Antemortem and postmortem influences on drug concentrations and metabolite patterns in postmortem specimens

When interpreting postmortem analytical data, toxicologists must be aware that postmortem concentrations of xenobiotics and/or their metabolites may be influenced by many factors. Some of these influences occur antemortem like the general pharmacokinetic properties of the xenobiotic or individual pharmacokinetics in the particular subject. They determine the concentrations at the time of death and may be relevant for the determination of the manner rather than the cause of death. Other influences occurring postmortem include continuing drug metabolism, chemical, and/or microbial degradation as well as potential postmortem formation of some toxicologically relevant compounds. Such postmortem effects may tremendously change the concentrations of xenobiotics and/or their metabolites at the time of death. If not adequately considered, this may lead to false conclusions regarding the involvement of the respective xenobiotic in the cause of death. The present article will provide an overview on antemortem and postmortem effects giving examples from the literature. It will also discuss if and how such effects may be identified based on postmortem specimens and, in case of the postmortem effects, how they may be reduced by proper storage and addition of stabilizers like fluoride salts. This article is categorized under: Toxicology > Post‐Mortem Toxicology Toxicology > Analytical Toxicology Toxicology > Drug Stability After uptake prior to death, the concentrations of xenobiotics in biological samples of the subject at the time of death (CTOD) are determined by various antemortem effects. Following death, these concentrations may be changed by postmortem effects resulting in different concentrations at the time of sample collection (CTSC).