Chantix May Cause Seizures And Alcohol Risk. Pfizer's smoking cessation drug Chantix (varenicline) is linked to seizures, the U.S. Food and Drug Administration (FDA) warned. Additionally, there are reports of some users becoming aggressive or blacking out while drinking alcohol with the drug. Reuters reports that the FDA approved a … [Read more...] about Chantix May Carry Seizure and Alcohol Risk