ATLANTA -- Overdose deaths from powerful painkillers have been surging at an alarming rate in the U.S., but here's a sliver of good news: The number blamed on methadone appears to have peaked.
Still, methadone accounts for nearly one-third of prescription painkiller deaths, the Centers for Disease Control and Prevention reported Tuesday.
Methadone, known mainly for treating heroin addiction, is also prescribed for pain. Health officials say most of the overdose deaths are people who take it for pain -- not heroin or drug addicts.
After a sharp rise, the number and rate of methadone-related overdose deaths have fallen since 2007, the CDC report shows.
Health officials describe the recent trend as closer to a levelling off than a reversal. But they also acknowledged it is a bit of good news in what has been a deteriorating situation.
"There aren't a lot of problems that have gotten so much worse so quickly as prescription drug overdose has," said CDC director Dr. Thomas Frieden.
Overall, overdose deaths from powerful painkillers have increased by about four times over a decade, he said. Besides methadone, painkiller deaths primarily involve Vicodin (hydrocodone), OxyContin (oxycodone) and Opana (oxymorphone).
Methadone is powerful drug that can be underestimated. It accounted for just 2 per cent of painkiller prescriptions in 2009, but more than 30 per cent of overdose deaths, according to the CDC.
The drug mimics the effects of heroin and has been used to wean heroin users off of their addiction. Regular doses of methadone can reduce heroin cravings and withdrawal symptoms.
Roughly 15 years ago, doctors started prescribing methadone more often for pain, partly because they were looking for an alternative to OxyContin, a narcotic pain reliever that increasingly was being tied to drug abuse and death. Methadone seemed like a safer alternative, said Dr. Len Paulozzi, the CDC study's lead author.
Insurers also encouraged doctors to prescribe methadone because it's cheaper than some other painkillers.
But too much methadone can disrupt breathing, causing death. It also can cause a fatal irregular heartbeat, CDC officials say.
The CDC researchers analyzed a decade of national prescription data, as well as drug-related death data from 13 states. The number of methadone-related deaths rose from fewer than 800 in 1999 to more than 5,500 in 2007, before slipping the next two years to 4,900 and 4,700.
What's behind the change? The researchers note that the Food and Drug Administration in 2006 warned doctors to be more careful in prescribing the drug. And in 2008, methadone manufacturers voluntarily limited distribution of the largest doses of the drug to only hospitals and to addiction treatment programs.
Meanwhile, more states started or toughened up programs to monitor prescriptions for painkillers and look for signs of abuse.
This all boiled down to more education of doctors about the dangers of prescribing methadone, said Bruce Goldberger, professor and director of toxicology at the University of Florida College of Medicine.
"The word got out," said Goldberger, who has been studying methadone overdose deaths for about a decade.
Doctors may be swinging back to prescribing oxycodone and hydrocodone, he said.
Despite all the warnings, the CDC researchers say too many prescriptions are still being written for pain, many by internists and family doctors, not pain specialists. And many of the prescriptions are for back pain and other conditions that methadone might not help in the long run, CDC officials said.