(WTAJ) — A popular drug to curb smoking habits is being recalled over consumer safety concerns.

Pfizer has announced a voluntary recall of all batches of Chantix 0.5 mg and 1 mg tablets due to the presence of an amount of nitrosamine above the Food and Drug Administration’s acceptable limit.

The recall comes two months after Pfizer paused the distribution of the drug in July and pulled nine lots from production and shelves. Pfizer has notified wholesalers and distributors with an existing inventory to stop distribution and production immediately.

The FDA approved Chantix in 2006 as a prescription medication used to help adults quit smoking. The drug is commonly used for 12 to 24 weeks.

According to a company statement posted on the FDA website, there is no immediate risk to patients currently taking Chantix. However, patients taking the medication should consult with their health care provider to determine if alternative treatments are available.

The affected lots were sent to distributors and wholesalers nationwide from May 2019 to September 2021.

According to the FDA, N-Nitroso-varenicline is in the nitrosamine class of compounds, some of which are considered probably human carcinogens (substances that could cause cancer), based on laboratory tests.

“Pfizer is undertaking this precautionary measure,” the company said in its statement. “Long-term ingestion of N-nitroso-varenicline may be associated with a theoretical potential increased cancer risk in humans.”

According to Pfizer, patients with Chantix Tablets should contact Stericycle Inc. at 888-276-6166 (Mon.-Fri. 8:00 am – 5:00 pm ET) for return and reimbursement information.