Pfizer has announced a recall of the anti-smoking treatment Chantix due to the presence of unacceptably high levels of N-nitroso-varenicline, a substance whose long-term use has been linked to a higher risk of cancer. The drugmaker said on Sept. 16 that it is voluntarily recalling all lots of 0.5 mg and 1 mg Chantix tablets distributed in the United States, U.S. Virgin Islands, and Puerto Rico from May 2019 to September 2021. The tablets were found to contain nitrosamine N-nitroso-varenicline at levels at or above levels deemed acceptable by the Food and Drug Administration (FDA). Pfizer said that long-term ingestion of the substance “may be associated with a theoretical potential increased cancer risk in humans, but there is no immediate risk of patients taking this medication.” “The health benefits of stopping smoking outweigh the theoretical potential cancer risk from the nitrosamine impurity in varenicline,” Pfizer said, adding that it believes that …