In its warning issued Thursday the FMCSA advised medical examiners "to not qualify anyone currently using this medication for commercial motor vehicle licenses," The Wall Street Journal reported Friday. The FMCSA oversees the interstate trucking and bus industry.
A U.S. Food and Drug Administration spokeswoman said the agency was focusing on likely links between Chantix and neuropsychiatric side effects. This year, the FDA and Pfizer, which manufactures the drug, updated warnings on Chantix's label to include depression and thoughts of suicide.
The Institute for Safe Medication Practices, a non-profit watchdog group in Horsham, Pa., conducted the Chantix study that reported the drug was linked to more than 900 serious episodes in the last quarter of 2007.
Pfizer said the report's findings weren't inconsistent with possible side effects listed on drug's label.