Increased prescribing of methadone for pain management and a lack of
prescriber knowledge about its pharmacological risks are the main contributing
factors to the spike of deaths associated with methadone overdose in recent
years, a government report has found.
A fivefold increase in methadone-associated overdose deaths from 1999 to
2005, as reported by the Centers for Disease Control and Prevention, has
caused growing concern among public-health experts. The Government
Accountability Office (GAO) conducted an investigation on the causes of this
trend and government efforts to curb it and released the findings in a report
on March 26.
One of the key factors in the spike in methadone-associated deaths is the
rising number of methadone prescriptions intended for pain management since
the late 1990s, after the abuse and deaths associated with OxyContin were
widely publicized, the report concluded. The increased prescribing may have
led to easier availability for diversion and misuse, since methadone
prescribed for pain is dispensed like other Schedule II narcotics and not
restricted to methadone clinics registered by the Drug Enforcement
Administration (DEA). In those clinics the medication is directly
administered. "Methadone prescriptions for pain management grew ...
nearly eightfold" from 1998 to 2006, the report found. Meanwhile, the
amount of methadone dispensed by opioid-addiction treatment programs increased
far more slowly.
The increased use of methadone for pain management carries additional
safety risks compared with its use by addiction specialists, because many
health care professionals are unfamiliar with the pharmacological properties
of methadone that set it apart from other opioid medications, the report
noted. Methadone has a slow onset of action as well as slow elimination and
remains in the body long after the pain-relief effect wears off.
Some organizations and experts told the GAO that many practitioners lack
adequate training in managing pain with methadone. If not fully warned of the
risks, patients may take more than the appropriate dosage or take methadone
with other narcotics, causing accumulation of the medication and leading to
respiratory suppression and overdose.
In addition, the DEA and other agencies indicated to GAO that increased
diversion and abuse of methadone appear to have contributed to the increased
deaths. This may be part of a national trend of increased prescription-drug
abuse in general, especially among younger populations, in recent years.
The GAO noted a number of public-health efforts that were conducted by the
federal government and five states to reduce and prevent methadone abuse,
overdose, and deaths, and these were reviewed for the report: Florida,
Kentucky, Maine, New Mexico, and West Virginia.
For example, the Substance Abuse and Mental Health Services Administration
has given a $1.5 million grant to the American Society of Addiction Medicine
to establish a Physician Clinical Support System to educate prescribers about
the safe use of methadone for pain management and addiction treatment. Other
educational initiatives through public and private organizations have been or
are being developed for health care professionals and consumers. Some experts
warned, however, that too much emphasis on methadone alone could"
unintentionally shift similar problems to a different drug,"
according to the report.
Following a request by the Food and Drug Administration in November 2006,
the labeling of methadone was revised and now carries strengthened safety
warnings and dosage guidelines, including suggesting a maximum daily dose of
30 mg for treating pain, the GAO report stated. On March 3 the agency and
manufacturers of certain opioid products, including methadone, held a joint
meeting to develop a "risk evaluation and mitigation strategy" to
monitor these medications continuously and ensure that they are used
"Methadone-Associated Overdose Deaths: Factors Contributing to
Increased Deaths and Efforts to Prevent Them" is posted at<www.gao.gov/cgi-bin/getrpt?GAO-09-341>.▪