Methadone deaths: a toxicological analysis

Aims-To perform a toxicological analysis of deaths involving methadone and to determine the fatal concentration of methadone in such deaths. Methods-Deaths in which methadone was mentioned in the cause of death were identified. Deaths were divided into those associated with methadone only a nd deaths in which the cause of death was a combination of methadone and ot her drugs. Toxicological findings in these deaths were analysed and compare d with previously published data. Results-One hundred and eleven cases were analysed. In 55 cases, methadone poisoning was given as the sole cause of death. Fifty victims were adults, age range 17-51 years (median, 23), with five victims under 14 years of age . The mean methadone concentration in the adult deaths was 584 mu g/litre ( median, 435; range, 84-2700). In 56 cases, age range 15-49 years, (median, 28), death was ascribed to a combination of methadone and other drugs. The mean methadone concentration in these deaths was 576 mu g/litre (median, 29 4; range, 49-2440). In 26 cases, multiple site sampling was performed. This revealed that there could be a 100% discrepancy between methadone concentr ations, and other drugs, in samples collected in different sites in the sam e body. Conclusions-There is an overlap between quoted therapeutic methadone concen trations and methadone concentrations seen in fatalities. However, those dy ing from methadone poisoning might not be the same as those in a methadone programme. A degree of caution must be exercised in determining a fatal con centration because of the phenomenon of postmortem redistribution. Patholog ists and toxicologists need to examine all the available postmortem finding s in identifying the cause of death.