Pfizer has recalled all in-date batches of the prescription-only smoking cessation medicine Champix (varenicline) as a precautionary measure, owing to the presence of a nitrosamine compound.
The recall from community pharmacies and wholesalers follows the detection of N-nitroso-varenicline, a probable human carcinogen, at levels that breach acceptable limits set by the European Medicines Agency (EMA) and the Medicines and Healthcare products Regulatory Agency (MHRA).
The EMA has previously said that the acceptable limit for N-nitroso-varenicline is 37ng per day.
The recall affects packs containing all strengths of the film-coated tablets: 0.5mg, 1mg, and mixed packs containing both 0.5mg and 1mg.
Instead, it said patients newly presenting for smoking cessation treatment should be offered nicotine replacement therapy (NRT) or bupropion 150mg prolonged-release tablets.
Anyone currently taking Champix will need to have their treatment reviewed and be switched to nicotine replacement therapy (NRT) where appropriate, it added.
The recall notice from the MHRA follows an earlier recall of Champix by the EMA on 30 September 2021 for the same reason.
According to a supply disruption alert published on 24 June 2021, Pfizer “stopped the distribution of all Champix (varenicline) 0.5mg and 1mg tablets in early June 2021 … following global regulatory investigations relating to the presence of nitrosamine impurities above Pfizer’s acceptable level of daily intake in several lots”.
However, batches of the medicine were not subject to a recall at the time.
In a statement to The Pharmaceutical Journal, a spokesperson for Pfizer said it was “unable to confirm a date for supply to be resumed”.
“We believe the benefits of Champix (varenicline tartrate) — an important treatment which aims to help people quit smoking and is intended to be used for 12 to 24 weeks — outweigh the very low potential risks, if any, posed by nitrosamine exposure from varenicline tartrate on top of other common sources over a lifetime,” they said.
“Pfizer is working closely with the MHRA on this recall process.”
In October 2019, the EMA asked drug manufacturers to test all medicines containing chemically synthesised active substances for the presence of nitrosamine.
The MHRA and the EMA both suspended the licences of gastrointestinal drug ranitidine following contamination with another nitrosamine, N-nitrosodimethylamine (NDMA), also a probable human carcinogen, in November 2020.
In August 2021, the MHRA recalled one batch of metformin oral solution after it was also found to contain traces of NDMA above accepted levels.
However, the EMA has previously said that the risk of cancer arising from the levels found in medicines is “very low”.
- This article was amended on 15 October 2021 to add a comment from Pfizer