Post-mortem drug concentrations

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.

Case Report of Lethal Concentrations of the Over-the-Counter Sleep Aids Diphenhydramine and Melatonin

ABSTRACT

Over-the-counter (OTC) medications are not typically considered "drugs of abuse" by the public, yet they are implicated in a portion of overdose cases. Although the toxicity of some OTC medications (such as acetaminophen, aspirin, and diphenhydramine [DPH]) has been extensively reported in the medical literature, the lethality of other substances (including melatonin) has not been well established.We report the case of a 21-year-old woman who was found deceased within her secure residence. Scene investigation revealed the presence of 5 empty containers of DPH and a partially empty container of melatonin, as well as a handwritten note of apparent suicidal nature. Upon autopsy examination, the gastric mucosa was notable for a green-blue discoloration, and the gastric contents were consisted of a green-tan viscous material with admixed blue particulate material. Further analysis revealed elevated concentrations of both DPH and melatonin within the blood and gastric contents. The death was certified as a suicide by acute combined DPH and melatonin toxicity.This paper will review the pharmacology of OTC sleep aid medications and provide a brief outline of their documented toxicity, in addition to reinforcing the role of death scene investigation and its correlation with autopsy findings.

Are the (New) Synthetic Opioids U-47700, Tramadol and Their Main Metabolites Prone to Time-Dependent Postmortem Redistribution?-A Systematic Study Using an In Vivo Pig Model

The interpretation of analytical results in forensic postmortem (PM) cases often poses a great challenge, in particular, due to possible PM redistribution (PMR) phenomena. In terms of new synthetic opioids, such data are usually not available and, if so, they are from case reports without the exact knowledge of dose, user habits, time of consumption or PM interval (PMI). Hence, a controlled toxicokinetic pig study was performed allowing the examination of PM tissue distribution and possible PMR of U-47700, tramadol and the main metabolites N-desmethyl-U-47700 and O-desmethyltramadol (ODT). For this purpose, 12 domestic pigs received an intravenous dose of 100 µg/kg body weight (BW) U-47700 or 1,000 µg/kg BW tramadol, respectively. The animals were put to death with T61 8 h after administration, and relevant organs, tissues and body fluids were sampled. Subsequently, the animals were stored at room temperature (RT), and the samples were taken again after 24, 48, and 72 h PM. Following homogenization and solid-phase extraction, quantification was performed applying a standard addition approach and liquid chromatography-tandem mass spectrometry. Only low-to-moderate concentration changes of U-47700, tramadol and their main metabolites were found in the analyzed tissue specimens and body fluids during storage at RT depending on the chosen PMI. On the contrary, a remarkable concentration increase of tramadol was observed in the liver tissue. These findings indicate that both synthetic opioids and their main metabolites are only slightly prone to PMR and central blood might be the matrix of choice for quantification of these substances.

The role of alcohol and drug intoxication in fatal drowning and other deaths that occur on the Australian coast

INTRODUCTION

Alcohol and drug (illicit or prescription) intoxication impairs motor skills, coordination, decision making abilities, hazard perception, and is known to increase the risk of death in coastal environments. Prior coastal safety research has focused largely on the impact of alcohol on drowning, with less research on the influence of drugs and leaving a significant number of other non-drowning fatalities largely excluded, despite being preventable with mitigation of injuries or medical factors.

METHOD

This retrospective cross-sectional study explored the impact of alcohol and drugs on unintentional Australian drowning deaths and other coastal fatalities over a 16-year period to identify higher-risk populations and coastal activity groups for which alcohol/drug use is increased.

