Mechanisms Underlying Postmortem Redistribution of Drugs: A Review

Abstract

Postmortem drug concentrations do not necessarily reflect concentrations at the time of death, as drug levels may vary according to the sampling site and the interval between death and specimen collection. These site- and time-dependent variations are called "postmortem redistribution" (PMR). The underlying mechanisms are complex and of different types. Passive drug release from drug reservoirs such as the gastrointestinal tract, liver, lungs, and myocardium may occur immediately after death and, later on, cell autolysis and the putrefactive process participate in redistribution. There is evidence that basic lipophilic drugs with a large distribution volume are particularly susceptible to PMR. Nevertheless, this cannot explain the actual PMR of some nonbasic, nonlipophilic drugs. In addition, the persistence of drug metabolism immediately after death must be considered. Consequently, it is of great importance to analyze specimens from different sampling sites in order to detect potential PMR and avoid misinterpretation of results.

Vitreous Humor: A Short Review on Post-mortem Applications

“…Cocaine (COC) is one of the most frequent causes of drug-related death reported by forensic pathologists [118]. The post-mortem redistribution hinders the interpretation of blood levels of cocaine [119].…”

“…The post-mortem redistribution hinders the interpretation of blood levels of cocaine [119]. VH is a better-preserved sample and is easier to collect [118]. Thus, VH is a good alternative to whole blood (WB) analysis in determining the concentration of COC and its metabolite, BE (benzoylecgonine) [120].…”

“…In addition, the results suggest that VH is useful to infer the COC concentrations in overdose cases. Besides, the VH was more adequate to identify the COC use than WB [118]. Although more studies are recommended to clarify this point, it means that VH supplies information that is qualitative (to determine the COC use) and quantitative (to estimate the blood COC concentrations and determine an overdose case) [118].…”

Comparative Study of Blood Metal Levels in Post-Mortem and Living Population Samples from Dammam, KSA

“…However, Postmortem changes, such as post-mortem diffusion and redistribution, make the interpretation of xenobiotic concentrations measured in post-mortem samples difficult or impossible. Moreover, postmortem xenobiotic concentrations unpredictably change with the site and time of sampling, as a result of the phenomenon of postmortem redistribution [16][17][18][19][20]. The phenomenon of post-mortem redistribution was coined by Pounder and Jones [21].…”

“…It is well documented that most drugs and toxic agents undergo post-mortem redistribution, particularly drugs in cardiac blood is affected by post-mortem redistribution from surrounding tissue (e.g., lung, gastrointestinal tract, and myocardium) [23,24]. Moreover, drugs excreted in the liver may be redistributed via the hepatic veins to inferior vena cava, right cardiac chamber, and pulmonary vessels [19]. The same principle apply to metals; Cd accumulates in very high concentrations in various body tissues (especially liver and kidney) during life [23,25,26].…”