Liver and peripheral blood concentration ratio (L/P) as a marker of postmortem drug redistribution: a literature review

Does a postmortem redistribution affect the concentrations of the 7 azaindole-derived synthetic cannabinoid 5F-MDMB-P7AICA in tissues and body fluids following pulmonary administration to pigs?

Many fatal intoxications have been reported in connection with the consumption of newer, highly potent synthetic cannabinoids. Yet, a possible postmortem redistribution (PMR) might complicate reliable interpretation of analytical results. Thus, it is necessary to investigate the PMR-potential of new synthetic cannabinoids. The pig model has already proven to be suitable for this purpose. Hence, the aim of this study was to study the PMR of the synthetic cannabinoid 5F-MDMB-P7AICA and its main metabolite 5F-MDMB-P7AICA-dimethylbutanoic acid (DBA). 5F-MDMB-P7AICA (200 µg/kg body weight) was administered by inhalation to anesthetized and ventilated pigs. At the end of the experiment, the animals were euthanized and stored at room temperature for 3 days. Tissue and body fluid samples were taken daily. Specimens were analyzed after solid phase extraction using a standard addition method and LC-MS/MS, blood was quantified after protein precipitation using a validated method. In perimortem samples, 5F-MDMB-P7AICA was found mainly in adipose tissue, bile fluid, and duodenum contents. Small amounts of 5F-MDMB-P7AICA were found in blood, muscle, brain, liver, and lung. High concentrations of DBA were found primarily in bile fluid, duodenum contents, urine, and kidney/perirenal fat tissue. In the remaining tissues, rather low amounts could be found. In comparison to older synthetic cannabinoids, PMR of 5F-MDMB-P7AICA was less pronounced. Concentrations in blood also appear to remain relatively stable at a low level postmortem. Muscle, kidney, fat, and duodenum content are suitable alternative matrices for the detection of 5F-MDMB-P7AICA and DBA, if blood specimens are not available. In conclusion, concentrations of 5F-MDMB-P7AICA and its main metabolite DBA are not relevantly affected by PMR.

A Tissue Distribution Study of Propafenone in an Intentional Fatal Poisoning Case

Propafenone (PPF) belongs to the class 1C antiarrhythmics and can cause electrocardiogram-associated adverse/toxic effects. Cases of PPF intoxication are rarely investigated. We developed a novel and selective GC-MS/MS method for the determination of PPF and its tissue distribution in an intentional fatal poisoning case, which is applicable to PPF quantification in the range of therapeutic to lethal concentrations in complex post-mortem samples. A simple and effective sample pretreatment was applied to all analyzed samples. PPF was determined without the need for dilution, even in highly complex samples containing a wide range of analyte concentrations. Quantification was performed using the standard addition method, developed and validated according to the ICH M10 guidelines. The obtained results indicated that the PPF concentration in the serum from blood taken while alive, before therapy, was the highest ever reported in the literature. Despite the intensive therapy after the patients' admission, the PPF concentrations in the lungs, spleen, femoral blood and cardiac blood were fatal or abnormally high. On the other hand, the concentrations in the liver and skeletal muscle were lower or approximately the same as observed in cases with therapeutic doses. To the best of our knowledge, the distribution of PPF has not been investigated in fatal intoxication cases and can be helpful in clinical or forensic toxicology.

Time- and temperature-dependent postmortem ∆9-tetrahydrocannabinol concentration changes in rabbits following controlled inhaled cannabis administration

ostmortem redistribution (PMR), a well-known phenomenon in forensic toxicology, can result in substantial changes in drug concentrations after death, depending on the chemical characteristics of the drug, blood collection site, storage conditions of the body and postmortem interval (PMI). Limited PMR data are available for ∆9-tetrahydrocannabinol (THC), the primary psychoactive component in Cannabis sativa. PMR was evaluated after controlled cannabis inhalation via a smoking machine and exposure chamber in New Zealand white rabbits. Necropsies were performed on five control rabbits immediately after euthanasia, whereas 27 others were stored at room temperature (21°C) or refrigerated conditions (4°C) until necropsy at 2, 6, 16, 24 or 36 h after death. THC and its Phase I and glucuronidated Phase II metabolites were quantified in blood, vitreous humor, urine, bile and tissues by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Under refrigerated temperature, heart blood THC concentrations significantly increased at PMI 2 h in rabbits, whereas peripheral blood THC concentrations showed a significant increase at PMI 16 h. Central:peripheral blood and liver:peripheral blood ratios for THC ranged from 0.13 to 4.1 and 0.28 to 8.9, respectively. Lung revealed the highest THC concentrations, while brain and liver exhibited the most stable THC concentrations over time. This report contributes much needed data to our understanding of postmortem THC behavior and can aid toxicologists in the interpretation of THC concentrations in medicolegal death investigations.

