Pilots and air traffic controllers who are taking Chantix to stop smoking must discontinue using the medication in order to continue flying or controlling air traffic. The FAA on May 21 announced the withdrawal of Chantix from its allowed medications list. The decision comes after a February alert from the Food and Drug Administration that the medication could have possible severe psychiatric side effects ranging from changes in behavior to suicide. Pilots cannot fly until 72 hours after the last dose of Chantix. The FAA will accept a personal statement from pilots stating that they have discontinued using the medication. The FAA will send a letter to all pilots and controllers who are currently certified to take Chantix under their medical.