Detection of the designer benzodiazepine metizolam in urine and preliminary data on its metabolism

Metabolism and detection of designer benzodiazepines: a systematic review

Synthesis and illicit use of designer benzodiazepines are growing concerns, with these new psychoactive substances (NPS) posing serious health consequences and new hurdles for toxicologists. Consumption marker identification and characterization is paramount in confirming their use. The benzodiazepine core structure is a fusion of benzene and a seven-membered heterocycle with two nitrogen atoms forming the diazepine ring. Minor variations on the core structure produce different classes of benzodiazepines with marked differences in physiological effects. The present review provides a comprehensive designer benzodiazepines metabolism overview and suggests suitable human consumption biomarkers for toxicology casework. A systematic literature search of PubMed®, ScopusTM, Web of ScienceTM, and Cochrane databases was conducted independently by two coauthors adhering to PRISMA guidelines. Data from 30 in vitro and in vivo models of designer benzodiazepines metabolism from January 2007 to February 2023 were included. 1,4-benzodiazepines (n = 10), 2,3-benzodiazepines (n = 1), triazolo-benzodiazepines (n = 9), and thieno-triazolo-benzodiazepines (n = 3) study design, sample pretreatment, analytical techniques, and major metabolites detected in various matrices are addressed. Metabolites following hydroxylation and phase II glucuronide conjugation were the most prevalent analytes. N-Glucuronidation of parent azole-fused benzodiazepines, and nitro-reduced and N-acetylated metabolites of nitro-containing designer benzodiazepines were also common. From these data, we propose a generic metabolic pathway for designer benzodiazepines. The sporadic illicit market presents challenges in toxicological casework and necessitates comprehensive biomarker investigations, especially in cases with legal implications. There are few metabolism data for many designer benzodiazepines, emphasizing the need for research focusing on closing these gaps.

In vitro and in vivo metabolism of 3-Methoxyeticyclidine in human liver microsomes, a zebrafish model, and two human urine samples based on liquid chromatography-high-resolution mass spectrometry

3-Methoxyeticyclidine (3-MeO-PCE), a phencyclidine-type substance, has a higher N-methyl-D-aspartate receptor binding affinity than phencyclidine and an involvement in fatal intoxication cases. The aim of this study was to identify new biomarkers and biotransformation pathways for 3-MeO-PCE. In vitro models were established using zebrafish and human liver microsomes for analysis of the phases I and II metabolites of 3-MeO-PCE by liquid chromatography-high-resolution mass spectrometry. Urine samples of known 3-MeO-PCE consumers in forensic cases were then subjected to analysis. Overall, 14 metabolites were identified in zebrafish and human liver microsomes, allowing postulation of the following metabolic pathways: hydroxylation, O-demethylation, N-dealkylation, dehydrogenation, combination, and glucuronidation or sulfation. 3-MeO-PCE and three metabolites (M2, M3, and M6) were detected in urine. We recommended M2 (the hydroxylation product) as a potential biomarker for documenting 3-MeO-PCE intake in clinical and forensic cases.

Overview of the bioanalytical methods used for the determination of benzodiazepines in biological samples and their suitability for emergency toxicological analysis

Benzodiazepines are one of the most widely used classes of drugs around the world. They are medically used in different therapeutic areas including insomnia, anxiety, epilepsy, and anesthesia. Unfortunately, these drugs are very widespread in the illicit market for recreational purposes and cause drug dependence, traffic accidents, and criminality. Furthermore, benzodiazepine misuse leads to acute poisoning cases that often end up in hospital emergency rooms. Therefore, it is crucial for hospitals to possess straightforward and efficient bioanalytical techniques that enable the swift detection of benzodiazepines in biological samples. This review provides a general overview of the different bioanalytical techniques used for the detection and quantification of benzodiazepines in biological samples and emphasizes their suitability for emergency toxicological analyzes.