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.

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.

Postmortem Drug Redistribution: A Compilation of Postmortem/Antemortem Drug Concentration Ratios

Postmortem drug redistribution (PMR) is a well-known phenomenon in forensic toxicology with implications for medico-legal death investigations. Paired antemortem (AM) specimen and postmortem (PM) mortuary admission femoral blood drug concentrations from 811 coronial cases were used to construct a retrospective compilation of PM/AM drug concentration ratios for 42 parent drugs and metabolites. The median PM/AM ratios for all antidepressants were > 1 and consistent with PMR In contrast, the median PM/AM ratios of most benzodiazepines were < 1. The antipsychotics were varied (0.63-3.3) and suggest the mixed effects of PMR and drug instability. Amphetamines exhibited no trends (0.90-0.95) and are likely confounded by many factors. The PM/AM ratios of cardiovascular drugs, opioids and other drugs are also reported. This research represents an expansive retrospective compilation of paired AM and PM drug concentrations for many toxicologically relevant drugs. While the median PM/AM ratios demonstrate some drug-dependent trends, there was no obvious relationship between AM specimens and PM femoral blood taken at mortuary admission.

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).

Quantitation and Validation of 34 Fentanyl Analogs from Liver Tissue Using a QuEChERS Extraction and LC-MS-MS Analysis

Since 2013, drug overdose deaths involving synthetic opioids (including fentanyl and fentanyl analogs) have increased from 3,105 to 31,335 in 2018. Postmortem toxicological analysis in fentanyl-related overdose deaths is complicated by the high potency of the drug, often resulting in low analyte concentrations and associations with toxicity, multidrug use, novelty of emerging fentanyl analogs and postmortem redistribution. Objectives for this study include the development of a quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction and subsequent liquid chromatography-mass spectrometry/mass spectrometry analysis, validation of the method following the American Academy of Forensic Sciences Standards Board (ASB) standard 036 requirements and application to authentic liver specimens for 34 analytes including fentanyl, metabolites and fentanyl analogs. The bias for all 34 fentanyl analogs did not exceed ±10% for any of the low, medium or high concentrations and the %CV did not exceed 20%. No interferences were identified. All 34 analytes were within the criteria for acceptable percent ionization suppression or enhancement with the low concentration ranging from -10.2% to 23.7% and the high concentration ranging from -7.1% to 11.0%. Liver specimens from 22 authentic postmortem cases were extracted and analyzed with all samples being positive for at least one target analyte from the 34 compounds. Of the 22 samples, 17 contained fentanyl and metabolites plus at least one fentanyl analog. The highest concentration for a fentanyl analog was 541.4 μg/kg of para-fluoroisobutyryl fentanyl (FIBF). The concentrations for fentanyl (n = 20) ranged between 3.6 and 164.9 μg/kg with a mean of 54.7 μg/kg. The fentanyl analog that was most encountered was methoxyacetyl fentanyl (n = 11) with a range of 0.2-4.6 μg/kg and a mean of 1.3 μg/kg. The QuEChERS extraction was fully validated using the ASB Standard 036 requirements for fentanyl, metabolites and fentanyl analogs in liver tissue.

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.

Hepatic Transcript Profiles of Cytochrome P450 Genes Predict Sex Differences in Drug Metabolism

