The Food and Drug Administration said on Wednesday that it had discovered that a cancer-causing impurity in some products based on ranitidine, known by the brand name Zantac, increases over time and when stored at higher temperatures. The agency said this may “result in consumer exposure to unacceptable levels of this impurity”.
The agency has been investigating the amount of N-nitrosodimethylamine, or NDMA — which is commonly ingested in small amounts but can cause cancer in humans when more is consumed — in Zantac since the summer of 2019.
The FDA first warned the public in September last year but said at the time it did not have the evidence for a recall. New FDA testing found that levels of the impurity increased under normal storage conditions and temperatures to which it could be exposed to during distribution.
Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, said it did not observe unacceptable levels in many of the samples of the drug it tested.
“However, since we don’t know how or for how long the product might have been stored, we decided that it should not be available to consumers and patients unless its quality can be assured,” she said.
Sanofi, the French drugmaker, conducted a voluntary recall of Zantac in October, instructing retailers and consumers to return or destroy the product.
“We take this issue seriously and continue to work closely with the FDA to evaluate any potential safety risks associated with Zantac,” a spokesperson said. “At Sanofi, we stand by the longstanding science that supports the safety of Zantac over-the-counter products, which have been used by consumers for over two decades.”
Shares in Sanofi fell 1.9 per cent to $42.91 on Wednesday in New York, less than the wider market. In the fourth quarter, revenue at Sanofi’s consumer health division declined by 5.2 per cent, partly because of the Zantac recall.
The FDA recommended consumers destroy the drug, rather than try to take it back, because of restrictions resulting from the coronavirus pandemic. The regulator said it had not found the carcinogen to date in alternative products including Pepcid and Tagamet.