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Drug use within prisons is increasingly complex and unpredictable. Benzodiazepines are currently one of the most common drugs detected in individuals leaving Scottish prisons; however, understanding illicit benzodiazepine use within prisons and assessing the potential harm to individuals is challenging due to the lack of available analytical data on the substances circulating. Increasingly, materials, such as paper and clothing, infused with novel benzodiazepines have been identified as a smuggling route into Scottish prisons. Methods were developed for the qualitative and quantitative analysis of benzodiazepines using gas chromatography-mass spectrometry (GC-MS) and applied to 495 seized samples from 11 Scottish prisons, including papers, cards, blotters, powders, tablets, and clothing. Evolution in the benzodiazepines being detected was demonstrated, with etizolam being the most prevalent throughout 2020/2021 following which flubromazepam and bromazolam detections increased. Additionally, significant changes in the smuggling methods and drug formats detected occurred over time following policy changes within prisons. These data represent the first reported widescale etizolam quantitation data and demonstrate high levels of variability across all sample types, most notably within tablets (0.34-2.33 mg per tablet). Additionally, concentration mapping of a whole seized card sample revealed the total concentration of drug present (312.5 mg) and demonstrated variability across the surface of the card (1.16-1.87 mg/cm 2 ). These data highlight the challenges of consistent dosing for individuals and the high risks of unintentional overdose. Increased understanding of the challenge of such drug smuggling and benzodiazepine use will aid in the development of strategies to reduce supply and mitigate harm., (© 2023 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)

As one of the most widely abused designer benzodiazepines in the world, etizolam has been found in many cases in many countries. In this study, UPLC-Q-Exactive-MS was used for the first time to establish a dynamic change model of etizolam and its metabolites in rats. Compared with previous studies, the detection sensitivity and reproducibility of the instrument were higher. In the experiment, we optimized the traditional pharmacokinetic model based on Gauss function. According to the significant difference of etizolam in the plasma elimination phase of rats, a new pharmacokinetic model based on Lorentz function was established to describe the dynamic changes of etizolam more rigorously, which made the error effects lower and the accuracy of the pharmacokinetic parameters was improved. At the same time, the pharmacokinetic parameters of etizolam were compared with four other designer benzodiazepines reported in previous studies in rats, and we found the direct reason for the popularity of etizolam in the NPS market and explored the future development of etizolam for the first time. In addition, 21 metabolites were found through rat experiments to effectively detect etizolam abuse for a long time, of which 4 metabolites had the longest detection window and could be used as long-acting metabolites for experiments, which greatly prolongs the detection window and extends the time range in which etizolam was detected in real cases. This study is the first to conduct a systematic and comprehensive study on the metabolism and pharmacokinetics of etizolam and find out the direct reason for the prevalence of etizolam abuse, and we also discuss the development trend of etizolam in the future market of new psychoactive substances, which is beneficial for forensic experts to assess the trend of drug abuse and can provide reference for relevant drug control and drug treatment., Competing Interests: Declaration of Competing Interest There is no conflict of interest between the authors., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Although not used clinically in North America, etizolam has been identified in forensic samples as an illicit 'designer' benzodiazepine. As a central nervous system depressant, analysis for etizolam has probative value in both death investigations and forensic cases where incapacitation or human psychomotor performance is relevant. This report examines toxicological findings and demographic data in a series of authentic forensic cases analyzed between November 2019 and December 2020 in which etizolam was quantified by liquid chromatography-tandem mass spectrometry analysis. Blood concentrations were determined in 191 individuals aged 1-75 years. In living individuals (i.e., impaired driving and sexual assaults), etizolam concentrations ranged from <5 to 767 ng/mL which overlapped with the range of <5 to 260 ng/mL reported in death investigations. In all but one case, other drugs were detected in combination with etizolam. Fentanyl was the most common co-occurring drug and was present in 164 cases (86%). Additional case details are provided for cases of forensic interest: two deaths involving children <3 years of age, two deaths involving body packing and an individual arrested for drug-impaired driving with, to our knowledge, the highest reported etizolam concentration to date., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: In British Columbia, Canada, illicit opioids have been increasingly combined with etizolam, a benzodiazepine analog, that continues to challenge popular portable drug checking technologies as it is often present in low concentrations as a result of its high potency. An unknown combination of opioids and benzodiazepines may have dangerous consequences due to unpredictable dosing, increased respiratory depression, and complicated overdose response measures., Methods: Surface-enhanced Raman spectroscopy (SERS) using a portable Raman spectrometer is used to establish a univariate model for the detection of etizolam in opioid drug mixtures (n=100) obtained from the Vancouver Island Drug Checking Project, where the presence of etizolam has been determined using paper-spray mass spectrometry. Benzodiazepine immunoassay test strips are also performed on all samples for comparison., Results: SERS is shown to detect etizolam with high sensitivity (96%) and specificity (86%). In contrast, benzodiazepine test strips demonstrate a low sensitivity (8%) for the detection of etizolam of the same samples (n=100), with only small improvements when studied over a larger subset of samples (n=506, sensitivity = 29%)., Conclusion: We have demonstrated the potential of SERS for trace detection of etizolam within complex sample matrices. Since SERS is one of the few portable technologies capable of trace detection, further studies on its ability for quantification and discrimination of trace adulterants in street samples is of significant interest for point-of-care applications., Competing Interests: Declarations of Interest Authors declare that they have no conflict of interest., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Benzodiazepines are a class of compounds used clinically to treat a variety of conditions including anxiety and insomnia. Their potential for abuse has led to a surge in their availability on the illegal drugs market. End users often rely on markings on illicit tablets to identify their contents. However, falsified tablets mimicking genuine pharmaceutical preparations often contain ingredients that differ from what people believe they are taking. The absence of any quality control of the content, purity, or strength of fake tablets can result in adverse effects or even fatal outcomes. In recent years, drug seizures involving illicit round yellow tablets marked "5" on one side and "5617" below a scoreline on the reverse have been submitted to Forensic Science Ireland (FSI) by An Garda Síochána (Irish Police) from throughout the Republic of Ireland. These findings relate to 26 different seizures; the cumulative tablet total seized was in excess of 20,000, and the total number of tablets of this description analyzed at FSI was 141. Irish users assume that the active ingredient present was diazepam. The qualitative analytical results for these tablets are reported. All tablets were found to contain 2-methylamino-5-chlorobenzophenone. In addition, the tablets contained either 2-amino-3-(2-chlorobenzoyl)-5-ethylthiophene or etizolam or both. The constituents were present in varying relative amounts in visually similar tablets. Neither 2-amino-5-chlorobenzophenone nor 2-amino-3-(2-chlorobenzoyl)-5-ethylthiophene had previously been found in tablets analyzed at FSI., (© 2021 John Wiley & Sons, Ltd.)

