Despite recommendations against the use of codeine in children, the pain killer continues to be prescribed in U.S. emergency rooms, according to a recent study CBS News reported.

Researchers from the University of California, San Franciso Benioff found that despite its potentially harmful effects in children, emergency room doctors prescribe codeine to children more than 500,000 times per year.

Codeine is an opioid used to treat mild to moderate pain and suppress cough. Because of variability in how children process the drug, about a third receive no symptom relief from taking it, while up to one in 12 can accumulate toxic amounts causing breathing to slow down and possible death, researchers said.

As a result, several national and international organizations advise against codeine use in children. Guidelines from the American Academy of Pediatrics (AAP) issued in 1997 and reaffirmed in 2006 warn of its potential dangers and lack of documented effectiveness in children with coughs and colds, according to a press release.

"Despite strong evidence against the use of codeine in children, the drug continues to be prescribed to large numbers of them each year," Sunitha Kaiser, lead author of the study, said in a statement. "It can be prescribed in any clinical setting, so it is important to decrease codeine prescription to children in other settings such as clinics and hospitals, in addition to emergency rooms."

For the study, researchers analyzed data from the National Hospital and Ambulatory Medical Care Survey, done by the National Center for Health Statistics, to determine the frequency of codeine prescriptions to children ages 3 to 17 during emergency room visits from 2001 to 2010.

They found that the rates of codeine prescriptions decreased from 3.7 percent to 2.9 percent during the 10-year period. However, a substantial number of children still were being prescribed the drug, from 559,000 to 877,000 prescriptions a year. They also saw no decline in codeine prescriptions associated with the 2006 professional recommendations.

"Many children are at risk of not getting any benefit from codeine, and we know there are safer, more effective alternatives available," Kaiser said. "A small portion of children are at risk of fatal toxicity from codeine, mainly in situations that make them more vulnerable to the effects of high drug levels such as after a tonsillectomy."

Kaiser said ibuprofen is equal to or better than codeine for treating injury pain, and hydrocodone is also a safer, more effective opiate alternative.

The findings were recently published in Pediatrics.