FDA Changes Chantix Label to Warn About Risks

The FDA has updated the label of Pfizer’s prescription smoking cessation agent, varenicline (Chantix), to warn about potential alcohol interaction and rare seizure risks.

After reviewing a case series submitted by Pfizer and incidents in the FDA Adverse Event Reporting System (FAERS) database, the agency found that some patients who consumed alcohol during Chantix treatment experienced decreased tolerance to alcohol, including increased drunkenness and unusual or aggressive behavior.

The FDA also identified cases in the FAERS and the medical literature where patients with either no history of seizures or a seizure disorder that had been well-controlled reported seizures while taking Chantix, most of which occurred within the first month of varenicline treatment.

Based on these findings, the FDA approved changes to the Chantix label to warn about these risks.

Additionally, the FDA updated the Warnings and Precautions section of the label to include information about several studies that investigated the risk of neuropsychiatric side effects on mood, behavior, or thinking.

“These studies did not show an increased risk of neuropsychiatric side effects with Chantix,” the FDA stated. “However, they did not examine all types of neuropsychiatric side effects, and they had limitations that prevented us from drawing reliable conclusions.”

Pfizer is currently conducting a large safety trial to investigate this risk, with results expected in late 2015.

The FDA will continue to update the public with new information as it becomes available. In the meantime, the agency urges health care professionals and patients to report any side effects involving Chantix to its MedWatch program.