The role of methadone in drug-related deaths in the west of Scotland.

AIMS: To determine the incidence of methadone as either the principal cause of death or as a contributing factor in drug related deaths in the Strathclyde Police region of Scotland and to assess the impact of supervised consumption of methadone on the number of deaths that occurred within each health board area within this region. DESIGN: Retrospective analysis of records held within the Department of Forensic Medicine and Science based at the University of Glasgow over the 11-year period 1991-2001. SETTING: The Strathclyde Police region of Scotland (population approximately 2.25 million). FINDINGS: In 1991, there was one death recorded which was attributable to methadone. Following the introduction of the methadone maintenance programme (MMP) in Glasgow during 1994, there was a 100% increase in these deaths compared to the previous year, a trend which continued over the subsequent 2 years. Following a confidential enquiry into these deaths and a greater compliance from pharmacies supervising methadone consumption, deaths involving methadone had decreased by 48% in 1997. This was particularly evident in the Greater Glasgow Health Board Area, where methadone prescribing has continued to rise annually. However, some difficulties still exist. Multiple take home doses are sometimes prescribed when a pharmacy is closed, which may lead to inadvertent overdose or facilitate diversion of legitimate supplies. In addition, continued use of heroin was found in approximately one-fifth of MMP patients, suggesting possible underdosing. CONCLUSIONS: A growing prevalence of heroin misuse has resulted in an increase in the number of individuals entering the MMP. Despite a continuing increase in the amount of methadone prescribed, methadone deaths in Strathclyde have decreased since 1996 due possibly to changes in both prescribing and clinical care. With efficient management to establish that the patient is complying with the guidelines of the programme and has stopped heroin misuse, methadone can be a safe drug for substitution therapy.