Death from heroin overdose: findings from hair analysis.
BACKGROUND
Morphine analysis of hair is used in forensic toxicology to study the addiction history of heroin addicts. To clarify the features underlying fatal heroin intake, we measured hair morphine content in a group of deceased heroin addicts, to verify a possible correlation between fatal heroin overdoses and the addiction behaviour of these individuals before death.


METHODS
91 deaths were attributed to heroin overdose in Verona, Italy, in 1993-96. We analysed the hair of 37 of these individuals, and of 37 active heroin addicts, 37 former heroin users abstinent from the drug for several months, and 20 individuals with no evidence of exposure to opioids. From each individual, a hair sample of about 150 mg was analysed by RIA and high-performance liquid chromatography, to measure the morphine content.


RESULTS
The mean morphine content in the hair of the addicts who had died was 1.15 ng/mg (SD 2.35 ng/mg; range 0-12.25 ng/mg) compared with 6.07 ng/mg (4.29; 1.15-17.0) in the active heroin addicts, 0.74 ng/mg (0.93; 0.10-3.32) in the abstinent former addicts, and values below the detection limit in the non-exposed group. Hair morphine content among those who had died was significantly lower than that in active heroin consumers (p<.00001), but not significantly different from that in the former addicts (p=0.978).


CONCLUSIONS
Although our findings may be subject to selection bias, since suitable hair samples were available for only 37 of the 91 addicts who had died, these findings support the theory of high susceptibility to opioid overdose after periods of intentional or unintentional abstinence, due to loss of tolerance. Medical staff running detoxification programmes should be aware of the risk inherent in relapse to heroin after a period of abstinence. Moreover, occasional heroin use without a build-up of tolerance could also give a high risk of overdose.
Tagliaro
F
F
Institute of Forensic Medicine, University of Verona, Policlinico, Italy.
De Battisti
Z
Z
Smith
F P
FP
Marigo
M
M
D000328:Adult; D002851:Chromatography, High Pressure Liquid; D062787:Drug Overdose / Q000175:diagnosis / Q000453:epidemiology; D004361:Drug Tolerance; D005260:Female; D006197:Hair / Q000737:chemistry*; D003932:Heroin / Q000032:analysis / Q000506:poisoning*; D006556:Heroin Dependence / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D009020:Morphine / Q000032:analysis; D011863:Radioimmunoassay; D015813:Substance Abuse Detection / Q000379:methods
D003932:Heroin; D009020:Morphine