Pfizer has issued voluntary recalls for several lots of its blood pressure medication Accuretic, and two generic versions of it, over concerns of higher than acceptable levels of a nitrosamine called N-nitroso-quinapril, which is associated with an increased risk of cancer.
The affected medications include six lots of Accuretic tablets and batches of two authorized generics of the drug distributed by Greenstone that include one lot of quinapril and hydrochlorothiazide tablets and four lots of quinapril HCl/hydrochlorothiazide tablets.
The Accuretic tablets have an expiration date of August 2024 and were distributed across the US and Puerto Rico between November 2019 and March 2022.
Nitrosamines are commonly found in drinking water, air and foods such as dairy products, vegetables and cured and grilled meats.
“Pfizer places the utmost emphasis on patient safety and product quality at every step in the manufacturing and supply chain process,” the company stated in a news release. “Pfizer has notified direct consignees by letter to arrange for return of any recalled product.”
Earlier this month, Pfizer Canada recalled eight lots of Accuretic due to nitrosamine impurities.
Last summer, Pfizer recalled a dozen lots of its smoking cessation drug Chantix due to nitrosamine contaminants.
Above acceptable daily intake (ADI) levels of nitrosamines have been plaguing pharmaceuticals for the last couple of years. Last year, a couple of sartan family blood pressure drugs, including losartan, were recalled over azido impurities.
The US Food and Drug Administration (FDA) has recognized the increasing problem of nitrosamine contamination in human drugs.
To address this, the federal regulatory agency issued a guidance document for drug makers in 2020, which includes the number of different ways nitrosamines can appear in final drug products. This includes conditions that involve the presence of secondary, tertiary or quaternary amines and nitrite salts under acidic reaction conditions, which upon reaction, can lead to the formation of nitrosamines. These amines may be present in starting materials, intermediates or the active pharmaceutical ingredient (API). Contamination of starting and raw materials sourced from vendors can also introduce nitrosamine impurities.
Diabetes medication metformin has also been subject to recalls in the last few years over contamination with a nitrosamine called N-nitrosodimethylamine (NDMA).
Pfizer has advised wholesalers and distributors to stop distribution of the affected products and quarantine them, and also notify accounts who received the medicines.