The Poison In Your Medicine Cabinet

How carcinogens and other impurities end up in the drug supply.

- Anna Edney, Susan Berfield and Evelyn Yu

The chemical N-Nitrosodimethylamine, or NDMA, is a yellow liquid that dissolves in water. It doesn’t have an odor or much of a taste. It’s known to cause cancer in animals and is classified as a probable carcinogen in humans—it’s most toxic to the liver. A single dose of less than a milligram can mutate mice cells and stimulate tumors, and 2 grams can kill a person in days. An Oklahoma man poisoned the family of an ex-girlfriend in 1978 by pouring a small vial of NDMA into a pitcher of lemonade. In 2018 a graduate student in Canada sickened a colleague by injecting the chemical into his apple pie.

NDMA no longer has industrial uses—it was once added to rocket fuel—but it can form during industrial processes at tanneries and foundries as well as at pesticide, dye, and tire makers. It can be found in drinking water disinfected with chloramine. It’s in tobacco smoke, which is one reason secondhand smoke is dangerous, and it’s what makes eating a lot of cured and grilled meat potentially risky. The U.S. Food and Drug Administration says it’s reasonably safe to consume as much as one microgram—one-millionth of a gram—of NDMA a day.

In July 2018 the FDA announced that NDMA had been found in the widely used blood-pressure medicine valsartan and started overseeing a recall of drugs from three companies. They’d all bought the active ingredient for their valsartan from Zhejiang Huahai Pharmaceutical Co., one of China’s biggest generic companies. The recall has since been expanded 51 times, to include two related drugs, irbesartan and losartan, made by at least 10 companies—some since 2014. Drugs sold to millions of people in 30 countries could be tainted.