Duragesic transdermal patch: postmortem tissue distribution of fentanyl in 25 cases

Detection and confirmation of fentanyls in high clay-content soil by electron ionization gas chromatography-mass spectrometry

Detection of illicit drugs in the environment, particularly in soils, often suggests the present or past location of a clandestine production center for these substances. Thus, development of efficient methods for the analysis and detection of these chemicals is of paramount importance in the field of chemical forensics. In this work, a method involving the extraction and retrospective confirmation of fentanyl, acetylfentanyl, thiofentanyl, and acetylthiofentanyl using trichloroethoxycarbonylation chemistry in a high clay-content soil is presented. The soil was spiked separately with each fentanyl at two concentrations (1 and 10 μg/g) and their extraction accomplished using ethyl acetate and aqueous NH4 OH (pH ~ 11.4) with extraction recoveries ranging from ~56% to 82% for the high-concentration (10 μg/g) samples while ranging from ~68% to 83% for the low-concentration (1 μg/g) samples. After their extraction, residues containing each fentanyl were reacted with 2,2,2-trichloroethoxycarbonyl chloride (Troc-Cl) to generate two unique and predictable products from each opioid that can be used to retrospectively confirm their presence and identity using EI-GC-MS. The method's limit of detection (MDL/LOD) for Troc-norfentanyl and Troc-noracetylfentanyl were estimated to be 29.4 and 31.8 ng/mL in the organic extracts. In addition, the method's limit of quantitation for Troc-norfentanyl and Troc-noracetylfentanyl were determined to be 88.2 and 95.5 ng/mL, respectively. Collectively, the results presented herein strengthen the use of chloroformate chemistry as an additional chemical tool to confirm the presence of these highly toxic and lethal substances in the environment.

Severe and Fatal Fentanyl Poisonings from Transdermal Systems after On-Skin and Ingestion Application

In recent years, the administration of fentanyl (FNTL) implicitly in transdermal drug delivery systems (TDDS) has vastly increased in chronic pain treatment. Non-medical and uncontrolled use of FNTL in TFDS (transdermal fentanyl delivery systems) may reveal toxic effects by the route of exposure, dermal or alternative, by ingestion of patches, and drug release in the stomach. The purpose of this study was to present three different cases of FNTL poisonings, two of which resulted in death due to TFDS abuse. The first case is a 66-year-old woman treated for accidental FTNL poisoning resulting in acute respiratory distress syndrome. Two remaining cases are a 31-year-old woman and a 25-year-old man who died as a result of FNTL overdose after on-skin and ingestion application of the drug patches. During the hospitalization of the 66-year-old patient, in blood samples, FNTL was confirmed at a concentration of 10.0 ng/mL. Tests run on blood taken from the corpses of 25- and 31-year-old patients exhibited FNTL presence in concentrations of 29.1 ng/mL and 38.7 ng/mL, respectively. The various routes of administration and ultimately toxic effects are important to present because, in TDDS, fentanyl can be a reason for severe to fatal poisoning, as shown by the three cases above.

The rise and rise of fentanyl in postmortem casework

Forensic toxicology laboratories are navigating a period of time with increasing drug overdose deaths, an opioid epidemic, the impact of the COVID-19 pandemic, and the illicit drug market flooded with novel psychoactive substances. In New York City, the Department of Forensic Toxicology has experienced a 56% increase in postmortem casework in the past decade with fentanyl detected in 80% of all overdose deaths. Over a period of 2.5 years, 15,638 postmortem cases were tested for the presence of fentanyl and fentanyl analogs using liquid-chromatography tandem mass spectrometry (LCMSMS). Fentanyl was detected in approximately one third of cases and of these 4447 cases with femoral blood. A twofold increase in cases with high concentrations of fentanyl (>100 ng/mL) was observed between 2021 and 2022. The minor metabolite and precursor chemical, 4-ANPP (4-anilino-N-phenethylpiperidine) may help differentiate between illicit and licit fentanyl. 4-ANPP blood concentrations were <10 ng/mL in 98% of the cases and the 4-ANPP:fentanyl ratio was <0.67 for 99.1% of blood specimens. Only six cases had 4-ANPP concentrations higher than the corresponding fentanyl blood concentration. This study also highlights, the changing fentanyl analogs found in postmortem cases since 2016 in NYC with the emergence of fluorofentanyl initially identified in 2020 and continuing to dominate in comparison with the prevalence of other analogs, many of which are no longer detected in casework. The detection of one of the latest drugs to be mixed with fentanyl, namely xylazine, has also increased in prevalence by 36.7% in 2022 compared with 2021.

