The heartburn medication ranitidine, brand-name Zantac, may contain low levels of a carcinogenic substance, according to recent information from the Food and Drug Administration. The agency has not ordered a recall, but it suggests people who take ranitidine contact their doctors about an alternative. Over-the-counter users should consider switching to another drug, too.
According to the New York Times, the European Medicines Agency is also examining the issue.
Brand-name Zantac is produced by the drug maker Sanofi, which has no plans to recall the product. Generic versions of ranitidine are produced by numerous manufacturers and sold widely, both by prescription and for over-the-counter use. The Times did not say whether the generic manufacturers were considering recalls.
The FDA says that it had tested only a few ranitidine products for contamination, but all of the products tested were contaminated, albeit at low levels. It is unclear how many manufacturers’ products could be affected.
In a statement, Sanofi said that it takes patient safety seriously and is cooperating with the FDA. It noted that the over-the-counter version “has been around for over a decade and meets all the specified safety requirements for use in the O.T.C. market.”
How did ranitidine get contaminated?
According to the Times, the contaminant is called nitrosodimethylamine, or NDMA. In March, NDMA was found at higher levels in some versions of a blood-pressure medicine called valsartan, brand-name Diovan. This led to several recalls and supply shortages.
NDMA doesn’t get accidentally added to the drugs. Instead, it is a substance that can form in the manufacturing process unless certain chemical reactions are carefully monitored and controlled. NDMA can also be created when certain molecules degrade under certain conditions — including the molecule for ranitidine. The ranitidine molecule is inherently unstable.
NDMA is part of a class of substances called nitrosamines, which have caused liver and other tumors in lab animals. Nitrosamines are believed to cause cancer in humans.
However, the FDA notes that NDMA is found in other drugs and some foods. And, it is not recommending a recall unless higher levels of the substance are found in subsequent tests.
The online pharmacy Valisure has petitioned the FDA to recall all ranitidine products after its own tests found high levels of NDMA in the drugs.
Is foreign manufacturing to blame?
Some observers question whether it’s safe to have American drugs manufactured abroad, far from the eye of the FDA. The NDMA-tainted valsartan was manufactured by a Chinese company. FDA oversight has lagged recently in China and India, where many other drugs are manufactured before being sold in the U.S.