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On every package of the quit-smoking drug Chantix, a warning label alerts doctors and consumers that some people taking the tablets have reported “serious neuropsychiatric events.”

As FairWarning has reported, Chantix’s so-called black box warning – the government’s strongest alert – was first imposed in 2009 after thousands of claims of side effects, including reported suicides or suicide attempts. The current label tells patients to stop taking Chantix if they experience unusual bouts of agitation, hostility or a depressed mood, or if they develop “suicidal behavior” or thoughts.

Today, members of two Food and Drug Administration advisory panels rejected a bid by the pharmaceutical giant that sells Chantix, Pfizer Inc., to remove the black box warning.

In all, 11 of the panelists voted for the status quo — at least until a broad Pfizer-financed study is completed over the next year or two – while six other panel members backed minor label changes, and one supported the company’s request to remove the black box warning.

The decision still awaits final action by the FDA, but the agency normally goes along with its advisory panels’ recommendations. Today’s vote was in line with a recommendation by FDA staffers.

Pfizer has argued for the removal of the black box warning based partly on its own “meta-analysis” of five studies that the company says show no increase in suicidal thoughts or actions among users of Chantix, whose scientific name is varenicline. But the FDA staffers found that eliminating the warning “could be interpreted as confirming ‘no association’ between varenicline use and neuropsychiatric risk, which is not supported by currently available observational data.”

In a statement after today’s vote, Pfizer said: “The completion of our currently ongoing safety study will represent one more step forward in the process of accurately characterizing the neuropsychiatric safety of this important medication. Chantix is a highly effective aid to smoking cessation treatment for smokers who want to quit.”

Today’s vote is another turn in a struggle that began soon after the FDA approved Chantix in May 2006. Once expected to be blockbuster drug, Chantix’s sales zoomed to to $883 million in 2007. But that turned out to be its peak year, after reports of tragedies linked to the drug emerged, triggering a torrent of lawsuits. As The Associated Press has reported, Pfizer has paid roughly $300 million to settle more than 2,500 lawsuits alleging that Chantix caused various psychiatric problems, injuries and suicides.

FairWarning’s 2010 investigation of Chantix found that Pfizer failed in its years of clinical trials to test the product on the mentally ill or those with a recent history of depression — even though millions of smokers suffer from psychiatric problems. Moreover, FDA regulators approved Chantix after a speeded-up “priority review” process. The agency did not request a follow-up study on mentally ill patients using the medication, even though the agency’s own safety reviewer reported that the exclusion of such smokers may have undermined the clinical trials.
It wasn’t until 2009, after thousands of reports of serious side effects, that the FDA told Pfizer to conduct trials including people with a history of mental illness. That’s when the agency also slapped the initial black box warning on Chantix.

Dr. Timothy Fong, a psychiatrist and director of the UCLA Addiction Medicine Clinic, said he hopes that the FDA keeps the black box warning when the agency makes its final decision.

On the one hand, he said, the drug is important because there aren’t many other effective tools to treat addiction to smoking, and it also shows promise in treating addictions to substances such as alcohol and methamphetamines.

“But at the same time, we have a medication that works on the very deepest regions of our brains that control emotions, reward, pleasure, self-control. So it stands to reason that when you give a medication like that to millions of humans, there probably will be a small percentage of folks who have untoward or adverse events from it,” said Fong. Until about two years ago, Fong was a paid member of Pfizer’s speakers bureau, giving talks to doctors and other health professionals about the drug.

From what he was witnessed professionally, Fong said, “It’s either been an amazing product for some patients who’ve been really able to stop smoking altogether, without really doing a lot of hard work. The urges to smoke are gone. They can resist the triggers to smoke. They just don’t turn automatically to cigarettes. On the flip side, though, there have been a number of patients we’ve seen who develop these purported side effects – the dreams, the suicidal ideation [thoughts], the agitation, the insomnia.”