Study, Nov/17: Combinations and concentrations of drugs in fatal intoxication...

The full title of this Norwegian study is "Differences in combinations and concentrations of drugs of abuse in fatal intoxication and driving under the influence cases".

"RESULTS:  A total of 194 autopsy cases and 4811 DUID cases were included. Opioids were detected in around 90% of the drug intoxication cases, but in only 16% of the DUID cases. The number of substances detected in fatal intoxications was 4.9 compared to 2.6 in the DUID cases. The total opioid concentrations were significantly higher in the fatal intoxication cases compared to DUID cases (229ng/mL versus 56.9ng/mL morphine equivalents, respectively). Benzodiazepines were detected in 90% of the fatal cases. Only one fatal opioid mono-intoxication was found; a case with a very high methadone concentration (1238ng/mL)."

https://www.ncbi.nlm.nih.gov/pubmed/29128652