Designer benzodiazepines' pharmacological effects and potencies: How to find the information

A strategy for the detection of benzodiazepine drugs using low-resolution paper-spray mass spectrometry for harm reduction drug checking

The ability to detect newly emerging substances is of great importance in reducing harms for people who use drugs. New psychoactive substances including novel benzodiazepines in the illicit drug supply have been linked to high rates of overdose deaths while complicating drug checking as an overdose prevention strategy. Paper-spray mass spectrometry (PS-MS) has emerged as a novel strategy to rapidly detect trace components in street drug samples. While targeted, low-resolution PS-MS methods have proven effective, newly emerging substances are often missed. To address this, a method was applied to low-resolution full-scan PS-MS data to aid in the early detection and identification of novel benzodiazepines in the unregulated drug supply. Using the developed method, true positives rates of 0.89 and 0.75 were achieved for bromazolam and etizolam in street samples obtained in a community drug checking service. The applicability of the method was further demonstrated for a novel benzodiazepine, desalkylgidazepam, that has recently emerged in the illicit drug supply.

Metabolism and detection of designer benzodiazepines; A systematic review

Synthesis and illicit use of designer benzodiazepines are growing concerns, withthese newpsychoactive 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 metabolismoverview and suggestssuitable human consumptionbiomarkers for toxicology casework. A systematic literature search of PubMed®, ScopusTM, Web of ScienceTM, and Cochranedatabaseswas conducted independently by two coauthorsadhering to PRISMA guidelines. Data from 30in 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, andnitro-reduced and N-acetylated metabolites of nitro-containing designer benzodiazepines were also common. From these data, we propose a generic metabolic pathwayfor designer benzodiazepines. The sporadic illicit market presents challenges in toxicological casework and necessitates comprehensive biomarker investigations, especially in cases with legal implications. There are fewmetabolismdata for many designer benzodiazepines, emphasizing the need for research focusing on closing these gaps.

Probe Electrospray Ionization Tandem Mass Spectrometry for the Detection and Quantification of Benzodiazepines

BACKGROUND

Legally prescribed benzodiazepines (BZDs) and designer BZDs are widely misused and must be determined in multiple contexts (eg, overdose, drug-facilitated sexual assaults, or driving under the influence of drugs). This study aimed to develop a method for measuring serum BZD levels using probe electrospray ionization (PESI) mass spectrometry and an isotope dilution approach.

METHODS

A tandem mass spectrometer equipped with a probe electrospray ionization source in multiple reaction monitoring mode was used. Isotope dilution was applied for quantification using a deuterated internal standard at a fixed concentration for alprazolam, bromazepam, diazepam, nordiazepam, oxazepam, temazepam, zolpidem, and zopiclone. This method included designer BZDs: clonazolam, deschloroetizolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam, meclonazepam, nifoxipam, and pyrazolam. Sample preparation was done by mixing 10 µL of serum with 500 µL of an ethanol/ammonium formate 0.01 mol/L buffer. Complete validation was performed, and the method was compared with liquid chromatography coupled with mass spectrometry (LC-MS/MS) and immunoassays (IC) by analyzing 40 real samples.

RESULTS

The analysis time for identification and quantification of the 18 molecules was 2.5 minutes. This method was fully validated, and the limits of quantification varied from 5 to 50 mcg/L depending on the molecule. In the 40 real samples, 100% of molecules (n = 89) were detected by both LC-MS/MS and PESI-MS/MS, and regression analysis showed excellent agreement between the 2 methods (r 2 = 0.98). On IC, bromazepam and zolpidem were not detected in 2 and 1 cases, respectively.

CONCLUSIONS

PESI-MS/MS allows serum BZD detection and measurement. Given the isotope dilution approach, a calibration curve was not required, and its performance was similar to that of LC-MS/MS, and its specificity was higher than that of IC.

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.

