On July 1, FDA announced that Chantix (varenicline), a smoking cessation drug, received a boxed warning to highlight the serious mental health risks, including suicidal thoughts, depression, hostility, changes in behavior and agitation. FDA also strengthened its caution about possible accidents and serious injuries with Chantix linked to loss of consciousness, mental confusion, dizziness and muscle spasms.

These new warnings resulted from an analysis of adverse events reported to FDA's MedWatch program. The Institute for Safe Medication Practices, which operates ConsumerMedSafety.org, originally called FDA's attention to hostile behavior, and a high incidence of accidents and falls in a series of QuarterWatch reports, which were published on this website (search QuarterWatch).

For more information about the boxed warning on Chantix, click here.

FDA has also asked the manufacturer to perform follow up studies to better define the extent of these and other side effects. FDA also required a boxed warning for Zyban (bupropion), another smoking cessation drug. However, our review of available data did not indicate that Zyban adverse effects were as frequent as those with Chantix.