The Food and Drug Administration released a decision Friday to no longer require a black box warning about psychiatric effects on Chantix, a drug meant to help people stop smoking, according to the drug's manufacturer Pfizer. Though this is a win for Pfizer, it's also a win for science: years of independent scientific research has shown there's no link between the drug and an increased risk of negative psychiatric effects.
The black box label is the FDA's most severe requirement on a drug and, for Chantix, it also included warnings about possible adverse psychological side effects including hostility, depressed mood, and suicidal thoughts. Those warnings will still be on the label, but without the scary black box formatting. The label has also been updated to include language that makes it clear these warnings are only based on consumer reports and that the scientific evidence shows no significant increased risk of mental side effects while taking the drug.
"We are pleased with the FDA's decision to update the Chantix labeling based on the largest clinical trial of smoking cessation medications, and we expect this new information may further facilitate an informed discussion about quitting with Chantix between smokers and healthcare providers," Dr. Freda Lewis-Hall,Pfizer's chief medical officer, said in a press release.
The FDA first required the black box warning back in 2009, after an avalanche of consumer reports linking the drug to everything from depression, to suicidal thoughts, to homicides. These reports came through the FDA's adverse events reporting system, a kind of hotline where anyone can report side effects for any drug. These reports are unconfirmed, and anecdotal, but are an important way for the FDA to monitor the side effects of drugs, which aren't always completely captured in pre-market clinical trials.
But since 2009 there have been multiple studies that failed to find a link between the drug and any adverse psychological effects. The FDA also ordered Pfizer, which makes Chantix, to do a large, double-blind, placebo-controlled trial specifically looking for any mental side effects, which did not find a significant increase in adverse psychiatric effects from Chantix.
In September, two of the FDA's drug safety and risk advisory committees met and released a report where the committees reviewed all of the available literature. These groups came to the conclusion that there wasn't good enough evidence to warrant the black box label, and recommended the FDA roll back the requirement.
Varenicline, the active drug in Chantix, helps smokers quit by binding to nicotinic receptors in the brain before nicotine can get there (smokers can keep puffing during the first few weeks of taking the drug). This not only makes smoking less enjoyable by not letting nicotine work its magic, but also curbs cravings by stimulating those receptors that crave a nicotine hit. It's been found to be quite effective: after using Chantix for 12 weeks, 23 percent of people are still tobacco-free (not a single puff) a year later. Nicotine patches and gum, for comparison, have about a 6 percent success rate.
Pfizer has been understandably keen to get the black box label requirement lifted—the intense formatting can make a lot of people wary about trying the drug.
But what about all those reports of suicidal thoughts or depressed mood? Were people just lying? Well, probably not, but it could be that the side-effects being attributed to Chantix were actually related to just quitting smoking—nicotine withdrawal can cause irritability, anxiety, and depression.
And those reports are still mentioned on the label, giving doctors and patients a clearer understanding of where they come from and what they mean.