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 will remove “black box warnings” put on their drugs amid anecdotal reports of serious psychiatric side effects.

The warnings — about “changes in behavior, hostility, agitation, depressed mood, and suicidal thoughts or actions” in some patients — scared off many doctors and smokers trying to quit. The black boxes also led to a U.S. ban against pilots and air traffic controllers using Chantix that’s still in effect.

Pfizer executives and longtime medicinal chemist Jotham Coe, the inventor of Chantix, think it's been vindicated. Coe, who still works at Pfizer and lives in Niantic, Conn., is a former smoker who quit cold turkey after his father, uncle, aunt and both grandmothers died of cancer or emphysema after years of smoking.

Meanwhile, experts say both Chantix and Zyban are safe — far safer than smoking, which kills about 440,000 Americans each year.