In another recall of products in the industry relating to nitrosamine impurities, Pfizer is voluntarily recalling 12 lots of its smoking-cessation product, Chantix (varenicline). This marks the latest product in the industry recalled/investigated over the past three years due to possible nitrosamine impurities.

Pfizer is voluntarily recalling two lots of Chantix 0.5-mg tablets, two lots of Chantix 1-mg tablets, and eight lots of a Chantix kit of 0.5-mg/1-mg tablets to the patient (consumer/user) level due to the presence of a nitrosamine, N-nitroso-varenicline, above the Pfizer established acceptable daily intake level. Pfizer has not received any reports of adverse events that have been related to this recall (as reported on July 16, 2021). The product lots were distributed nationwide to wholesalers and distributors in the US and Puerto Rico from June 2019 to June 2021.

Long-term ingestion of N-nitroso-varenicline may be associated with a theoretical potential increased cancer risk in humans, but there is no immediate risk to patients taking this medication, according to information from the US Food and Drug Administration.

The recall follows ongoing investigations by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) into nitrosamine impurities in certain active pharmaceutical ingredients (APIs) and subsequent product recalls. In 2018, the FDA and the EMA initiated investigations of nitrosamine impurities in certain “sartan”-containing APIs, used in anti-hypertensive and cardiovascular drugs, such as valsartan candesartan, irbesartan, losartan, and olmesartan. They later broadened those investigations into prescription and over-the-counter forms of ranitidine, a H2 (histamine-2) blocker used to decrease the amount of acid created by the stomach, and later metformin extended-release products.

The nitrosamine impurities in those investigations/recalls were principally for elevated levels of N-nitrosodimethylamine (NDMA), a potential carcinogen. As part of their investigations, the regulatory agencies issued guidelines for testing of products to detect nitrosamine impurities, acceptable daily intake levels, and risk evaluation and risk assessment.

Source: US Food and Drug Administration