SAN FRANCISCO – The increasing use of methadone for pain management has been shadowed by steep increases in the number of emergency department visits and deaths associated with the drug, according to an analysis of two national databases.
The trend is worrisome, and studies to identify the causes of methadone-related morbidity and mortality–as well as potential solutions to the problem–are critically needed, said Mario Moric, Ph.D., in a poster presentation at the annual meeting of the American Society of Anesthesiologists.
His study gathered data from the Drug Abuse Warning Network, which draws on in-hospital emergency records and coroner's data, and from the National Vital Statistics System, which provides poisoning information from death certificate data.
Records of emergency department (ED) visits from 1999 to 2005 that included mention of methadone showed an increase of 659%, accounting for 41,216 visits in 2005, according to Dr. Moric and his associates at Rush University, Chicago.
Death certificates listing methadone poisoning as the cause showed an increase from 786 deaths in 1999 to 3,849 deaths in 2004, a 390% jump that roughly paralleled a 487% rise in ED visits mentioning methadone during that same period, they reported.
In the past decade, methadone has become increasingly popular in pain treatment regimens, Dr. Moric said. Efforts to correct the undertreatment of pain have been followed by reports of wide-ranging abuse of certain pain medications such as oxycodone, especially in its controlled-release formulation, he added.
His study also looked at ED visits and deaths related to oxycodone and to all narcotics from 1999 to 2005. ED visits mentioning oxycodone increased 566% in this period, which surprisingly was not as large as the 659% growth in methadone-associated visits, he said. In 2005, 42,810 emergency visits were associated with oxycodone.
When data on all narcotics were lumped together, ED visits that mentioned any narcotic increased by 132% from 1999 to 2005. All opioid-associated deaths totalled 5,242 in 2004, compared with the 3,849 deaths in 2004 that were associated with methadone.
The Food and Drug Association issued an alert in 2006 about reports of deaths and respiratory depression, cardiac arrhythmias, and other life-threatening problems in patients taking methadone for chronic pain (www.fda.gov/cder/drug/InfoSheets/HCP/methadoneHCP.pdf
Dr. Moric speculated that the upswing in ED visits and deaths associated with methadone may be attributable to cardiovascular issues related to methadone metabolites or to issues related to abuse or overdosing.