RESULTS

It was found that alcohol, benzodiazepines/sedatives, and amphetamine usage was prevalent in coastal deaths. Of the 2,884 coastal deaths, 80.6% of decedents had known toxicological data. Alcohol and/or drug intoxication contributed to 23% of coastal drowning deaths and 19% of fatalities. For drowning and other fatalities combined, 8.7% were due to alcohol, 8.7% due to drugs, and 4.1% due to both alcohol and drugs. Australian-born decedents were more likely to involve alcohol (RR = 1.7, 95%CI = 1.26-2.3, p < 0.001), drugs (RR = 2.62, 95%CI = 1.85-3.7, p < 0.001), or both alcohol and drugs (RR = 4.43, 95%CI = 2.51-7.82, p < 0.001) with an increased risk identified in Indigenous Australian populations (RR = 2.17, 95%CI = 1.12-4.24, p = 0.04). The impact of alcohol and drug intoxication varied by activity, with Personal Watercraft users more likely to die due to alcohol intoxication (RR = 2.67, 95%CI = 1.23-5.78, p = 0.035), while scuba divers (RR = 0, p < 0.001), snorkelers (RR = 0.14, 95%CI = 0.036-0.57, p < 0.001), and rock fishers (RR = 0.46, 95%CI = 0.22-0.96, p = 0.03) were less likely. Recreational jumping and fall-related coastal deaths were more likely to involve alcohol and alcohol/drugs combined.

PRACTICAL APPLICATIONS

This study identifies factors to further investigate or target with prevention strategies to decrease the holistic burden of mortality due to alcohol and/or drug usage on the Australian coast.

The DI-SPME Method for Determination of Selected Narcotics and Their Metabolites, and Application to Bone Marrow and Whole Blood Analysis

The present investigation utilised the quick and easy SPME/LC-MS method to determine selected narcotic substances and their metabolites in whole blood. The study included qualitative analysis and validation of the method. Analytes were determined in the linearity range of 25−300 ng/mL. The precision during and between days (in general CV < 13.41%), and the LOD which results in between 0.36 and 11.08 ng/mL, and the LOQ between 1.20 and 36.90 ng/mL were investigated. The validation results obtained, as well as the results of subsequent in-laboratory tests, confirmed the applicability of the method in the analysis of blood samples. An attempt to apply the method to the analysis of bone marrow samples has yielded promising results; however, more detailed studies are needed in this area.

Case report on postmortem fentanyl measurement after overdose with more than 67 fentanyl patches

Purpose

Fentanyl is an analgesic that is frequently prescribed, which resulted in non-intentional as well as intentional misuse and deaths. Here, we present a postmortem case of a patient who clearly died of a fentanyl overdose due to an extensive number of fentanyl patches combined with oral intake of fentanyl and cocaine. We aimed to show how postmortem analysis can be used to interpret postmortem fentanyl concentrations in unique cases like the one we present.

Case description

A 23-year-old male was found dead in his bedroom with 67 non-prescribed patches of fentanyl on his body. In the room, there also were fentanyl tablets of 100 µg and cocaine powder, which had possibly also been taken by the deceased. To confirm the cause of death, urine and subclavian blood were retrieved to perform a standard postmortem toxicology screening. The toxicological screening revealed the presence of several drugs, including cocaine, fentanyl, lidocaine and paracetamol. Further analysis of the quantitative postmortem values of fentanyl with ultra-performance liquid chromatography-tandem mass spectrometry revealed a fentanyl concentration of 57.9 µg/L. Considering several issues around postmortem drug analyses, this value seemed to be in line with concentrations found in previously reported postmortem cases.

Conclusion

We were able to confirm the expected cause of death with an extensive toxicological screening in combination with the circumstantial evidence. We identified fentanyl as most important cause for the fatal outcome in this specific case and simultaneously contributed to the limited availability of knowledge on postmortem fentanyl concentrations.

The role of QT-prolonging medications in a forensic autopsy study from Western Denmark

Medication-induced prolongation of the QT-interval (miQTP) can lead to cardiac arrhythmia. Our aim was to investigate the prevalence of forensic autopsy cases where fatal cardiac arrhythmia related to treatment with QT-prolonging medications (QT-PMs) could be suspected. We performed a cross-sectional study of 741 forensic autopsies undertaken at our institution in non-drug addicts aged 15 years or above from 2017 to 2019. We defined a high risk of miQTP by one detected QT-PM in a concentration above therapeutic level, or two or more detected QT-PMs in post mortem blood. We reviewed the autopsy reports from cases with a high miQTP-risk to identify cases with no other apparent cause of death. We discarded suicides and cases with lethal levels of QT-PMs. We identified 167 cases (22.5%) with high risk of miQTP, and discarded 36 suicides (4.9%) and 7 (0.9%) with lethal levels of QT-PMs. Apart from a high risk of miQTP, no other apparent explanation of the cause of death was present in seven (0.9%). In 18 cases (2.4%) with high miQTP-risk, the cause of death was primarily attributed to cardiac changes other than acute cardiovascular events. In conclusion, 22.5% had a high risk of miQTP, and fatal cardiac arrhythmia related to treatment with QT-PMs could be suspected in 0.9%. However, a genetic pro-arrhythmic background could not be excluded in our study. Furthermore, it is possible that QT-PMs could have played a role in some of the 2.4% of cases where the cause of death was mainly attributed to cardiac changes and the risk of miQTP was high.