Analysis, identification and confirmation of synthetic opioids using chloroformate chemistry: Retrospective detection of fentanyl and acetylfentanyl in urine and plasma samples by EI-GC-MS and HR-LC-MS

Electron Impact Gas Chromatography-Mass Spectrometry (EI-GC-MS) and High Resolution Liquid Chromatography-Mass Spectrometry (HR-LC-MS) have been used in the analysis of products arising from the trichloroethoxycarbonylation of fentanyl and acetylfentanyl in urine and plasma matrices. The method involves the initial extraction of both synthetic opioids separately from the matrices followed by detection of the unique products that arise from their reaction with 2,2,2-trichloroethoxycarbonyl chloride (Troc-Cl), namely Troc-norfentanyl and Troc-noracetylfentanyl. The optimized protocol was successfully evaluated for its efficacy at detecting these species formed from fentanyl and acetylfentanyl when present at low and high levels in urine (fentanyl: 5 and 10 ng/mL and acetylfentanyl: 20 and 100 ng/mL) and plasma (fentanyl: 10 and 20 ng/mL and acetylfentanyl: 50 and 200 ng/mL), values that reflect levels reported in overdose victims. The HR-LC-MS method's LOQ (limit of quantitation) for the Troc-norfentanyl and Troc-noracetylfentanyl products was determined to be ~10 ng/mL for both species. Even though the superiority in the detection of these species by HR-LC-MS over EI-GC-MS, the latter method proved to be important in the detection of the second product from the reaction, namely 2-phenylethyl chloride that is crucial in the determination of the original opioid. This observation highlights the importance of using complimentary analytical techniques in the analysis of a sample, whether biological or environmental in nature. The method herein serves as a complementary, qualitative confirmation for the presence of a fentanyl in collected urine, plasma and by extension other biological samples amenable to the common extraction procedures described for opioid analysis. More importantly, the method's main strength comes from its ability to react with unknown fentanyls to yield products that can be not only detected by EI-GC-MS and HR-LC-MS but can then be used to retrospectively identify an unknown fentanyl.

Fentanyl use disorder characterized by unprescribed use of transdermal patches: a case report

BACKGROUND

Fentanyl is a synthetic opioid with analgesic potency 75-100 times higher than that of morphine, and its analgesic effect is used for pain treatment, mostly in cancer patients. Using fentanyl patches may reduce misuse potential due to the transdermal route of administration, long-acting action, sustained release delivery property, and maintenance of steady-state serum concentration of the drug. Although there have been reports of transdermal fentanyl patches (TFPs) misuse via transmucosal, trans-nasal, intravenous, and oral routes of administration, fentanyl use disorder via the transdermal route is very rare.

CASE

In this case report, we present a patient with a history of substance use disorder who developed fentanyl use disorder via transdermal route after using unprescribed TFP in order to quit opium gum. The CARE guidance was followed in the preparation of this case report.

CONCLUSION

The risk of use disorder may be higher, especially in individuals with a history of substance use disorders. This risk should be taken into account when clinicians prescribe this medication.

Predictors of intentional fentanyl use: Market availability vs consumer demand

BACKGROUND

Attempts to reduce opioid overdoses have been complicated by the dramatic rise in fentanyl use. While market forces contributing to fentanyl proliferation in the illicit drug supply have increased inadvertent exposure to the drug, rising fentanyl use may also be driven by growing consumer demand. Interventions to reduce the spread of fentanyl must be based on an understanding of the motivations underlying its use.

METHODS

Data for this cross-sectional study were derived from a computerized self-administered survey completed by a convenience sample of 432 people who use illicit opioids (PWUO) recruited from methadone and detoxification programs in NJ. The anonymous survey was based on a prior qualitative study of attitudes and behaviors surrounding opioid use. Multivariate analysis identified correlates of intentional fentanyl use in the full sample and among sub-populations of white and non-white PWUO.

RESULTS

In the full sample, intentional fentanyl use was associated with white race/ethnicity, younger age, polydrug use, and a preference for the drug effects of fentanyl, which more than tripled the probability of intentional use (AOR=3.02; 95% CI=1.86-4.89; p=.000). Among whites, a preference for the fentanyl drug effects was also the strongest predictor of intentional use (AOR=5.34; 95% CI=2.78-10.28; p=.000). Among non-whites, however, exposure, not preference, was the primary driver of use, with intentional use more than doubling (AOR=2.48; 95% CI=1.04-5.91; p<.05) among those living in high fentanyl dispersion counties.

CONCLUSION

The motivations underlying fentanyl use are multifactorial and vary across populations of PWUO, indicating a need for targeted interventions to counter the increasing spread and adverse consequences of fentanyl use. In order to counteract the increasing spread and adverse consequences of fentanyl use, these findings indicate a need for harm-reduction interventions, like drug testing or supervised injection sites, that address the differing motivations for fentanyl use among PWUO.

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.

Gas Chromatography-Mass Spectrometry Analysis of Synthetic Opioids Belonging to the Fentanyl Class: A Review

The rising number of deaths caused by fentanyl overdosing in the US due to the overwhelming illicit use of this synthetic opioid has started a global campaign to develop efficient ways to control its production and distribution as well as discovering efficient antidotes to mitigate its lethal effects. Another important vein of focused research established by various agencies lies in the development of efficient and practical protocols for the detection of this opioid and analogs thereof in various matrices, whether environmental or biological in nature, particularly in the field of gas chromatography-mass spectrometry (GC-MS). The following review will cover the literature dealing with the detection and identification of synthetic opioids belonging to the fentanyl class by GC-MS means and hyphenated versions of the technique. Detailed descriptions will be given for the GC-MS methods employed for the analysis of the opioid, starting with the nature of the extraction protocol employed prior to analysis to the actual findings presented by the cited reports. Great effort has gone into describing the methods involved in each paper in a detailed manner and these have been compiled by year in tables at the end of each section for the reader's convenience. Lastly, the review will end with concluding remarks about the state of GC-MS analysis with regards to these powerful opioids and what lies ahead for this analytical field.

