Stop-smoking drug Chantix might cause depression

The U.S. Food and Drug Administration (FDA) has issued a notice that it is conducting a safety review of the stop-smoking drug Chantix (varenicline) due to reports of suicidal thoughts and aggressive and erratic behavior in patients who were taking it.

In conducting its review, the FDA will be looking at postmarketing cases submitted by the drug's manufacturer, Pfizer, as well as reports in the press and on internet sites. Chantix (varenicline) is a medication used to quit smoking. Starting from November 2007, when the FDA began investigating reports of depression, agitation, and suicidal behavior among patients taking the medicine as much as 37 Chantix suicides and more than 400 reports of suicidal behavior that may have been linked to Chantix have been received by the end of the year. According to the FDA, a link between Chantix and serious psychiatric complications is becoming progressively probable. Additionally, the drug may worsen preexisting psychiatric illness or cause a recurrence of past issues. By May 2008, Chantix was linked to more than 3,000 reports of serious side effects. By November of the same year, data from the FDA’s Adverse Event Reporting System showed that more reported serious injuries resulted from Chantix than any other prescription drug.

The Federal Motor Carrier Safety Administration announced that the use of Chantix may adversely affect a driver's ability to safely operate a commercial motor vehicle and the FAA has already banned the use of Chantix among pilots and air traffic controllers.

The investigation into Chantix's safety was first triggered by the death of a musician named Carter Albrecht, who played keyboards for singer Edie Brickell. While he was taking Chantix, he began banging on the door of his neighbor’s house, yelling and ranting. The neighbor responded by shooting and killing him. While Albrecht's girlfriend has publicly blamed Chantix, he was also drinking around the time of his erratic behavior and it is unclear what role that may have played.

Preliminary assessment of the reports indicates that many patients developed symptoms of depression and suicidal ideation within days or weeks of starting the medication. In addition, not all patients had pre-existing mental illness or were experiencing nicotine withdrawal, both of which could have potentially explained their symptoms had they existed.

While the investigation continues, the FDA is advising health care providers to monitor their patients for any changes in behavior or mood and advises that patients should communicate with their doctors if they experience any changes as well.

One of the latest studies on Chantix suggests that its side effects are no worse with pre-existing history of the patient’s depressive disorder. The findings by Group Health, Free & Clear, and SRI International researchers are reported in a Journal of General Internal Medicine article. The National Cancer Institute (NCI)-funded, randomized COMPASS trial tracked more than 1,100 Group Health patients receiving behavioral treatment and varenicline to quit smoking. It's the first "real-world" examination of varenicline use since the original Food and Drug Administration (FDA) studies that the manufacturer funded.

"People tend to feel more depressed or irritable while quitting smoking, especially if they have had depression before," said lead author Jennifer McClure, PhD, Group Health Center for Health Studies' associate director for research. "And concerns have been raised that varenicline may increase neuropsychiatric symptoms including depressed mood in people with prior depression." Yet she and colleagues found using varenicline didn't worsen mood symptoms such as depression, anxiety, or irritability in people with a likely history of depression compared to others. "Still," she added, "it's prudent for clinicians to follow the FDA's advice of closely monitoring patients on this drug."

For those who consider Chantix for the smoking withdrawal, be aware on the full list of the potential side effects that has been reported (in no particular order):