Postmortem redistribution of cannabinoids: Statistical analysis of a novel dataset and meta-analysis.

The assessment of human postmortem concentrations of Δ9-THC (THC) and its metabolites, 11-nor-9-carboxy-THC (THCCOOH) and 11-hydroxy-THC (11-OH-THC), is routinely performed in forensic toxicology laboratories. However, the literature on cannabinoids postmortem redistribution (PMR) is scarce and highlights their complex postmortem changes. This study aims to investigate the postmortem behavior of THC and its metabolites in order to provide practitioners with potential indicators of PMR. To do so, antemortem and postmortem cases positive for cannabinoids were compiled in a database. Its analysis shows significantly higher THC concentrations in postmortem blood than in antemortem blood. Antemortem and postmortem blood also present significantly different profiles for their THC to THCCOOH ratios. Whereas antemortem blood generally shows THCCOOH concentrations higher or equal to THC, several postmortem cases show the opposite, with THC concentrations higher than THCCOOH. While occurrence of postmortem redistribution (PMR) is difficult to measure directly, an evaluation was performed using the central to peripheral (C/P) blood concentrations ratio as a proxy. With a C/P significantly lower than 1.0 for THC and significantly higher than 1.0 for THCCOOH, the PMR hypothesis is supported for both compounds, with redistribution towards peripheral blood for THC and towards central blood for THCCOOH. On the other hand, 11-OH-THC does not show a C/P significantly different than 1.0, suggesting the absence of PMR. Influence of body mass index, conservation state and postmortem interval on C/P was statistically analyzed and no significant impact was observed. To compare and contrast C/P observed in the database with those published in the literature, a meta-analysis was performed using a median of median (MM) model. THC PMR towards peripheral blood is supported by a global estimate of 0.81 (CI95%: 0.51 to 1.2). Redistribution towards femoral blood appears to be stronger than towards iliac blood; indeed, the median estimate of C/P decreases to 0.64 (CI95%: 0.40 to 1.1) when studies with iliac blood were removed from the meta-analysis. THCCOOH PMR towards central blood is supported by a C/P median estimate of 1.3 (CI95%: 0.97 to 1.6). THC PMR can be suspected when these indicators are observed (i) high THC blood concentration (>50 ng/mL), (ii) THC C/P lower than 1.0 (iii) blood THC/THCCOOH concentration ratios greater than 1.0 and (iv) non-detectability of THCCOOH in urine. In postmortem samples, many factors may contribute to the overestimation of THC concentration, therefore a careful interpretation is required, relying on both central and peripheral blood samples.

Postmortem redistribution of drugs: a literature review.

Postmortem drug analysis is crucial in identifying the potential cause and manner of death. However, it is threatened by a significant phenomenon called postmortem redistribution (PMR), which refers to the alterations in drug levels occurring after death. This review aims to describe the PMR phenomenon, the mechanisms involved in the PMR of drugs, the various methods used to predict it, and various artifacts of postmortem drug concentrations. Several mechanisms, including passive diffusion from solid organs that act as drug reservoirs to the surrounding tissues, cadaveric changes after death (e.g., cell death, blood coagulation, hypostasis, and movements), and the putrefactive process, can result in artifacts of postmortem drug concentrations. The drug's chemical and pharmacokinetic properties (such as acidic/basic properties, lipophilicity, protein binding, high volume of distribution, and residual metabolic activity) are additional factors. Several markers, including cardiac blood-to-peripheral blood ratio (C/P), liver-to-peripheral blood ratio (L/P), amino acid markers such as methionine, quantitative structure-activity relationship (QSAR) approach, and F factor, have been proposed for interpreting the liability of drugs to PMR. Several artifacts may affect the reliability of postmortem drug analysis. Peripheral blood is preferred for postmortem drug sample collection. Numerous laboratories evaluate the redistribution potential of drugs after death using the C/P concentration ratio. Nevertheless, the L/P concentration ratio is proposed to be a more reliable marker for PMR determination.

