Source: onthepharm.net Chantix

It just keeps getting worse. Pfizer, which is staring down the loss of a $13 billion-a-year drug (Lipitor) in the 2010-11 timeframe, needs the rest of its product portfolio and its drug development pipeline to be firing on all cylinders.

But one of them keeps sputtering. Sales of the stop-smoking drug Chantix were revving up. It looked like the pill might be on the fast track to becoming a billion-dollar blockbuster. But then reports surfaced about psychiatric and suicidal side effects. And now there's a new report that the drug might be associated with physical side effects. The critical mass has prompted the Federal Aviation Administration to ban pilots and air traffic controllers from taking Chantix.

Last night, a non-profit watchdog group, the Institute for Safe Medication Practices issued this report (varenicline, which you'll see in the title of the document, is the scientific name for Chantix) exposing hundreds of so-called adverse events submitted in recent months to the Food and Drug Administration.

They include accidents, heart trouble, seizures, vision problems, skin reactions and diabetes. ISMP gave the FAA a heads up about its findings earlier this week. But the group thinks pilots and air traffic controllers are not the only ones at risk. It's also concerned about locomotive engineers, bus drivers, crane operators, etc. who might be taking the drug. "We believe (Chantix) may not be safe to use in these settings," the ISMP writes.

In a prepared written statement Pfizer

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[PFE  Loading...      ()   ] cautioned that "spontaneous" adverse event reports can be misleading and don't offer any scientific evidence that the drug caused them. In addition, the company points out that patients can have other health problems or "confounding factors", as Pfizer put it, that could be responsible for the events. A spokesperson for the FDA says it will look into the ISMP's report, but for now the agency remains focused on its ongoing investigation into the suspected psychiatric side effects.

An FAA spokesman says through routine checkups the agency is aware of approximately 150 pilots and 30 air traffic controllers who have volunteered that they've taken or are taking Chantix. It's telling those folks they can't fly or guide flights for three days after they get off the drug. But it's essentially relying on the honor system.

The FAA isn't going to test people. And the spokesman wouldn't speculate on any possible penalties if someone's "caught" on Chantix. I suspect the FAA's quick and decisive action, though, could have a ripple effect across other equipment-operating and public safety sectors. At the very least, it could give smokers more pause about choosing Chantix.

According to analyst and data monitoring reports, Chantix prescriptions have been falling in recent weeks. First quarter sales of the drug dropped--albeit ever so slightly--from the fourth quarter. And at least a couple of analysts this morning think that trend will accelerate. Dr. Tim Anderson at Bernstein is cutting his 2012 Chantix sales estimates more than in half and shaving seven cents off of his earnings per share estimate for that year. Bernstein makes a market in PFE and owns at least one percent of the shares.

But Miller Tabak healthcare analyst Les Funtleyder is less focused on the numbers and waxes more poetic on the situation Pfizer finds itself in. In a research note to clients today he writes: "We cannot make this stuff up--the FAA bans Chantix. We continue to not understand PFE's strategy nor how it will deal with a seemingly endless list of business challenges. PFE continues to be a Murphy's Law writ logarithmic with an avalanche of bad news."

Questions?  Comments?