Pfizer Inc.'s once promising anti-smoking drug Chantix received another blow Wednesday after a nonprofit group's report about serious physical side effects prompted the Federal Aviation Administration to ban the drug's use by pilots and air traffic controllers.

The report, from the Institute for Safe Medication Practices, points out hundreds of serious problems reported since the popular drug was approved in May 2006, including vision and heart problems, dizziness, loss of consciousness, seizures, and abnormal spasms and movements.