HPLC-MS/MS determination and the postmortem distribution or postmortem redistribution of paraquat and its metabolites in four fatal intoxication cases.

HPLC-MS/MS analysis and postmortem distribution or postmortem redistribution of paraquat and its two metabolites in poisoning death cases were reported. Paraquat, monoquat, and paraquat monopyridone were extracted from the sample with acetonitrile or methanol, respectively, detected by ZORBAX HILIC Plus (4.6 × 100 mm, 3.5 µm) chromatographic column, with 0.1 % formic acid aqueous solution - 0.1 % formic acid acetonitrile solution (v/v) as mobile phase. Paraquat, monoquat, and paraquat monopyridone had a good linear relationship within the range of 10-1000, 1-400, and 1-1000 ng/mL (or g), the correlation coefficient (r) were all ≥ 0.9996. Their detection limits were lower than 1 ng/mL (or g). The detection accuracy was 91.25∼113.44 %. The intra-day and inter-day precision were 1.51-3.99 % and 1.92-4.93 %, respectively. This method was used to detect and analyze four rare paraquat poisoning cases. The distribution of paraquat, monoquat, and paraquat monopyridone is uneven, which is relatively high in the heart, blood, lung, and kidney. Heart blood/Peripheral blood ratio of paraquat, monoquat, paraquat monopyridone concentration in two poisoned cases were 1.4, 2.0, 1.5 and 1.9, 1.3, 1.2, which showed a location dependent postmortem redistribution. This is the first time that HPLC-MS/MS and the postmortem distribution or postmortem redistribution of paraquat metabolites in poisoned death cases have been reported. This research provides scientific basis for forensic identification of paraquat poisoning cases and extraction of biological specimen.

A simple and rapid method for quantifying aconitines and their metabolites in whole blood by modified QuEChERS and liquid chromatography/tandem mass spectrometry (LC/MS/MS).

Aconitum contains highly toxic alkaloids such as aconitine, hypaconitine, jesaconitine, and mesaconitine. Since Aconitum ingestion causes fatal intoxication, it is important to analyze aconitines and their metabolites in the blood. In forensic toxicology, postmortem drug redistribution is known as one factor that would hamper accurate evaluation of concentrations. Therefore, it is recommended to collect multiple blood samples from various sites and compare the results to avoid miss identification of causative compounds for intoxication. In this study, we evaluated aconitines and their metabolites in postmortem blood specimens from ten sites by QuEChERS extraction and liquid chromatography-tandem mass spectrometry (LC/MS/MS). The recovery rates and matrix effects of analytes were approximately 74-80% and 94-100%, respectively. The correlation coefficients were over 0.99. The validation studies revealed that accuracies and precisions were around 97-2% (intraday) and 100-4% (interday), respectively. Finally, the concentrations of aconitine and jesaconitine were from 2.72 to 7.20 ng/mL and from 14.9 to 26.3 ng/mL, respectively. The concentrations of mesaconitine were from 0.32 to 0.88 ng/mL in four samples and detected in two. The concentrations were highest in the right atrium and lowest in the femoral vein. Our results suggest that aconitine and jesaconitne are accumulated in right atrium blood after death, and that right atrium specimen is suitable for measuring aconitine compounds in fatal intoxication cases.

Postmortem Distribution and Postmortem Redistribution of Carbofuran-7-Phenyl Glucuronic Acid in Rabbits.

