look for links between ranitidine use and cancer risk in the population, and he hopes other scientists start looking as well.
“There needs to be more eyes on this. And I don’t think this is the last we’re going to hear about the impact of what’s happened with this drug,”he said. “Ranitidine is, unfortunately, just a bad drug that’s been out there for a very long time.”
This article has been updated with comments from Valisure CEO David Light.