Post-mortem redistribution of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") in the rabbit

Abstract

Drug concentrations in autopsy samples can also be influenced by post-mortem gastric diffusion when the stomach contains a substantial amount of the drug or by diffusion from the trachea when agonal aspiration or post-mortem regurgitation of vomit occurs. This was studied in a rabbit animal model in which MDMA solutions were infused post mortem either in the trachea or in the stomach. At 24, 48 or 72 h post mortem, samples including cardiac blood, vitreous humour, urine, bile, gastric content and several tissues were taken for toxicological analysis. After post-mortem tracheal infusion, MDMA can easily diffuse not only into the lungs but also in great quantities into the cardiac blood and, to a lesser extent, into the cardiac muscle. MDMA was also found in the closely adjacent diaphragm and in the upper abdominal organs, including the liver and the stomach. Following post-mortem infusion into the stomach, considerable MDMA levels were found in cardiac blood and muscle, both lungs, diaphragm and liver tissue when the solution was concentrated nearby the lower oesophageal sphincter. However, when the MDMA solution was present deeper in the stomach, MDMA levels were high in the spleen and the liver and relatively low in cardiac blood and muscle. In both experiments, MDA levels in most tissues were low or below the limit of quantitation, but were substantial in cardiac blood and muscle, lungs and diaphragm, indicating that MDMA can be metabolised to MDA after death. These results in the rabbit model indicate that the diffusion of MDMA out of the stomach content, or due to aspirated vomit and gastro-oesophageal reflux can lead to considerable post-mortem redistribution and thus should be taken into account in current forensic practice in order to draw the right conclusions when a peripheral blood sample is not available.