Methadone, Buprenorphine, Oxycodone, Fentanyl, and Tramadol in Multiple Postmortem Matrices

Peripheral blood (PB) concentrations are generally preferred for postmortem toxicological interpretation, but some autopsy cases may lack blood for sampling due to decomposition or large traumas, etc. In such cases, other tissues or bodily fluids must be sampled; however, limited information exists on postmortem concentrations in matrices other than blood. Pericardial fluid (PF), muscle and vitreous humor (VH) have been suggested as alternatives to blood, but only a few studies have investigated the detection of opioids in these matrices. In this study, we aimed to investigate the detection of methadone, buprenorphine, oxycodone, fentanyl and tramadol in postmortem samples of PF, skeletal muscle and VH, in addition to PB and cardiac blood and if drug concentrations in these alternative matrices were comparable to those in PB and thereby useful for interpretation. In most of the 54 included cases, only one opioid was detected. Methadone, oxycodone, fentanyl and tramadol were detected in all of the alternative matrices in almost all cases, while buprenorphine was detected less often. For methadone, the concentrations in the alternative matrices, except in VH, were relatively similar to those in PB. Larger variations in concentrations were found for buprenorphine, oxycodone and tramadol. Quantitative analyses appeared useful for fentanyl, in all of the alternative matrices, but only four cases were included. Toxicological analyses of opioids in these alternative postmortem matrices can be useful for detection, but quantitative results must be interpreted with caution.

Designer benzodiazepines versus prescription benzodiazepines: can structural relation predict the next step?

Designer benzodiazepines are a part of the recently discovered abuse synthetic drugs called Novel Psychoactive Substances (NPS) which need to be controlled due to their constantly growing market. Most of them are derived from the medically approved benzodiazepines used nowadays yet, may possess stronger effects, more toxicity, and longer durations of action. Some differences have also been observed in their detection and characteristics, in addition to the variations discovered in postmortem redistribution and drug stability. All these major alterations in features can result from only minor structural modifications. For example, a classic benzodiazepine (BZD) like diazepam only lacks one fluorine atom which exists in its derivatized designer drug, diclazepam, making substantial differences in activity. For this reason, it is essential to study the designer drugs in order to identify their dangers and distinguish them thus rule out their abuse and control the spread of such drugs. This review would highlight the distinct characteristics of some of the most commonly abused designer benzodiazepine analogies in relation to their original prescription BZD compounds.

Time- and Site-Dependent Postmortem Redistribution of Antidepressants and Neuroleptics in Blood and Alternative Matrices