OBJECTIVES: To establish a carbofuran intragastric administration death model in rabbits, and to observe the postmortem distribution and postmortem redistribution of carbofuran-7-phenyl glucuronic acid (Glu-7PH) in rabbits. METHODS: The postmortem distribution: Rabbits were given an administration of 1/2LD50, LD50, 2LD50 carbofuran. Dead rabbits were dissected immediately. Rabbits that had remained alive 2 hours were sacrificed by carbon dioxide (CO2) inhalation and dissected immediately. The myocardium, cardiac blood, liver, spleen, lung, kidney, brain and right hindlimb muscle were collected. The postmortem redistribution: After giving an administration of 4LD50 carbofuran, the myocardium, cardiac blood, liver, spleen, lung, kidney, brain, and right hindlimb muscle were collected at 0, 12, 24, 48, and 72 h postmortem in supine position at 15 ℃ room temperature. The quantity of Glu-7PH was determined by LC-MS/MS. RESULTS: The postmortem distribution: Among the three dose groups, there were significant differences in the quantities of Glu-7PH in different tissues. The postmortem redistribution: There was no significant difference in the Glu-7PH quantities in cardiac blood, mycardium, spleen, kidney, brain and right hindlimb muscle, but there was a significant difference in the Glu-7PH quantities in the liver and lung. CONCLUSIONS: The mycardium, cardiac blood, liver, lung, kidney, brain and hindlimb muscle of rabbits can be used as appropriate samples for Glu-7PH detection. However, it should be noted that Glu-7PH was redistributed postmortem in rabbit liver and lung.

Postmortem Distribution and Postmortem Redistribution of Carbofuran-7-Phenyl Glucuronic Acid in Rabbits / 法医学杂志

OBJECTIVES@#To establish a carbofuran intragastric administration death model in rabbits, and to observe the postmortem distribution and postmortem redistribution of carbofuran-7-phenyl glucuronic acid (Glu-7PH) in rabbits.@*METHODS@#The postmortem distribution: Rabbits were given an administration of 1/2LD50, LD50, 2LD50 carbofuran. Dead rabbits were dissected immediately. Rabbits that had remained alive 2 hours were sacrificed by carbon dioxide (CO2) inhalation and dissected immediately. The myocardium, cardiac blood, liver, spleen, lung, kidney, brain and right hindlimb muscle were collected. The postmortem redistribution: After giving an administration of 4LD50 carbofuran, the myocardium, cardiac blood, liver, spleen, lung, kidney, brain, and right hindlimb muscle were collected at 0, 12, 24, 48, and 72 h postmortem in supine position at 15 ℃ room temperature. The quantity of Glu-7PH was determined by LC-MS/MS.@*RESULTS@#The postmortem distribution: Among the three dose groups, there were significant differences in the quantities of Glu-7PH in different tissues. The postmortem redistribution: There was no significant difference in the Glu-7PH quantities in cardiac blood, mycardium, spleen, kidney, brain and right hindlimb muscle, but there was a significant difference in the Glu-7PH quantities in the liver and lung.@*CONCLUSIONS@#The mycardium, cardiac blood, liver, lung, kidney, brain and hindlimb muscle of rabbits can be used as appropriate samples for Glu-7PH detection. However, it should be noted that Glu-7PH was redistributed postmortem in rabbit liver and lung.

Postmortem Metabolomics: Strategies to Assess Time-Dependent Postmortem Changes of Diazepam, Nordiazepam, Morphine, Codeine, Mirtazapine and Citalopram.

Postmortem redistribution (PMR) can result in artificial drug concentration changes following death and complicate forensic case interpretation. Currently, no accurate methods for PMR prediction exist. Hence, alternative strategies were developed investigating the time-dependent postmortem behavior of diazepam, nordiazepam, morphine, codeine, mirtazapine and citalopram. For 477 authentic postmortem cases, femoral blood samples were collected at two postmortem time-points. All samples were quantified for drugs of abuse (targeted; liquid chromatography-tandem mass spectrometry LC-MS/MS) and characterized for small endogenous molecules (untargeted; gas chromatography-high resolution MS (GC-HRMS). Trends for significant time-dependent concentration decreases (diazepam (n = 137), nordiazepam (n = 126)), increases (mirtazapine (n = 55), citalopram (n = 50)) or minimal median postmortem changes (morphine (n = 122), codeine (n = 92)) could be observed. Robust mathematical mixed effect models were created for the generalized postmortem behavior of diazepam and nordiazepam, which could be used to back-calculate drug concentrations towards a time-point closer to the estimated time of death (caution: inter-individual variability). Significant correlations between time-dependent concentration changes of morphine, mirtazapine and citalopram with individual endogenous molecules could be determined; no correlation was deemed strong enough for successful a posteriori estimation on the occurrence of PMR for specific cases. The current dataset did successfully lead to a significant knowledge gain in further understanding the time-dependent postmortem behavior of the studied drugs (of abuse).

