The Food and Drug Administration warns about suicidal behaviour and other psychiatric side effects of Pfizer's anti-smoking drug Chantix.
Following reports of suicidal tendencies and violent or bizarre behaviour among some patients, the FDA's strongest warning label since 2009 continues to appear on the label.
The FDA outlined several updates to Chantix's labelling, including a new warning about its potential interaction with alcohol. Some patients have reported unusual or aggressive behaviour when drinking while on Chantix.
The drug's labeling currently tells patients to stop taking Chantix immediately if they experience agitation, depressed mood, suicidal thinking and other behavioural changes. Doctors are advised to weigh the drug's risks against its potential benefits of helping patients quit smoking.
The drug, known generically as varenicline, works by binding to the same spots in the brain that are activated by nicotine when people smoke. The blocks prevent the release of "feel-good" brain chemicals that make smoking so addictive.