The smoking cessation drug, Champix, has been recalled over concerns the product may contain elevated levels of nitrosamines.

The Medicines and Healthcare products Regulatory Agency (MHRA) requested the manufacturer, Pfizer, to recall all batches of its product as a ‘precautionary measure’ due to the presence of levels of N-nitroso-varenicline above the acceptable level set by the MHRA.

NDMA has been identified as a risk factor in the development of certain cancers and has genotoxic potential, the MHRA said.

Pharmacists should stop dispensing the affected products (Champix 0.5mg and 1mg tablets) immediately, quarantine all remaining stock and return it to the supplier, the MHRA explained.

In a supply disruption alert, the Department of Health and Social Care (DHSC) said patients who are currently taking this medication will require a review and switching to nicotine replacement therapy (NRT).

Prescribers starting patients on smoking cessation treatments should consider prescribing NRT or bupropion 150mg prolonged-release tablets.

It also said that no new patients should be initiated on Champix.

There have been ongoing supply issues of Champix since June, following several global regulatory investigations relating to the presence of nitrosamine impurities above Pfizer’s acceptable level of daily intake in numerous batches.

Pfizer said: ‘For those patients currently prescribed Champix, we believe the benefits outweigh the very low potential risks, if any, posed by nitrosamine exposure from varenicline on top of other common sources over a lifetime.’