Chantix Study

Safety Announcement

[10-24-2011] The U.S. Food and Drug Administration (FDA) has reviewed the results from two FDA-sponsored epidemiological studies that evaluated the risk of neuropsychiatric adverse events associated with the smoking cessation drug Chantix (varenicline).

Facts about Chantix (varenicline)

A prescription medicine used to help adults quit smoking Increases the likelihood of abstinence from smoking for as long as one year compared to treatment with placebo. Works by blocking the effects of nicotine (from smoking) on the brain.1 From approval in May 2006 through July 2011, approximately 21.8 million Chantix prescriptions were dispensed and approximately 8.9 million patients received Chantix prescriptions from U.S. outpatient retail pharmacies.2

Neither study found a difference in risk of neuropsychiatric hospitalizations between Chantix and nicotine replacement therapy (NRT; e.g., NicoDerm patches). However, both studies had a number of study design limitations, including only assessing neuropsychiatric events that resulted in hospitalization, and not having a large enough sample size to detect rare adverse events (see Data Summary below for more information). Although these two studies did not suggest an increased risk of neuropsychiatric events that result in hospitalization, they do not rule out an increased risk of other neuropsychiatric events with Chantix.

Healthcare professionals and patients should continue to follow the recommendations in the physician label and the patient Medication Guide, and to monitor for neuropsychiatric symptoms when prescribing or using Chantix. Based on FDA’s assessment of currently available data, the Agency continues to believe that the drug’s benefits outweigh the risks and the current warnings in the Chantix drug label are appropriate.

The risk of serious neuropsychiatric events with Chantix is currently highlighted in theBoxed Warning and Warnings and Precautions section of the physician label and in the patient Medication Guide. Such events can include changes in behavior, hostility, agitation, depressed mood, and suicidal thoughts or actions. These warnings were based on postmarketing reports describing changes in mood and behavior during and after Chantix use (see 2008 Public Health Advisory and 2009 Public Health Advisory).

FDA is continuing to evaluate the risk of neuropsychiatric events with Chantix. The drug manufacturer is conducting a large safety clinical trial of Chantix to assess neuropsychiatric adverse events, and results from this study are expected in 2017.

Additional Information for Patients 

• Some patients have experienced changes in behavior, hostility, agitation, depressed mood, and suicidal thoughts or actions while using Chantix to help them quit smoking. Some patients had these symptoms soon after they began taking Chantix, and others developed them after several weeks of treatment, or after stopping Chantix.
• Before taking Chantix, patients should inform their healthcare professional if they have ever had depression or other mental health problems.
• If a patient develops agitation, hostility, depressed mood, or changes in behavior or thinking that are not typical for them, or if a patient develops suicidal ideation or behavior, they should immediately discontinue Chantix and report these symptoms to their healthcare professional.
• Patients should read the Medication Guide that they get along with their Chantix prescription. It explains the risks associated with the use of Chantix.
• Patients should report serious side effects from the use of Chantix to the FDA MedWatch program.