New and Emerging Opioid Overdose Risk Factors

Purpose of Review

The purpose of this review is to provide a review of the current literature surrounding opioid overdose risk factors, focusing on relatively new factors in the opioid crisis.

Recent Findings

Both a market supply driving force and a subpopulation of people who use opioids actively seeking out fentanyl are contributing to its recent proliferation in the opioid market. Harm reduction techniques such as fentanyl testing strips, naloxone education and distribution, drug sampling behaviors, and supervised injection facilities are all seeing expanded use with increasing amounts of research being published regarding their effectiveness. Availability and use of interventions such as medication for opioid use disorder and peer recovery coaching programs are also on the rise to prevent opioid overdose.

Summary

The opioid epidemic is an evolving crisis, necessitating continuing research to identify novel overdose risk factors and the development of new interventions targeting at-risk populations.

Higher naloxone dosing in a quantitative systems pharmacology model that predicts naloxone-fentanyl competition at the opioid mu receptor level

Rapid resuscitation of an opioid overdose with naloxone, an opioid antagonist, is critical. We developed an opioid receptor quantitative systems pharmacology (QSP) model for evaluation of naloxone dosing. In this model we examined three opioid exposure levels that have been reported in the literature (25 ng/ml, 50 ng/ml, and 75 ng/ml of fentanyl). The model predicted naloxone-fentanyl interaction at the mu opioid receptor over a range of three naloxone doses. For a 2 mg intramuscular (IM) dose of naloxone at lower fentanyl exposure levels (25 ng/ml and 50 ng/ml), the time to decreasing mu receptor occupancy by fentanyl to 50% was 3 and 10 minutes, respectively. However, at a higher fentanyl exposure level (75 ng/ml), a dose of 2 mg IM of the naloxone failed to reduce mu receptor occupancy by fentanyl to 50%. In contrast, naloxone doses of 5 mg and 10 mg IM reduced mu receptor occupancy by fentanyl to 50% in 5.5 and 4 minutes respectively. These results suggest that the current doses of naloxone (2 mg IM or 4 mg intranasal (IN)) may be inadequate for rapid reversal of toxicity due to fentanyl exposure and that increasing the dose of naloxone is likely to improve outcomes.

Distribution of synthetic opioids in postmortem blood, vitreous humor and brain

In the US, the use of synthetic opioids (e.g. fentanyl and derivatives) has become an increasing health issue with thousands of overdose deaths being observed since 2013. With the high mortality rate associated with these substances, postmortem analyses and interpretation of synthetic opioids has become extremely important. However, due to the novelty of these compounds, the available data are limited and provides challenges to toxicologists. The objectives of this study were (1) to develop and validate analytical methods for the determination of synthetic opioids in vitreous humor and brain, and (2) to investigate the postmortem distribution of new synthetic opioids in blood, vitreous humor, and brain tissue. Vitreous humor (0.5mL) and brain tissue (5g) homogenized in water (diluted 1:3, w/w) were extracted by mixed mode cation exchange-reversed phase solid phase extraction. Extracts were analyzed by liquid chromatography tandem mass spectrometry (LC-MSMS). The chromatographic separation was performed by reversed-phase with 0.1% formic acid in water and in acetonitrile as mobile phases in gradient mode, with a total run time of 21min. Data were acquired with ESI+ in dynamic multiple reaction mode (dMRM), monitoring 2 transitions per compound. The methods were succesfully validated following SWGTOX guidelines, with limits of quantification of 0.1ng/mL in vitreous humor and 0.1ng/g in brain. Fifty-eight authentic case samples from the New York City Office of the Chief Medical Examiner (NYC-OCME) were analyzed to assess the distribution and detectability of synthetic opioids in these postmortem samples. Of the fifteen synthetic opioids included in the method, six synthetic opioids and metabolites (4-ANPP, acetylfentanyl, fentanyl, furanylfentanyl, norfentanyl, U-47700) were detected in the authentic cases. Concentrations for most analytes were within the 0.1 to 100ng/mL or ng/g calibration range across all three matrices, with only concentrations from acetylfentanyl and U-47700 exceeding 100ng/mL or ng/g. The highest concentrations were observed in brain (except norfentanyl), followed by blood and vitreous humor. Most analytes were detected in all three matrices in a given case. This was followed by detection of an analyte in combinations of brain and another matrix or brain only. Through the case analyses, vitreous humor and brain demonstrated to be viable alternatives to blood when performing postmortem analyses of synthetic opioids. Brain exhibited a higher detectability for most analytes when compared to blood and vitreous humor.

