TRENTON, N.J. (AP) — Seven years after U.S. regulators slapped their strictest warning on two popular smoking-cessation medicines citing risks of suicidal behavior, a large international study found no such risk. Now Chantix maker Pfizer and Zyban maker GlaxoSmithKline hope the Food and Drug Administration, which ordered them to do the study, will remove the so-called "black box warnings" put on their prescription drugs due to anecdotal patient reports of serious psychiatric side effects. The warnings — about "changes in behavior, hostility, agitation, depressed mood, and suicidal thoughts or actions" in some patients, all potential problems for people quitting without medication — scared off many doctors and smokers trying to quit.Read more on NewsOK.com