Postmortem redistribution (PMR) leads to challenges in postmortem case interpretation. Particularly antidepressants and neuroleptics are expected to undergo PMR based on their physico-chemical properties. For the current study, time- and site-dependent PMR of 20 antidepressants and neuroleptics were investigated in humans (authentic cases); five of which are discussed in detail (citalopram, mirtazapine, quetiapine, risperidone and venlafaxine) along with two metabolites (9-OH-risperidone and O-desmethylvenlafaxine). Blood [femoral (pB) and heart blood (HB)] and tissue biopsy samples (lung, kidney, liver, spleen, thigh muscle and adipose tissue) were collected upon admission to the institute utilizing a computed tomography-guided sample collection workflow (t1). Approximately 24 h later (t2; mean 23 ± 9.3 h), samples from the same body regions were collected manually. Liquid chromatography-tandem mass spectrometry was used for quantification. Most antidepressants and neuroleptics showed significant time-dependent concentration changes indicating the occurrence of PMR. For the first time, two phases of redistribution in pB for quetiapine were proposed (concentration decreases in the early postmortem phase, followed by concentration increases) and contrasting existing literature, both concentration increases and decreases in pB overtime were observed for risperidone and 9-OH-risperidone. Venlafaxine and its metabolite only showed minimal concentration changes, while citalopram exhibited a trend for concentration increases and mirtazapine for concentration decreases in pB overtime. Based on time-dependent tissue data, passive diffusion processes along the muscle-to-pB, liver-to-HB and lung-to-HB concentration gradients could be proposed along with bacterial degradation. Overall, no case interpretation had to be adjusted, which suggests that PMR changes of antidepressants and neuroleptics do not seem to be relevant for forensic case interpretation within the 24 h period that was investigated. However, limitations of the current study (e.g., temperature-controlled storage of the bodies) could have led to an underestimation of occurring postmortem changes, hence, interpretation of postmortem results should always be conducted with care, considering PMR phenomena and inter-individual variability.

Post-mortem distribution of mephedrone and its metabolites in body fluids and organ tissues of an intoxication case

New psychoactive substances (NPS) are substances that continue to appear on the drug market to bypass controlled substance legislation. Mephedrone or 4-methylmethcathinone is becoming the most popular new psychoactive substance among youth as a recreational drug. The present study describes the optimization and validation of a sensitive method that combined clean up procedure and LC-MS/MS technique designed to simultaneously determine the presence of Mephedrone and its two metabolites (normephedrone as active metabolite and dyhidromephedrone) in post-mortem specimens (body fluids and organ tissues). To date, this is the first determination of Mephedrone metabolites in post-mortem specimens. The validated method was applied to a fatal Mephedrone intoxication case. The distribution of the three analytes in different post-mortem matrices was presented. The toxicological results of the studied case are discussed, along with autopsy, histopathological evidence and crime-scene information. The toxicological results presented in the study provide new data relative to mephedrone and the distribution of its metabolites in post-mortem specimens. In our opinion, the metabolite concentration database must be developed because the metabolites may be linked to toxicity. The pattern of parent drug and its metabolites can be helpful in the interpretation of fatal cases involving mephedrone, which will contribute to the currently limited knowledge about mephedrone and metabolites concentrations.

Acidic Drug Concentrations in Postmortem Vitreous Humor and Peripheral Blood

Vitreous humor is a potential alternative matrix for postmortem toxicology drug screens when peripheral blood is unavailable. It is easily and reliably collected and may not suffer from the same postmortem redistribution as seen in blood. Here, we compared the concentrations of 7 acidic drugs (acetaminophen, ibuprofen, naproxen, salicylic acid, carbamazepine, phenobarbital and phenytoin) in peripheral blood and vitreous fluid collected in 89 autopsy cases. Analysis was done by high-performance liquid chromatography with diode-array detection. Overall, we found that vitreous drug concentrations were significantly lower than peripheral blood with median vitreous to peripheral blood (V/PB) ratios ranging from 0.0 to 0.6 (mean, 0.1-0.6). The correlations between the concentrations of over-the-counter analgesics in peripheral blood versus vitreous fluid were poor, with acetaminophen exhibiting the best linearity (R2 = 0.72). The antiepileptic drugs (carbamazepine, phenytoin and phenobarbital) exhibited good correlations between peripheral blood and vitreous humor, with all exhibiting an R2 ≥ 0.95. Overall, we have demonstrated the potential of vitreous fluid as an alternative matrix for the detection of select acidic drugs.

Quantitation of Fentanyl and Metabolites from Liver Tissue Using a Validated QuEChERS Extraction and LC-MS-MS Analysis

