CHICAGO -

There's new evidence that the potent painkiller codeine is being given to hundreds of thousands of children in emergency rooms despite guidelines on limiting its use.

That is the conclusion of a study based on an analysis of 10 years of national data.

Codeine prescriptions were given in about 3 percent of kids' ER visits in 2010. But that amounts to more than half a million visits.

The Food and Drug Administration issued its strictest warning last year about a rare risk for life-threatening complications or death in children given the drug after certain surgeries. It advises using codeine for children's pain only if anticipated benefits outweigh the risks.