Pfizer has announced a voluntary recall of its blood pressure lowering medication, Accuretic, due to concerns over a potentially-carcinogenic impurity, NPR reported. 

The recall, announced March 21, was issued after the company detected a particular nitrosamine—N-nitroso-quinapril—in several lots of Accuretic, as well as two generic versions, quinapril and hydrochlorothiazide. Accuretic is a combination of both quinapril and hydrochlorothiazide. 

Nitrosamines are a family of compounds prevalent in air, water and certain foods, most notably cured and processed meats. The U.S. Food & Drug Administration (FDA) has established an Acceptable Daily Intake Level (ADIL) of the compounds, and the recalled lots of Accuretic far exceeded the FDA’s ADIL guidelines, which were most recently revised for pharmaceuticals in February 2021

Another kind of nitrosamine is also at the center of thousands of lawsuits against the pharmaceutical manufacturer GlaxoSmithKline over their heartburn medication, Zantac.  Plaintiffs in Zantac litigation allege that daily use of the acid-lowering drug, when taken over the course of several years, is associated with several types of cancer. 

Independent testing in 2018 by the laboratory Valisure detected unsafe levels of nitrosamines. Later testing by the FDA confirmed Valisure’s initial analysis and determined that the manufacturing process of Zantac (ranitidine) allowed the compound to break down when stored in conditions higher than room temperature, resulting in levels of NDMA, another type of nitrosamine, that were 30,000 times higher than the permissible daily intake limit established by the FDA. 

Zantac was totally recalled from the marketplace on April 1, 2020. 

It’s unclear whether the presence of nitrosamine in Accuretic, which was approved 20 years ago, is limited to the recalled lots, or if higher-than-acceptable levels of nitrosamine are present in many Accuretic products. 

At the time of the recall, Pfizer said that there had been no reports of adverse events related to the drug.