Chantix Side Effects No Worse With Depression History, Study Suggests

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."

Varenicline is the latest drug the FDA has approved to help tobacco users quit. It seems more effective than other cessation medications, McClure explained, but post-marketing surveillance and case reports have raised concerns about its side effects. These include depression, agitation, and suicidal thoughts and actions, especially in people with a history of psychiatric problems. This has led to several FDA advisories.

COMPASS confirmed previous findings that varenicline side effects, especially nausea, are relatively common. At 3 weeks and 3 months after their target quit date, people with a likely history of depression tended to report these side effects slightly more often—although with no more intensity—than did people without a history of depression.

Feelings of stress and depression tended to decline in both groups—with and without a probable history of depression, said McClure. The trial detected only one serious psychiatric event involving suicidal thoughts and requiring hospitalization. It was in a person who had a previously undisclosed history of bipolar disorder.