Safety assessments of new drug candidates are an important part of the drug development and approval process. Often, possible sex-associated susceptibilities are not adequately addressed, and better assessment tools are needed. We hypothesized that hepatic transcript profiles of cytochrome P450 (P450) enzymes can be used to predict sex-associated differences in drug metabolism and possible adverse events. Comprehensive hepatic transcript profiles were generated for F344 rats of both sexes at nine ages, from 2 weeks (preweaning) to 104 weeks (elderly). Large differences in the transcript profiles of 29 drug metabolizing enzymes and transporters were found between adult males and females (8-52 weeks). Using the PharmaPendium data base, 41 drugs were found to be metabolized by one or two P450 enzymes encoded by sexually dimorphic mRNAs and thus were candidates for evaluation of possible sexually dimorphic metabolism and/or toxicities. Suspension cultures of primary hepatocytes from three male and three female adult rats (10-13 weeks old) were used to evaluate the metabolism of 11 drugs predicted to have sexually dimorphic metabolism. The pharmacokinetics of the drug or its metabolite was analyzed by liquid chromatography/tandem mass spectrometry using multiple reaction monitoring. Of those drugs with adequate metabolism, the predicted significant sex-different metabolism was found for six of seven drugs, with half-lives 37%-400% longer in female hepatocytes than in male hepatocytes. Thus, in this rat model, transcript profiles may allow identification of potential sex-related differences in drug metabolism. SIGNIFICANCE STATEMENT: The present study showed that sex-different expression of genes coding for drug metabolizing enzymes, specifically cytochrome P450s, could be used to predict sex-different drug metabolism and, thus, provide a new tool for protecting susceptible subpopulations from possible adverse drug events.

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.

Evaluation of Acetylfentanyl Following Suspected Heroin Overdose When Complicated by the Presence of Toxic Fentanyl and Alprazolam Concentrations

A 34-year-old male was reported to be snorting a white powder that was believed to contain heroin. Toxicological analysis revealed free morphine (356 μg/L), fentanyl (34.7 μg/L), alprazolam (64.9 μg/L), and acetylfentanyl (32.9 μg/L) in femoral blood and 6-monoacetylmorphine (6-MAM, <10.0 μg/L) in vitreous fluid. Norfentanyl was only detected in stomach contents (<1.00 μg/total). Heroin, fentanyl, and acetylfentanyl were also detected in solid dose evidence submitted by law enforcement. The fentanyl and alprazolam concentrations might normally be associated with a fatal outcome and are supported with the distribution of fentanyl and alprazolam being consistent with an acute intoxication. In addition, the presence of 6-MAM and a free versus total morphine ratio of 67.9% provide supporting evidence of a rapid death following intranasal (IN) administration. However, the presence of illicit acetylfentanyl complicates toxicologic interpretation due to overlapping recreational and fatal concentrations of this compound reported in the literature as well as a potential for postmortem redistribution (PMR). Reported acetylfentanyl concentrations have also varied when presented with significant fentanyl concentrations and underscore the need to consider a wide range of illicit opioid compounds when investigating drug-related deaths. Based on our comprehensive toxicologic analysis, the results suggest an acute intoxication primarily by IN administration of acetylfentanyl and fentanyl. In addition, we suggest the presence of alprazolam, 6-MAM, and a percentage free morphine is also consistent with rapid death. The cause of death was officially attributed to an acute combined intoxication of acetylfentanyl, fentanyl, alprazolam, and heroin, with the manner of death as accidental.

Adherence to psychotropic medication in completed suicide in Sweden 2006-2013: a forensic-toxicological matched case-control study

OBJECTIVE

To investigate the influence of adherence to psychotropic medications upon the risk of completed suicide by comparing person-level prescriptions and postmortem toxicological findings among complete-suicide cases and non-suicide controls in Sweden 2006-2013.

METHODS

Using national registries with full coverage on dispensed prescriptions, results of medico-legal autopsies, causes of death, and diagnoses from inpatient care, estimated continuous drug use for 30 commonly prescribed psychotropic medications was compared with forensic-toxicological findings. Subjects who had died by suicide (cases) were matched (1:2) with subjects who had died of other causes (controls) for age, sex, and year of death. Odds ratios were calculated using logistic regression to estimate the risk of completed suicide conferred by partial adherence and non-adherence to pharmacotherapy. Adjustments were made for previous inpatient care and the ratio of initiated and discontinued dispensed prescriptions, a measure of the continued need of treatment preceding death.

RESULTS

In 5294 suicide cases and 9879 non-suicide controls, after adjusting for the dispensation ratio and other covariates, partial adherence and non-adherence to antipsychotics were associated with 6.7-fold and 12.4-fold risks of completed suicide, respectively, whereas corresponding risk estimates for antidepressant treatment were not statistically significant and corresponding risk increases for incomplete adherence to antidepressant treatment were lower (1.6-fold and 1.5-fold, respectively) and lacked statistical significance.

