The levels of the probable cancer-causing impurity NDMA found in the heartburn drug Zantac and other ranitidine-containing products may increase to unsafe levels, not only by exposure to high temperature, but also due to the presence of oxygen and humidity, according to a new study published in the Chemical and Pharmaceutical Bulletin.
The study was conducted to better explain how NDMA can increase in Zantac stored at high temperatures, a cause the Food and Drug Administration (FDA) announced April 1, when it ordered the withdrawal of all Zantac products from the market because the products posed health risks. The agency also said that levels of NDMA also appeared to increase in the drug as more time passed since its manufacturing date.
But the new study points to yet another issue that appears to increase NDMA to unsafe levels in Zantac — exposure to oxygen and humidity. “These data indicate the necessity of controlling/monitoring stability-related factors, in addition to controlling impurities during the manufacturing process, in order to mitigate nitrosamine-related health risks of certain pharmaceuticals,” the researchers said.
NDMA is a known environmental contaminant that can be found in water and some foods. The FDA considers consuming up to 96 nanograms of NDMA per day to be reasonably safe based on lifetime consumption. But, the FDA cautioned, higher amounts over long periods of time may increase someone’s risk for cancer. Some cancers that may be linked to NDMA in Zantac include stomach, small intestine, bladder, kidney, colorectal, esophageal, prostate and pancreatic, as well as leukemia, non-Hodgkin’s lymphoma, and multiple myeloma.