After reviewing the results of two epidemiological studies that compared the controversial Chantix smoking-cessation pill with NicoDerm patches, the FDA has decided that the benefits of the Pfizer pill continue to outweigh the risks. The decision comes three years after the drugmaker added warnings its anti-smoking drug is connected to suicidal thoughts and behavior (back story).
Due to the myriad reports linking Chantix to psychiatric side effects, the FDA had sponsored two observational studies of neuropsychiatric adverse events with Chantix. One was conducted by the Department of Veterans Affairs’ Center for Medication Safety and the other by the Department of Defense’s US Army Medical Command’s Pharmacovigilance Center.
The VA study population included 14,131 Chantix users and an equal number of NRT users. The DoD study was also a retrospective cohort study comparing 30-day rates of hospitalizations for neuropsychiatric adverse events among 19,933 new Chantix users and 15,867 NRT patch users who started therapy from August 1, 2006 to August 31, 2007 in the Military Health System. Patients were drawn from active duty military personnel, military retirees and their dependents.
“Neither study found a difference in risk of neuropsychiatric hospitalizations between Chantix and nicotine replacement therapy,” the FDA says in a statement. “However, both studies had a number of study design limitations, including only assessing neuropsychiatric events that resulted in hospitalization, and not having a large enough sample size to detect rare adverse events.
“Although these two studies did not suggest an increased risk of neuropsychiatric events that result in hospitalization, they do not rule out an increased risk of other neuropsychiatric events with Chantix…(But) based on FDA’s assessment of currently available data, the agency continues to believe that the drug’s benefits outweigh the risks and the current warnings in the Chantix drug label are appropriate.”
The verdict is a big win for Pfizer, which has struggled to promote Chantix against a rising mound of studies that its pill is more trouble than it’s worth. In addition to concerns about suicide, studies have suggested Chantix can be responsible for violent behavior and cause serious cardiovascular risks (see here, here and here). The European Medicines Agency, however, recently ruled that Chantix benefits outweigh any heart risks (see this).