A large number of potential Chantix side effects – including suicides – were not reported to the U.S. Food & Drug Administration (FDA) in a timely manner,according to a report from the Institute for Safe Medicine Practices (ISMP). Because of the reporting problems detailed by the ISMP, the true seriousness of Chantix psychiatric side effects may have been underestimated.
Chantix was approved as a smoking cessation aid in 2006. In 2009, the FDA mandated that Pfizer add a Black Box Warning to the Chantix label regarding its association with changes in behavior, depression and suicidal thoughts. Since then, Chantix has been associated with more reports of disturbing behavior.
Earlier this month, the ISMP reported that there had been 1,055 serious adverse-events related to Chantix reported to the FDA in the third quarter of 2010. According to the ISMP, this represented a spike in the number of the reports. This jump occurred because the Chantix side effect reports received by the FDA at that time included 589 serious adverse-event reports that had occurred in prior years but were entered into FDA’s adverse-event reporting database for the first time in 2010, the ISMP said. The reports included 150 completed suicides dating back to 2007. Previously, the FDA was aware of 122 reports of suicide submitted by Pfizer, health care professionals and consumers.
Federal drug regulations require companies to file serious adverse event reports within 15 days of receiving them. According to the ISMP, Pfizer would not say why so many Chantix side effect reports were not submitted in a timely manner because of ongoing litigation surrounding the drug.
According to the ISMP:
“This breakdown in safety surveillance meant that until July 2010 FDA safety analysts were not aware of more than half of the reported suicide cases in which varenicline was the primary suspect drug, and did not have available hundreds of other reported cases of serious psychiatric side effects. In the full report we explain what went wrong and explore the still-unanswered questions.”
The ISMP report concludes that the “new data from the third quarter show that the risks of serious psychiatric side effects were previously underestimated because so many of these events were not promptly reported.” The ISMP report asserts that Chantix is “unsafe for widespread clinical use” and calls on the FDA to investigate why the 150 suicides and scores of additional suicide attempts were not properly reported by Pfizer. It also urges the agency to reassess the Chantix safety profile in light of the new information.
According to a report from Dow Jones newswires, the FDA said the additional Chantix side effect reports “have not changed the agency’s position on the drug’s risk and benefits given that these reports were consistent with those that led to the 2009 labeling change.”