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.

Monoclonal Antibodies for Combating Synthetic Opioid Intoxication

Opioid abuse in the United States has been declared a national crisis and is exacerbated by an inexpensive, readily available, and illicit supply of synthetic opioids. Specifically, fentanyl and related analogues such as carfentanil pose a significant danger to opioid users due to their high potency and rapid acting depression of respiration. In recent years these synthetic opioids have become the number one cause of drug-related deaths. In our research efforts to combat the public health threat posed by synthetic opioids, we have developed monoclonal antibodies (mAbs) against the fentanyl class of drugs. The mAbs were generated in hybridomas derived from mice vaccinated with a fentanyl conjugate vaccine. Guided by a surface plasmon resonance (SPR) binding assay, we selected six hybridomas that produced mAbs with 10^-11 M binding affinity for fentanyl, yet broad cross-reactivity with related fentanyl analogues. In mouse antinociception models, our lead mAb (6A4) could blunt the effects of both fentanyl and carfentanil in a dose-responsive manner. Additionally, mice pretreated with 6A4 displayed enhanced survival when subjected to fentanyl above LD₅₀ doses. Pharmacokinetic analysis revealed that the antibody sequesters large amounts of these drugs in the blood, thus reducing drug biodistribution to the brain and other tissue. Lastly, the 6A4 mAb could effectively reverse fentanyl/carfentanil-induced antinociception comparable to the opioid antagonist naloxone, the standard of care drug for treating opioid overdose. While naloxone is known for its short half-life, we found the half-life of 6A4 to be approximately 6 days in mice, thus monoclonal antibodies could theoretically be useful in preventing renarcotization events in which opioid intoxication recurs following quick metabolism of naloxone. Our results as a whole demonstrate that monoclonal antibodies could be a desirable treatment modality for synthetic opioid overdose and possibly opioid use disorder.

Fatal misuse of transdermal fentanyl patches

Fentanyl is a potent synthetic opioid with a variety of possible applications. Transdermal fentanyl patches are regularly prescribed for patients with severe chronic or cancer-related pain. The potential for abuse is well-known and cases associated with illicit fentanyl intake are common. Fentanyl related fatalities due to unintentional misuse are relatively rare. This study focused on those instances and their identification in forensic examinations and adds new cases and consolidates the existing femoral blood concentrations in the event of fatal fentanyl patch misapplications. A total of 35 cases between 2010 and 2018 in which transdermal fentanyl patches were detected during forensic autopsies were identified and reviewed for the frequency of unspecific macroscopic signs of opioid intoxication. Furthermore, a detailed examination is presented for 11 cases in which toxicological results were available. The cause of death was eventually considered to be related to fentanyl patch misuse in 5 of these 11 cases. Co-administered drugs and signs of opioid intoxication, especially pulmonary edema, were frequently found. Lastly, it is advised to include norfentanyl and hair analysis in the interpretation of post-mortem fentanyl concentrations.

The forensic spleen: Morphological, radiological, and toxicological investigations

The spleen is only uncommonly investigated in the forensic setting. Thorough examinations are performed in some specific situations such as splenic trauma (including iatrogenic trauma from cardiopulmonary resuscitation attempts), anaphylaxis, drowning, and sepsis-related deaths. The aim of this review is to present the available literature focusing on a few selected splenic diseases as well as forensic investigations performed on the spleen in order to summarize the most frequent situations in which this routinely unexplored organ may merit more extensive examination.

Postmortem Toxicology of New Synthetic Opioids

One hundred fifteen Americans die every day from opioid overdose. These overdose fatalities have been augmented by the increased availability of potent synthetic opioids, such as fentanyl and its derivatives. The death rate of synthetic opioids, other than methadone, increased by 72.2% from 2014 to 2015, and doubled from 2015 to 2016, situating the USA in the midst of an opioid overdose epidemic. The analytical identification of these opioids in postmortem samples and the correct toxicological data interpretation is critical to identify and implement preventive strategies. This article reviews the current knowledge of postmortem toxicology of synthetic opioids and the chemical and pharmacological factors that may affect drug concentrations in the different postmortem matrices and therefore, their interpretation. These factors include key chemical properties, essential pharmacokinetics parameters (metabolism), postmortem redistribution and stability data in postmortem samples. Range and ratios of concentrations reported in traditional and non-traditional postmortem specimens, blood, urine, vitreous humor, liver and brain, are summarized in tables. The review is focused on fentanyl and derivatives (e.g., acetyl fentanyl, butyryl fentanyl, carfentanil, furanyl fentanyl, 4-methoxybutyrylfentanyl, 4-fluorobutyrylfentanyl, ocfentanil) and non-traditional opioid agonists (e.g., AH-7921, MT-45, U-47700). All of these data are critically compared to postmortem data, and chemical and pharmacological properties of natural opioids (morphine), semi-synthetic (oxycodone, hydrocodone, hydromorphone, and oxymorphone), and synthetic opioids (methadone and buprenorphine). The interpretation of drug intoxication in death investigation is based on the available published literature. This review serves to facilitate the evaluation of cases where synthetic opioids may be implicated in a fatality through the critical review of peer reviewed published case reports and research articles.

