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.

Bromazolam in Impaired Driving Investigations.

The designer benzodiazepine bromazolam is increasingly encountered in forensic casework, including impaired driving investigations. A series of suspected impaired driving cases that tested positive for bromazolam are described herein along with information about driving performance, driver appearance and observed behavior. Bromazolam was indicated in casework either through screening by liquid chromatography time of flight mass spectrometry (LC-TOF/MS) and/or a positive benzodiazepine immunoassay screen. Blood samples were forwarded for quantitative confirmatory analysis using a liquid chromatography tandem mass spectrometry (LC-MS/MS) method with a reporting limit of 2.0 ng/mL. Bromazolam was reported in 98 impaired driving cases from samples reported between January 2021 and December 2023, with the earliest detection from September 2020. Mean and median blood concentrations were 125 ± 145 ng/mL and 84 ng/mL respectively, with a range of 4.2 - 990 ng/mL. Additional positive findings were reported in almost all cases, with the highest result (990 ng/mL) being the only case in which bromazolam was the only finding. Fentanyl was the most frequent drug found in combination with bromazolam. Driving behaviors reported in these cases included erratic driving, errors in Standardized Field Sobriety Tests (SFSTs), and symptoms consistent with Central Nervous System (CNS) depressants, including slurred speech, incoordination, and lethargic behavior. Based on its prevalence and demonstrated impairing effects, bromazolam should be included in the scope of impaired driving testing as long as it continues to be prevalent in the drug supply.

A Postmortem Case Report involving Fentanyl, Desalkylgidazepam and Bromazolam.

The emergence of new psychoactive substances (NPS) and the number of new chemically diverse substances in the global illicit drug market have significantly increased over the last few years. Designer benzodiazepines are some of the most misused NPS worldwide, contributing to both nonfatal and fatal drug overdose cases. The use of desalkylgidazepam and bromazolam has recently emerged, and their prevalence has been internationally reported. In this study, we quantified desalkylgidazepam and bromazolam using gas chromatography coupled with mass spectrometry (GC-MS) in the postmortem specimens of a subject found deceased due to suspected drug overdose. A 24-year-old white male with a history of drug use was found unresponsive and not breathing in his home with drug paraphernalia nearby. A yellow powdery substance and prescription tablets were also found at the scene. The GC-MS analysis of the postmortem blood and urine samples confirmed the presence of fentanyl, desalkylgidazepam, and bromazolam. The desalkylgidazepam concentration was 1100 ng/mL in the blood, which was higher than previous reports in the literature, and estimated to be 89 ng/mL in the urine. The bromazolam concentration was 352 ng/mL in the blood and estimated to be 398 ng/mL in the urine. Additionally, fentanyl was detected in the blood (11 ng/mL) and fentanyl, norfentanyl, and gabapentin were detected in the urine. The present study aims to provide the toxicological community with information regarding a fit-for-purpose analysis of two NPS benzodiazepines.

Despite the improved clinical sensitivity of the Roche benzodiazepines II assay it cannot replace mass spectrometry in all patient populations.

Introduction: Benzodiazepines are frequently prescribed and misused therefore urine drug screening (UDS) is performed in many patient populations. Most current benzodiazepine immunoassays have poor sensitivity, particularly for detecting the metabolites of newer benzodiazepines such as lorazepam in urine. Objectives: We aimed to verify the clinical performance of the new qualitative Roche Benzodiazepines II (BNZ2) immunoassay, as well as compare its performance to the Roche Benzodiazepines Plus (BENZ) assay in two patient populations: UDS in the emergency department (ED) and compliance monitoring. Methods: An initial verification study was performed, selecting for samples containing clonazepam and lorazepam metabolites. Performance of the BNZ2 and BENZ assays was compared to liquid chromatography-tandem mass spectrometry (LC-MS/MS) as the reference method. Sensitivity, specificity, false positive rate (FPR) and false negative rate (FNR) were determined. Results: We verified the performance claims in the initial verification and demonstrated similar precision, with coefficient of variations (CVs) of 12.8% and 7.7% for negative and positive controls, respectively. Furthermore, we observed higher clinical sensitivity and lower FNR with the BNZ2 assay in both the ED and compliance monitoring populations due to improved cross-reactivity for lorazepam and clonazepam metabolites. Despite these improvements, the BNZ2 assay was unable to detect 27% of specimens positive by LC-MS/MS, including specimens from patients using benzodiazepines without prescription. Discussion: Due to its improved performance and rapid turnaround time, the BNZ2 assay should be implemented for UDS in the ED. However, the assay should not replace LC-MS/MS testing for compliance monitoring, as unsuspected benzodiazepine use may go undetected.

