Brain-blood ratio of morphine in heroin and morphine autopsy cases

In the case of extensively putrefied bodies, the analysis of entomological samples may support and complement the toxicological results obtained with other alternative matrices

Entomotoxicological analysis is not part of routine toxicological analysis. This work aims to present two cases to illustrate the potential of entomological samples as complementary matrices to identify substances in cases of advanced putrefaction. (Case#1) A woman wasexhumed after 14 months to ascertain the exact cause of death. She died after six weeks of hospitalization because of intestinal ischemia followed by multiorgan failure. (Case#2) The corpse of a woman, known to have a psychiatric disorder, was discovered in her apartment. The state of decomposition of the body was consistent with a post-mortem period of several weeks (approximately 6 weeks). Toxicological investigations were performed in the biological and entomological samples of case#1 (hair, adipocere, brain, and pupae) and of case#2 (hair, bone, flies, and pupae) using liquid chromatography with high-resolution mass spectrometry and tandem mass spectrometry detection methods. In case#1, several drugs and metabolites were detected. In particular, the pupae analyses allowed the objectification of morphine administration, whereas morphine was only found in adipocere, but not in hair nor in brain. In case#2, the pupae analyses allowed the detection of three metabolites of quetiapine, and the flies analyses allowed the detection of valpromide, which was only detected in hair. In conclusion, the pupae and flies analyses in these two cases complemented the results obtained in the other alternative biological samples, which may guide hypotheses about the possible causes of death. Nevertheless, additional data and case reports would be of benefit to assess the value of entomotoxicology in routine forensic investigations.

Suitability of cardiac blood, brain tissue, and muscle tissue as alternative matrices for toxicological evaluation in postmortem cases

Drug concentrations in peripheral blood are often used to evaluate whether death was caused by drug intoxication. In some cases, peripheral blood is not available, and analytical results of alternative matrices should instead be used in the toxicological evaluation. However, reference concentrations of alternative matrices are few, which makes interpretation of results a challenge. In this study, concentrations of selected benzodiazepines, opioids, illicit drugs, and other commonly used drugs in postmortem femoral blood, cardiac blood, brain tissue, and muscle tissue are presented. Alternative matrix-to-femoral blood drug concentration ratios and correlations of blood and alternative matrix drug concentrations were calculated to examine which of the investigated alternative matrices were most suited to use for toxicological evaluation in cases where peripheral blood is not available. The results showed that concentrations in cardiac blood, brain tissue, and muscle tissue could be useful in the postmortem evaluation of most of the 19 selected analytes. In most cases, analytes were detected in all the alternative matrices. The median concentration ratios for the selected analytes in brain tissue, cardiac blood, and muscle tissue relative to femoral blood ranged from 0.57 to 3.42, 0.59 to 1.87, and 0.67 to 7.04, respectively. Overall, cardiac blood provided the concentrations most comparable with femoral blood concentrations, indicating that cardiac blood can be useful in cases where femoral blood is not available. However, the measured concentrations should be interpreted with caution.

Pharmacological data science perspective on fatal incidents of morphine treatment

Morphine prescribed for analgesia has caused drug-related deaths at an estimated incidence of 0.3% to 4%. Morphine has pharmacological properties that make it particularly difficult to assess the causality of morphine administration with a patient's death, such as its slow transfer between plasma and central nervous sites of action and the existence of the active metabolite morphine-6-glucuronide with opioid agonistic effects, Furthermore, there is no well-defined toxic dose or plasma/blood concentration for morphine. Dosing is often adjusted for adequate pain relief. Here, we summarize reported deaths associated with morphine therapy, including associated morphine exposure and modulating patient factors such as pharmacogenetics, concomitant medications, or comorbidities. In addition, we systematically analyzed published numerical information on the stability of concentrations of morphine and its relevant metabolites in biological samples collected postmortem. A medicolegal case is presented in which the causality of morphine administration with death was in dispute and pharmacokinetic modeling was applied to infer the administered dose. The results of this analytical review suggest that (i) inference from postmortem blood concentrations to the morphine dose administered has low validity and (ii) causality between a patient's death and the morphine dose administered remains a highly context-dependent and collaborative assessment among experts from different medical specialties.

Postmortem Brain-Blood Ratios of Codeine, Fentanyl, Oxycodone and Tramadol

The analgesics, codeine, fentanyl, oxycodone and tramadol, frequently occur in postmortem cases and determining their role in the cause of death can be challenging. However, postmortem blood is susceptible to redistribution and may not be available in cases of severe blood loss, putrefaction or burns. Brain tissue may serve as a viable supplement to blood or on its own, as it is resistant to postmortem redistribution and often available as a sample matrix when blood is not available. We present brain and blood concentrations and brain-blood ratios of the four analgesics from 210 autopsy cases. The cases were classified according to the presumed cause of death: A: The compound was believed to have solely caused a fatal intoxication. B: The compound was assumed to have contributed to a fatal outcome in combination with other drugs, alcohol or disease. C: The compound was not regarded as being related to the cause of death. Blood and brain samples were prepared by automatic solid phase extraction and quantified by liquid chromatography-mass spectrometry. The squared correlation coefficients between concentrations in brain tissue and blood ranged 0.45-0.91. The median brain-blood ratios were codeine 1.8 (range 0.47-4.6), fentanyl 2.1 (range 0.29-16), oxycodone 1.8 (range 0.11-6.0) and tramadol 1.8 (range 0.047-6.8). A significantly higher brain-blood ratio of codeine was observed in cases where heroin had been administered, although there was a wide overlap. Intravenous and transdermal fentanyl administration could not be distinguished based on the blood or brain concentration or the brain-blood ratio. The results of this study may benefit the toxicological investigation in postmortem cases where one of the four analgesics are suspected of having contributed to or caused a fatal intoxication.

Postmortem Liver and Kidney Tissue Concentrations of Heroin Biomarkers and Their Metabolites in Heroin-Related Fatalities*†

A method was developed and validated for analyzing 6-monoacetylmorphine, morphine, 6-acetylcodeine, and codeine in routine postmortem liver and kidney specimens using liquid chromatography-tandem mass spectrometry. Samples were prepared with a Stomacher instrument followed by solid-phase extraction. All calibration curves [0.5-1000 ng/g] were linear with coefficients of determination greater than 0.99 and limits of quantification of 1.0 ng/g. Within-run precision ranged between 2.0% and 8.0%, between-run precision ranged between 1.0% and 9.0%, and accuracy ranged between -5.0% and +3.0%. Matrix effects ranged from -18% to +9%. After matrix effects were excluded, analytical recoveries ranged from 76% to 94%. The distributions of 6-monoacetylmorphine, morphine, 6-acetylcodeine, and codeine were investigated in 31 postmortem cases in which heroin was the primary cause of death. In the current study, the median free morphine ratios were calculated for liver to blood and kidney to blood, which were 2.2 and 4.0, respectively. The current report highlights the importance of testing multiple specimens, including liver and kidney, in heroin-related deaths, especially if no blood samples are available. Furthermore, this work presents new information regarding the distribution of heroin metabolites in liver and kidney.