Novel Synthetic Opioids: The Pathologist's Point of View

Background: New Psychoactive Substances (NPS) constitute a broad range of hundreds of natural and synthetic drugs, including synthetic opioids, synthetic cannabinoids, synthetic cathinones, and other NPS classes, which were not controlled from 1961 to 1971 by the United Nations drug control conventions. Among these, synthetic opioids represent a major threat to public health. Methods: A literature search was carried out using public databases (such as PubMed, Google Scholar, and Scopus) to survey fentanyl-, fentanyl analogs-, and other synthetic opioid-related deaths. Keywords including “fentanyl”, “fentanyl analogs”, “death”, “overdose”, “intoxication”, “synthetic opioids”, “Novel Psychoactive Substances”, “MT-45”, “AH-7921”, and “U-47700” were used for the inquiry. Results: From our literature examination, we inferred the frequent implication of fentanyls and synthetic opioids in side effects, which primarily affected the central nervous system and the cardiovascular and pulmonary systems. The data showed a great variety of substances and lethal concentrations. Multidrug-related deaths appeared very common, in most reported cases. Conclusions: The investigation of the contribution of novel synthetic opioid intoxication to death should be based on a multidisciplinary approach aimed at framing each case and directing the investigation towards targeted toxicological analyses.

The forensic spleen: Morphological, radiological, and toxicological investigations

The spleen is infrequently investigated in forensic pathology routine. Thorough examinations are performed in very specific situations such as splenic trauma (including iatrogenic trauma from cardiopulmonary resuscitation attempts), anaphylaxis-related deaths, drowning and sepsis. The purpose of this review article is to provide a general overview of available literature focusing on a few selected splenic diseases as well as available forensic investigation techniques performed on the spleen in order to summarize the most frequent situations of forensic interest in which this routinely unexplored organ may merit more extensive examination.

Fatalities caused by novel opioids: a review

Drugs related to morphine represent not only large range of important therapeutic applications for the relief of moderate to severe pain but also give rise to a relatively large series of novel opioids that mimic the action of this naturally occurring analgesic. Most of these are based on fentanyl structures that are much more potent, and dangerous, than fentanyl itself. This publication reviews reports of fatalities attributed to 15 novel opioids with the view to assessing mortality associated with their misuse as well as reviewing published analytical procedures that would be able to detect these and other novel opioids. These drugs include reports of deaths to acetylfentanyl, acrylfentanyl, butr(yl)fentanyl, carfentanil, 2- and 4-fluorofentanyls, 4-fluorobutyrfentanyl, 4-fluoroisobutyrfentanyl, furanylfentanyl, α- and 3-methylfentanyls, 4-methoxyfentanyl, ocfentanil, as well as AH-7921, U-47700 and MT-45. Most of these cases reporting a drug-caused death involved other drugs in addition to the opioid. No obvious minimum fatal concentration was discerned for any of the opioids for which details were provided, however, the more potent members required detection limits well under 1 ng/mL and often even well below 0.1 ng/mL requiring use of the most sensitive mass spectral detection procedures, particularly when screening specimens using a non-targeted mode. Four other novel opioids have been reported in admissions to hospitals include 4-chloroisobutryfentanyl, cyclopentylfentanyl and tetrahydrofuranfentanyl, all of which are likely to have the potential to cause death. It is also likely that other analogues will appear with time.

Two Hospitalizations and One Death After Exposure to Ortho-Fluorofentanyl

Two young males were hospitalized with miosis and respiratory dysfunction after exposure to a white powder obtained from a foreign source by mail. A few days later, one of the males was found dead at his home. A serum sample from one of the hospitalized patients and a blood sample from the deceased contained ortho-fluorofentanyl in concentrations of 2.5 and 2.4 ng/mL, respectively. It was concluded that death was caused by ortho-fluorofentanyl.

Fentanyl novel derivative-related deaths

OBJECTIVE

Fentanyl (FEN) is a potent, synthetic narcotic used as an anaesthetic and a pain reliever, but also illegally manufactured. For diversion purpose, it is being steadily modified to produce new analogous compounds and derivatives (FENS), categorised as novel psychoactive substances. While potential FEN abuse is already known, even in the absence of a clear lethal dosage, there is still a shortage of data on its derivatives.

METHODS

A literature review of FENS-related deaths was performed, to better understand potential damage and future perspectives of FEN congeners.

RESULTS

Epidemiological data, pathological findings, administration routes, average concentrations and lethal doses, toxicological issues, trends in misuses, comparison among FENS, and possible explanation for FENS abuse are reviewed and discussed in depth.

CONCLUSIONS

This study provides a medical-legal and toxicological assessment of this phenomenon in order to understand the role of illegal fentanyl and its congeners in deaths from FENS overdose.