Fake Xanax: Designer Emerging Benzodiazepine Epidemic Linked to Morbidity and Mortality a Narrative Review.

Etizolam is a thienodiazepine derivative which produces an anxiolytic effect similar to benzodiazepines such as alprazolam (Xanax). Like classic benzodiazepines, etizolam has a high affinity towards the GABAA receptor, and allosterically potentiates the effects of GABA resulting in neuronal hyperpolarization related to chloride influx. When taken in therapeutic doses, etizolam produces a similar effect to Xanax. Counterfeit Xanax tablets contain variable amounts of etizolam. Tablets with high amounts of etizolam can cause toxicity if ingested, especially when combined with other substances. When toxic symptoms occur in patients, they may include severe sedation, unconsciousness, and depression of the medullary respiratory center. In this regard, there is the potential for death. Additionally, the rise in fake Xanax tablets containing etizolam and other counterfeit medications has been exacerbated by the difference in regulations regarding these substances in different countries as well as the illegal drug trade. Healthcare providers may also play a role through the over- or underprescribing of certain medications. Thus, in order to combat the rise in counterfeit medications such as fake Xanax, international cooperation, regulation, and enforcement of laws pertaining to the manufacture, prescription, and distribution of these substances are needed.

The surge of bromazolam-related fatalities replacing other novel designer benzodiazepines-related fatalities in San Francisco.

BACKGROUND AND AIM: Bromazolam, a novel designer benzodiazepine (NBD), exhibits potent sedative, hypnotic and anxiolytic effects, raising concerns regarding its potential for misuse and fatal outcomes, particularly when combined with opioids such as fentanyl. Despite limited documented fatalities globally, its use poses a significant threat, exacerbated by under-reporting and a lack of routine testing. This study analysed NBD-related deaths in a major US city over a 4-year period. METHODS: Analysis of accidental overdose deaths involving NBDs in San Francisco, CA, USA from 2020 to 2023, was performed utilizing medico-legal death investigations including comprehensive forensic toxicology, pathology and demographic information. San Francisco conducts thorough investigations into all non-natural and sudden unexpected deaths, including routine alcohol and drug testing of decedents under its jurisdiction, including etizolam, flualprazolam, flubromazolam and bromazolam analysis. RESULTS: There was a sudden surge in bromazolam-related deaths, with 44 fatalities documented in 2023, contrasting with relatively fewer deaths related to other NBDs. Bromazolam fatalities frequently involved co-ingestion with opioids, primarily fentanyl, and stimulants such as methamphetamine and cocaine. Demographic characteristics indicated a predominance of males, with a significant proportion lacking fixed addresses. Blood concentrations of bromazolam increased during the study period, suggesting heightened availability and/or purity in the community. CONCLUSION: There was a surge in bromazolam-related deaths during 2023 in San Francisco, CA, USA, contrasting with relatively stable numbers of deaths associated with other NBDs over the preceding years. The findings underscore the urgency for enhanced death investigation, testing and reporting to facilitate targeted harm reduction strategies for individuals at risk of bromazolam-related morbidity and mortality.

Benzodiazepine Boom: Tracking Etizolam, Pyrazolam, and Flubromazepam from Pre-UK Psychoactive Act 2016 to Present Using Analytical and Social Listening Techniques.