Association between sexual activity-related death and non-prescription use of phosphodiesterase type 5 inhibitors.

In recent years, there has been an increase in the use of phosphodiesterase type 5 inhibitors (PDE5i) that are purchased from abroad without a doctor's diagnosis via the Internet or other means. We report six cases in which nonprescription use of PDE5i may have led to death. Among the four deceased individuals who were believed to have experienced sudden cardiac death, three (cases 1-3) had a history of cardiovascular disease, which is a contraindication, and the remaining case (case 4) involved combined use of multiple PDE5i. Sildenafil (0.063 µg/mL, 0.087 µg/mL) was detected in two of the four cases of sudden cardiac death. Tadalafil (0.096 µg/mL) was detected in one of the remaining two cases, and tadalafil (0.197 µg/mL) and vardenafil (0.011 µg/mL) were detected in the other case. Sildenafil (0.032 µg/mL), tadalafil (0.062 µg/mL), and ethanol were detected in a traffic accident case with a history of contraindications. In a case of asphyxiation by vomit aspiration, autopsy showed 90% stenosis in the anterior descending branch of the coronary artery, and sildenafil (0.063 µg/mL) was detected. To the best of our knowledge, this is the first report of postmortem blood levels of tadalafil and vardenafil likely contributing to the cause of death. Despite all the warnings about the dangers of using PDE5 inhibitors, cases of PDE5i contributing to death are still identified during autopsies. Therefore, raising public awareness of the risks of the risks associated with the imported drug use by individuals is necessary.

An evaluation of postmortem concentrations of Δ9-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH).

Δ9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, leads to impaired cognitive and psychomotor function resulting in an increased risk of fatal motor vehicle collisions and other traumas resulting in death. It is important to measure cannabinoids in postmortem cases to improve understanding of this growing public safety issue. However, postmortem concentrations of THC and its primary inactive metabolite, 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH), have not been extensively studied. We aim to further characterize postmortem concentrations of THC and THCCOOH in peripheral blood with and without preservation, central blood, and central "serum" to support improved forensic interpretation. Cannabinoids were extracted from blood and "serum" from twenty-five decedents using solid phase extraction followed by quantification using gas chromatography - mass spectrometry. We evaluated the impact of sample preservation, reported central blood-to-peripheral blood (CB:PB) ratios and blood-to-"serum" ratios, and assessed the relationship of CB:PB and postmortem interval for THC and THCCOOH. Correlations of preserved compared to unpreserved blood were strong with r2 > 0.97. The median CB:PB ratios were 1.1 and 1.3 for THC and THCCOOH, respectively. THCCOOH CB:PB was significantly higher than 1.0 (p-value < 0.001). The CB:PB ratio was only weakly correlated with PMI for both compounds. The median blood-to-"serum" ratio was 1.0 for THC and 0.8 for THCCOOH. The blood-to-"serum" ratio of THCCOOH was significantly lower than 1.0 (p-value < 0.001). Results demonstrated minimal potential for postmortem redistribution of THC and THCCOOH and that the ratio of blood-to-"serum" in postmortem samples differs from the blood-to-plasma ratio established in living humans. Based on these results, it is not recommended to apply a correction factor to THC and THCCOOH concentrations from postmortem blood samples. Our study improves the understanding of postmortem cannabinoid concentrations to support forensic interpretation in cases of fatal motor vehicle accidents.

Is adipose tissue suitable for detection of (synthetic) cannabinoids? A comparative study analyzing antemortem and postmortem specimens following pulmonary administration of JWH-210, RCS-4, as well as ∆9-tetrahydrocannabinol to pigs.

