Pfizer’s purported anti-smoking wonder drug Chantix continues to draw fire from medical professionals and non-profit patient advocacy groups as the FDA considers revising their already-severe warnings about the drug. We’ve reported on the evolving problems encountered by Pfizer after the drug’s 2006 FDA approval and, as one can gather from the user comments posted at the end of nearly every Chantix story, personal experiences vary wildly. Some patients have given up tobacco after years of failed attempts with the help of Chantix while others report disturbingly severe side-effects including deep depression, anxiety, nausea, and, in some cases, diabetes-like symptoms.

Pfizer has already weathered reports of increase suicidal ideation among Chantix patients. And the bad news only continues to pile up. The Institute for Safe Medication Practices, a non-profit drug-safety advocacy group, released a statement in May 2008 in order to highlight the fact that nearly 1000 Chantix-related adverse-effects reports were filed by both doctors and patients in the fourth quarter of 2007. And the symptoms aren’t limited to irritating tremors or slight anxiety. According to ISMP’s latest update, the numbers for 2008’s first quarter are even worse: at least 1001 serious incidents were reported. More adverse claims have been made regarding Chantix than any other medication currently on the market. And the affected patient pool is very much a low-risk group. The drug is only approved for prescription as a smoking cessation aide, and it will almost certainly never be approved for individuals with serious mental or physical disorders due to widespread concern over potential complications.

The current uproar centers on the apparent risks posed by driving or operating heavy machinery while taking Chantix. Accidents, particularly those of the motor vehicle variety that appeared to be triggered by Chantix side-effects (convulsions, blackouts, seizures, etc.) were one of the ISMP update’s major areas of concern, and their mention touched a nerve: the Federal Aviation Administration and the U.S. Department of Defense responded dramatically by banning the use of Chantix among pilots and air-traffic controllers. Pfizer’s current warning label reads “Patients should be advised to use caution driving or operating machinery until they know how quitting smoking with CHANTIX may affect them,” but researchers at ISMP argue that this language is not strong enough. Given the fact that Pfizer also officially warns of symptoms like dizziness, disorientation and “disturbance of attention,” we have to agree. While Chantix cannot be definitively linked to each of the incidents reported, the trend itself is not in any way encouraging.

And trouble on the road is hardly the only concern regarding Chantix-related side-effects. Reports of irregular heart rhythms, movement disorders like Tourette’s and, most commonly, glycemic problems resembling diabetes were even more common. Pfizer’s Chantix fortunes will most likely not be improving anytime soon. Harsher warnings are needed, but they won’t solve the problem. Until the medication can be altered and improved in some way, concerns about its possible side-effects are absolutely warranted. We cannot recommend it even for heavy smokers desperate to give up their habit.