FDA Examines Reports Involving Smoking Cessation Drug

The FDA on Nov. 20 announced it is in the process of evaluating the safety of the smoking cessation drug varenicline, sold as Chantix. The agency's move comes after Pfizer Inc., the drug's manufacturer, submitted to FDA officials postmarketing cases that describe suicidal ideation and occasional suicidal behavior in some patients who have taken varenicline. The FDA is reviewing those cases and a number of other recent reports, but has reached no conclusion on the need for regulatory action at this time.

The FDA's preliminary assessment of the postmarketing reports shows that in many of these cases, patients experienced new onset of depressed mood, suicidal ideation and changes in emotion and behavior within days to weeks of beginning treatment with varenicline. The FDA said in an early communication about the ongoing safety review, the role of varenicline in these cases is not clear because smoking cessation -- whether treated or untreated -- can cause nicotine withdrawal symptoms and exacerbate underlying psychiatric illness.

However, the agency noted, among the cases submitted, not all of the patients had preexisting psychiatric illness, and not all had stopped smoking.

Also in that early communication, the FDA said it was aware of one highly publicized case of an adult patient who was using varenicline to quit smoking. The patient was reported to have exhibited erratic behavior that eventually led to his death. Although other factors, including alcohol consumption, appear to have played a role in this incident, FDA officials asked Pfizer specifically to provide information on similar cases and now are evaluating the information submitted in response to that request.

In addition, the reports from Pfizer showed that many patients who have taken varenicline experienced drowsiness that affected their ability to drive or operate machinery. The FDA currently is evaluating these reports.

Until the analysis is complete, the FDA recommends that health care professionals monitor patients who are taking varenicline for behavior and mood changes. Patients who experience such changes should contact their physicians. The FDA also encourages health care professionals to urge their patients who are taking this drug to use caution when driving or operating machinery.

The FDA urges both health care professionals and patients to report side effects associated with varenicline use to MedWatch, the FDA's Safety Information and Adverse Event Reporting Program, either by going online or by calling (800) 332-1088.