Examining fatal poisonings, chronic exposure may be reflected by the concentration in tissues known for long-term storage of drugs. Δ9-tetrahydrocannabinol (THC) persists in adipose tissue (AT), but sparse data on synthetic cannabinoids (SC) are available. Thus, a controlled pig study evaluating antemortem (AM) disposition and postmortem (PM) concentration changes of the SC 4-ethylnaphthalene-1-yl-(1-pentylindole-3-yl)methanone (JWH-210) and 2-(4-methoxyphenyl)-1-(1-pentyl-indole-3-yl)methanone (RCS-4) as well as THC in AT was performed. The drugs were administered pulmonarily (200 µg/kg body weight) to twelve pigs. Subcutaneous (s.c.) AT specimens were collected after 15 and 30 min and then hourly up to 8 h. At the end, pigs were sacrificed and s.c., perirenal, and dorsal AT specimens were collected. The carcasses were stored at room temperature (RT; n = 6) or 4 °C (n = 6) and specimens were collected after 24, 48, and 72 h. After homogenization in acetonitrile and standard addition, LC-MS/MS was performed. Maximum concentrations were reached 0.5-2 h after administration amounting to 21 ± 13 ng/g (JWH-210), 24 ± 13 ng/g (RCS-4), and 22 ± 20 ng/g (THC) and stayed at a plateau level. Regarding the metabolites, very low concentrations of N-hydroxypentyl-RCS-4 (HO-RCS-4) were detected from 0.5 to 8 h. PM concentrations of parent compounds did not change significantly (p > 0.05) over time under both storage conditions. Concentrations of HO-RCS-4 significantly (p < 0.05) increased in perirenal AT during storage at RT. These results suggest a rapid distribution and persistence in s.c. AT. Furthermore, AT might be resistant to PM redistribution of parent compounds. However, significant PM increases of metabolite concentrations might be considered in perirenal AT.

Postmortem metabolomics: Correlating time-dependent concentration changes of xenobiotic and endogenous compounds.

Postmortem redistribution (PMR) describes the artificial postmortem concentration changes of xenobiotics that may pose major challenges in forensic toxicology. Only a few studies have systematically investigated time-dependent postmortem drug concentration changes so far and the a posteriori estimation of the occurrence of PMR is not yet possible. In this context, the general concept that postmortem biochemical changes in blood might parallel drug redistribution mechanisms seems promising. Thus, the current study investigated the possible correlations between time-dependent postmortem concentration changes of xenobiotic and endogenous compounds; exemplified for authentic morphine (n = 19) and methadone (n = 11) cases. Peripheral blood samples at two time-points postmortem were analyzed for morphine and methadone concentrations and an (un)targeted postmortem metabolomics approach was utilized to combine targeted quantitative analysis of 56 endogenous analytes and untargeted screening for endogenous compounds (characterizing 1174 features); liquid and gas chromatography-mass spectrometry was used respectively. Individual statistically significant correlations between morphine/methadone and endogenous compounds/features could be determined. Hence, the general applicability of the proposed concept could successfully be confirmed. To verify the reproducibility and robustness of the correlating behavior, a larger dataset must be analyzed next. Once a marker/set of markers is found (e.g. robust correlation with specific xenobiotic or xenobiotic class), these could be used as surrogates to further study the time-dependent PMR in a broader variety of cases (e.g. independent of a xenobiotic drug present). A crucial next step will also be the attempt to create a statistical model that allows a posteriori estimation of PMR occurrence of xenobiotics to assist forensic toxicologists in postmortem case interpretation.

Using µX-Ray CT to observe postmortem diffusion from the stomach in a rat model.