INTRODUCTION: The designer benzodiazepine (DBZD) market continues to expand whilst evading regulatory controls. The widespread adoption of social media by pro-drug use communities encourages positive discussions around DBZD use/misuse, driving demand. This research addresses the evolution of three popular DBZDs, etizolam (E), flubromazepam (F), and pyrazolam (P), available on the drug market for over a decade, comparing the quantitative chemical analyses of tablet samples, purchased from the internet prior to the implementation of the Psychoactive Substances Act UK 2016, with the thematic netnographic analyses of social media content. METHOD: Drug samples were purchased from the internet in early 2016. The characterisation of all drug batches were performed using UHPLC-MS and supported with 1H NMR. In addition, netnographic studies across the platforms X (formerly Twitter) and Reddit, between 2016-2023, were conducted. The latter was supported by both manual and artificial intelligence (AI)-driven thematic analyses, using numerous.ai and ChatGPT, of social media threads and discussions. RESULTS: UHPLC-MS confirmed the expected drug in every sample, showing remarkable inter/intra batch variability across all batches (E = 13.8 ± 0.6 to 24.7 ± 0.9 mg; F = 4.0 ± 0.2 to 23.5 ± 0.8 mg; P = 5.2 ± 0.2 to 11.5 ± 0.4 mg). 1H NMR could not confirm etizolam as a lone compound in any etizolam batch. Thematic analyses showed etizolam dominated social media discussions (59% of all posts), with 24.2% of posts involving sale/purchase and 17.8% detailing new administration trends/poly-drug use scenarios. Artificial intelligence confirmed three of the top five trends identified manually. CONCLUSIONS: Purity variability identified across all tested samples emphasises the increased potential health risks associated with DBZD consumption. We propose the global DBZD market is exacerbated by surface web social media discussions, recorded across X and Reddit. Despite the appearance of newer analogues, these three DBZDs remain prevalent and popularised. Reporting themes on harm/effects and new developments in poly-drug use trends, demand for DBZDs continues to grow, despite their potent nature and potential risk to life. It is proposed that greater controls and constant live monitoring of social media user content is warranted to drive active regulation strategies and targeted, effective, harm reduction strategies.

Designer benzodiazepine rat pharmacokinetics: A comparison of alprazolam, flualprazolam and flubromazolam.

Designer benzodiazepines, including flualprazolam and flubromazolam, are clandestinely produced to circumvent federal regulations. Although flualprazolam and flubromazolam are structurally similar to alprazolam, they do not have an approved medical indication. Flualprazolam differs from alprazolam by the addition of a single fluorine atom. Whereas, flubromazolam differs by the addition of a single fluorine atom and substitution of a bromine for a chlorine atom. The pharmacokinetics of these designer compounds have not been extensively evaluated. In the present study, we evaluated flualprazolam and flubromazolam in a rat model and compared the pharmacokinetics of both compounds to alprazolam. Twelve male, Sprague-Dawley rats were given a 2 mg/kg subcutaneous dose of alprazolam, flualprazolam and flubromazolam and plasma pharmacokinetic parameters were evaluated. Both compounds displayed significant two-fold increases in volume of distribution and clearance. Additionally, flualprazolam displayed a significant increase in half-life leading to a nearly double half-life when compared to alprazolam. The findings of this study demonstrate that fluorination of the alprazolam pharmacophore increases pharmacokinetic parameters including half-life and volume of distribution. The increase in these parameters for flualprazolam and flubromazolam leads to an overall increased exposure in the body and a potential for greater toxicity than alprazolam.

Benzodiazepine analysis by an improved LC-MS/MS method illustrates usage patterns in Washington State.

BACKGROUND: The standard approach for benzodiazepine detection often includes immunoassay followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The illicit use of non-prescribed benzodiazepines has been trending up nationally. METHODS: We developed and validated an improved LC-MS/MS assay for benzodiazepine detection in urine. We expanded the testing panel by adding five drugs to the previous panel of ten. We determined the prevalence of individual benzodiazepines in our patient population. Immunoassay results were compared with LC-MS/MS to evaluate assay performance. RESULTS: Clonazepam and alprazolam were the most common benzodiazepines present. Etizolam and flualprazolam were also prevalent in Washington State. Compared with the LC-MS/MS assay, the immunoassay had variable cross-reactivity, which explained false negative and false positive immunoassay results. The inclusion of new drugs in the LC-MS/MS panel significantly reduced the incidence of immunoassay results interpreted as falsely positive. CONCLUSION: New illicit benzodiazepines have emerged regionally and nationally. The inclusion of novel drugs in LC-MS/MS assay was helpful in properly characterizing the epidemiology of benzodiazepine use in our patient population. This information will lead to better assay result interpretations and patient care, and our experiences provide a roadmap for other clinical laboratories looking to expand their testing menu or transition to new instrumentation.