Discriminative stimulus and reinforcing effects of diclazepam in rodents

Diclazepam, a designer benzodiazepine, is a lesser-known novel anxiolytic substance and a structural analog of diazepam. Although several case studies have reported the adverse effects of diclazepam, their potential impacts remain unknown. Therefore, this study aimed to determine the effects of diclazepam in rodents using drug discrimination, locomotor activity, self-administration (SA), and conditioned place preference (CPP) tests. Sprague-Dawley rats (male, 8 weeks old, weighing 220-450 g, n = 12 per group) and C57BL/6 mice (male, 7 weeks old, weighing 20-25 g, n = 7-8 per group) were administered alprazolam, morphine, and diclazepam. Diclazepam fully elicited alprazolam-appropriate dose-dependent lever responses (>80 %) similar to those of alprazolam. In rats administered 0.5 mg/kg of morphine, a partial substitution (80 %-20 %) was observed. Mice receiving intraperitoneal injections of diclazepam (0.05, 0.2, and 2 mg/kg) showed decreased locomotor activity. In the SA experiment, mice that self-administered intravenous diclazepam (2 μg/kg/infusion) showed significantly higher infusion and active lever responses compared to the vehicle group. No statistically significant rewarding effects of diclazepam at the doses of 0.2 and 2 mg/kg evaluated using the CPP paradigm were found. In conclusion, diclazepam has reinforcing effects and shares the interoceptive effects of alprazolam. Therefore, legal restrictions on the use of diclazepam should be carefully considered.

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.

Comprehensive evaluation of the pharmacological and toxicological effects of γ-valerolactone as compared to γ-hydroxybutyric acid: Insights from in vivo and in silico models

Γ-valerolactone (GVL), marketed online as "Tranquilli-G" and "excellent Valium", is used as a legal substitute for γ-hydroxybutyric acid (GHB); however, until now, GVL has only been connected to one Drug-Facilitated Sexual Assault (DFSA) case. Moreover, the pharmaco-toxicological effects of GVL are poorly studied. The aim of this study was to investigate the 1) in vivo effects of gavage administration of GVL (100-3000 mg/kg) on neurological (myoclonia, convulsions), sensorimotor (visual, acoustic, and overall tactile) responses, righting reflex, thermoregulation, motor activity (bar, drag, and accelerod test) and cardiorespiratory changes (heart rate, breath rate, oxygen saturation, and pulse distension) in CD-1 male mice and the 2) in silico ADMET profile of GVL in comparison to GHB and the open active form γ-hydroxyvaleric acid (GHV). The present study demonstrates that GVL inhibits, in a dose-dependent manner, sensorimotor and motor responses and induces cardiorespiratory depression (at a dose of 3000 mg/kg) in mice. The determination of the ED50 in sensorimotor and motor responses revealed that GVL is about 4-5 times less potent than GHB. In silico prediction of ADMET profiles revealed toxicokinetic similarities between GHB and GHV, and differences with GVL. These results suggest that GVL could be used as a substitute for GHB and should be added to forensic toxicology screenings.

Increasing prevalence of designer benzodiazepines in impaired driving: A 5-year analysis from 2017 to 2021

Designer benzodiazepine (DBZD) use has been increasing over the past decade and poses a threat to human health and safety, particularly when involved in driving under the influence of drug (DUID) cases. Over a 5-year period between 2017 and 2021, there were 1,145 reported DBZDs in 805 blood samples submitted from law enforcement agencies for DUID testing. Eleven different DBZDs were detected, including three metabolite pairs: etizolam/alpha-hydroxyetizolam, clonazolam/8-aminoclonazolam, diclazepam/delorazepam, flualprazolam, flubromazolam, flubromazepam, bromazolam and bromazepam. Etizolam/alpha-hydroxyetizolam (n = 485) and flualprazolam (n = 149) were the most frequently detected DBZDs, at 60% and 18%, respectively. Driving behavior, standardized field sobriety test performance and physical observations of individuals suspected of DUIDs, whose blood sample was toxicologically confirmed for one or more DBZDs, were consistent with the effects caused by central nervous system depressants. Each DBZD has its own unique timeline, and toxicology testing had to be frequently updated to reflect the state of the novel psychoactive substance market. DBZDs play a role in impaired driving and can be the sole intoxicant in DUID cases.

