chantixIn a safety announcement, the US FDA has updated the label for the prescription smoking cessation medicine Chantix, warning that it could change the way the body reacts to alcohol and on rare occasions lead to seizures.

Pfizer, the manufacturer of Chantix (varenicline), submitted a case series to the Food and Drug Administration (FDA) which was reviewed alongside reported cases of patients experiencing adverse reactions to the drug from the FDA Adverse Event Reporting System (FAERS) database.

In a review of the case series presented by Pfizer and the FAERS database, the FDA noted a number of adverse reactions were experienced by patients drinking alcohol while being treated with Chantix.

These adverse reactions were related to a decreased tolerance for alcohol and included increased intoxication, loss of memory and aggressive or uncharacteristic behavior.