Benzodiazepines in complex biological matrices: Recent updates on pretreatment and detection methods

Benzodiazepines (BDZs) are used in clinics for anxiolysis, anticonvulsants, sedative hypnosis, and muscle relaxation. They have high consumptions worldwide because of their easy availability and potential addiction. They are often used for suicide or criminal practices such as abduction and drug-facilitated sexual assault. The pharmacological effects of using small doses of BDZs and their detections from complex biological matrices are challenging. Efficient pretreatment methods followed by accurate and sensitive detections are necessary. Herein, pretreatment methods for the extraction, enrichment, and preconcentration of BDZs as well as the strategies for their screening, identification, and quantitation developed in the past five years have been reviewed. Moreover, recent advances in various methods are summarized. Characteristics and advantages of each method are encompassed. Future directions of the pretreatment and detection methods for BDZs are also reviewed.

Characterization of 3-Hydroxyeticyclidine (3-HO-PCE) Metabolism in Human Liver Microsomes and Biological Samples Using High-Resolution Mass Spectrometry

3-Hydroxyeticyclidine (3-HO-PCE) is a ketamine derivative that produces dissociative, hallucinogenic, and euphoric effects when consumed, but little is known about its pharmacological properties, metabolism, and toxicity compared to other designer ketamine analogs. To address this gap in knowledge, this study explored for the first time the metabolism of 3-HO-PCE. Based on this investigation, it is hypothesized that combining the use of Human Liver Microsomes (HLM) as an In vitro model with urine and hair samples from drug users may enable the identification of key analytes that can extend the detection window of 3-HO-PCE, particularly in cases of overdose. The analysis identified 15 putative metabolites, 12 of which are produced through phase I metabolism involving N-dealkylation, deamination, and oxidation, and 3 through phase II O-glucuronidation. The metabolism of 3-HO-PCE is similar to that of O-PCE, another designer ketamine of the eticyclidine family. The study identified M2a and hydroxy-PCA as reliable biomarkers for untargeted screening of the eticyclidine family in urine and hair, respectively. For targeted screening of 3-HO-PCE, M10 is recommended as the target analyte in urine, and M5 shows promise for long-term monitoring of 3-HO-PCE using hair analysis.

The Evolution Toward Designer Benzodiazepines in Drug-Facilitated Sexual Assault Cases

Drug-facilitated sexual assault (DFSA) is a crime where the victim is unable to provide sexual consent due to incapacitation resulting from alcohol or drug consumption. Due to the large number of substances possibly used in DFSA, including illicit, prescription and over-the-counter drugs, DFSA faces many toxicological challenges. Benzodiazepines (BZDs) are ideal candidates for DFSA, as they are active at low doses, have a fast onset of action and can be easily administered orally. The last decade has seen the emergence of designer benzodiazepines (DBZDs), which show slight modifications compared with BZDs and similar pharmacological effects but are not controlled under the international drug control system. DBZDs represent an additional challenge due to the number of new entities regularly appearing in the market, their possibly higher potency and the limited knowledge available on their pharmacokinetic and pharmacodynamics properties. Many BZDs and DBZDs have a short half-life, leading to rapid metabolism and excretion. The low concentrations and short time windows for the detection of BZD in body fluids require the use of highly sensitive analysis methods to enable the detection of drugs and their respective metabolites. This review discusses the current state of the toxicological analysis of BZDs and DBZDs in forensic casework and their pharmacokinetic properties (i.e., absorption, distribution, metabolism, and elimination), as well as their analysis in biosamples typically encountered in DFSA (i.e., blood, urine and hair).