CONCLUSION

After adjustment for the need of treatment, biochemically verified incomplete adherence to antipsychotic pharmacotherapy was associated with markedly increased risks of completed suicide.

Death cases involving certain new psychoactive substances: A review of the literature

In the last decades, more and more new psychoactive substances (NPS) were introduced on the drug market which were sold as "legal" alternatives for classic drugs and misused medications. Due to an increased number of available substances and a growing utilization by users of common drugs but also by inexperienced users because of the supposed "legal" status, also undesired adverse effects of these NPS, at worst leading to death, became apparent. This review summarizes fatalities previously described in scientific literature which were attributed to the use of NPS or such cases, in which intake of NPS was proven or even assumed to contribute to death. This summary includes an overview of substances involved (particularly synthetic cannabinoids ("spice"), novel opioids and synthetic cathinones ("bath salts")) as well as of postmortem concentrations determined in various biological matrices. The compiled data assist forensic toxicologists with the interpretation of death cases involving NPS.

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.

Distribution of furanyl fentanyl and 4-ANPP in an accidental acute death: A case report

Fatalities from emerging synthetic opioids have continued to reach new epidemic proportions throughout the world in recent years. Due to the sparsity of research in new opioid analogs, commonly observed lethal concentrations and their distribution following death have yet to be well documented. The prevalence of furanyl fentanyl in postmortem casework contributes to the opioid related deaths that are amongst half of drug-induced fatalities in the United States. In this case study, a 23-year-old man was found dead in San Francisco following the ingestion of blue pills imitating oxycodone. Initial toxicology screening did not detect oxycodone in blood. However, a positive fentanyl immunoassay result was obtained and analysis of the pills collected at the scene showed the presence of furanyl fentanyl. Analysis of postmortem samples revealed concentrations of furanyl fentanyl at 1.9ng/mL in peripheral blood, 2.8ng/mL in cardiac blood, and ∼55,000ng in gastric contents. Metabolite 4-anilino-N-phenethyl-piperidine (4-ANPP) was also confirmed at 4.3ng/mL and 5.8ng/mL in peripheral blood and cardiac blood, respectively. Trace amounts of both analytes were detected in urine and the vitreous humor. Liver 4-ANPP concentrations of >40ng/g were also detected. This case study of acute furanyl fentanyl overdose in a young male thought to be using oxycodone highlights illicit drug users are often subject to unknown drug entities. The toxicological analysis provides preliminary information of the distribution of furanyl fentanyl and its metabolite in a range of postmortem specimens and collection sites.

A Fatality Related to the Synthetic Opioid U-47700: Postmortem Concentration Distribution

In this case report, we present an evaluation of the distribution of postmortem concentrations of 3,4-dichloro-N-[2-(dimethylamino)cyclohexyl]-N-methylbenzamide (U-47700) in a fatality attributed principally to the drug. A man who had a history of drug abuse was found unresponsive and not breathing on his bed. Drug paraphernalia, indicating drug insufflation, was located in the decedent's room. Toxicology screening tests in peripheral blood initially identified U-47700 using an alkaline drug screen with gas chromatography-mass spectrometry (GC-MS) following solid-phase extraction. It was subsequently confirmed and quantitated by GC-MS-specific ion monitoring analysis following liquid-liquid extraction. The U-47700 peripheral blood concentration was quantitated at 190 ng/mL compared to the central blood concentration of 340 ng/mL. The liver concentration was 1,700 ng/g, the vitreous was 170 ng/mL, the urine was 360 ng/mL and the gastric contained only a trace amount (<1 mg). Other drugs detected in peripheral blood were alprazolam (0.12 mg/L), nordiazepam (<0.05 mg/L), doxylamine (0.30 mg/L), diphenhydramine (0.14 mg/L), ibuprofen (2.4 mg/L), salicylic acid (<20 mg/L) and 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (2.4 ng/mL). The cause of death was certified as acute U-47700 and alprazolam abuse, and the manner of death was certified as accident.

