The Centers for Disease Control and Prevention says the drug accounts for one in three deaths from prescription painkillers.
Methadone is better known as an addiction treatment, but health officials explain most of the overdose deaths are people who take it for pain, not drug addicts.
Experts say overall painkiller deaths have increased by about four times over the last decade, and besides methadone they involve other drugs such as vicodin, oxycontin, and opana.
