Redistribution, postmortem

When dealing with deceased individuals, the forensic pathologist (usually the medical examiner) will provide samples of blood taken from both the heart and the leg s femoral vein. The results will be compared to avoid reaching an incorrect conclusion of drug concentration for those drugs that exhibit postmortem redistribution, which is when substances that were concentrated... 

Postmortem redistribution After death, drugs that were concentrated in heart and adjacent organs may leak back out into the blood, producing abnormally high values. 

Kerswill RM, Vicente MR. Clozapine and postmortem redistribution. Am J Psychiatry 2003 160 184. 

Barnhart FE, Fogacci JR, Reed DW. Methamphetamine— a study of postmortem redistribution. J Anal Toxicol 1999 23(l) 69-70. 

Langford, A. M., and D. J. Pounder. 1997. Possible markers for postmortem redistribution. Journal of Forensic Sciences 41 (7) 88-92. 

Postmortem redistribution is a common concern with both antipsychotic and antidepressant analytes. Another concern for toxicological analysis is second matrix confirmation. Routinely, two different matrices are used for confirming an analyte s presence. Femoral blood is considered the most accurate representation of an analyte s concentration and is most often used for defining therapeutic and toxic levels. Therefore, for this analysis an alternate blood specimen as well as a liver specimen is analyzed if femoral blood is not available. 

The process of death imparts a number of other special processes that affect the collection and analysis of specimens obtained at autopsy. These include postmortem redistribution in which the concentration of a drag in blood has been affected by diffusion of drag from neighboring tissue sites and organs such as stomach contents. This is minimized, but not arrested, by using peripheral blood from the femoral region. Even liver concentrations are affected... 

TABLE III Likely Extent of Postmortem Redistribution for Selected Drugs ... 

Drug/drug class Likely extent of postmortem redistribution... 

Moriya F, Hashimoto Y. Redistribution of methamphetamine in the early postmortem period. J Anal Toxicol 2000 24(2) 153-5. 

Rogde S, Hilberg T, Teige B. Fatal combined intoxication with new antidepressants. Human cases andane erimental study of postmortem moclobemide redistribution. Forensic Sci Int (1999) 100,109-16. 

In postmortem cases, all reports should indicate the site of blood sampling and provide (where relevant) some comment on the possibility of postmortem artefacts such as redistribution. By incorporating these comments, those reading the report are less likely to unwittingly misinterpret the results. 

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