In silico studies on recreational drugs: 3D quantitative structure activity relationship prediction of classified and de novo designer benzodiazepines.

Currently, increasing availability and popularity of designer benzodiazepines (DBZDs) constitutes a primary threat to public health. To assess this threat, the biological activity/potency of DBZDs was investigated using in silico studies. Specific Quantitative Structure Activity Relationship (QSAR) models were developed in Forge™ for the prediction of biological activity (IC50 ) on the γ-aminobutyric acid A receptor (GABA-AR) of previously identified classified and unclassified DBDZs. A set of new potential ligands resulting from scaffold hopping studies conducted with MOE® was also evaluated. Two generated QSAR models (i.e. 3D-field QSAR and RVM) returned very good performance statistics (r2  = 0.98 [both] and q2  = 0.75 and 0.72, respectively). The DBZDs predicted to be the most active were flubrotizolam, clonazolam, pynazolam and flucotizolam, consistently with what reported in literature and/or drug discussion fora. The scaffold hopping studies strongly suggest that replacement of the pendant phenyl moiety with a five-membered ring could increase biological activity and highlight the existence of a still unexplored chemical space for DBZDs. QSAR could be of use as a preliminary risk assessment model for (newly) identified DBZDs, as well as scaffold hopping for the creation of computational libraries that could be used by regulatory bodies as support tools for scheduling procedures.

Metabolic interactions of benzodiazepines with oxycodone ex vivo and toxicity depending on usage patterns in an animal model.

BACKGROUND AND PURPOSE: Opioids and benzodiazepines are frequently combined in medical as well as in non-medical contexts. At high doses, such combinations often result in serious health complications attributed to pharmacodynamics interactions. Here, we investigate the contribution of the metabolic interactions between oxycodone, diazepam and diclazepam (a designer benzodiazepine) in abuse/overdose conditions through ex vivo, in vivo and in silico approaches. EXPERIMENTAL APPROACH: A preparation of pooled human liver microsomes was used to study oxycodone metabolism in the presence or absence of diazepam or diclazepam. In mice, diazepam or diclazepam was concomitantly administered with oxycodone to mimic acute intoxication. Diclazepam was introduced on Day 10 in mice continuously infused with oxycodone for 15 days to mimic chronic intoxication. In silico modelling was used to study the molecular interactions of the three drugs with CYP3A4 and 2D6. KEY RESULTS: In mice, in acute conditions, both diazepam and diclazepam inhibited the metabolism of oxycodone. In chronic conditions and at pharmacologically equivalent doses, diclazepam drastically enhanced the production of oxymorphone. In silico, the affinity of benzodiazepines was higher than oxycodone for CYP3A4, inhibiting oxycodone metabolism through CYP3A4. Oxycodone metabolism is likely to be diverted towards CYP2D6. CONCLUSION AND IMPLICATIONS: Acute doses of diazepam or diclazepam result in the accumulation of oxycodone, whereas chronic administration induces the accumulation of oxymorphone, the toxic metabolite. This suggests that overdoses of opioids in the presence of benzodiazepines are partly due to metabolic interactions, which in turn explain the patterns of toxicity dependent on usage. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.

Rhabdomyolysis in the Context of Designer Benzodiazepine Misuse.

Designer benzodiazepines belong to a class of lab-created psychoactive compounds, with limited federal regulation, no toxicity testing, and reported high potency, leading to substantial overdose risk and harmful clinical syndromes. Benzodiazepine misuse has been previously documented to be associated with rhabdomyolysis, with elevated creatine kinase (CK) during and after acute episodes of intoxication. Here, we present a case of profound rhabdomyolysis and associated acute kidney injury (AKI) after acute designer benzodiazepine intoxication. A 26-year-old male with a history of poly-substance misuse, including alcohol, psychedelics, opiates, kratom, and benzodiazepines, presented to the emergency department with altered mental status and agitation after an accidental overdose on liquid flubromazolam and clonazolam, designer benzodiazepines purchased online. He went on to develop seizure-like activity. Additional labs revealed AKI with creatinine 2.22 mg/dL (reference 0.74-1.35 mg/dL, baseline 0.88 mg/dL). He was discovered to have severe rhabdomyolysis that peaked at 131,920 U/L (reference 55-170 U/L) on the fourth day of admission. This case demonstrates the potential deleterious effects of the designer benzodiazepine class, including prolonged sedation, AKI, and severe rhabdomyolysis. In addition, seizure-like manifestations may occur during the intoxication or withdrawal phase. Designer benzodiazepines may produce rhabdomyolysis; however, the mechanism is unknown. Direct myotoxicity or prolonged immobilization may be contributors to rhabdomyolysis. More research is needed to elucidate the consequences of designer benzodiazepine misuse. Clinicians should be aware of their use given the ease of availability online and rising popularity.

