A critical review of the causes of death among post‐mortem toxicological investigations: analysis of 34 buprenorphine‐associated and 35 methadone‐associated deaths

Analysis of causes of death reveals the difficulties in determining the role of substitution drugs in the death process, as many other factors may be involved, including circumstances surrounding death, past history, differential selection of subjects into either substitution modality and concomitant intake of other drugs (especially benzodiazepines and neuroleptics). The potential for synergistic or additive actions by other isolated molecules-particularly opioids, benzodiazepines, other psychotropes and alcohol-must be also considered.