WASHINGTON - The Federal Aviation Administration banned pilots and air traffic controllers yesterday from using a popular anti-smoking drug after a study found that it had apparently contributed to auto accidents and other mishaps that posed risks to both users and others.
The drug, marketed as Chantix, has been hailed as an innovative treatment to help smokers quit. But a study by a medical safety group - also issued yesterday - linked it to a variety of unusual and serious side effects, including loss of consciousness and seizures, and prompted the FAA to act, said spokesman Les Dorr.
The agency approved the drug last summer, before federal safety regulators began investigating reports of serious psychiatric problems, including suicidal behavior, sharp shifts in mood and vivid nighttime episodes some patients call "Chantix dreams."
A new warning came from a report by the Institute for Safe Medication Practices, based on an analysis of "adverse events" reports submitted to the Food and Drug Administration.
"We have immediate safety concerns about the use of [Chantix] among persons operating aircraft, trains, buses and other vehicles, or in other settings where a lapse in alertness or motor control could lead to massive, serious injury," the study said.
It remained unclear whether the Pentagon or the civilian agencies that oversee transportation would follow the FAA's example.
The study also noted other serious reported side effects, including vision problems, heart rhythm disturbances, seizures and skin reactions. The nonprofit group that conducted the study advises hospitals and doctors on the prevention of medication errors.
"These data provide a strong signal that the risks of [Chantix] treatment have been underestimated, and show that a wide spectrum of serious injuries are being reported in large numbers," the report said.
Prescription drugs are usually tested on a few thousand people before approval, but serious problems might not emerge until many more patients have used the medication for a sustained period.
Responding to the study, FDA spokeswoman Susan Cruzan said: "We agree that these findings are a signal that requires further investigation and confirmation, and the FDA has been conducting a review of the adverse events associated with Chantix."
The agency recently issued warnings about the drug's effects on mental health and the possibility that taking it could impair driving.
Manufacturer Pfizer Inc. strongly defended Chantix.
Smoking "is one of the largest problems we face in the world," said Dr. Anjan Chatterjee, a Pfizer medical director. "When you think about it in that perspective, the risk-benefit analysis is still substantially toward benefit. Even medications most people consider innocuous have side effects."
In a statement, the company said it believes that warnings on Chantix accurately reflected the drug's risks and benefits, suggesting that no further FDA action was needed. And it cautioned that the raw data on which the safety group based its study often lacked sufficient detail to prove direct cause-and-effect.
Chantix has become a top seller for Pfizer since its approval in May 2006. It acts at sites in the brain affected by nicotine, easing withdrawal symptoms by providing some of the effects of nicotine and blocking those effects if smokers take up the habit again, according to the FDA.
Ricardo Alonso-Zaldivar writes for the Los Angeles Times.