Overdose deaths from methadone -- a drug used to alleviate heroin addiction and, increasingly, as a powerful painkiller -- have risen nearly tenfold in Maryland over the past six years.
Through November, 29 people in the state died from methadone intoxication -- more than half in Baltimore City -- compared with three deaths in 1998, according to figures from the state Office of the Chief Medical Examiner.
The deaths represent only about 4 percent of the 662 deaths caused by illegal and abused prescription drugs through November, the figures show. But officials are concerned by the emerging trend.
"We're paying attention to it," said Peter F. Luongo, director of the state's Alcohol and Drug Abuse Administration.
The clinics that distribute methadone to drug addicts have been a source of dispute, often igniting fierce opposition from communities. But health care officials say they doubt such clinics are the source of the abused methadone. The distribution of methadone is subject to tight controls at the 45 drug treatment clinics in Maryland, said Luongo and other state and local officials.
"We have had no diversion from any methadone clinics that would cause us to have any concerns that drug treatment is a source" of these deaths, Luongo said.
Health officials and researchers concede that more research must be been done to determine whether those who died in Maryland were enrolled in addiction treatment programs, used methadone legitimately for pain treatment or illicitly obtained and abused the drug.
But experts believe that people who obtain methadone through a prescription for pain treatment -- sometimes fraudulently -- are abusing or diverting the drug to street sales.
In addition to Maryland, Maine, Virginia, North Carolina and Florida have also dealt with rising cases of methadone-related overdose deaths.
The trend is part of a nationwide increase in the abuse of powerful painkillers over the past decade, statistics show.
From 1994 to 2001, the number of emergency department visits involving abuse of narcotic painkillers more than doubled, from nearly 42,000 to more than 90,000, according to the federal Drug Abuse Warning Network, which monitors emerging drug threats.
Oxycodone, which is sold under brand names such as OxyContin, and methadone were among the top prescription drugs abused in that period.
Methadone, a synthetic opiate, is tightly regulated by the federal government when used for addiction treatment, experts said. Physicians also increasingly prescribe the drug as a treatment for chronic pain because it's considered an effective, and cheaper, alternative to other costlier painkillers, including OxyContin.
Although OxyContin has received heightened attention, in part because of radio talk show host Rush Limbaugh's admitted abuse of it, methadone accounted for more fatal overdoses than OxyContin in Maryland.
The Maryland medical examiner's office recorded 15 deaths through November in which oxycodone was found alone or combined with other substances -- nearly half the fatal overdoses caused by methadone.
Chronic heroin users and oxycodone abusers trying to ease the effects of opiate withdrawal are the most likely abusers of methadone, according to a September report by the National Drug Intelligence Center, a component of the U.S. Department of Justice.
Methadone is available mainly in liquid or pill form. Pills can be swallowed whole or illicitly ground into a powder that is inhaled or injected.
Some doctors who treat chronic pain worry that the rise in methadone-related deaths -- and greater scrutiny by law enforcement of prescription drug abuse -- could pressure them to shy away from prescribing the drug for those in need of relief.
"I've taken care of cancer patients who've thanked me multiple times because I saved them so much money and took care of their pain, all in the same step" by prescribing methadone, said Dr. Joel Kent, director of the University of Maryland Pain Management Center in Baltimore.
"To not have opioids, including methadone, available for patients would be a major step back in our ability to care for patients," Kent said. "There's no doubt about it."
Methadone's characteristics could play a role in the higher death figures, experts said.
Drug users seeking a euphoric "high"-- or chronic pain sufferers who attempt to self-medicate without physician oversight -- can be fooled into consuming too much methadone because it can be hours before a user feels an effect, experts said.
"It's very unique," said Tom Cargiulo, director of substance abuse services for the Howard County Health Department. "There aren't many medications where that's the case."
Another factor in the rising death count could be the increasing amount of methadone produced in the United States. Amounts of methadone distributed nationwide to doctors, hospitals, pharmacies and teaching institutions nearly quadrupled from 1998 to 2002 -- thus increasing chances for diversion and black-market sales, experts said.