Pfizer Slammed Over Chantix Side Effect Reporting


Pfizer’s failure to correctly submit adverse event data on the smoking-cessation drug Chantix resulted in underestimated risks of psychiatric side effects.  According to the Institute for Safe Medicine Practice (ISMP), data from the third quarter of 2010 is inaccurate due to the manufacturer’s method of reporting suicide cases.

In 2006, the U.S. Food & Drug Administration (FDA)  approved the smoking-cessation drug Chantix, also referred to as varenicline, marketed by Pfizer.  Chantix reduces nicotine cravings by blocking receptors and decreasing the pleasurable effects of cigarettes and other tobacco products.  

The ISMP, a non-profit organization that reviews the FDA adverse event database, asserts they found 150 cases of completed suicides some dating back to 2007, which Pfizer never reported to the FDA as required.  The non-profit explained that serious adverse events have a 15 day reporting requirement, while non-serious events take place on a quarterly basis.  Pfizer avoided the reporting requirement by coding the suicides for 26,000 events as “expected adverse events”, which were ultimately added to the quarterly periodic report.

Until July 2010, the FDA analysts were “not aware of more than half the reported suicide cases in which Chantix was the primary suspect” reports ISMP.  Additionally, due to Pfizer’s failed reporting the FDA also did not have reported cases of psychosis, depression, or attempted suicide.

This is not the first time concerns of Pfizer’s adverse event reporting actions have been placed under scrutiny.

A study in PLoS One linked Chantix with serious acts of violence such as physical abuse, physical assault, and homicide.   While another study, published in the Annals of Pharmacotherapy concluded that Chantix “is associated with thoughts and acts of aggression and/or violence.”

In November 2007, the FDA announced the agency was initiating a safety review of Chantix.  Pfizer responded by updating the label with a warning “that patients who are attempting to quit smoking with Chantix should be observed for serious neuropsychiatric symptoms, including changes in behavior, agitation, depressed mood, suicidal ideation and suicidal behavior,” says Pharmalot.

Then in May 2010, the FDA sent the drug manufacturer a warning letter  claiming deficient reporting of adverse events dating back to 2004, reports ISMP.  Although Chantix was not listed in the letter, the violations alleged were misclassifying and downgrading events without reasonable justification and failure to submit serious adverse reports within 15 days as required.

Pfizer has also faced consumer lawsuits for Chantix.  In May, the Pittsburgh Post-Gazette reported that the children of a Pittsburg man filed a lawsuit against the company alleging Chantix led to the death of their parents and “that consumers of Chantix were not sufficiently warned at the time that it can cause rage, hostility and suicide.”   Sean Wain was taking Chantix a week or two prior to killing his wife and himself in an early morning shooting in May 2009.