The blood-to-plasma ratio and predicted GABAA-binding affinity of designer benzodiazepines.

PURPOSE: The number of benzodiazepines appearing as new psychoactive substances (NPS) is continually increasing. Information about the pharmacological parameters of these compounds is required to fully understand their potential effects and harms. One parameter that has yet to be described is the blood-to-plasma ratio. Knowledge of the pharmacodynamics of designer benzodiazepines is also important, and the use of quantitative structure-activity relationship (QSAR) modelling provides a fast and inexpensive method of predicting binding affinity to the GABAA receptor. METHODS: In this work, the blood-to-plasma ratios for six designer benzodiazepines (deschloroetizolam, diclazepam, etizolam, meclonazepam, phenazepam, and pyrazolam) were determined. A previously developed QSAR model was used to predict the binding affinity of nine designer benzodiazepines that have recently appeared. RESULTS: Blood-to-plasma values ranged from 0.57 for phenazepam to 1.18 to pyrazolam. Four designer benzodiazepines appearing since 2017 (fluclotizolam, difludiazepam, flualprazolam, and clobromazolam) had predicted binding affinities to the GABAA receptor that were greater than previously predicted binding affinities for other designer benzodiazepines. CONCLUSIONS: This work highlights the diverse nature of the designer benzodiazepines and adds to our understanding of their pharmacology. The greater predicted binding affinities are a potential indication of the increasing potency of designer benzodiazepines appearing on the illicit drugs market.

Determination of Traditional and Designer Benzodiazepines in Urine through LC-MS/MS.

BACKGROUND: The detection of new designer benzodiazepines in biological fluids and tissues, together with the traditional ones, could represent an important analytical update for laboratories performing clinical and forensic toxicological analysis. OBJECTIVE: A liquid chromatography tandem mass spectrometry method (LC-MS/MS) has been developed, fully validated, and applied to a cohort of real urine samples collected from patients under withdrawal treatment and from intoxication cases. METHODS: 100 µL urines were added to a buffer solution containing deuterated internal standards; the samples were then extracted through a liquid/liquid procedure, dried under a nitrogen stream, and reconstituted in mobile phase. The chromatographic separation was performed in reverse phase through a C18 column with gradient elution. Mass spectrometry operated in positive polarization and multiple reaction monitoring mode. RESULTS: 25 molecules were optimized for instrumental analysis: 9 designer benzodiazepines and 16 traditional compounds (parent drugs and main metabolites). Sensitivity, specificity, linearity, accuracy, imprecision, recovery, matrix effects, and carry-over have been evaluated for all molecules. Only cinazepam did not satisfy all acceptance criteria for validation. 10 among the 50 analyzed samples tested positive for at least one of the monitored molecules. In particular, two different samples collected from the same case provided positive results for flubromazepam, a designer benzodiazepine. CONCLUSION: The method was proven to be useful in detecting not only traditional benzodiazepines but also new designer ones. The identification of a New Psychoactive Substance in real samples confirmed that analytical procedures should be updated to include as many substances as possible.

Designer benzodiazepine dependence and the difficulties of outpatient management; a case report.

BACKGROUND: Novel psychoactive substances, such as designer benzodiazepines (DBZD), are a growing public health concern. There are about 30 different DZBDs reported, which can vary widely in their effect and potential for harmful outcomes, ranging from agitation to confusion to coma. Despite the scope of this widespread phenomena, little information on the management of DBZD dependence is available in the literature. CASE: In this case report, we present a patient with DBZD dependence requesting assistance tapering off the DBZD, clonazolam. He began self-medicating with clonazolam seven years prior for panic attacks to the point he was using 40 drops per day and having significant withdrawal during the day. He was prescribed gabapentin for his underlying anxiety while he tapered his clonazolam dose. Once he achieved a 75% reduction in his use of clonazolam, he had trouble managing withdrawal and anxiety symptoms and could not taper further. DISCUSSION: We discuss the challenges of treating patients with DBZD use disorder in an outpatient setting. Switching a patient from a DZBD to a prescription benzodiazepine for the purposes of a taper can be dangerous as an outpatient due to the inability to monitor at-home DBZD usage and the resulting risk of overdose. DBZDs can also be highly potent and make it difficult to achieve success using current withdrawal guidelines.

