Pfizer has expanded the recall of its Chantix smoking cessation medication to include all lots of 0.5 mg and 1 mg tablets due to a possible cancer-causing ingredient that may be present above the acceptable intake limit set by the Food and Drug Administration.

The Chantix medication may have the presence of N-nitroso-varenicline in higher-than-acceptable FDA interim intake levels, which has the potential for cancer risks with long-term ingestion.

Pfizer said there is no immediate risk to patients taking the medication, and the benefits of taking the medication outweigh the potential for causing cancer from the drug.

N-nitroso-varenicline or nitrosamines are commonly found in water and foods as well as cured and grilled meats, dairy products, and vegetables. At high levels and over long periods of time, they can cause cancer.

Chantix, which is used to help people quit smoking, is intended for short-term use.

The recalled medication was distributed nationwide in the U.S., U.S. Virgin Islands, and Puerto Rico from May 2019 to September 2021. The recall applies to all NDC, lot numbers, and expiration dates listed here.

Individuals that are currently taking the recalled Chantix should consult with their healthcare provider about an alternative treatment option. They should also contact Stericycle at 1-888-276-6166, Monday through Friday, from 8 a.m. to 5 p.m. ET for instructions on how to return the product and receive a reimbursement for the cost of the unused medication.

Pfizer said in a statement about the recall, “Pfizer places the utmost emphasis on patient safety and product quality at every step in the manufacturing and supply chain process.”

The drugmaker said it has not received any reports of adverse events related to the recall.

Pfizer initially recalled the stop-smoking medication on July 16 and expanded the recall on Aug. 16.

Smoking Cigarettes Stop Philip Morris U.K. Managing Director Peter Nixon appeared on 'Good Morning Britain' on Wednesday, where he told viewers that they should give up cigarettes for heated tobacco products. A cigarette smoker is pictured on March 1, 2018, in Lille, northern France, on the day when the price of a packet of cigarettes was increased by one euro to fight against smoking. The government plans regular increases to bring the cost of a packet to 10 euros by 2020. Photo: Getty Images/PHILIPPE HUGUEN