Analysis of phenazepam and 3-hydroxyphenazepam in post-mortem fluids and tissues

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.

[Personalized character of toxic effects through mass nonlethal poisoning by phenazepam and other psychoactive substances]

Over several months, 14 people were admitted in 6 hospitals with severe symptoms of intoxication with psychoactive substances as a result of mass poisoning. All symptoms occurred after taking a drink that contained crushed phenazepam tablets. Samples of blood (n=10) and urine (n=6) taken from 14 sufferers for forensic, chemical and toxicological examination were analyzed using the HPLC-MS/MS method. Phenazepam was detected in the biomaterial of all 14 patients. Other psychoactive substances (baclofen, pregabalin, chlorprothixene, chlorpromazine, phenibut, tramadol, diazepam), narcotic substances and ethanol were also found in the sufferers. The phenazepam concentration in the blood was in the range of 109.75-786.50 ng/ml, in the urine - 8.97-101.28 ng/ml. The pharmacokinetic and toxicokinetic characteristics of toxicants as well as additional factors characterizing the phenotype of the sufferer in addition to drug's content in the biological material must be taken into account to determine the toxicity level of phenazepam against the background of combined action with other psychoactive substances.

Desalkylgidazepam blood concentrations in 63 forensic investigation cases

Desalkylgidazepam, also known as bromonordiazepam, is the latest designer benzodiazepine to appear in postmortem blood samples in British Columbia. Our laboratory was first alerted to the presence of desalkylgidazepam in seized drug samples in May 2022, and the analyte was added to an in-house library shortly thereafter. Previously acquired spectra from routine death investigation cases were reprocessed using the updated library with the first presumptive identification of desalkylgidazepam occurring in a sample received in April 2022. A standard addition method for the quantitation of desalkylgidazepam in blood samples (from femoral, iliac, jugular and subclavian veins) was validated and consequently used to confirm presence and concentrations of the drug in 63 cases, with an average concentration of 42.2 ± 44.0 ng/mL (median concentration: 24.5 ng/mL; range: 3.7-220.6 ng/mL). Similar to detections of other novel benzodiazepines, co-occurrence of desalkylgidazepam with opioids and/or stimulants was common. To our knowledge, this paper is the first to report desalkylgidazepam concentrations in postmortem blood samples.

A model of evaluative opinion to encourage greater transparency and justification of interpretation in postmortem forensic toxicology

Over the past decades, the calls to improve the robustness of interpretation in forensic science have increased in magnitude. Forensic toxicology has seen limited progress in this regard. In this work, we propose a transparent interpretive pathway for use in postmortem forensic toxicology cases. This process allows the selection of the interpretive methodology based on the amount of previous information that is available for the drug(s) in question. One approach is an assessment of various pharmacological and circumstantial considerations resulting in a toxicological significance score (TSS), which is particularly useful in situations where limited information about a drug is available. When there is a robust amount of case data available, then a probabilistic approach, through the evaluation of likelihood ratios by the forensic toxicologist and of prior probabilities by the fact finder, is utilized. This methodology provides a transparent means of making an interpretive decision on the role of a drug in the cause of death. This will allow the field of forensic toxicology to take a step forward in using best practice in evaluative reporting, a tool already used by many other forensic science disciplines.

Comparative Study of Postmortem Concentrations of Benzodiazepines and Z-Hypnotics in Several Different Matrices

Benzodiazepines and z-hypnotics are detected in the majority of fatal overdose cases in Norway, often in combination with other drugs of abuse, and their concentrations in peripheral blood (PB) might be important to elucidate the cause of death. In some forensic autopsies, PB is however not available. The aim of the present study was to compare concentrations of benzodiazepines and z-hypnotics in five alternative matrices to assess whether these concentrations are comparable to concentrations in PB. A total of 109 forensic autopsy cases were included. PB, cardiac blood (CB), pericardial fluid (PF), psoas muscle (PM), lateral vastus muscle (LVM) and vitreous humor (VH) from each case were analyzed using ultra high performance liquid chromatography--tandem mass spectrometry. We were able to detect clonazepam, 7-aminoclonazepam, flunitrazepam, 7-aminoflunitrazepam, nitrazepam, 7-aminonitrazepam, diazepam, nordiazepam, oxazepam, alprazolam, midazolam, zopiclone and zolpidem in all the analyzed matrices. Concentrations measured in VH were generally much lower than those of PB for all compounds except zopiclone. 7-Amino metabolite concentrations were high compared to the parent compounds, although less so for the muscle samples. Concentrations of the parent nitrobenzodiazepines in muscles were higher than those in PB, but for the other compounds, concentrations in muscle showed good correspondence with PB. Both CB and PF were viable alternative matrices for PB, although a larger variation and a tendency for higher concentrations in PF were observed. This study shows that CB, PM, LVM and PF can give comparable concentrations to PB for benzodiazepines and z-hypnotics, while VH was less suitable. The concentrations in alternative matrices must, however, be interpreted carefully.