According to the National Institute on Drug Abuse (NIDA), more than one hundred people die every day from opioid overdose. Overdose fatalities have risen as the availability of potent synthetic opioids, such as fentanyl, has increased. A forensic postmortem toxicological specimen is often in various stages of decomposition, experiencing autolysis and putrefaction, which complicates the extraction, creating a difficult challenge for toxicologists. Isolating the target drug, while creating an efficient and simplified analytical scheme, is a goal for most toxicology laboratories. The validation of a quick, easy, cheap, effective, rugged and safe extraction protocol is presented in this study as an alternative analytical method for efficient extraction and detection of fentanyl and its major metabolites: norfentanyl and despropionyl fentanyl (4-ANPP). The liquid Chromatography with tandem mass spectrometry analysis was validated following the American Academy of Forensic Sciences Standards Board (ASB) standard 036 proposed requirements. Evaluated parameters include selectivity, matrix effects (MEs), linearity, processed sample stability, bias, precision and proof of applicability using liver samples from authentic postmortem cases. MEs (represented as percent ionization suppression or enhancement) at low and high concentrations were -10.0% and 1.4% for fentanyl, -2.1% and -0.3% for 4-ANPP and 3.1% and 2.8% for norfentanyl, respectively. Bias for the three analytes ranged from -8.5% to -19.9% for the low concentrations, -3.6% to -14.7% for the medium concentrations and 1.5% to -16.1% for the high concentrations with all being within the ±20% guideline. Precision for the three analytes ranged from 2.2% to 15.1%. The linear range for the fentanyl and norfentanyl was 0.5-100 and 4-ANPP had a linear range of 0.4-80 μg/kg. The authentic postmortem liver samples ranged in fentanyl concentrations from 56.6 to 462.3 μg/kg with a mean of 149.2 μg/kg (n = 10). The range of norfentanyl concentrations were 1.9 to 50.0 μg/kg with a mean of 14.1 μg/kg (n = 10). The range of 4-ANPP concentrations were 3.2 to 23.7 μg/kg with a mean of 7.5 μg/kg (n = 7).

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.

Organ distribution of diclazepam, pyrazolam and 3-fluorophenmetrazine

The organ distribution of 3-fluorophenmetrazine (3-FPM), pyrazolam, diclazepam as well as its main metabolites delorazepam, lormetazepam and lorazepam, was investigated. A solid phase extraction (SPE) and a QuEChERS (acronym for quick, easy, cheap, effective, rugged and safe) - approach were used for the extraction of the analytes from human tissues, body fluids and stomach contents. The detection was performed on a liquid chromatography-tandem mass spectrometry system (LCMS/MS). The analytes of interest were detected in all body fluids and tissues. Results showed femoral blood concentrations of 10 μg/L for 3-FPM, 28 μg/L for pyrazolam, 1 μg/L for diclazepam, 100 μg/L for delorazepam, 6 μg/L for lormetazepam, and 22 μg/L for lorazepam. Tissues (muscle, kidney and liver) and bile exhibited higher concentrations of the mentioned analytes than in blood. Additional positive findings in femoral blood were for 2-fluoroamphetamine (2-FA, approx. 89 μg/L), 2-flourometamphetamine (2-FMA, hint), methiopropamine (approx. 2.2 μg/L), amphetamine (approx. 21 μg/L) and caffeine (positive). Delorazepam showed the highest ratio of heart (C) and femoral blood (P) concentration (C/P ratio = 2.5), supported by the concentrations detected in psoas muscle (430 μg/kg) and stomach content (approx. 210 μg/L, absolute 84 μg). The C/P ratio indicates that delorazepam displays susceptibility for post-mortem redistribution (PMR), supported by the findings in muscle tissue. 3-FPM, pyrazolam, diclazepam, lorazepam and lormetazepam did apparently not exhibit any PMR. The cause of death, in conjunction with autopsy findings was concluded as a positional asphyxia promoted by poly-drug intoxication by arising from designer benzodiazepines and the presence of synthetic stimulants.

Time-Dependent Postmortem Redistribution of Opioids in Blood and Alternative Matrices