At the Origins of Tobacco-Smoking and Tea Consumption in a Virgin Population (Yakutia, 1650–1900 A.D.): Comparison of Pharmacological, Histological, Economic and Cultural Data

(1) Background: The way tobacco and tea spread among virgin populations is of major interest our understanding of how ancient economic and cultural practices could have influenced current habits. (2) Methods: hair concentrations of theobromine, theophylline, caffeine, nicotine, and cotinine were measured in hair samples from 47 frozen bodies of people from eastern Siberia, dated from the contact with Europeans to the assimilation of people into Russian society. (3) Results: hair concentration of theobromine, theophylline, and caffeine vary with the type of beverage consumed: green, black, or local herbal teas. Shortly after the first contacts, a few heavy consumers of tobacco were found among light or passive consumers. Tobacco-related co-morbidities began to be recorded one century after and heavy tea users were only found from the 19th century (4) Conclusions: Economic factors and social and family contacts seem to have played a decisive role in tobacco consumption very early on. Behavioral evolution governed the process of substance integration into Siberian culture and was a determinant for the continuity of its use across long periods of time. Analyzing the respective contributions of social and economic processes in the use of these substances opens avenues of investigation for today’s public health.

Metabolic profiling of deschloro-N-ethyl-ketamine and identification of new target metabolites in urine and hair using human liver microsomes and high-resolution accurate mass spectrometry

The aim of this study was to identify new markers of deschloro-N-ethyl-ketamine (O-PCE), a ketamine analogue that has been involved in acute intoxications with severe outcomes including death and whose metabolism has never been studied before. In vitro study after 2-h incubation with pooled human liver microsomes (HLMs) cross-checked by the analysis of urine and hair from a 43-year-old O-PCE user (male) were performed by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Acquired data were processed by the Compound Discoverer® software, and a full metabolic profile of O-PCE was proposed. In total, 15 metabolites were identified, 10 were detected in vitro (HLMs) and confirmed in vivo (urine and/or hair), two were present only in HLMs, and the remaining three metabolites were identified only in biological specimens. While O-PCE was no longer detected in urine, nine metabolites were identified allowing to increase its detection window. In descending order of metabolites abundance, we suggest using 2-en-PCA-N-Glu (34%, first), M3 (16%, second), O-PCA-N-Glu (15.4%, third), OH-O-PCE (15%, fourth) and OH-PCE (11.9%, fifth) as target metabolites to increase the detection window of O-PCE in urine. In hair, nine metabolites were identified. OH-PCA was the major compound (78%) with a relevant metabolite to parent drug ratio (=6) showing its good integration into hair and making it the best marker for long-term monitoring of O-PCE exposure.

Overview of the major classes of new psychoactive substances, psychoactive effects, analytical determination and conformational analysis of selected illegal drugs

The misuse of psychoactive substances is attracting a great deal of attention from the general public. An increase use of psychoactive substances is observed among young people who do not have enough awareness of the harmful effects of these substances. Easy access to illicit drugs at low cost and lack of effective means of routine screening for new psychoactive substances (NPS) have contributed to the rapid increase in their use. New research and evidence suggest that drug use can cause a variety of adverse psychological and physiological effects on human health (anxiety, panic, paranoia, psychosis, and seizures). We describe different classes of these NPS drugs with emphasis on the methods used to identify them and the identification of their metabolites in biological specimens. This is the first review that thoroughly gives the literature on both natural and synthetic illegal drugs with old known data and very hot new topics and investigations, which enables the researcher to use it as a starting point in the literature exploration and planning of the own research. For the first time, the conformational analysis was done for selected illegal drugs, giving rise to the search of the biologically active conformations both theoretically and using lab experiments.

Recent bionalytical methods for the determination of new psychoactive substances in biological specimens

One of the problems associated with the consumption of new psychoactive substances is that in most scenarios of acute toxicity the possibility of quick clinical action may be impaired because many screening methods are not responsive to them, and laboratories are not able to keep pace with the appearance of new substances. For these reasons, developing and validating new analytical methods is mandatory in order to efficiently face those problems, allowing laboratories to be one step ahead. The goal of this work is to perform a critical review regarding bionalytical methods that can be used for the determination of new psychoactive substances (phenylethylamines, cathinones, synthetic cannabinoids, opioids, benzodiazepines, etc), particularly concerning sample preparation techniques and associated analytical methods.

