Gerostamoulos J., Drummer O.H.

Victorian Institute of Forensic Medicine and Department of Forensic Medicine, Monash University,57-83 Kavanagh Street, Southbank, Melbourne, Victoria, 3006, Australia

Two studies on morphine (Sawyer and Forney, 1988; Logan and Smirnow, 1996), show conflicting data on the extent of postmortem redistribution. Studies were conducted to assess whether morphine and its metabolites were subject to the process of postmortem redistribution.
Redistribution was assessed by comparing drug concentrations in admission blood (adm) to autopsy blood (aut). Concentrations were determined as follows (adm vs aut): morphine-3-glucuronide - 0.66 vs 0.72 mg/L; morphine-6-glucuronide - 0.16 vs 0.21 mg/L; free morphine-0.32 vs 0.49 mg/L; and total morphine - 0.85 vs 1.07 mg/L. From our observations, significant postmortem redistribution for morphine seems unlikely. There was no significant difference in concentrations between admission and autopsy blood in which the postmortem interval averaged 59 h. Morphine and morphine-glucuronide (M3G and M6G) concentrations were also similar in blood taken from sub-clavian, heart and femoral regions.
While caution has been suggested when interpreting heart blood concentrations of morphine in the absence of femoral data, our results are in agreement with Logan and Smirnow (1996) who demonstrated that concentrations of free morphine do not alter with postmortem interval at either central or peripheral sites. It is widely recognised that femoral blood is the specimen of choice for toxicological analysis. While morphine may not be subject to significant redistribution, femoral blood would still be preferable since contamination with other body fluids is minimised and the distribution for other drugs seen in heroin users is minimised (eg codeine, methadone).

References

1. K. Logan and D. Smimow., J Forensic Sci, 1996, 41, 37-46;
2. W.R. Sawyer and R.B. Forney., Forensic Sci. Int., 1988, 38, 259-73.