Forensic postmortem case interpretation can be challenging, in particular due to postmortem redistribution (PMR) phenomena. Recent studies have shown that computed tomography (CT)-guided collection of biopsy samples using a robotic arm (virtobot) provides a valuable tool for systematic studies on time-dependent PMR. Utilizing this strategy, several cases involving opioid use such as methadone, fentanyl, tramadol, codeine, oxycodone and hydrocodone were evaluated for time-dependent concentration changes and potential redistribution mechanisms. Upon admission to the institute (t1), blood (femoral and right ventricle heart blood) and tissue biopsy samples (lung, kidney, liver, spleen, thigh muscle and adipose tissue) were collected utilizing CT-guided biopsy. Approximately 24 h later (t2; mean 28 ± 15 h), during the autopsy, samples from the same body regions were collected manually and in addition brain tissue, gastric content, urine and left ventricle heart blood. Analysis was conducted with liquid chromatography tandem mass spectrometry. Significant time-dependent methadone concentration increases in femoral blood (pB) indicate the occurrence of PMR, however, ultimately not relevant for forensic interpretation. The main metabolite of methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), showed a less significant trend for PMR. Redistribution by passive diffusion along the muscle-to-pB concentration gradient seems likely for methadone, but not for EDDP. Results for fentanyl suggest extensive PMR. Other opioids such as tramadol, codeine, hydrocodone and oxycodone showed no consistent trend for significant PMR. Overall, CT-guided biopsy sampling proved to be a valuable tool for the investigation of PMR mechanisms.

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 redistribution of olanzapine following intramuscular administration of olanzapine pamoate in dogs

The potential for postmortem redistribution of olanzapine was investigated in beagle dogs. Olanzapine pamoate monohydrate was administered once every 14 days by intramuscular injection for 3 months to fed male dogs (n=15) at a dose of 20 mg/kg olanzapine (equivalent to 46 mg/kg olanzapine pamoate monohydrate). Blood samples were collected after the fifth (Day 57) and sixth (Day 71) doses to determine olanzapine and N-oxide olanzapine concentrations. On Day 71 at 72 h postdose, dogs were euthanized and placed on their backs without additional manipulation and held for postmortem blood, urine, and tissue collection at room temperature for up to 168 h postdose (96 h after euthanasia). Concentrations of olanzapine and N-oxide olanzapine were determined by liquid chromatography-mass spectroscopy/mass spectroscopy (LC-MS/MS). Postmortem olanzapine concentrations in blood increased up to seven-fold compared to the last quantified antemortem blood concentration. Olanzapine concentrations in vein tissue samples (surrogates for peripheral blood) also increased, whereas other tissue concentrations, such as myocardium, lung, liver, and kidney decreased over the postmortem period. An increase in blood concentration of olanzapine after death was observed in all but one animal, suggesting that postmortem redistribution may occur in dogs following biweekly intramuscular administration of olanzapine pamoate monohydrate. The rise in olanzapine concentrations in blood after death in this study may potentially be attributed to diffusion from multiple tissues to blood and, to a lesser extent, reduction of the N-oxide olanzapine metabolite back to olanzapine. However, the generalizability of these results to humans cannot be confirmed by the present study.

Plasma vs heart tissue concentration in humans - literature data analysis of drugs distribution

Little is known about the uptake of drugs into the human heart, although it is of great importance nowadays, when science desires to predict tissue level behavior rather than to measure it. Although the drug concentration in cardiac tissue seems a better predictor for physiological and electrophysiological changes than its level in plasma, knowledge of this value is very limited. Tissue to plasma partition coefficients (Kp) come to rescue since they characterize the distribution of a drug among tissues as being one of the input parameters in physiologically based pharmacokinetic (PBPK) models. The article reviews cardiac surgery and forensic medical studies to provide a reference for drug concentrations in human cardiac tissue. Firstly, the focus is on whether a drug penetrates into heart tissue at a therapeutic level; the provided values refer to antibiotics, antifungals and anticancer drugs. Drugs that directly affect cardiomyocyte electrophysiology are another group of interest. Measured levels of amiodarone, digoxin, perhexiline and verapamil in different sites in human cardiac tissue where the compounds might meet ion channels, gives an insight into how these more lipophilic drugs penetrate the heart. Much data are derived from postmortem studies and they provide insight to the cardiac distribution of more than 200 drugs. The analysis depicts potential problems in defining the active concentration location, what may indirectly suggest multiple mechanisms involved in the drug distribution within the heart. Copyright © 2015 John Wiley & Sons, Ltd.

