WASHINGTON, D.C. -- While the drug methadone only makes up 2 percent of painkiller prescriptions, it is responsible for a third of painkiller overdose deaths, according to a new study by the Centers for Disease Control and Prevention.
The new report analyzed national drug data from 1999 to 2010.
During that time, 4 out of every 10 deaths from a painkiller involved methadone, which is 2 times higher than any other pain reliever.
Methadone was originally used to help heroin addicts, but has been increasingly used as a painkiller. The drug builds up in the body over time and can disrupt breathing and heart rhythm.
Researchers found 6 times as many people died from methadone overdoses in 2009 compared to 10 years earlier.
Many general practitioners, who don't have experience prescribing complex drugs like methadone, are writing prescriptions for the drug. Experts say methadone should not be a first choice pain reliever.