The US Food and Drug Administration (FDA) has approved a labeling change for varenicline (CHANTIX/Pfizer) removing a boxed warning on potentially serious neuropsychiatric events in people who use the drug to try to stop smoking. It made a similar decision regarding buproprion (Zyban/GlaxoSmithKline)
The FDA said the change is based on favorable results from a trial called EAGLES, which Pfizer described as the largest smoking cessation clinical trial in patients who have a history of mental health problems, a trial that included healthier controls. That study was published earlier this year in The Lancet
In a news release, the FDA said its decision is based on its assessment that both were more effective than placebo for helping people quit smoking regardless of whether or not they had a history of mental illness.
Pfizer announced the labeling change earlier today, and FDA followed up late in the afternoon with an announcement that the change also applied to Zyban.
According to Pfizer, it will also be allowed to add information on "the superior efficacy of CHANTIX compared to Zyban, or the nicotine patch."
While there have been post-marketing reports of adverse events including psychosis, hallucinations, paranoia, and even some suicides, the labeling change merely lists them and suggests that patients using CHANTIX should be observed for such problems and discontinue it and contact a healthcare provider should they experience such symptoms.
The boxed warning was ordered in 2009, and CHANTIX sales dropped sharply to 2.2 million in the US in 2015 from a high of 7.3million in 2007.
According to Pfizer the drug had $198 million in global sales last year, the Wall Street Journal
The EAGLES study showed that patients without psychiatric problems who used CHANTIX did not show an increased incidence of clinically significant neuropsychiatric adverse events.
In the patients who had a history of psychiatric events, the rate of serious events was the same in CHANTIX patients (0.6%) as in those getting a placebo.
That trial was conducted in collaboration with GlaxoSmithKline and designed with assistance from the FDA and its European equivalent, the European Medicines Agency. It involved 8,000 patients both with and without mental health problems and looked at the comparative risks of CHANTIX, buproprion, nicotine replacement therapy and placebo over 12 weeks.
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