The March 2010 issue of FDAA, contained an article about substantial increases in the number of deaths attributable to methadone abuse. The increase appears to be just one facet of the generalized increase in deaths related to prescription opiate abuse. There are no reliable figures for the last year, but the numbers of deaths, particularly those attributable to methadone, seem to be rising at an alarming rate.

This is bad news for several reasons, not the least of which is that many people are dying. It is also bad news for Medical Examiners, because making the diagnosis of methadone-related death is often very difficult and, sometimes, impossible. FDAA thought it might be a good time to review some of these problems. Table #1 shows the result of 18 different observational studies that have been published since 1998. Table #1 shows the range of postmortem concentrations that have been reported in methadone deaths. The report by Buchard et al., published a few months ago, shows that methadone concentrations in methadone-related deaths may range from 11 ng/ml to 8000 ng/ml, a range so vast as to be of no value, at least not forensic purposes, because if you believe the graph, any concentration of methadone can be fatal!

Put another way, postmortem methadone concentrations simply cannot be considered in a vacuum, because there is no clear dose-response curve. If any methadone is detected, that proves methadone is present and more or less suggests voluntary methadone ingestion (although with very low concentrations, environmental contamination cannot be ruled out).

The absence of anything resembling a clear dose-response curve was recognized a number of years ago, when Caplehorn and Drummer (JR Caplehorn and OH Drummer, “Methadone dose and post-mortem blood concentration.” Drug Alcohol Rev. 2002 Dec; 21(4): 329-33) concluded, “post-mortem methadone redistribution is probably the principal cause of the observed differences between males and females in post-mortem blood concentrations and the differences between estimated concentrations for living and deceased subjects.”. . .