Generic Chantix Launched Following Recall of Name Brand Drug Due To Toxic Contaminant

Amid recent concerns about cancer-causing chemical byproducts found in name-brand Chantix pills, which led Pfizer to halt production of the stop-smoking drug and recall all versions last month, the first generic Chantix equivalent will be introduced in the U.S.

Endo International PLC issued a press release on September 22, announcing the launch of generic Chantix (varenicline), which will be distributed by one of its subsidiaries, Par Pharmaceutical, Inc.

Chantix (varenicline) is a prescription medication introduced by Pfizer in 2006, to help people quit smoking. However, the drug has been plagued by problems this year, after high levels of the chemical byproduct N-nitroso-varenicline has been found in pills, leading to a series of Chantix recalls issued over the past few months.

In June 2021, Pfizer first disclosed the Chantix problems, after halting distribution for the drug and recalling one lot in Canada. Weeks later, the Chantix recall was expanded to include 12 batches of the medication sold in the United States in July 2021, and the drug maker announced that it was recalling another four lots of Chantix in August 2021.

Earlier this month, Pfizer announced a complete Chantix recall for all lots of both its 0.5 mg and 1 mg tablets, impacting any pills distributed throughout the U.S., U.S. Virgin Islands, and Puerto Rico from May 2019 to September 2021.

N-nitroso-varenicline is a chemical impurity that may increase the risk of cancer in humans, which is similar to other contaminants that have led to massive Zantac, valsartan and metformin recalls in recent years, involving the presence of a nitrosamine known as N-Nitrosodimethylamine (NDMA). While the recalls for valsartan and metformin were blamed on changes to the generic drug manufacturing process, the Zantac recalls impacted all versions of the blockbuster heartburn drug, after it was determined that the active ingredient may convert to the chemical impurity during storage or as it passes through the body.

Pfizer has maintained that it has received no reports of adverse events linked to this recall, but exposure to the chemicals in these other pills has been linked to reports of cancer as the chemicals move through the body. However, at this time, the FDA is not calling on users to stop taking the drug, and no information has been released that suggests the concerns may extend to generic Chantix versions.