'New/Designer Benzodiazepines': An Analysis of the Literature and Psychonauts' Trip Reports

BACKGROUND

NPS belonging to the benzodiazepine (BZD) class, e.g., 'legal/designer BZDs'/'research chemicals', have recently emerged in the drug (mainly online/virtual) market.

OBJECTIVE

While certain NPS belonging to the BZD class possess pharmacological profiles similar to controlled pharmaceutical BZDs, clinical and pharmacological profiles of current emerging BZDs are still not well-described. Therefore, there is a need to increase clinicians'/public health knowledge/awareness, to incentive harm reduction strategies.

METHOD

A comprehensive overview was carried out by using the EMCDDA/EDND database regularly monitored by our research team, by specifically looking at the 'new BZDs' so far notified. Furthermore, given the limitation of peer-reviewed data published so far, a nonparticipant multilingual qualitative netnographic study was conducted to obtain further clinical/pharmacological/ toxicological data, including psychonauts' online trip reports.

RESULTS

First designer BZDs appeared as NPS around 2007. So far, 29 designer BZDs have been notified to the EMCDDA, being some of them extremely powerful, also at lower dosages. They are sold as tablets/powder/pellets/capsules/blotters/liquids, at very affordable prices, and variably administered. Some are also sold on the illicit drugmarket as counterfeit forms of traditional BZDs or as either adulterants or diluents in heroin or other synthetic opioids/cannabinoids. Nowadays, there is no guarantee of the quality of designer BZDs composition/purification and, hence, most NPS consumers may be inadvertently exposed to unsafe and harmful compounds.

CONCLUSION

Given the limited information on their pharmacology/toxicity, variations in dosage, onset of effects, combination of substances, potency, and general patient or individual variability, the concomitant use of these substances with other drugs entails several and unpredictable risks.

Pyroglutamide-Based P2X7 Receptor Antagonists Targeting Inflammatory Bowel Disease

This report deals with the design, the synthesis, and the pharmacological evaluation of pyroglutamide-based P2X7 antagonists. A dozen were shown to possess improved properties, among which inhibition of YO-PRO-1/TO-PRO-3 uptake and IL1β release upon BzATP activation of the receptor and dampening signs of DSS-induced colitis on mice, in comparison with reference antagonist GSK1370319A. Docking study and biological evaluation of synthesized compounds has highlighted new SAR, and low toxicity profiles of pyroglutamides herein described are clues for the finding of a usable h-P2X7 antagonist drug. Such a drug would raise the hope for a cure to many P2X7-dependent pathologies, including inflammatory, neurological, and immune diseases.

Characterization and in vitro phase I microsomal metabolism of designer benzodiazepines: An update comprising flunitrazolam, norflurazepam, and 4'-chlorodiazepam (Ro5-4864)

The number of newly appearing benzodiazepine derivatives on the new psychoactive substances (NPS) drug market has increased over the last couple of years totaling 23 'designer benzodiazepines' monitored at the end of 2017 by the European Monitoring Centre for Drugs and Drug Addiction. In the present study, three benzodiazepines [flunitrazolam, norflurazepam, and 4'-chlorodiazepam (Ro5-4864)] offered as 'research chemicals' on the Internet were characterized and their main in vitro phase I metabolites tentatively identified after incubation with pooled human liver microsomes. For all compounds, the structural formula declared by the vendor was confirmed by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC MS/MS), liquid chromatography-quadrupole time of flight-mass spectrometry (LC-QTOF-MS) analysis and nuclear magnetic resonance (NMR) spectroscopy. The metabolic steps of flunitrazolam were monohydroxylation, dihydroxylation, and reduction of the nitro function. The detected in vitro phase I metabolites of norflurazepam were hydroxynorflurazepam and dihydroxynorflurazepam. 4'-Chlorodiazepam biotransformation consisted of N-dealkylation and hydroxylation. It has to be noted that 4'-chlorodiazepam and its metabolites show almost identical LC-MS/MS fragmentation patterns to diclazepam and its metabolites (delorazepam, lormetazepam, and lorazepam), making a sufficient chromatographic separation inevitable. Sale of norflurazepam, the metabolite of the prescribed benzodiazepines flurazepam and fludiazepam, presents the risk of incorrect interpretation of analytical findings.