Health outcomes associated with illicit prescription opioid injection: A systematic review

Prescription opioid injection is a growing concern among people who use illicit drugs. Little is known about the potential health-related harms of injecting prescription opioids. Therefore, the authors undertook a systematic review to identify health outcomes associated with injecting prescription opioids. PubMed, Ovid MEDLINE®, EMBASE, Journals@Ovid, CINAHL, PsycInfo, Web of Science® Core Collection, CAB Direct, and ERIC databases were searched to identify English articles published between January 1990 and February 2015 that matched the inclusion criteria. Potentially relevant articles were those examining a clinical health outcome among people who use illicit drugs, in which a sub-group injects prescription opioids. The International Classification of Diseases (ICD-10) was used to clinically classify health outcomes. In total, 31 studies that met the inclusion criteria were identified and summarized. A modified version of the Downs and Black checklist was used to assess individual study quality and identify sources of bias. Findings supported associations between prescription opioid injection and hepatitis C infection, substance dependence and other mental health indicators, and lower general health. Associations with human immunodeficiency virus, overdose, and cutaneous infection were less consistent and varied according to prescription opioid type(s). Several potential sources of bias were identified as well as a need for more longitudinal research and more rigorous confounding adjustment. The current findings highlight a need to consider the growing popularity of prescription opioid injection in efforts to reduce drug-related harm among people who inject drugs.

Postmortem Toxicology Findings of Acetyl Fentanyl, Fentanyl, and Morphine in Heroin Fatalities in Tampa, Florida

In the last two years, an epidemic of 40 fatal heroin overdose cases has occurred in the Tampa area of Florida. Of these cases, 14 involved fentanyl and acetyl fentanyl. Victim demographics, case histories, toxicology findings, and causes and manners of death for all 40 deaths are presented. In 26 deaths in which acetyl fentanyl or fentanyl were not involved, free and total peripheral blood morphine concentrations were consistent with fatal heroin intoxications, averaging 0.16 mg/L and 0.35 mg/L, respectively. In the heroin cases with fentanyl present (n=7), the average free morphine concentration was 0.040 mg/L, the average total morphine concentration was 0.080 mg/L, and the average fentanyl concentration was 0.012 mg/L. In the cases with heroin, fentanyl, and acetyl fentanyl (n=3), the average free morphine concentration was 0.010 mg/L, the average total morphine concentration was 0.030 mg/L, the average fentanyl concentration was 0.018 mg/L, and the average acetyl fentanyl concentration was 0.008 mg/L. In the cases involving only acetyl fentanyl (without heroin or fentanyl, n=4), the average acetyl fentanyl concentration was 0.47 mg/L and the average acetyl norfentanyl concentration was 0.053 mg/L. The presented cases, with associated drug concentrations, case histories, demographics, and causes and manners of death may help provide assistance with the interpretation of the postmortem findings. Based on case circumstances, autopsy results, and toxicology results, it is evident that fentanyl and/or acetyl fentanyl, when present, contributed to the cause of death.

Vitreous humor analysis for the detection of xenobiotics in forensic toxicology: a review

Vitreous humor (VH) is a gelatinous substance contained in the posterior chamber of the eye, playing a mechanical role in the eyeball. It has been the subject of numerous studies in various forensic applications, primarily for the assessment of postmortem interval and for postmortem chemical analysis. Since most of the xenobiotics present in the bloodstream are detected in VH after crossing the selective blood-retinal barrier, VH is an alternative matrix useful for forensic toxicology. VH analysis offers particular advantages over other biological matrices: it is less prone to postmortem redistribution, is easy to collect, has relatively few interfering compounds for the analytical process, and shows sample stability over time after death. The present study is an overview of VH physiology, drug transport and elimination. Collection, storage, analytical techniques and interpretation of results from qualitative and quantitative points of view are dealt with. The distribution of xenobiotics in VH samples is thus discussed and illustrated by a table reporting the concentrations of 106 drugs from more than 300 case reports. For this purpose, a survey was conducted of publications found in the MEDLINE database from 1969 through April 30, 2015.

Postmortem tissue distribution of acetyl fentanyl, fentanyl and their respective nor-metabolites analyzed by ultrahigh performance liquid chromatography with tandem mass spectrometry

In the last two years, an epidemic of fatal narcotic overdose cases has occurred in the Tampa area of Florida. Fourteen of these deaths involved fentanyl and/or the new designer drug, acetyl fentanyl. Victim demographics, case histories, toxicology findings and causes and manners of death, as well as, disposition of fentanyl derivatives and their nor-metabolites in postmortem heart blood, peripheral blood, bile, brain, liver, urine and vitreous humor are presented. In the cases involving only acetyl fentanyl (without fentanyl, n=4), the average peripheral blood acetyl fentanyl concentration was 0.467 mg/L (range 0.31 to 0.60 mg/L) and average acetyl norfentanyl concentration was 0.053 mg/L (range 0.002 to 0.086 mg/L). In the cases involving fentanyl (without acetyl fentanyl, n=7), the average peripheral blood fentanyl concentration was 0.012 mg/L (range 0.004 to 0.027 mg/L) and average norfentanyl blood concentration was 0.001 mg/L (range 0.0002 to 0.003 mg/L). In the cases involving both acetyl fentanyl and fentanyl (n=3), the average peripheral blood acetyl fentanyl concentration was 0.008 mg/L (range 0.006 to 0.012 mg/L), the average peripheral blood acetyl norfentanyl concentration was 0.001 mg/L (range 0.001 to 0.002 mg/L), the average peripheral blood fentanyl concentration was 0.018 mg/L (range 0.015 to 0.021mg/L) and the average peripheral blood norfentanyl concentration was 0.002 mg/L (range 0.001 mg/L to 0.003 mg/L). Based on the toxicology results, it is evident that when fentanyl and/or acetyl fentanyl were present, they contributed to the cause of death. A novel ultrahigh performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) method to identify and quantify acetyl fentanyl, acetyl norfentanyl, fentanyl and norfentanyl in postmortem fluids and tissues is also presented.