The stomach has long been recognised as a depot for postmortem diffusion. A better understanding of the phenomena of postmortem diffusion would aid forensic practitioners in their interpretation of toxicological results. A limitation of previous stomach diffusion studies was the lack of ability to visualise postmortem diffusion in real time, the use of µX-ray Computed Tomography (CT) could overcome this problem. We utilised CT to track the diffusion of the contrast medium caesium ions (Cs+) (administered by oral gavage) from the rat stomach over 6 days. We investigated the influence of temperature (4°C and 20°C) and body position (horizontal and vertical). The results show that the a) diffusion of Cs+ from the stomach can be visualised over 6 days, over which a significant amount (∼50%) of the diffusion occurs in the first 24h following administration; b) storing the rat at 4°C reduces the distance of diffusion from the stomach by ∼66%; c) body position influences the route of diffusion and d) in 2 of the 16 rats studied Cs+ was found in the right lobe of the liver. Overall these results show that CT using Cs+ is a good model to visualise postmortem diffusion and that bodies show significant variation in postmortem diffusion. It is also clear that bodies should be refrigerated and postmortem samples should be taken as soon as possible to minimise the influences of postmortem diffusion from the stomach.

Time- and temperature-dependent postmortem concentration changes of the (synthetic) cannabinoids JWH-210, RCS-4, as well as ∆9-tetrahydrocannabinol following pulmonary administration to pigs.

In forensic toxicology, interpretation of postmortem (PM) drug concentrations might be complicated due to the lack of data concerning drug stability or PM redistribution (PMR). Regarding synthetic cannabinoids (SC), only sparse data are available, which derived from single case reports without any knowledge of dose and time of consumption. Thus, a controlled pig toxicokinetic study allowing for examination of PMR of SC was performed. Twelve pigs received a pulmonary dose of 200 µg/kg BW each of 4-ethylnaphthalene-1-yl-(1-pentylindole-3-yl)methanone (JWH-210), 2-(4-methoxyphenyl)-1-(1-pentyl-indole-3-yl)methanone (RCS-4), and Δ9-tetrahydrocannabinol via an ultrasonic nebulizer. Eight hours after, the pigs were put to death with T61 and specimens of relevant tissues and body fluids were collected. Subsequently, the animals were stored at room temperature (n = 6) or 4 °C (n = 6) and further samples were collected after 24, 48, and 72 h each. Concentrations were determined following enzymatic cleavage and solid-phase extraction by liquid-chromatography tandem mass spectrometry applying the standard addition approach. High concentrations of the parent compounds were observed in lung, liver, kidney and bile fluid/duodenum content as well as brain. HO-RCS-4 was the most prevalent metabolite detected in PM specimens. In general, changes of PM concentrations were found in every tissue and body fluid depending on the PM interval as well as storage temperature.

Forty-Three Fatalities Involving the Synthetic Cannabinoid, 5-Fluoro-ADB: Forensic Pathology and Toxicology Implications.

Forty-three fatalities involving the potent synthetic cannabinoid, 5-Fluoro-ADB, are summarized. For each case, a description of the terminal event, autopsy findings, cause of death, qualitative identification of 5-Fluoro-ADB and its ester hydrolysis metabolite, 5-Fluoro-ADB metabolite 7, in urine, and the quantitative values obtained in the blood specimens are outlined. Central blood concentrations ranged from 0.010 to 2.2 ng/mL for 5-Fluoro-ADB and 2.0 to 166 ng/mL for 5-Fluoro-ADB metabolite 7. Peripheral blood concentrations ranged from 0.010 to 0.77 ng/mL and 2.0 to 110 ng/mL for 5-Fluoro-ADB and 5-Fluoro-ADB metabolite 7, respectively. The majority of cases resulted in central to peripheral blood concentration ratios greater than 1 for 5-Fluoro-ADB (58%) and 5-Fluoro-ADB metabolite 7 (71%) suggesting that postmortem redistribution occurs to some extent. Combining the increased cardiac weight and/or gastric volume and toxicology data identifying 5-Fluoro-ADB, it is hypothesized that abuse of this substance may precipitate a dysrhythmia and cause sudden death.

Fast increase of postmortem fentanyl blood concentrations after transdermal application: A call to careful interpretation.

