U.S. health officials have found a potential cancer-causing chemical in ranitidine, a popular generic drug used to treat heartburn and gastroesophageal reflux disease (GERD).
The disturbing finding came after the U.S. Food and Drug Administration (FDA) started conducting trials on samples of ranitidine drugs, including the common brand-name drug Zantac.
Scientists detected a contaminant called N-nitrosodimethylamine (NDMA) in the drugs. This organic chemical had gained attention in 2018 after scientists found it caused cancer in lab animals.
The contaminant has since been classified as a “probable human carcinogen.” Nonetheless, small amounts of it can still be detected in cosmetics and foods, including beer, cured meat, fish products and some cheeses.
The cancer-causing chemical in heartburn medications
In 2017, the U.S. Environmental Protection Agency (EPA) issued a technical fact sheet on NDMA. The chemical used to be a major component of rocket fuel and the EPA has long since listed it as a toxic pollutant.
Some of the adverse health effects due to exposure to this toxic chemical include liver damage, jaundice, nausea, abdominal cramps and renal damage.
French drugmaker Sanofi has since announced a recall of Zantac, their OTC heartburn medication popular in both the US and Canada, over concerns of possible contamination from the probable carcinogen.
The sudden recall occurred despite reports from the FDA in September 2019 that the NDMA levels their experts found in the drug samples do not exceed the amount found in foods and cosmetic products cleared for human consumption.
However, the FDA released another report not more than a month later, citing the NDMA levels in the drugs, finding them to be “unacceptable” and contradicting their earlier statement.
Asked to explain the sudden shift, FDA spokesperson Jeremy Kahn said that although the detected NDMA in the ranitidine samples is less than that found in foods, it still exceeds the acceptable levels that the FDA has designated for medications.
Despite the long list of health concerns surrounding NDMA, the Consumer Healthcare Products Association (CHPA), an American trade group for over-the-counter (OTC) drug and nutritional supplement manufacturers, noted that the FDA had not called for recalls of the drug at the time.
The group also cited the apparent benefits of using ranitidine products for consumers suffering from heartburn or GERD as reasons enough to not call for recalls or a total ban.
But it appears that the group spoke too soon. The FDA announced last April that it is requesting manufacturers to recall all prescription and OTC ranitidine drugs from the market at the soonest possible time. This is the FDA’s latest step in its ongoing investigation of NDMA in ranitidine medications.
The decision also came about after further trials demonstrated that impurities in ranitidine products increase over time and, if stored at higher than room temperatures, can expose consumers to unacceptable levels of the toxins. The ban is set to take effect throughout the US.
In Canada, authorities had directed companies to stop distributing ranitidine drugs last September, when the investigation began, as an initial preventive measure.
Health officials plan to use the interim to assess the risk of NDMA detected in some of the drugs sold there. Since then, a number of companies and manufacturers have recalled ranitidine products from the Canadian market, but some had resumed sales during the first quarter of 2020.
NDMA in blood pressure medications
This isn’t the first time that scientists detected the infamous cancer-causing chemical in OTC and prescription medications.
In the summer of 2018, manufacturers recalled a number of blood pressure medications containing the generic drug valsartan after the FDA also found “unacceptable levels” of cancer-causing substances in them.
Most of the contaminants belonged to a group of organic compounds called nitrosamines. This group includes NDMA and N-nitrosodiethylamine (NDEA), another compound considered to be a probable carcinogen.
On top of their prevalence in certain medications, experts also found traces of the chemicals in other products, including leather, pesticides and tires. Humans could also be exposed to nitrosamines from toiletries.
For this reason, some healthcare professionals believe that individuals face an equal risk of nitrosamine exposure from medications and common household products.
Nonetheless, the FDA is still conducting investigations and trials on nitrosamines and impurities in medicines.
Because of the controversy and uncertainty about these drugs, many physicians are recommending medications that do not contain nitrosamines over those that do, like ranitidine and valsartan drugs.
Written by Divina Ramirez for Cancer News, September 8, 2020