In 2018, one of the bestselling blood pressure drugs, valsartan—sold as Diovan—was found to be contaminated by the “probably carcinogenic” nitrosamine known as N-nitrosodimethylamine (NDMA). It’s believed that approximately 20 million people worldwide were prescribed the drug tainted with this contaminant whose cancer risk has been shown to exceed that of many known potent carcinogens, including asbestos, benzo[a]pyrene, and PCBs.
The U.S. Food and Drug Administration (FDA) estimated that taking the drug for a few years could cause cancer in as many as 1 in 8,000 people, whereas the European equivalent of the FDA estimated the cancer risk could be as high as 1 in 5,000. It is unlikely, researchers wrote in this Spring 2019 paper, that drugs like valsartan are a unique case. And indeed, a few months later, the FDA announced it had found NDMA in ranitidine.