BACKGROUND: Interpretation of postmortem fentanyl concentrations after transdermal application remains a challenge. There are indications that fentanyl shows relevant postmortem redistribution. The aim of this study was to investigate the time course of these changes and to develop recommendations for toxicological case work. MATERIAL AND METHOD: Blood specimens were collected from palliative care patients who were treated with fentanyl transdermal patches. Antemortem reference samples (ethylenediaminetetraacetic acid (EDTA) and serum specimens) were collected at stable dose rates. Postmortem femoral venous blood specimens were collected at four postmortem time-points: 2hpm (hours postmortem), 6-8hpm, 11-16hpm and approximately 24hpm. Liquid chromatography tandem mass spectrometry was applied to quantify fentanyl and norfentanyl. RESULTS: Ten patients were included in the study (8 men, 2 women). Fentanyl patches with delivery rates of 12-150µg/h were applied. Antemortem fentanyl levels in EDTA samples varied between 0.19 and 4.64µg/L. At 6 to 8hpm, blood concentrations of fentanyl were already significantly (p=0.05) higher in postmortem samples compared to the paired antemortem reference. On average, the antemortem concentration (range: 0.19-4.64µg/L) increased 3-fold within 6-8hpm (range: 0.4-14.9µg/L), and 5.5-fold within 24hpm (range: 0.39-21.88µg/L). Norfentanyl concentrations increased significantly (p=0.01) within 6-8hpm, too. In half of the patients, norfentanyl concentrations were below fentanyl concentrations, antemortem as well as postmortem. CONCLUSION: Postmortem fentanyl concentrations increased quickly. As early as 6-8h after death, postmortem concentrations differ significantly from antemortem ones. Our results strongly indicate that postmortem blood concentrations of fentanyl after transdermal application should be interpreted carefully.

Postmortem concentrations of the synthetic opioid U-47700 in 26 fatalities associated with the drug.

Most recently, the synthetic opioid U-47700 has emerged on the illicit drug market and is sold on the Internet as a "research chemical". Its structure is closely related to the synthetic opioid AH-7921. U-47700 is a µ-opioid receptor agonist with a potency of approximately 7.5 times that of morphine. In this study, postmortem concentrations of U-47700 are presented in 26 fatalities which occurred between April 2016 and August 2017 in the southern part of Germany. In 18 of these cases, quantitative analyses of U-47700 were carried out in femoral blood, heart blood, liver, urine, vitreous humor, pericardial fluid, and gastric content. In five cases, concentrations of U-47700 were determined in femoral blood, whereas in one case, the concentration of U-47700 was analyzed in heart blood. Due to advanced putrefaction, the analysis of U-47700 could only be performed in putrefaction fluid in two cases. Quantification of U-47700 was carried out using liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) with electrospray ionization operated in positive mode. The median femoral blood concentration of U-47700 (n = 23) was 610 ng/mL (range: 27-2200 ng/mL). Except for one female, all decedents were male and aged between 23 and 56 years (mean age: 34 years). In all fatalities, the cause of death was attributed to an intoxication with U-47700 either alone or in combination with other psychoactive substances. In 15 of the 26 cases, there was a combined use of U-47700 with other new psychoactive substances (NPS). Therefore, not only new synthetic opioids but also additional NPS including synthetic cannabinoids, new stimulant drugs, and designer benzodiazepines should be included in the routine toxicological screening methods.

The relationship between antemortem and postmortem morphine concentrations.

Context of the Article: An important forensic problem is whether the presence of a drug such as morphine caused or contributed to a death or was merely incidental. The reliance that can be based on postmortem drug concentrations remains controversial. To investigate this further we obtained antemortem and postmortem samples of individuals admitted to hospital who were receiving morphine and who died in hospital.Methods: Eleven subjects were recruited. Samples were sent for analysis for free and total morphine concentrations.Results: The median difference (postmortem - antemortem) free morphine concentration was 25.5 (range 0 to +126) µg/L, p < .01; the mean difference between postmortem and antemortem total morphine concentration was 34.5 (range -225 to 342) µg/L (not significant).Discussion: Our study supports previous investigators who note that there is an inconstant and sometimes tenuous relationship between ante- and postmortem morphine concentrations.