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.

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.

Etizolam and Its Major Metabolites: A Short Review

Etizolam is a benzodiazepine (BZD). Etizolam is structurally different from BZDs as a thiophene replaces the benzene ring and a triazole ring is fused to the diazepine ring, but etizolam's pharmacological profile is similar. Etizolam has been used to treat anxiety and panic disorders, to reduce depressive and somatization symptoms and to induce muscle relaxation. Etizolam is used recreationally due to its reinforcing and sedative effects. Etizolam is available in tablet or powder form or administered on blotter paper that can be placed on the tongue for oral absorption. Etizolam metabolizes into two major metabolites: α-hydroxyetizolam and 8-hydroxyetizolam, and all three compounds can be detected in different biological specimens using various common analytical techniques such as immunoassay, chromatography and mass spectrometry. Etizolam is a controlled drug in many countries around the globe but is approved for medical use in some countries, such as Japan, South Korea and Italy. This work is a collation and review of available literature on etizolam to help improve the fundamental understanding of its toxicology, outline best analytical practice, and aid interpretation of toxicology results.

New Psychoactive Substances: Major Groups, Laboratory Testing Challenges, Public Health Concerns, and Community-Based Solutions

Across communities worldwide, various new psychoactive substances (NPSs) continue to emerge, which worsens the challenges to global mental health, drug rules, and public health risks, as well as combats their usage. Specifically, the vast number of NPSs that are currently available, coupled with the rate at which new ones emerge worldwide, increasingly challenges both forensic and clinical testing strategies. The well-established NPS detection techniques include immunoassays, colorimetric tests, mass spectrometric techniques, chromatographic techniques, and hyphenated types. Nonetheless, mitigating drug abuse and NPS usage is achievable through extensive community-based initiatives, with increased focus on harm reduction. Clinically validated and reliable testing of NPS from human samples, along with community-driven solution, such as harm reduction, will be of great importance, especially in combating their prevalence and the use of other illicit synthetic substances. There is a need for continued literature synthesis to reiterate the importance of NPS, given the continuous emergence of illicit substances in the recent years. All these are discussed in this overview, as we performed another look into NPS, from differentiating the major groups and identifying with laboratory testing challenges to community-based initiatives.

Designer benzodiazepines: an update

INTRODUCTION

Designer benzodiazepines (DBs) are a subclass of novel psychoactive substances (NPS). DBs mimic the properties of approved and prescribed benzodiazepines.

AREA COVERED

A systematic search of literature on DB classification, structure-activity relationships, pharmacologic properties, and adverse effects.

EXPERT OPINION

The prevalence of DB use has increased substantially over the last decade. All DBs are full-agonist ligands at the gamma-aminobutyric acid type A-benzodiazepine (GABA_A-BZ) receptor system. This is not surprising, since DBs largely represent either minor structural modifications, or well-recognized active metabolites, of existing approved benzodiazepines. As such, the pharmacologic profile and associated risks and hazards of DBs are similar or identical to clinically approved and legitimately prescribed benzodiazepines, most of which have been in use for decades. Concurrent use of DBs along with other abusable or recreational drugs (alcohol, opioids, cocaine, stimulants, hallucinogens, other sedative-hypnotics) represents the principal public health risk. The increasing illicit availability and use of DBs is of concern and requires regulatory attention, but DBs do not rank highly among designer psychotropic agents in terms of health risk to humans.