Analytical Methods Used for the Detection and Quantification of Benzodiazepines

The prescription of psychotropic drugs, especially benzodiazepines (BZDs), occupies a preponderant place in the management of mental illnesses. Indeed, the BZDs have been used in different therapeutic areas including insomnia, anxiety, seizure disorders, or general anesthesia. Unfortunately, these drugs are present in the illegal street market, leading to a lot of drug abuse amongst some addicted users, road insecurity, and suicide. Hence, it has become essential to analyze the BZDs drugs in human biological specimens for drug abuse in forensic sciences. The present review provides a summary of sample preparation techniques (solid-phase extraction and Liquid-liquid phase extraction) and the methods for the detection and quantification of BZDs molecules in the commonly used biological specimens over the ten last years which may potentially lead to better and accurate evaluation of the physiological state of a given person. The commonly used methods for the detection and quantification of BZDs include nuclear magnetic resonance (NMR), chromatography (GC-MS, HPLC, and TLC), immunoassay (ELISA, RIA, LFA, CEDEA, FPIA, and KIMS), and electroanalytical methods (voltammetry and potentiometry).

Self-Experiments with Psychoactive Substances: A Historical Perspective

The purpose of this chapter is to highlight the rich tradition of self-experiments (SEs) with psychoactive substances carried out by scientists and therapists for more than a century. Scientifically inspired controlled SEs dominated until the end of the twentieth century, when ethical requirements minimized controlled SEs and "wild" SEs expanded particularly with the emergence of new psychoactive substances. The review focuses on laughing gas (nitrous oxide), cannabis, cocaine, hallucinogens, entactogens, and dissociative hallucinogens. This is due to the fact that substances that induce "complex" effects such as alteration of space/time experience, ego dissolution, and increased feelings and insights (e.g., hallucinogens, entactogens) represent by far the majority of SEs, whereas SEs with substances inducing "simple" effects such as euphoria, anxiolysis, dissociation, or emotional blunting (e.g., cocaine, opioids) are much rarer or even absent (e.g., benzodiazepines). Complex drug effects are much harder to describe, thus allowing SEs to fulfill a more important function.SEs with psychoactive drugs appeared to emerge in the mid-eighteenth century, which triggered a long-standing tradition throughout the nineteenth and early twentieth century. SEs have been de facto performed for a variety of reasons, ranging from establishing scientific knowledge and gaining philosophical insights to compensating for personal deficits. Self-experimenters can be divided into two general types. Besides their scientific intentions, "exploratory" self-experimenters intend to expand awareness and insight, whereas "compensatory" self-experimenters might aim for coping with psychiatric symptoms or personality deficits. Scientific limitations of SEs are obvious when compared to double-blind, randomized, placebo-controlled trials. Whereas the former might lead to more "realistic" detailed description of subjective effects, the latter lead to more solid results in respect to objectively measurable "average" effects. Possible adverse effects of SEs were identified that resulted in loss of scientific objectivity and decreased control over substance use and addiction, development of isolation, problematic group dynamics, and "social autism."