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.

Blood Concentrations of Designer Benzodiazepines: Relation to Impairment and Findings in Forensic Cases

The use of designer benzodiazepines appears to be increasing in many countries, but data concerning blood concentrations are scarce, making interpretation of concentrations difficult. The aim of this study was to report blood concentrations of clonazolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam and phenazepam and to investigate the relationship between blood concentrations and impairment. The concentration data are from blood samples collected from living cases (apprehended drivers and other drug offences) and medico-legal autopsies. The blood samples were analysed for the seven designer benzodiazepines mentioned above by ultra high performance liquid chromatography–tandem mass spectrometry. Positive cases from between 1 June 2016 and 30 September 2019 were included. Blood concentrations and the conclusion from a clinical test of impairment (when available) are reported. The presented seven benzodiazepines were detected in a total of 575 cases, where 554 of these cases concerned apprehended drivers or other criminal offenders. The number of findings and the median (range) concentrations were as follows: clonazolam, n = 22, 0.0041 mg/L (0.0017–0.053 mg/L); diclazepam, n = 334, 0.0096 mg/L (0.0016–0.25 mg/L); etizolam, n = 40, 0.054 mg/L (0.015–0.30 mg/L); flualprazolam, n = 10, 0.0080 mg/L (0.0033–0.056 mg/L); flubromazepam, n = 5, 0.037 mg/L (0.0070–0.70 mg/L); flubromazolam, n = 20, 0.0056 mg/L (0.0004–0.036 mg/L); and phenazepam, n = 138, 0.022 mg/L (0.0018–0.85 mg/L). A designer benzodiazepine was the only drug detected with relevance for impairment in 25 of the 554 living cases. The physician concluded with impairment in 19 of the 25 cases. Most of the concentrations in these cases were relatively similar to or higher than the median reported concentrations. The most frequent other drugs detected were amphetamine, tetrahydrocannabinol, clonazepam and methamphetamine. The presented blood concentrations can be helpful with the interpretation of cases involving one or more of these seven benzodiazepines. The results indicate that concentrations commonly observed in forensic cases are associated with impairment.

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.

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.

'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.

Characterization and in vitro phase I microsomal metabolism of designer benzodiazepines - an update comprising adinazolam, cloniprazepam, fonazepam, 3-hydroxyphenazepam, metizolam and nitrazolam

Designer benzodiazepines represent an emerging class of new psychoactive substances. While other classes of new psychoactive substances such as cannabinoid receptor agonists and designer stimulants are mainly consumed for hedonistic reasons, designer benzodiazepines may also be consumed as 'self-medication' by persons suffering from anxiety or other psychiatric disorders or as stand-by 'antidote' by users of stimulant and hallucinogenic drugs. In the present study, five benzodiazepines (adinazolam, cloniprazepam, fonazepam, 3-hydroxyphenazepam and nitrazolam) and one thienodiazepine (metizolam) 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 nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry (MS), liquid chromatography MS/MS and liquid chromatography quadrupole time-of-flight MS analysis. The detected in vitro phase I metabolites of adinazolam were N-desmethyladinazolam and N-didesmethyladinazolam. Metizolam showed a similar metabolism to other thienodiazepines comprising monohydroxylations and dihydroxylation. Cloniprazepam was metabolized to numerous metabolites with the main metabolic steps being N-dealkylation, hydroxylation and reduction of the nitro function. It has to be noted that clonazepam is a metabolite of cloniprazepam, which may lead to difficulties when interpreting analytical findings. Nitrazolam and fonazepam both underwent monohydroxylation and reduction of the nitro function. In the case of 3-OH-phenazepam, no in vitro phase I metabolites were detected. Formation of licensed benzodiazepines (clonazepam after uptake of cloniprazepam) and the sale of metabolites of prescribed benzodiazepines (fonazepam, identical to norflunitrazepam, and 3-hydroxyphenazepam) present the risk of incorrect interpretation of analytical findings. Copyright © 2016 John Wiley & Sons, Ltd.

Detection of phenazepam in illicitly manufactured Erimin 5 tablets

A validated ultra-high-performance liquid chromatographic (UHPLC) method was used to determine the phenazepam dosage in clandestinely produced Erimin 5 tablets. Tablets from five different seizures submitted to the laboratory in 2013 were found to have a dosage of about 2.4 milligrams. The measurement uncertainty of the assay was estimated to be 3.2 % (relative) at a coverage factor of k=2. As an adjunct study the dyes in the tablets from several seizures were determined by thin-layer chromatography (TLC) for future comparative studies.

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

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