Background: There has been a recent increase in adulteration of opioids with low concentration actives such as fentanyl analogues and benzodiazepines. As drug checking projects using vibrational spectroscopy continue to seek confirmatory lab-based testing, the concern and reality of missing these potentially harmful substances in point-of-care testing is prevalent., Methods: A portable GC-MS was used to analyze select opioid samples acquired at a drug checking service in Victoria, Canada (n=59). Certified reference standards of several fentanyl analogues and benzodiazepines were measured to guide targeted analysis of these samples. Results were compared with those obtained using a lab-based paper spray mass spectrometer., Results: Portable GC-MS was able to identify 62% of samples containing carfentanil and 36% of samples containing etizolam. In the case of etizolam, the success rate was higher for more potent samples: 78% of etizolam-containing samples were identified when the etizolam concentration was above 3% by weight. In comparison, infrared spectroscopy was able to detect etizolam in only 9% of the etizolam-containing samples, and is not sensitive enough to detect carfentanil at relevant concentrations., Conclusions: Portable GC-MS has potential in identifying low concentration substances in a point-of-care setting, without relying on subsequent off-site confirmatory testing., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Etizolam is a novel psychoactive substance and novel benzodiazepine of the thienotriazolodiazepine class, which has recently seen an increasing trend in use worldwide. We report a case series of 10 decedents with etizolam and opioids in their systems. Death investigation, expanded toxicology and medical investigation information were included for contextualization of etizolam in death. Etizolam was detected and confirmed within peripheral and cardiac blood, urine, vitreous humor and, in one case, gastric fluid, by liquid chromatography-tandem mass spectrometry and liquid chromatography-quadrupole time of flight mass spectrometry methodologies. Death investigation indicated nonmedical use of most drugs. Medical investigation commonly noted pulmonary edema, cardiomegaly and cerebral swelling. The majority of the decedents appeared to be unaware of the presence of etizolam and succumbed to the mixed drug toxicity of their routine depressant and narcotic analgesic drug of abuse in combination with etizolam. Etizolam use continues to be observed and poses as a potentially lethal contribution to multiple drug toxicity, especially in the age of the opioid crisis. Assessment of analytes like etizolam requires up-to-date methodologies and vigilance in testing to better characterize the toxicology and interpret the contribution to death., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

