FDA Warnings Yield Lower Chantix Use: Study
Researchers from the University of Pittsburgh and Veterans Health Administration (VHA) say that prescriptions for Pfizer’s Chantix (varenicline) fell following FDA drug safety communications and a Boxed Warning. The research, published online at JAMA Network Open, says that FDA drug safety communications often are based on limited evidence of safety signals after a drug is approved. They said Chantix makes a good case study because there were several agency safety communications in 2008 and 2009. The EAGLES study dismissed safety concerns on increased suicidal thoughts and aggressive and erratic behavior on 12/16/16.
“Early communications from FDA and VHA followed by a labeling change appeared to be associated with a considerable decrease in drug use, which may have been associated with negative public health consequences,” the article says. The researchers estimate that the reduction in number of VHA patients who did not quit smoking owing to decreased Chantix use in the VHA led to a potential 454 deaths.
“Because varenicline has been shown to be more effective than other pharmacotherapy options in assisting quit attempts in both clinical trials and real-world situations,” the researchers write, “it is likely that FDA warnings regarding varenicline safety and resultant actions of healthcare organizations and prescribing clinicians led to a net health care loss.”
The researchers write that they recognize that part of FDA’s responsibility for the safe and effective use of medications requires assessment of early signals for adverse clinical outcomes associated with use of medications after approval. They say the early warnings are released to inform clinicians and the public about the potential for drug-related safety concerns prior to conclusive evidence for causality and often describe the occurrence of less common outcomes that were not identified in clinical trials owing to small sample sizes or limited follow-up.
“Given the uncertain nature of early safety signals,” the article concludes, “it will be important to reexamine the evidence base necessary to release safety communications and ponder it against the strength of the evidence collected from preapproval clinical trials. Conversely, although our report and previous reports have focused on unintended adverse events of these FDA communications, we acknowledge the likelihood of positive clinical outcomes associated with these early communications. Future investigations should examine both positive and negative consequences of these drug safety communications.”