Lethal methadone intoxications in Geneva, Switzerland, from 1994 to 1998

Aims. To estimate the number of methadone lethal intoxications in Geneva fr om 1994 to 1998, where the number of patients in methadone treatment has mo re than doubled since 1990. Design. Retrospective study of all toxicologica l, autopsy and clinical data. Setting. The Geneva Department of Forensic Me dicine. Participants. All suspected overdose deaths in Geneva from 1994 to 1998. Cases were selected on the basis that the only cause of death was a p otentially lethal drug concentration in the postmortem blood sample. Measur ement. Toxicology and autopsy findings, clinical and drug history. Findings . There were 106 lethal drug intoxications over the period. The overall num ber of drug intoxication deaths went from 33 in 1994 to nine in 1998. Thirt y-six cases had methadone identified in their blood. All the 36 cases but o ne had medications or other drugs used illicitly present in the blood or ur ine. Of these 36 cases, 21 were attributed to methadone lethal intoxication . Only seven of these 21 decedents were enrolled in a methadone programmes. The number of deaths attributed to methadone intoxication ranged from thre e to five per year. Conclusion. Most lethal methadone intoxication is due t o diverted or illegal methadone in association with medications or other dr ugs used illicitly. Furthermore, the increase in methadone prescription und er strict medical control with health measures aimed at drug abuse preventi on did not lead, in our study, to an increase of methadone lethal intoxicat ion and may have been partly responsible for the large decrease of overall drug intoxication deaths during the time of our study.