Pfizer Recalls FDA-Approved ‘Anti-Smoking’ Drug That Causes Cancer

Pfizer has recalled its popular anti-smoking drug Chantix after it was found to contain high levels of cancer-causing agents called nitrosamines.

According to a notice posted on the Food and Drug Administration’s (FDA) website Thursday, the drug maker is ‘voluntarily recalling all lots of Chantix 0.5mg and 1mg tablets to the patient level due to the presence of a nitrosamine, N-nitroso-varenicline (NDMA), at or above the FDA interim acceptable intake limit’.

Then, in an update posted on Friday, the FDA advised ‘patients taking recalled varenicline to continue taking their current medicine until their pharmacist provides a replacement or their doctor prescribes a different treatment’.

‘The health benefits of stopping smoking outweigh the cancer risk from the nitrosamine impurity in varenicline,’ it added.

Pfizer paused distribution of Chantix back in July after finding elevated levels of nitrosamines in the pills and announced it was recalling 12 lots of the anti-smoking drug.

The drug giant – currently best known for its COVID vaccine – insisted there was no immediate risk to patients taking this medication’ and said the recall is out of an abundance of caution.

In the past the US drug regulator has reached out to companies whose drugs had NDMA over accepted levels.

Chantix was approved by the FDA in May 2006 as a prescription medication which helps adults aged 18 and over quit smoking and is used for 12 to 24 weeks.

Pfizer said in its July 2021 release that people who smoke cigarettes are 15 to 30 times more likely to get lung cancer than people who do not smoke.

Nitrosamines are naturally-occurring organic compounds found in a variety of foods, including meat, dairy and vegetables, according to the FDA. Everyone is exposed to the chemicals at some level.

However, if ingested in high amounts over long periods of time, nitrosamines could increase someone’s risk of developing cancer.

The FDA began asking pharmaceutical companies to test their drugs for nitrosamines after high amounts were found in several different kinds of blood pressure medications three years ago.

Last year, the FDA found high levels of nitrosamines in the popular diabetes drug, metformin, Bloomberg reported. In 2019, Sanofi SA recalled its heartburn drug Zantac for having high amounts of the carcinogenic ingredient.

Pfizer didn’t indicate how the nitrosamines got in Chantix. The source of the chemicals in medication could come from its manufacturing process, its chemical structure or even the conditions under which they are stored and packaged.

Pfizer first announced that it was planning a recall of the drug on June 24 after discovering the likely carcinogen. Then, on July 2, it listed a recall on nine lots of the drug that were impacted and sitting in warehouses.

The July 16 recall, however, included 12 more lots of the drug, which were already distributed to wholesalers in the U.S. and Puerto Rico between June 2019 and June 2021.

The company released a list of the lot numbers and urged consumers to check if their prescription is affected. They include 00019213, EC6994, EA6080, EC9843, 00020231, 00020232, 00020357, 00020358, 00020716, ET1600, ET1607 and ET1609.

‘Patients currently taking Chantix should consult with their doctor to confirm if they received an affected lot, and if appropriate, about alternative treatment options,’ the company said, adding, ‘To date, Pfizer has not received any reports of adverse events that have been related to this recall’.’

Chantix sales dropped 17 per cent in 2020, from $1.1billion to $919 million, after the company lost protection on one of its main patents in the United States in November, according to Bloomberg.

While ‘generic competition for Chantix has not yet begun, it could commence at any time,’ Pfizer said in its quarterly report in May.

Source: The Daily Mail

Update [9/17/2021] FDA is alerting patients and health care professionals that Pfizer is expanding its voluntary recall to include all lots of varenicline (Chantix) 0.5 mg and 1 mg tablets. Pfizer is recalling these lots due to the presence of unacceptable N-nitroso-varenicline levels.

To lessen the impact to patients from a drug shortage due to this ongoing recall, FDA will not object to certain manufacturers distributing varenicline tablets containing N-nitroso-varenicline above FDA’s acceptable intake limit of 37 ng per day but below the interim acceptable intake limit of 185 ng per day until the impurity can be eliminated or reduced to acceptable levels.

The agency has temporarily exercised regulatory flexibility and discretion with respect to Apotex’s distribution of Health Canada-approved Apo-Varenicline tablets in the U.S. containing N-nitroso-varenicline up to FDA’s interim acceptable intake limit in order to help maintain adequate varenicline supply in the U.S. for the near term.

FDA reminds patients taking recalled varenicline to continue taking their current medicine until their pharmacist provides a replacement or their doctor prescribes a different treatment. The health benefits of stopping smoking outweigh the cancer risk from the nitrosamine impurity in varenicline.

Source: US Food and Drug Administration