Distribution of enantiomers of methadone and its main metabolite EDDP in human tissues and blood of postmortem cases

Knowledge concerning the distribution of methadone in postmortem human tissue and the effect of postmortem redistribution on methadone is today limited making the choice of a suitable substitute for femoral blood difficult when this is not available. Cardiac blood, femoral blood, muscle, and brain tissue concentrations of the enantiomers of methadone and its metabolite 2-ethyl-1,5-dimethyl-3,3-diphenylpyrrolinium were recorded for 155 postmortem cases. Brain and muscle tissue concentrations exceeded the femoral blood concentrations with a median fold of 2.3 and 1.6, respectively, but both had a better correlation than cardiac blood to femoral blood concentrations. The Kruskal-Wallis test showed a significant dependency on time and body mass index for some of the matrix ratios over femoral blood. We conclude brain or muscle tissue may constitute a better alternative for measurement of methadone than cardiac blood for situations in which femoral blood is not available, despite concentrations in both matrices being systematically higher.

The postmortem redistribution of iso-α-acids in postmortem specimens

Iso-α-acids (IAA) and reduced IAA can be used as beer-specific ingredient congeners to confirm beer consumption when detected in blood and other specimens using a UHPLC-MS/MS method. Recent analysis of postmortem casework demonstrated a high prevalence of beer consumption and the possibility of providing the source of alcohol in forensic casework. Research outlined in this manuscript has examined the degree to which the interval after death and quality of blood affects the concentration of IAA in postmortem cases. Postmortem whole blood and serum were analyzed in cases where natural or reduced IAA groups were detected. The trans-IAA, cis-IAA, and tetrahydro-IAA (TIAA) groups were subject to postmortem redistribution, although only weakly associated with the length of time from death to collection of specimens. Serum had threefold higher concentrations than blood for trans-IAA, cis-IAA, and TIAA. These studies confirm that although postmortem concentrations cannot be easily compared to concentrations found in living persons the presented findings do provide some understanding to assist in interpretation where the confirmation of beer consumption is required in forensic casework.

Drug concentrations in post-mortem femoral blood compared with therapeutic concentrations in plasma

Therapeutic drug concentrations measured in plasma are of limited value as reference intervals for interpretation in post-mortem (PM) toxicology. In this study, drug concentration distributions were studied in PM femoral venous blood from 57 903 Finnish autopsy cases representing all causes of death during an 11-year period. Cause-of-death information was obtained from death certificates issued by forensic pathologists. Median, mean, and upper percentile (90th, 95th, 97.5th) concentrations were calculated for 129 drugs. To illustrate how PM median concentrations relate to established therapeutic ranges in plasma, a PM blood/plasma relationship was calculated for each drug. Males represented 75% of the subjects and showed a lower median age (55 yrs) than females (59 yrs). In 43% of these cases, blood alcohol concentration was higher than 0.2‰, and the median was 1.8‰. Sixty-one (47%) of the 129 drugs showed a PM blood/plasma relationship of 1. For 22 drugs (17%), the relationship was <1, and for 46 drugs (35%), the relationship was >1. No marked correlation was found between the PM blood/plasma relationship and the volume of distribution (V_d). For 36 drugs, more than 10% of cases were fatal poisonings attributed to this drug as the main finding. These drug concentration distributions based on a large database provide a helpful reference not only to forensic toxicologists and pathologists but also to clinical pharmacologists in charge of interpreting drug concentrations in PM cases. © 2013 The Authors. Drug Testing and Analysis published by John Wiley & Sons, Ltd.

Postmortem drug levels: innocent bystander or guilty as charged

Determining the etiology or cause of an event in forensic cases often creates many theories. On piece of additional information which may be helpful in cases involving a drug or medication are concentrations or serum levels. Although many confounders can affect the interpretation of the drug level, it is imperative to also relate the data to the clinical scenario presented. Drug levels can be highly variable, depending on the time drawn, location from where the sample was obtained, and reference/references utilized in its interpretation. Postmortem drugs levels often do not reflect the blood levels before death. A drug level can be elevated exclusively because of postmortem distribution. This may result in a conclusion of a poisoning as the cause of death when in fact the death resulted from nonpharmacologic or nontoxicologic causes. Caution is advised from making any conclusions based solely on the drug level; rather an in-depth review of the clinical scenario, reference literature, and drug characteristics are required.