Metabolic profiling of clonazolam in human liver microsomes and zebrafish models using liquid chromatography quadrupole Orbitrap mass spectrometry

Clonazolam is a designer benzodiazepine with strong sedative and amnesic effects. As we all know, the detection of metabolites is the key to confirming the use of substances in the field of forensic toxicology. In order to better describe clonazolam metabolism completely, we performed the two different experiments exploiting the unique characteristics of the models used. In this study, in vivo and in vitro samples were analyzed with liquid chromatography-quadrupole/electrostatic field orbitrap mass spectrometry. The results showed that seven Phase I metabolites and one Phase II metabolite were detected in zebrafish model. The remaining Phase I and II metabolites were also found in the incubation solution of pooled human liver microsomes. The main types of metabolic reactions of clonazolam included hydroxylation, dealkylation, nitroreduction, dechlorination, N-Acetylation, and O-glucuronidation. In this paper, the main metabolites and metabolic pathways of clonazolam are clarified in detail in order to further improve the metabolic rule of clonazolam. Based on these results, to better detect and judge the abuse of clonazolam, we suggest that M1, its nitro reduction product, is used as its biomarker. The results of this study provide a theoretical basis for the pharmacokinetics and forensic medicine of clonazolam.

Combined Use of Flubromazepam and Stimulants: Blood and Oral Fluid Concentrations and Impact on Driving Ability

"Designer" benzodiazepines (DBZDs) are becoming increasingly available in Europe, with the European Monitoring Centre of Drugs and Drug Addiction currently monitoring ∼30 new benzodiazepines. The following driving under the influence of drug (DUID) case describes the oral fluid (OF) and blood concentrations, as well as the observed effects after the combined use of stimulants and flubromazepam. Both OF, collected via the Intercept i2 collector (Immunalysis, Pomona, CA, USA), and blood (collected in containers with various stabilizers) were screened using a liquid chromatographic (LC) time-of-flight (TOF) mass spectrometric (MS-MS) method. In addition, various LC-MS-MS methods in multi-reaction monitoring mode were applied for confirmation and quantification. The OF and blood samples were taken 2 h 25 min and 9 h 19 min after the accident, respectively. OF contained 789 ng/mL amphetamine, 5,173 ng/mL MDMA, 168 ng/mL benzoylecgonine, 492 ng/mL cocaine, 134 ng/mL 4-methylmethcathinone (4-MMC) and traces of flubromazepam (less than limit of quantification (LLOQ); 2 ng/mL). The sodium-fluoride blood samples contained 19 ng/mL amphetamine, 284 ng/mL MDMA, 20 ng/mL MDA, 38 ng/mL benzoylecgonine, 4 ng/mL methylecgonine, 161 ng/mL flubromazepam and traces of 4-MMC (<LLOQ; 2.5 ng/mL). The driver was observed to have an irregular speed driving pattern and could not keep his lane. He demonstrated the following effects after the accident: bloodshot eyes, red face, sweating, fatigue, disorientation in time and space and mental confusion. Even 24 h after the accident, the driver was confused, disoriented, had red spots on his face and could not keep his balance. The effects of flubromazepam combined with several stimulants are demonstrated. Moreover, this case illustrates well the pros and cons of the different biological matrices applied in a DUID context. Differences between the biological matrices are not only observed concerning the ease/practicality of (on-site) collection, but also in the final drug detectability due to the large variations in OF/blood drug concentration ratios and metabolism/elimination rates as a result of the different chemical entities of the compounds.

Treatment of concurrent etizolam and tianeptine withdrawal following accidental overdose

Background

The availability of nonapproved psychoactive substances with addiction potential from internet sources poses a significant threat to public health. Polysubstance abuse or inadvertent contamination of preparations may result in clinically challenging intoxication and withdrawal syndromes.

Case Report

We report a case of a 32-year-old male with an approximate 2-year history of taking internet-obtained etizolam and tianeptine who presented to the hospital following an overdose. He experienced subsequent withdrawal symptoms consistent with benzodiazepine and opioid withdrawal. Initial attempts at managing symptoms with chlordiazepoxide 25 mg every 6 hours did not relieve his symptoms. On day 3 of admission, addiction medicine was consulted and his regimen was changed to diazepam 80 mg daily with additional as-needed diazepam based on etizolam equivalence. He also received a 5-day methadone taper with plans to transition to buprenorphine in the outpatient setting. Upon discharge he was referred to an addiction medicine specialist who was willing to continue a slow diazepam taper and initiate medications for opioid use disorder to manage both substance use disorders.