Designer Benzodiazepines: Another Class of New Psychoactive Substances

Benzodiazepines have been introduced as medical drugs in the 1960s. They replaced the more toxic barbiturates, which were commonly used for treatment of anxiety or sleep disorders at the time. However, benzodiazepines show a high potential of misuse and dependence. Although being of great value as medicines, dependence to these drugs is a concern worldwide, in part due to overprescription and easy availability. Therefore, the phenomenon of benzodiazepines sold via Internet shops without restrictions at low prices is alarming and poses a serious threat to public health. Most of these compounds (with the exception of, e.g., phenazepam and etizolam) have never been licensed as medical drugs in any part of the world and are structurally derived from medically used benzodiazepines. Strategies of clandestine producers to generate new compounds include typical structural variations of medically used 1,4-benzodiazepines based on structure-activity relationships as well as synthesis of active metabolites and triazolo analogs of these compounds. As they were obviously designed to circumvent national narcotics laws or international control, they can be referred to as "designer benzodiazepines." The majority of these compounds, such as diclazepam, clonazolam, and nitrazolam, have been described in scientific or patent literature. However, little is known about their pharmacological properties and specific risks related to their use. This chapter describes the phenomenon of designer benzodiazepines and summarizes the available data on pharmacokinetics and pharmacodynamics as well as analytical approaches for their detection.

The use of a quantitative structure-activity relationship (QSAR) model to predict GABA-A receptor binding of newly emerging benzodiazepines

The illicit market for new psychoactive substances is forever expanding. Benzodiazepines and their derivatives are one of a number of groups of these substances and thus far their number has grown year upon year. For both forensic and clinical purposes it is important to be able to rapidly understand these emerging substances. However as a consequence of the illicit nature of these compounds, there is a deficiency in the pharmacological data available for these 'new' benzodiazepines. In order to further understand the pharmacology of 'new' benzodiazepines we utilised a quantitative structure-activity relationship (QSAR) approach. A set of 69 benzodiazepine-based compounds was analysed to develop a QSAR training set with respect to published binding values to GABA_A receptors. The QSAR model returned an R² value of 0.90. The most influential factors were found to be the positioning of two H-bond acceptors, two aromatic rings and a hydrophobic group. A test set of nine random compounds was then selected for internal validation to determine the predictive ability of the model and gave an R² value of 0.86 when comparing the binding values with their experimental data. The QSAR model was then used to predict the binding for 22 benzodiazepines that are classed as new psychoactive substances. This model will allow rapid prediction of the binding activity of emerging benzodiazepines in a rapid and economic way, compared with lengthy and expensive in vitro/in vivo analysis. This will enable forensic chemists and toxicologists to better understand both recently developed compounds and prediction of substances likely to emerge in the future.

Fatality involving ocfentanil documented by identification of metabolites

The use of new psychoactive substances (NPS) has rapidly increased over the last decade. In the last 4 years, producers increasingly appear to be targeting non-controlled synthetic opioids, involving fentanyl derivatives such as ocfentanil (OcF). Identification of metabolites is of major importance in the context of NPS use, as it could improve the detection window in biological matrices in clinical and forensic intoxication cases. Hence, this work aims to report a fatality involving OcF documented by the identification of metabolites. A 30-year-old woman was found dead at home: an unidentified powder was found near her body and some injection sites were found at the autopsy. Toxicological analyses allowed to determine the presence of OcF in the powder, blood (3.7/3.9 μg/L, peripheral/cardiac) and in other post-mortem samples. The most relevant potential CYP- and UGT-dependent metabolites of OcF were investigated in vitro using human liver microsome incubation and liquid chromatography coupled with high resolution mass spectrometry, and subsequently confirmed in post-mortem samples. Four OcF metabolites were produced in vitro (a mono-hydroxylated OcF, O-desmethylOcF, a hydroxylated desmethylOcF and a glucuronidated form of the O-desmethylOcF), and all except the glucuronide were observed in blood and bile post-mortem samples. Considering the relative intensity of the chromatographic peak areas, O-desmethylOcF can be suggested to be an abundant metabolite of OcF. Nevertheless, the relevance of O-desmethylOcF as being a complementary analytical target of OcF for OcF use detection needs further in vivo confirmation, especially through analysis of urines from users.