Pfizer said Thursday it is stopping distribution of its anti-smoking treatment, Chantix, after finding elevated levels of carcinogens called nitrosamines in the pills.
The drug manufacturer is recalling a number of batches of the anti-smoking drug.
Pfizer said the affected batches of Chantix contain nitrosamines, but emphasized that there is “no immediate risk to patients taking this drug” and that the recall is from a high degree of caution.
The Food and Drug Administration shared the company’s press release on its website, noting that the company is not authorized by the federal agency to conduct the recall.
The US drug regulatory agency has in the past contacted companies whose drugs had N-nitrosodimethylamine (NDMA) above accepted levels.
Chantix was approved by the FDA in May 2006 as a prescription drug that helps adults ages 18 and older to quit smoking and is used for 12 to 24 weeks.
The batches involved contain levels of cancer-causing chemicals called nitrosamines that exceed the company’s own acceptable daily intake levels
Pfizer said in its publication, “The health benefits of smoking cessation outweigh the theoretical potential cancer risk of the nitrosamine impurity in varenicline.”
The company added that people who smoke cigarettes are 15 to 30 times more likely to develop lung cancer than people who don’t 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 nitrosamines are taken in large amounts for a long time, they can increase a person’s risk of developing cancer.
The FDA began asking drug companies to test their drugs for nitrosamines after large amounts were found in various types 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 because it contained high amounts of the cancer-causing ingredient.
Pfizer did not specify how the nitrosamines got into Chantix. The source of the chemicals in drugs can come from the manufacturing process, chemical structure, or even the conditions under which they are stored and packaged.
Pfizer first announced it planned to recall the drug on June 24 after it was discovered to be a likely carcinogen. Then, on July 2, it listed a recall of nine batches of the drug that had been affected and were in warehouses.
However, the July 16 recall includes 12 more batches of the drug, which have already been distributed to wholesalers in the U.S. and Puerto Rico between June 2019 and June 2021.
The company released a list of lottery numbers and urged consumers to check if their prescription has been affected. They include 00019213, EC6994, EA6080, EC9843, 00020231, 00020232, 00020357, 00020358, 00020716, ET1600, ET1607 and ET1609.
The FDA approved Chantix in 2006 as a prescription drug for adults, ages 18 and older, to use for 12 to 24 weeks to help quit smoking
“Patients currently taking Chantix should consult their physician to confirm whether they have suffered an affected fate and, if applicable, about alternative treatment options,” the company said, adding: “To date, Pfizer has not received any reports of adverse events. associated with this recall.”
Chantix’s sales fell 17 percent in 2020, from $1.1 billion to $919 million, after the company lost protection on one of its most important patents in the United States in November, according to Bloomberg.
While “general competition for Chantix has not yet begun, it may begin at any time,” Pfizer said in its May quarterly report.