According to a review of adverse event reports submitted to the FDA, the smoking cessation drug Chantix is cited as the likely cause of more reports involving suicidal thoughts and behaviors than any other medication sold in the U.S.
The Institute for Safe Medication Practices (ISMP) issued its Quarterwatch report (PDF) on September 24, which monitors activity in the FDA’s adverse events reporting program.
Although Pfizer recently indicated that it plans to ask the FDA to remove a “black box” suicide waring from the Chantix label, the ISMP report suggests that no other medication results in nearly the same number of adverse event reports involving suicide or suicidal thoughts.
Between 2007 and 2013, Chantix was associated with 2,748 adverse event reports of suicide, self-injurious behavior or homicidal ideation. The next closest drug was Singulair, an asthma drug that only accounted for 835 such cases during the same time period; less than one third of those linked to Chantix.
Rather than removing the Chantix black box warning, ISMP indicates that the information should be strengthened to more clearly indicate the potential risk of homicidal ideation, aggression and violence.
Chantix Black Box Warning
Chantix (varenicline) is a prescription medication introduced in 2006, designed to help people quit smoking by reducing the positive feelings that come from cigarettes.
Shortly after it was introduced, concerns emerged about the psychiatric side effects of Chantix, following reports of unusually aggressive behavior, suicidal thoughts and behavior.
In July 2009, the FDA required a “black box” warning about the risk of suicide and other psychiatric problems that may be caused by the medication, which is the strongest label warning that can be placed on a medication. The information remains prominently placed in a box on the label to alert healthcare providers and consumers.
After the release of several studies in recent years that contradict prior findings involving the link between Chantix and suicide, the FDA announced earlier this month that it is updating the Chantix label to add information about these studies.
Pfizer officials now indicates that the inclusion of the new data means that the FDA should remove the black box label warning from their medication, which was previously viewed as a blockbuster product before concerns emerged about the risk of suicide.
The FDA has scheduled a joint meeting of two advisory committees for October 16, to review the most up-to-date data on Chantix side effects and make recommendations on whether the label needs to be changed further. While the advisory committee’s recommendations are not binding, they are often weighed heavily in any final regulator decisions.
The ISMP report raises questions as to why the FDA would feel the warning needs a review, and points out that Chantix use is currently banned for pilots and air traffic controllers by the Federal Aviation Administration due to its psychological side effects, and the Departments of Defense and Transportation does not allow its use by those in sensitive occupations.
The drug’s side effects also led to thousands of Chantix lawsuits, which Pfizer opted not to fight in court, instead paying an estimated $300 million to settle claims.
“More than 3,000 patients sued Pfizer Inc., the manufacturer of varenicline, over psychiatric side effects that included suicide, psychosis and violence,” the ISMP report notes. “On the eve of the first potential trial in open court with batteries of experts on both sides prepared to testify, Pfizer opted to pay most claimants rather than try even a small group of bellwether cases. It is not clear why the FDA opted to convene two advisory committees to reconsider the warnings about suicidal behavior and other psychiatric side effects.”
Instead of weakening the warning label, ISMP indicates that the black box warning should be strengthened, with promotional language about the benefits of smoking cessation removed. In addition, the group indicates that the indications section should indicate that Chantix is not recommended for people in sensitive occupations, such as pilots, air traffic controllers, missile crews, armed military personnel, police, fire and emergency professionals.
In addition to the risk of psychiatric side effects for individuals in sensitive occupations, other side effects of Chantix may post neurologic or cardiac risks, including blackouts, convulsions and impaired vision, according to ISMP.