Screening suspect pharmaceuticals for illicit designer benzodiazepines using raman, SERS, and FT-IR prior to comprehensive analysis using LC-MS.

The emergence of illicit designer benzodiazepines with high dependency and no approved clinical use are of great US public health concern. Due to the increasing numbers of illicit designer benzodiazepines encountered in the US supply chain, there is a need to develop robust analytical methods that can rapidly detect these chemicals. Suspect counterfeit tablets, powders, or liquid formulations were first screened using Raman spectroscopy and surface-enhanced Raman scattering spectroscopy (SERS) for the presence of legal or illicit benzodiazepines, and then further analyzed using Fourier-transform infrared (FT-IR) spectroscopy and liquid chromatography with tandem mass spectrometric detection (LC-MS). Several microextraction procedures were developed and used to extract benzodiazepines from samples prior to SERS, FT-IR, and LC-MS analysis. Conventional Raman analyses using handheld Raman spectrometers afforded the ability to examine samples through enclosed plastic bags but were only able to detect high concentrations of various benzodiazepines in the suspect samples. The developed SERS methods were sufficient for detecting at least one benzodiazepine in the low-dose suspect samples, thereby allowing prioritization using other analytical tools that require more sample preparation and time-consuming analyses. The use of FT-IR spectroscopy coupled with extraction and spectral subtraction was found to be selective to multiple benzodiazepines and various excipients in the analyzed samples. This study demonstrated that the developed SERS and FT-IR procedures could be used in satellite laboratories to screen suspect packages at ports of entry and prioritize samples for additional laboratory-based analyses in an effort to prevent dangerous and illicit pharmaceutical products from reaching the US supply chain.

A New Strategy for Efficient Retrospective Data Analyses for Designer Benzodiazepines in Large LC-HRMS Datasets.

The expanding and dynamic market of new psychoactive substances (NPSs) poses challenges for laboratories worldwide. The retrospective data analysis (RDA) of previously analyzed samples for new targets can be used to investigate analytes missed in the first data analysis. However, RDA has historically been unsuitable for routine evaluation because reprocessing and reevaluating large numbers of forensic samples are highly work- and time-consuming. In this project, we developed an efficient and scalable retrospective data analysis workflow that can easily be tailored and optimized for groups of NPSs. The objectives of the study were to establish a retrospective data analysis workflow for benzodiazepines in whole blood samples and apply it on previously analyzed driving-under-the-influence-of-drugs (DUID) cases. The RDA workflow was based on a training set of hits in ultrahigh-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS) data files, corresponding to common benzodiazepines that also had been analyzed with a complementary UHPLC-tandem mass spectrometry (MS/MS) method. Quantitative results in the training set were used as the true condition to evaluate whether a hit in the UHPLC-QTOF-MS data file was true or false positive. The training set was used to evaluate and set filters. The RDA was used to extract information from 47 DBZDs in 13,514 UHPLC-QTOF-MS data files from DUID cases analyzed from 2014 to 2020, with filters on the retention time window, count level, and mass error. Sixteen designer and uncommon benzodiazepines (DBZDs) were detected, where 47 identifications had been confirmed by using complementary methods when the case was open (confirmed positive finding), and 43 targets were not reported when the case was open (tentative positive finding). The most common tentative and confirmed findings were etizolam (n = 26), phenazepam (n = 13), lorazepam (n = 9), and flualprazolam (n = 8). This method efficiently found DBZDs in previously acquired UHPLC-QTOF-MS data files, with only nine false-positive hits. When the standard of an emerging DBZD becomes available, all previously acquired DUID data files can be screened in less than 1 min. Being able to perform a fast and accurate retrospective data analysis across previously acquired data files is a major technological advancement in monitoring NPS abuse.

