Recently, the U.S. Food and Drug Administration announced that it had detected small amounts of a carcinogenic contaminant when testing samples of the heartburn medication ranitidine, which is commonly known as Zantac.
Although it hasn’t ordered a recall, the FDA advises people who use ranitidine over the counter to consider switching to another heartburn medicine.
What is the contaminant and where does it come from?
The contaminant is called nitrosodimethylamine, or NDMA. The substance was also recently found in some versions of a blood-pressure medication called valsartan, or by the brand name Diovan. The discovery of NDMA in valsartan prompted several recalls of the commonly prescribed drug. Chemicals related to NDMA were then found in two other blood-pressure medicines, irbesartan and losartan.
The FDA discovered the NDMA in ranitidine because it began testing other drugs after finding it in valsartan.
According to the FDA, NDMA can be formed during the manufacturing process if certain chemical reactions aren’t carefully controlled. It has been found to cause tumors in lab animals and is believed to cause cancer in humans.
An online pharmacy called Valisure has discovered NDMA in ranitidine, as well. In fact, it petitioned the FDA to recall the drug because Valisure had found NDMA levels above the FDA’s acceptable limit. It suggested that NDMA could be the result of ranitidine being an inherently unstable molecule that can degrade in certain conditions, including during digestion.
The FDA denies that it has found NDMA levels higher than the allowable limit in ranitidine, citing the low levels of the contaminant as the reason it is not issuing a recall.
Contamination calls into question the safety of the international pharmaceutical trade
Prescription drugs in the United States — especially over-the-counter drugs — are frequently composed of raw ingredients sourced from China, India and other nations where the FDA’s oversight is limited.
“I think this is another good example of how our regulations need to change,” a drug-safety advocate told the New York Times. He claims the FDA’s testing regime is too lax. “Things like this will never get caught, unless somebody is actually actively looking for stuff.”
Unfortunately, it may not be clear for years or even decades whether the contamination in ranitidine will cause cancers in patients. If you use ranitidine, especially the over-the-counter version, it may be in your best interest to switch to another heartburn drug as soon as possible. If you are being treated by a doctor, be sure to check before switching.