The fentanyl story

Fentanyl, introduced more than 50 years ago, has become the most often used opioid for intraoperative analgesia. Since the early 1990s the fentanyl patch has been available for management of chronic pain of all forms of cancer as well as the persistent, intense pain from many noncancerous maladies. More than a half dozen rapid-onset transmucosal fentanyl preparations have been developed, approved, launched, and popularized for "breakthrough" pain syndromes in the past 20 years. The purpose of this article is to describe why this opioid has become so important in the treatment of pain in modern clinical practice. The data indicate that fentanyl's popularity has occurred because it has minimal cardiovascular effects, does not result in increases in plasma histamine, is relatively short in onset of action and duration of effect, is easy and inexpensive to synthesize and prepare for the marketplace, and is now familiar to clinicians working in pain and perioperative medicine throughout the world.

Parent and Metabolite Opioid Drug Concentrations in Unintentional Deaths Involving Opioid and Benzodiazepine Combinations

Effects of benzodiazepines on postmortem opioid parent and parent/metabolite blood concentration ratios were determined for fentanyl-, hydrocodone-, methadone-, or oxycodone-related accidental deaths. These opioids are partially metabolized by the CYP3A4 enzyme system, which is also affected by diazepam and alprazolam. Opioid/metabolite combinations examined were as follows: fentanyl/norfentanyl, hydrocodone/dihydrocodeine, methadone/EDDP, and oxycodone/oxymorphone. Parent opioid concentrations were analyzed for 877 deaths. Parent/metabolite concentration ratios were analyzed for 349 deaths, excluding cases with co-intoxicants present known to interfere with opioid elimination. Alprazolam in combination with diazepam significantly decreased median hydrocodone concentrations by 48% (p = 0.01) compared to hydrocodone alone. The methadone parent/metabolite concentration ratio was reduced by 35% in the presence of diazepam compared to methadone alone (p = 0.03). Benzodiazepines did not statistically significantly affect fentanyl or oxycodone concentrations. Possible factors affecting opioid concentrations and possible toxicity development, including any differential effects on specific opioids, should continue to be explored.

Quantitative low-volume assay for simultaneous determination of fentanyl, norfentanyl, and minor metabolites in human plasma and urine by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

A rapid and sensitive liquid chromatography/tandem mass spectrometric (LC-MS/MS) method for simultaneous quantification of fentanyl (F), norfentanyl (NF), despropionylfentanyl (DPF), and hydroxynorfentanyl (OHNF) in human plasma and urine specimens has been developed and validated according to international guidelines. Analytes were extracted from 250-μL plasma or urine by liquid-liquid extraction. OHNF in urine affords a second extraction step and analysis with a different column. Calibration curves in plasma were linear from 0.05-10 ng/mL for F, 0.07-0.5 ng/mL for NF, 0.02-1.0 ng/ml for DPF, and 0.67-3.0 ng/mL for OHNF; in urine, from 0.09-10.0, 0.17-50, 0.08-1.0, and 1.0-5.0 ng/mL for F, NF, DPF, and OHNF, respectively. Analytical bias and intra- and inter-assay imprecision were within ± 15 % of target, except for OHNF in plasma and DPF in urine at the respective lower quality control level. All analytes were stable in processed samples when stored for 24 h at room temperature. Recoveries and process efficiencies were above 82.9 and 75.1 % for all analytes in plasma and urine. The low level of DPF in plasma indicated with a matrix effect of 71.3 % moderate ion suppression, all other analytes in plasma and urine showed no matrix effects. The lower limit of quantification (LOQ) in plasma was 0.05, 0.07, 0.02 and 0.67 ng/mL for F, NF, DPF, and OHNF, respectively. In urine, the LOQ of F, NF, DPF, and OHNF were 0.09, 0.17, 0.08, and 1.28 ng/mL, respectively. This assay has been applied to human specimens collected during a clinical drug-drug interaction study.