Designer Benzodiazepines' Activity on Opioid Receptors: A Docking Study.

BACKGROUND: Previous studies have reported that benzodiazepines (BZDs) seem to enhance euphoric and reinforcing properties of opioids in opioid users so that a direct effect on opioid receptors has been postulated, together with a possible synergistic induction of severe side effects due to co use of BDZs and opioids. This is particularly worrisome given the appearance on the market of designer benzodiazepines (DBZDs), whose activity/toxicity profiles are scarcely known. OBJECTIVES: This study aimed to evaluate, through computational studies, the binding affinity (or lack thereof) of 101 DBZDs identified online on the kappa, mu, and delta opioid receptors (K, M, DOR); and to assess whether their mechanism of action could include activation of the latter. METHODS: MOE® was used for the computational studies. Pharmacophore mapping based on strong opioids agonist binders' 3D chemical features was used to filter the DBZDs. Resultant DBZDs were docked into the crystallised 3D active conformation of KOR (PDB6B73), DOR (PDB6PT3) and MOR (PDB5C1M). Co-crystallised ligands and four strong agonists were used as reference compounds. A score (S, Kcal/mol) representative of the predicted binding affinity, and a description of ligand interactions were obtained from MOE®. RESULTS: The docking results, filtered for S < -8.0 and the interaction with the Asp residue, identified five DBZDs as putative binders of the three ORs : ciclotizolam, fluloprazolam, JQ1, Ro 48-6791, and Ro 48-8684. CONCLUSION: It may be inferred that at least some DBZDs may have the potential to activate opioid receptors. This could mediate/increase their anxiolytic, analgesic, and addiction potentials, as well as worsen the side effects associated with opioid co-use.

Toxicity of designer benzodiazepines: A case of etizolam and cocaine intoxication.

During the last decade, only few cases of acute etizolam intoxication have been detailed. Little is known about the toxic effects of etizolam overdose. Here, the authors report the case of a 42-year-old man who was admitted to the emergency department for intense agitation following etizolam and cocaine consumption. Detection and determination of etizolam and cocaine (including metabolites) were achieved using liquid chromatography tandem mass spectrometry. Etizolam and benzoylecgonine (BZE) were detected in plasma at 64 and 10 ng/mL, respectively. The level of cocaine was below the limit of quantification (< 5 ng/mL). To the authors' knowledge, the only report detailing an etizolam overdose was provided by O'Connell et al. and was characterized by the presence of central nervous system (CNS) depression signs. Interestingly, here, there were no signs of CNS depression but only signs of CNS excitation. With regard to cocaine and BZE plasma concentrations, the clinical presentation cannot be only explained by the co-consumption of cocaine. It may be hypothesized that the clinical presentation was related to a paradoxical reaction to etizolam overdose. To date, no case of paradoxical excitation related to etizolam use has been reported in adults. The case presented here appears particularly interesting, given the limited data relating to high-dose etizolam toxicity.

The Psychonauts' Benzodiazepines; Quantitative Structure-Activity Relationship (QSAR) Analysis and Docking Prediction of Their Biological Activity.

Designer benzodiazepines (DBZDs) represent a serious health concern and are increasingly reported in polydrug consumption-related fatalities. When new DBZDs are identified, very limited information is available on their pharmacodynamics. Here, computational models (i.e., quantitative structure-activity relationship/QSAR and Molecular Docking) were used to analyse DBZDs identified online by an automated web crawler (NPSfinder®) and to predict their possible activity/affinity on the gamma-aminobutyric acid A receptors (GABA-ARs). The computational software MOE was used to calculate 2D QSAR models, perform docking studies on crystallised GABA-A receptors (6HUO, 6HUP) and generate pharmacophore queries from the docking conformational results. 101 DBZDs were identified online by NPSfinder®. The validated QSAR model predicted high biological activity values for 41% of these DBDZs. These predictions were supported by the docking studies (good binding affinity) and the pharmacophore modelling confirmed the importance of the presence and location of hydrophobic and polar functions identified by QSAR. This study confirms once again the importance of web-based analysis in the assessment of drug scenarios (DBZDs), and how computational models could be used to acquire fast and reliable information on biological activity for index novel DBZDs, as preliminary data for further investigations.