Discussion

This case report demonstrates the effectiveness of diazepam in managing benzodiazepine withdrawal from etizolam while concurrently using methadone to manage opioid withdrawal symptoms from tianeptine in a hospitalized patient following overdose. We highlight the importance of a warm handoff in considering the outpatient discharge plan.

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.

Novel Designer Benzodiazepines: Comprehensive Review of Evolving Clinical and Adverse Effects

As tranquilizers, benzodiazepines have a wide range of clinical uses. Recently, there has been a significant rise in the number of novel psychoactive substances, including designer benzodiazepines. Flubromazolam(8-bromo-6-(2-fluorophenyl)-1-methyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazeZpine) is a triazolo-analogue of flubromazepam. The most common effects noted by recreational users include heavy hypnosis and sedation, long-lasting amnesia, and rapid development of tolerance. Other effects included anxiolysis, muscle-relaxing effects, euphoria, loss of control, and severe withdrawals. Clonazolam, or 6-(2-chlorophenyl)-1-methyl-8-nitro-4H-[1,2,4]triazolo[4,3-α]-[1,4]-benzodiazepine, is a triazolo-analog of clonazepam. It is reported to be over twice as potent as alprazolam. Deschloroetizolam (2-Ethyl-9-methyl-4-phenyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine) is part of the thienodiazepine drug class, which, like benzodiazepines, stimulates GABA-A receptors. Meclonazepam ((3S)-5-(2-chlorophenyl)-3-methyl-7-nitro-1,3-dihydro-1,4-benzodiazepin-2-one) is a designer benzodiazepine with additional anti-parasitic effects. Although it has proven to be an efficacious therapy for schistosomiasis, its sedative side effects have prevented it from being marketed as a therapeutic agent. The use of DBZs has been a subject of multiple recent clinical studies, likely related to increasing presence and availability on the internet drug market and lack of regulation. Many studies have aimed to identify the prevalence of DBZs and their effects on those using them. This review discussed these designer benzodiazepines and the dangers and adverse effects that the clinician should know.

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).

Challenges of Diagnosing and Managing Designer Benzodiazepine Dependence and Withdrawal: A Case Report

BACKGROUND

Over the last 10 years, an increasing number of unregulated novel psychoactive substances, including "designer benzodiazepines" (DBZDs), have emerged on the recreational drug market. Despite the rapidly increasing usage of DBZDs, there is a significant lack of information regarding clinical management. Here we present a case illustrating the difficulties of diagnosing and managing DBZD related sedative-hypnotic use disorder.

CASE PRESENTATION

Our patient is a 30-year-old man with severe opioid and sedative-hypnotic use disorders. He had a 10-year history of using heroin, clonazolam, and alprazolam. He stopped using heroin when on methadone maintenance therapy but continued using clonazolam and nonprescribed alprazolam. His opioid treatment program discontinued methadone due to benzodiazepine intoxication, and he returned to heroin use. He then presented for residential withdrawal management where he underwent successful buprenorphine induction and benzodiazepine withdrawal management. During a 3-month period of benzodiazepine abstinence, he struggled with ongoing cravings and post-acute withdrawal syndrome, ultimately leading to return to DBZD use.

DISCUSSION

Despite the increasing prevalence of DBZD use, the usage of DBZDs is likely under-recognized because these compounds are generally not included on standard in-office urine drug immunoassay tests. Initial studies suggest that DBZDs have high potencies, shorter half-lives, are more addictive, and can result in more severe withdrawal symptoms compared to known benzodiazepines. However, there remains a lack of information about the pharmacokinetics and pharmacodynamics of DBZDs, making clinical management for DBZD related sedative-hypnotic use disorders challenging to treat.

