Several consumer groups have petitioned the FDA to increase the warnings about the controversial Chantix smoking-cessation drug, which has been linked to risks of suicidal behavior and hostility, based on new scientific information they say has become available since a serious warning was placed on the product labeling five years ago.
In their petition, the groups cite fresh analyses of studies and side effect reports to argue the pill causes distinct psychiatric side effects – suicidal ideation and behavior, aggression and violence, psychosis, and depression – which should be more clearly spelled out in the product labeling.
The move comes one week before an agency advisory panel will review whether some of the existing warnings on the Chantix labeling should be removed, a step that Pfizer, which sells the drug, has requested based on the results of several studies. Last month, in fact, the FDA updated the labeling to indicate the drug may not carry the risks of suicidal behavior.
Pfizer maintains that change was warranted based on a meta-analysis of five studies involving nearly 2,000 patients that did not show an increase in suicidal thoughts or actions among those who took Chantix compared with a placebo. The drug maker also pointed to four observational studies of thousands of patients that did not find differences in risk between its pill and other nicotine treatments.
The petition, however, also argues that those recent studies had methodological flaws and other limitations. “None of the studies are of sufficient quality to establish a convincing estimate of incidence, provide a valid comparison to other treatments, or have the scientific weight to refute evidence from other scientific methods,” the groups wrote.