Analytical data supporting the "theoretical" postmortem redistribution factor (Ft ): a new model to evaluate postmortem redistribution

The concepts of postmortem redistribution (PMR, F) factor, and "theoretical" PMR (Ft ) - based upon a drug's characteristic L/P ratio - have been defined to express the direct relationship between postmortem peripheral blood and the corresponding antemortem whole-blood concentration. This paper applies recent data describing liver/peripheral blood (L/P) ratios for many commonly detected drugs to assess these models, and provide a ranking of drugs' propensity for (and degree of) PMR.

A tapentadol related fatality: Case report with postmortem concentrations

Tapentadol (TAP) is an analgesic agent indicated for the management of different types of pain. It has a novel mechanism of action in that it induces analgesia via both μ-opioid receptor agonism and norepinephrine reuptake inhibition. Although deaths associated with TAP use have been reported, there is a paucity of published literature regarding TAP concentrations in biological samples obtained from TAP-associated fatalities. We report a case of TAP toxicity resulting in death with postmortem peripheral and central blood concentrations, liver, vitreous, urine, and gastric contents. A 41-year-old female was found slumped over a sink at home following a welfare check by police. She was transported to a local hospital where she was pronounced dead despite all resuscitative measures. The autopsy was remarkable only for pulmonary edema and signs of aspiration pneumonia. Postmortem concentrations of TAP were confirmed in peripheral blood at 1.1mg/L, central blood 1.3mg/L, liver 9.9mg/kg, vitreous humor 0.94mg/L, urine 88mg/L, and the gastric contained 2mg. Also of note, oxycodone was found in the decedent's blood at a concentration of 0.58mg/L. We report a death related to an intentional ingestion of TAP and oxycodone-the cause and manner of death were determined to be mixed drug intoxication; suicide. We hope that the variety of TAP concentrations identified in this case provide valuable points of reference for future cases of TAP intoxication.

Postmortem memantine concentration in a non-intoxication case, and the possibility of postmortem redistribution: A case report

In this case study, we measured the concentration of memantine in the heart blood, peripheral blood, urine, liver, thigh muscle, and subcutaneous fat of a 64-year-old woman who was prescribed memantine for early-onset Alzheimer's disease. She died in hospital after an altercation with her husband. Cause of death was clearly not drug intoxication or overdose, so we investigated the postmortem redistribution (PMR) of memantine in the various tissues and blood ratios of the postmortem samples. Memantine concentrations detected were 1.31 μg/mL in the peripheral blood, 3.95 μg/mL in central blood, 2.09 μg/mL in the urine, 25.54 μg/g in the liver, 1.16 μg/g in the thigh muscle and 2.13 μg/g in the subcutaneous fat. In all samples, the concentrations were higher than the accepted therapeutic range (which is approximately 0.09-0.15 μg/mL). The central blood to peripheral blood (C/P) memantine ratio was 3.01 while the liver to peripheral blood (L/P) ratio was 19.5. It is documented that a C/P ratio exceeding 2 and L/P ratio exceeding 20 highlight a propensity for significant PMR. Although this is a single case study, our data suggest that memantine exhibits PMR. Additionally, a lowered pH was found in peripheral blood (pH 6.2) and central blood (pH 6.1). This postmortem reduction in blood pH may also promote the PMR of memantine. Because there is very little available postmortem toxicological data on memantine, our case study will serve as a foundation to assist in future forensic investigations.

An acute gabapentin fatality: a case report with postmortem concentrations

Gabapentin (GBP) (Neurontin®, Horizant®, Gralise®) is a widely prescribed medication used primarily for the treatment of epilepsy and neuropathic pain. GBP has a favorable adverse effect profile in therapeutic dosing with the most common reported effects being dizziness, fatigue, drowsiness, weight gain, and peripheral edema. Even with intentional GBP self-poisonings, serious effects are rare. A 47-year-old female was found dead at work with her daughter's bottle of GBP 600 mg. There were 26 tablets missing and the decedent's only known medication was hydrocodone/acetaminophen. Following initial detection by an alkaline drug screen (GC-MS), analysis utilizing specific liquid chromatography-mass spectrometry revealed an elevated postmortem GBP peripheral blood concentration of 37 mg/L, central blood 32 mg/L, liver 26 mg/kg, vitreous 32 mg/L, and gastric contents 6 mg. Screening for volatiles, drugs of abuse, alkaline compounds, and acid/neutral compounds was negative with the exception of ibuprofen (<2 mg/L) detected in peripheral blood. This report presents a fatality that appears to be associated with an isolated and acute GBP ingestion.