The U.S. Food and Drug Administration (FDA) has issued an early warning about Pfizer Inc's anti-smoking drug Chantix, amid reports of suicidal thoughts and behaviour.

The FDA is evaluating adverse event reports submitted by Pfizer about Chantix, a prescription drug that is known generically as varenicline.
An early assessment "reveals that many of the cases reflect new-onset of depressed mood, suicidal ideation (thoughts) and changes in emotion and behaviour within days to weeks of initiating Chantix treatment," the FDA said in a posting about the new warning. The FDA cited one case of a patient who had died after using the drug.
Doctors are advised to monitor patients taking the drug for changes in behaviour and mood, the FDA said. (ci)