Evaluation of postmortem redistribution phenomena for commonly encountered drugs

We described the findings of a study into the post-mortem redistribution (PMR) of 76 drugs found in 129 drug-related cases between 2006 and 2009. Seventy six drugs (psychotropic drugs (n=14), antidepressants (n=9), sedatives (n=6) and so on) were simultaneously quantified in cardiac and peripheral blood by gas chromatography-mass spectrometry (GC/MS) or liquid chromatography-tandem mass spectrometry (LC/MS/MS). The absence, possibility or presence of PMR of drugs was determined according to the ratios of cardiac to femoral blood concentrations (C/P ratios). Proxyphylline (C/P ratio: 0.85) showed no PMR; carbamazepine was not subject to PMR; a potential for PMR of lorazepam and mirtrazapine cannot be excluded; chlordiazepoxide is subject to PMR; acetaminophen and alprazolam exhibit minimal PMR; amitriptyline and benztropine exhibit PMR. Codeine (C/P ratio: 4.9), zolpidem (C/P ratio: 3.74), chlorpromazine (C/P ratio: 2.97), fluoxetine (C/P ratio: 2.83) and propranolol (C/P ratio: 2.72) had the largest C/P ratios. Postmortem drug concentrations showed variations depending on sampling sites and characteristics of the drugs. It is continuously necessary to analyze commonly used or abused drugs in simultaneously collected cardiac and peripheral blood to establish significant reference values for PMR. These findings can be used to reach a conclusion about the cause and manner of death.