Benzodiazepines and Related Sedatives

Benzodiazepine and related sedative use has been increasing. There has been a growing number of unregulated novel psychoactive substances, including designer benzodiazepines. Benzodiazepines have neurobiological and pharmacologic properties that result in a high potential for misuse and physical dependence. Options for discontinuing long-term benzodiazepine use include an outpatient benzodiazepine taper or inpatient withdrawal management at a hospital or detoxification facility. The quality of evidence on medications for benzodiazepine discontinuation is overall low, whereas cognitive behavioral therapy has shown the most benefit in terms of behavioral treatments. Benzodiazepines may also have significant adverse effects, increasing the risk of overdose and death.

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.

Designer Benzodiazepines: A Review of Toxicology and Public Health Risks

The rising use of designer benzodiazepines (DBZD) is a cat-and-mouse game between organized crime and law enforcement. Non-prohibited benzodiazepines are introduced onto the global drug market and scheduled as rapidly as possible by international authorities. In response, DBZD are continuously modified to avoid legal sanctions and drug seizures and generally to increase the abuse potential of the DBZD. This results in an unpredictable fluctuation between the appearance and disappearance of DBZD in the illicit market. Thirty-one DBZD were considered for review after consulting the international early warning database, but only 3-hydroxyphenazepam, adinazolam, clonazolam, etizolam, deschloroetizolam, diclazepam, flualprazolam, flubromazepam, flubromazolam, meclonazepam, phenazepam and pyrazolam had sufficient data to contribute to this scoping review. A total of 49 reports describing 1 drug offense, 2 self-administration studies, 3 outpatient department admissions, 44 emergency department (ED) admissions, 63 driving under the influence of drugs (DUID) and 141 deaths reported between 2008 and 2021 are included in this study. Etizolam, flualprazolam flubromazolam and phenazepam were implicated in the majority of adverse-events, drug offenses and deaths. However, due to a general lack of knowledge of DBZD pharmacokinetics and toxicity, and due to a lack of validated analytical methods, total cases are much likely higher. Between 2019 and April 2020, DBZD were identified in 48% and 83% of postmortem and DUID cases reported to the UNODC, respectively, with flualprazolam, flubromazolam and etizolam as the most frequently detected substances. DBZD toxicology, public health risks and adverse events are reported.

Detection of flubromazolam in patients with suspected non-medical drug use attending emergency departments in the United Kingdom

INTRODUCTION

Non-medical use of novel benzodiazepines has recently become common. Here, we describe the recent frequent detection of flubromazolam in patients attending United Kingdom emergency departments.

METHODS

Adults presenting to participating hospitals with toxicity after suspected drug misuse were studied between March 2015 and January 2021. Clinical features were recorded using consistent methodology and biological samples analysed using liquid chromatography-tandem mass-spectrometry.

RESULTS

Flubromazolam and/or its mono-hydroxylated metabolite were detected in samples from 14 of 957 patients, all presenting since July 2020. Reported clinical features included reduced level of consciousness (10), confusion/agitation (6) and acidosis (5) but multiple other substances were detected in all patients. All patients survived to discharge (length of hospital stay 3.0 to 213 h, median 24.1 h). There was no correlation between admission blood/serum flubromazolam concentrations (range 1.7-480.5 ng/ml, median 7.4 ng/ml) and Glasgow Coma Scale or length of hospital stay. In one patient who needed intubation and ventilation for five days, there was an exponential decline in flubromazolam concentrations with time (calculated half-life 39.8 h). Hydroxyl-flubromazolam was also identified at all time points.

CONCLUSIONS

Flubromazolam has been detected frequently in drug users presenting to UK emergency departments since July 2020. Prolonged toxicity may occur as a result of the long half-life of flubromazolam and the production of metabolites likely to be active.

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

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

An outbreak of novel psychoactive substance benzodiazepines in the unregulated drug supply: Preliminary results from a community drug checking program using point-of-care and confirmatory methods

BACKGROUND

From mid-2018, an increase in novel psychoactive substance (NPS) benzodiazepines was noted on surveillance of the unregulated drug market around Vancouver, British Columbia, Canada. The rise was concordant with an outbreak of atypical overdoses suspicious for benzodiazepine adulteration of unregulated opioids. This study sought to describe the number and type of NPS benzodiazepines in a sample drawn from a community drug checking program during this period, and to explore accuracy of point-of-care drug checking technologies when compared to confirmatory methods in this sample.

