The Role of Risk or Contributory Death Factors in Methadone-Related Fatalities: A Review and Pooled Analysis

• Published in: Metabolites 2021-03, Vol.11 (3), p.189
• Main Authors: Giorgetti, Arianna, Pascali, Jennifer, Montisci, Massimo, Amico, Irene, Bonvicini, Barbara, Fais, Paolo, Viero, Alessia, Giorgetti, Raffaele, Cecchetto, Giovanni, Viel, Guido
• Format: Article
• Language: English
• Subjects: drug-related death; forensic toxicology; methadone; post-mortem examination
• ISSN: 2218-1989; 2218-1989
• DOI: 10.3390/metabo11030189

Methadone-related deaths are characterized by a wide range of post-mortem blood concentrations, due to the high pharmacokinetic/dynamic inter-individual variability, the potential subjective tolerance state and to other risk factors or comorbidities, which might enhance methadone acute toxicity. In the present study, the association among pre-existing and external conditions and diseases and the resultant methadone death capacity have been investigated. Beside a systematic literature review, a retrospective case-control study was done, dividing cases in which methadone was the only cause of death (controls), and those with associated clinical-circumstantial (naive/non-tolerant state), pathological (pulmonary or cardiovascular diseases) or toxicological (other drugs detected) conditions. Methadone concentrations were compared between the two groups and the association with conditions/diseases was assessed by multiple linear and binomial logistic regressions. Literature cases were 139, in house 35, consisting of 22 controls and 152 cases with associated conditions/diseases. Mean methadone concentrations were 2122 ng/mL and 715 ng/mL in controls and cases respectively, with a statistically significant difference ( < 0.05). Lower methadone concentrations (by 24, 19 and 33% respectively) were detected in association with naive/non-tolerant state, pulmonary diseases and presence of other drugs, and low levels of methadone (