Efficacy of drug screening in forensic autopsy: retrospective investigation of routine toxicological findings.

Toxicological analysis is indispensable in forensic autopsy laboratories, but often depends on the limitations of individual institutions. The present study reviewed routine drug screening data of forensic autopsy cases (n=2996) during an 18.5-year period (January 1996-June 2014) at our institute to examine the efficacy of the procedures and findings in autopsy diagnosis and interpretation. Drug screening was performed using on-site immunoassay screening devices and gas chromatography/mass spectrometry (GC/MS) in all cases, followed by re-examination using GC/MS and liquid chromatography/tandem mass spectrometry (LC/MS/MS) at a cooperating institute in specific cases in the last 4 years. GC/MS detected drugs in 486 cases (16.2%), including amphetamines (n=160), major tranquilizers (n=72), minor tranquilizers (n=294), antidepressants (n=21), cold remedies (n=77), and other drugs (n=19). Among these cases, fatal intoxication (n=123) involved amphetamines (n=73), major tranquilizers (n=37), minor tranquilizers (n=86), antidepressants (n=3), and cold remedies (n=9); most cases involved self-administration, alleged suicide and accidental overdose, while homicide was not included. These drugs were also identified in other manners of death, including homicide (n=40/372), suicide (n=34/226), accidental falls (n=27/129), and natural death (n=72/514). In these cases, on-site immunoassay screening of drugs of abuse showed negative findings in 2440 cases (81.4% in all cases), while GC/MS detected other drugs in 218 cases (7.3% in all cases), including several antipsychotic drugs, acetaminophen and salicylic acid. Further analysis using LC/MS/MS detected low concentrations of benzodiazepines in 32 cases, and also anti-diabetic and hypertensive drugs in a case of fatal abuse. These observations indicate the efficacy of systematic routine toxicological analysis to investigate not only the cause of death but also the background of fatalities in forensic autopsy. The provision of extensive drug screening is needed for forensic and social risk management, considering the marked diversity of medical and illicit drugs.