Assisted suicide by fentanyl intoxication due to excessive transdermal application

Herein, we report a case of an assisted suicide committed by application of 34 matrix-based fentanyl-containing transdermal therapeutic systems (TTS) with different release rates. The TTS were supplied by the husband but administered by the deceased herself. Besides routine systematic toxicological analysis (STA), the concentrations of fentanyl and norfentanyl were determined in the blood (femoral and heart), urine, stomach content, brain, lung tissue, musculus iliopsoas, liver, kidney, bile and in some of the used TTS by LC-MS/MS. Blood levels of fentanyl were 60.6 μg/L in femoral blood and 94.1 μg/L in heart blood. These concentrations are in good concordance with levels described in cases with accidental or lethal suicidal fentanyl patch application. The organ distribution indicates an influence of post-mortem redistribution. The levels of residual fentanyl in the TTS were also determined. STA furthermore revealed supratherapeutic levels of bromazepam. Thus, the cause of death was a combination of fentanyl and bromazepam intoxication. However, considering the determined levels of fentanyl and norfentanyl in the entire set of specimens and the high toxicity in comparison to bromazepam, fentanyl was the leading toxic noxa.

Reliability of postmortem fentanyl concentrations in determining the cause of death

INTRODUCTION

Transdermal fentanyl, an opioid used for management of marked pain, also is abused and may cause death.

METHODS

We reviewed medical examiner reports of 92 decedents who had one or more fentanyl transdermal patches on their body and had fentanyl detected in their postmortem toxicology analysis.

RESULTS

The manners of death included 40 accidents, 36 natural, 8 suicides, 5 therapeutic complications, and 3 undetermined deaths. Among the accidental fentanyl intoxication deaths, 32 of 37 involved substance abuse. The majority (95 %) of the 37 accidental deaths involving fentanyl were multi-drug intoxications. The substance abuse deaths had a mean fentanyl blood concentration (26.4 ng/ml or μg/L) that was over twice that of the natural group (11.8 ng/ml). Our analysis suggests a relationship between total patch dosage and mean postmortem fentanyl concentration up to the 100-μg/h dose.

CONCLUSIONS

The very wide and overlapping ranges of postmortem fentanyl concentrations effectively nullify the utility of correlating the dose and expected postmortem concentration for any particular death. Based on the variable relationship between dose and blood concentration, the antemortem dose cannot be reliably predicted based on the postmortem concentration. This does not, however, render the medical examiner/coroner unable to determine the cause and manner of death because the toxicology results are only one datum point among several that are considered. Although there was a weakly positive relationship between body mass index and fentanyl concentration, further research is needed to determine whether adipose tissue represents a significant depot for postmortem release of fentanyl.

Recommendations for the Investigation, Diagnosis, and Certification of Deaths Related to Opioid Drugs

The American College of Medical Toxicology and the National Association of Medical Examiners convened an expert panel to generate evidence-based recommendations for the practice of death investigation and autopsy, toxicological analysis, interpretation of the toxicology findings, and death certification to improve the precision of death certificate data available for public health surveillance. The panel finds the following: 1. A complete autopsy is necessary for optimal interpretation of toxicology results, which must also be considered in the context of the circumstances surrounding death, medical history, and scene findings. 2. A complete scene investigation extends to reconciliation of prescription information and pill counts. 3. Blood, urine, and vitreous humor, when available, should be retained in all cases. Blood from the femoral vein is preferable to blood from other sites. 4. A toxicological panel should be comprehensive and include opioid and benzodiazepine analytes, as well as other potent depressant, stimulant, and antidepressant medications. 5. Interpretation of postmortem opioid concentrations requires correlation with medical history, scene investigation, and autopsy findings. 6. If death is attributed to any drug or combination of drugs (whether as cause or contributing factor), the certifier should list all the responsible substances by generic name in the autopsy report and on the death certificate. 7. The best classification for manner in deaths due to the misuse or abuse of opioids without any apparent intent of self-harm is “accident.” Reserve “undetermined” as the manner for the rare cases in which evidence exists to support more than one possible determination.

Fatal Overdose due to Confusion of an Transdermal Fentanyl Delivery System

Background. The use of transdermal fentanyl systems has increased over recent years, especially in patients with chronic pain. Large misuse potential and fatal outcomes have been described. Case Presentation. A 58-year-old patient presenting with clinical signs of opioid poisoning (hypoventilation, bradycardia, hypotension, and miosis) was admitted to our ICU. The first body check revealed a 75 mcg per hour fentanyl patch at the patient's right scapula. Some months ago, patient's aunt died after suffering from an oncological disease. During breaking up of her household, the patches were saved by the patient. Not knowing the risk of this drug, he mistook it as a heat plaster. Investigations. Laboratory test showed an impaired renal function and metabolic acidosis. Urine drug test was negative at admittance and 12 h later. CCT scan presented a global hypoxic brain disease. Treatment and Outcome. The patient was discharged 30 days after admittance in a hemodynamic stable condition but a vegetative state and transferred to a rehabilitation center. Learning Points. With the ongoing increase in fentanyl patch prescriptions for therapeutic reasons, it is likely that misuse cases will become more relevant. Conventional urine drug screening tests are not able to exclude the diagnosis fentanyl intoxication. History taking should include family member's drug prescriptions.