On January 18, 2008, Pfizer updated the label on its antismoking pill Chantix to include numerous reports of suicidiality, erratic behavior, and depression in patients. The label advises doctors to monitor patients who are taking Chantix, and to investigate each patient’s previous mental health history before prescribing the drug.

In November 2007, the company included these warnings on Chantix’s label, but in a less prominent section.

Pfizer said there is no established causal link between the behavioral reports and Chantix, but the seriousness of these side effects prompted the updated label.

Sources: Philip Dawdy, “Pfizer adds warning to Chantix,” Furious Seasons, January 18, 2008; Avery Johnson, “Pfizer beefs up warnings on Chantix,” Wall Street Journal, January 18, 2008.