Fatal poisoning involving cyclopropylfentanyl - Investigation of time-dependent postmortem redistribution.

A growing number of fatal overdoses involving opioid drugs, in particular involving fentanyl and its analogues, pose an immense threat to public health. Postmortem casework of forensic toxicologists in such cases is challenging, as data on pharmacodynamic and pharmacokinetic properties as well as reference values for acute toxicities and data on potential postmortem redistribution (PMR) mechanisms often do not exist. A fatal case involving cyclopropylfentanyl was investigated at the Zurich Institute of Forensic Medicine and the Zurich Forensic Science Institute; an unknown powder found at the scene was reliably identified as cyclopropylfentanyl by gas chromatography-infrared spectroscopy (GC-IR). Femoral blood samples were collected at two time points after death; 11h postmortem (t1) and during the medico-legal autopsy 29h after death (t2). At the autopsy, additional samples from the heart blood, urine and gastric content were collected. Cyclopropylfentanyl was quantified using a validated liquid chromatography-tandem mass spectrometric (LC-MS/MS) method. Femoral blood concentration of cyclopropylfentanyl at autopsy was 19.8ng/mL (t1=15.7ng/mL; heart blood concentration at autopsy=52.4ng/mL). In the light of the current literature and under the exclusion that no other morphological findings could explain the cause of death, contribution of cyclopropylfentanyl to death was proposed (polydrug use). Significant postmortem concentration increases of cyclopropylfentanyl in femoral blood during 18h after the first sampling were observed, thus indicating a relevant potential to undergo PMR. A central-to-peripheral blood concentration ratio of 2.6 supports this. Consequently, the current case suggests that postmortem cyclopropylfentanyl concentration should always be interpreted with care.

Postmortem tissue distribution of morphine and its metabolites in a series of heroin-related deaths.

The abuse of heroin (diamorphine) and heroin-related deaths are increasing around the world. The interpretation of the toxicological results from suspected heroin-related deaths is notoriously difficult, especially in cases where there may be limited samples. To help forensic practitioners with heroin interpretation, we determined the concentration of morphine (M), morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G) in blood (femoral and cardiac), brain (thalamus), liver (deep right lobe), bone marrow (sternum), skeletal muscle (psoas), and vitreous humor in 44 heroin-related deaths. The presence of 6-monoacetylmorphine (6-MAM) in any of the postmortem samples was used as confirmation of heroin use. Quantitation was carried out using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with solid-phase extraction. We also determined the presence of papaverine, noscapine and codeine in the samples, substances often found in illicit heroin and that may help determine illicit heroin use. The results of this study show that vitreous is the best sample to detect 6-MAM (100% of cases), and thus heroin use. The results of the M, M3G, and M6G quantitation in this study allow a degree of interpretation when samples are limited. However in some cases it may not be possible to determine heroin/morphine use as in four cases in muscle (three cases in bone marrow) no morphine, M3G, or M6G were detected, even though they were detected in other case samples. As always, postmortem cases of suspected morphine/heroin intoxication should be interpreted with care and with as much case knowledge as possible.

[Cause of Death: 'Intoxication' - a Matter of the Concentration?] / Todesursache «Intoxikation¼ ­ alles eine Frage der Konzentration?

Cause of Death: 'Intoxication' - a Matter of the Concentration? Abstract. Elucidation of the cause of death is one of the main reasons for medico-legal investigations. In clinical toxicology, the severity of a given poisoning is typically assessed with the blood concentration of a pharmacologically or toxicologically active compound. Such an interpretation proves to be difficult or even impossible in postmortem toxicology. Numerous biochemical and biological processes beginning immediately after death may render the calculated drug concentration unreliable. Concentrations obtained from postmortem samples do not necessarily reflect the blood concentration at the time of death. A prediction if and to what extent such postmortem changes might have occurred is still impossible for individual cases. Interpretation therefore needs to be done with care, considering case circumstances and all available information.