Postmortem Oxycodone Toxicology: A Systematic Review and Meta-Analysis of Concentrations and Interpretative Markers

Area of Science:

• Forensic Toxicology
• Pharmacology
• Clinical Chemistry

Background:

• Oxycodone is a crucial semi-synthetic opioid for pain management.
• Determining its role in postmortem deaths is challenging due to limited quantitative data.
• Forensic interpretation of postmortem oxycodone concentrations requires further evidence.

Purpose of the Study:

• To systematically review and meta-analyze quantitative postmortem oxycodone concentrations.
• To compare oxycodone levels in fatal intoxications versus non-intoxication deaths.
• To analyze mono- versus mixed-intoxication cases and explore contributing factors.

Main Methods:

• Systematic review and meta-analysis following PRISMA 2020 guidelines.
• Searched PubMed and Scopus for studies reporting quantitative postmortem oxycodone concentrations.
• Performed random-effects meta-analysis on peripheral blood concentrations, with secondary analyses of metabolites, alternative matrices, and postmortem interval.

Main Results:

• Included 23 studies with 4335 oxycodone-positive decedents; 14 studies in meta-analysis.
• Fatal intoxication cases (n=1555) had a pooled geometric mean peripheral blood oxycodone of 0.37 mg/L vs. 0.08 mg/L in non-intoxication deaths (n=1409).
• Mono-intoxication cases (n=135) showed higher concentrations (0.52 mg/L) than mixed-drug fatalities (n=511; 0.29 mg/L).

Conclusions:

• Higher peripheral blood oxycodone levels are associated with fatal intoxications.
• Substantial heterogeneity prevents defining absolute concentration cut-offs.
• Postmortem oxycodone interpretation necessitates a probabilistic forensic framework integrating multiple data points.