Last month, Pfizer agreed, after consulting with the FDA, to update packages of Chantix sold in the United States to more prominently display a warning that users should be monitored for suicidal behavior, depressed mood, and other mental health symptoms.
The FDA approved Chantix in May 2006 as a smoking-cessation drug. It acts in areas of the brain affected by nicotine and may ease withdrawal symptoms and block the effects of nicotine if users resume smoking.
On Friday, FDA officials advised patients to tell their doctor about any history of psychiatric illness before starting Chantix. The drug can cause current psychiatric illness to get worse even if it is under control. Chantix may also cause the recurrence of an old psychiatric illness, the officials warned.
Patients should also report changes in mood and behavior to their doctor. Symptoms to look out for include anxiety, nervousness, tension, depressed mood, unusual behaviors and thinking about or attempting suicide, the FDA officials said.
In most cases, these symptoms developed while taking Chantix, but they can also appear after stopping the drug, the officials noted.
"We are continuing with the review process over the next several months as we try to pin down to what extent these problems are being seen with Chantix," Rappaport said.
Vivid, unusual, or strange dreams may occur while taking the drug. Patients may also experience impaired ability to drive or operate heavy machinery, the officials said.
For more on quitting smoking, visit Smokefree.gov.
SOURCES: Feb. 1, 2008, teleconference with Bob Rappaport, M.D., director, and Celia Winchell, M.D., team leader, Division of Anesthesia, Analgesia and Rheumatology Products, Office of Drug Evaluation II, Center for Drug Evaluation and Research, U.S. Food and D
All rights reserved