METHODS

Point-of-care drug checking data using fentanyl and benzodiazepine test strips as well as Fourier transform infrared spectroscopy were gathered at harm reduction sites in the Vancouver area from October 2018 to January 2020. A convenience subsample underwent confirmatory testing with gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, or quantitative nuclear magnetic resonance spectroscopy.

RESULTS

Of 159 samples with both point-of-care and confirmatory results, 24 (15.1%) contained at least one NPS benzodiazepine, including etizolam (n = 18), flubromazolam (n = 3), flualprazolam (4), and flubromazepam (n = 1). Of 114 confirmatory samples expected by participants on self-report to contain opioids, 18 (15.8%) contained some NPS benzodiazepine, with 16 (14.0%) containing both an NPS benzodiazepine and an opioid, always fentanyl. False positive and negative rates were 15.5% and 37.5% for test strips, and 3.9% and 91.7% for FTIR, respectively. Combined together, false positive and negative rates of point-of-care methods were 17.8% and 29.2%.

CONCLUSIONS

NPS benzodiazepine adulteration in an unregulated drug supply sample reveals new risks compounding ongoing harms associated with the synthetic opioid epidemic. Given substantial false positive and false negative rates noted in our sample for point-of-care detection methods, cautious use of combined point-of-care methods, routinely paired with confirmatory drug checking may aid in early detection and monitoring of unregulated drug markets and inform targeted harm reduction strategies and health policy approaches.

New psychoactive substances: a review and updates

New psychoactive substances (NPS) are a heterogeneous group of substances. They are associated with a number of health and social harms on an individual and societal level. NPS toxicity and dependence syndromes are recognised in primary care, emergency departments, psychiatric inpatient and community care settings. One pragmatic classification system is to divide NPS into one of four groups: synthetic stimulants, synthetic cannabinoids, synthetic hallucinogens and synthetic depressants (which include synthetic opioids and benzodiazepines). We review these four classes of NPS, including their chemical structures, mechanism of action, modes of use, intended intoxicant effects, and their associated physical and mental health harms. The current challenges faced by laboratory testing for NPS are also explored, in the context of the diverse range of NPS currently available, rate of production and emergence of new substances, the different formulations, and methods of acquisition and distribution.

Designer drugs: mechanism of action and adverse effects

Psychoactive substances with chemical structures or pharmacological profiles that are similar to traditional drugs of abuse continue to emerge on the recreational drug market. Internet vendors may at least temporarily sell these so-called designer drugs without adhering to legal statutes or facing legal consequences. Overall, the mechanism of action and adverse effects of designer drugs are similar to traditional drugs of abuse. Stimulants, such as amphetamines and cathinones, primarily interact with monoamine transporters and mostly induce sympathomimetic adverse effects. Agonism at μ-opioid receptors and γ-aminobutyric acid-A (GABAA) or GABAB receptors mediates the pharmacological effects of sedatives, which may induce cardiorespiratory depression. Dissociative designer drugs primarily act as N-methyl-D-aspartate receptor antagonists and pose similar health risks as the medically approved dissociative anesthetic ketamine. The cannabinoid type 1 (CB1) receptor is thought to drive the psychoactive effects of synthetic cannabinoids, which are associated with a less desirable effect profile and more severe adverse effects compared with cannabis. Serotonergic 5-hydroxytryptamine-2A (5-HT2A) receptors mediate alterations of perception and cognition that are induced by serotonergic psychedelics. Because of their novelty, designer drugs may remain undetected by routine drug screening, thus hampering evaluations of adverse effects. Intoxication reports suggest that several designer drugs are used concurrently, posing a high risk for severe adverse effects and even death.