In order to obtain fundamental information on the disposition of hypnotics into hair after a single oral dose the quantitative hair analysis of triazolam (TZ), etizolam (EZ), flunitrazepam (FNZ), nitrazepam (NZ) and zolpidem (ZP) have been performed using a validated LC-MS/MS procedure. Hair specimens (straight, black) were collected from three subjects about one month and three months after a single 0.25 mg dose of TZ, 1 mg of EZ, 2 mg of FNZ, 5 mg of NZ and 10 mg of ZP tartrate. The subjects ingested just one out of five different hypnotics on each day, each of five days in turn. All ingested hypnotics have been detected in hair from each subject both one month and three months after intake, and their concentrations were in the range of 0.023-0.043 pg/hair strand (0.077-0.36 pg/mg) for TZ, 0.11-0.63 pg/hair strand (0.44-5.2 pg/mg) for EZ, 0.14-2.6 pg/hair strand (0.56-22 pg/mg) for FNZ, 0.33-1.7 pg/hair strand (1.3-17 pg/mg) for NZ and 20-40 pg/hair strand (120-270 pg/mg) for ZP. For FNZ and NZ, not only the parent drugs but also their metabolites, 7-amino-FNZ and 7-amino-NZ, were detected in the range of 2.3-9.2 pg/hair strand (9.2-82 pg/mg) and 2.4-9.1 pg/hair strand (8.0-55 pg/mg), respectively. The calculated incorporation ratios into hair against the dose were found to exhibit similarity between the four benzodiazepines. This finding suggests the ability to apply these quantitative data to approximately estimating the amounts of other benzodiazepines, which have similar chemical structures, in hair although it should be noted that the amounts of drugs in hair varies considerably depending on the hair color. On the other hand, the incorporation ratio of ZP showed 15-29 times higher than that of TZ, indicating that lipophilic ZP was more likely to incorporate into hair than benzodiazepines. In addition, the application of the present data to a drug-facilitated sexual assault was shown., Competing Interests: Conflict of Interest There are no financial or other relations that could lead to a conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Etizolam is a thienodiazepine that although licensed for clinical usage in Japan, India and South Korea is commonly abused and detected in post-mortem cases around the world. To date, there are limited data in the literature to allow for the interpretation of blood concentrations of etizolam in post-mortem cases. A liquid chromatography with tandem mass spectrometry method was used to quantitate etizolam concentrations in 28 post-mortem cases where etizolam was detected. The median concentration of etizolam in femoral blood was 8.5 ng/mL (range 1.0-172.0 ng/mL; n  = 24); in antemortem plasma, the etizolam concentration range was 4-44 ng/mL ( n  = 4). The mean age of the individuals abusing etizolam was 38.5 ± 8.4 years (median 39 years), with the majority being male (86%). In all of the cases, multiple drugs were detected, with the most common being pregabalin (61%) followed by morphine/heroin (54%), diazepam (54%) and benzoylecgonine (21%), illustrating the increasing problem of poly-substance use in drug abusers. The cause of death in the cases in which etizolam was detected was multi-drug toxicity in 87.5% of the cases, with 12.5% unrelated to drug use (hangings and blunt-force trauma). These data will further help forensic practitioners with the interpretation of post-mortem etizolam concentrations.

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.

Etizolam is a benzodiazepine analogue that is approved for use in Japan, Italy and India but has recently appeared as a nonapproved product on the illicit drug market in Europe and North America. Etizolam was identified in a crystalline material seized at a Kentucky racetrack, raising concerns that this drug may have been used in racing. The aim of this study was to characterize the metabolism and excretion of etizolam in horses to generate information on its disposition and to incorporate the correct urinary and serum target analytes into anti-doping screening procedures. Etizolam was administered both intravenous and orally at a dose of 0.1 mg/kg of body weight to three horses using a two-way crossover design. Pre-administration and post-administration serum and urine samples were collected and experiments conducted to identify potential metabolites in these samples. Additionally, in vitro metabolism studies using horse liver S9 were undertaken to complement the in vivo metabolism studies. Numerous metabolites were id1entified in both serum and urine in additional to parent drug, with α-hydroxy-etizolam producing the most abundant analytical signal (in terms of signal intensity and duration of detection) of the identified metabolites in both matrices. Therefore, α-hydroxy-etizolam is considered to be the most appropriate analyte for detection for anti-doping purposes. Analytical methods were developed and validated and then applied to post-administration samples to generate concentrations of etizolam and its major metabolites in serum and urine, resulting in excretion profiles that can be used to guide approaches to detecting the use of the drug., (© 2020 John Wiley & Sons Ltd.)

This study describes 12 cases of drivers stopped for impaired driving, where a designer benzodiazepine was detected, specifically etizolam or flubromazolam. Etizolam was detected in three cases, with blood concentrations ranging from 40 to 330 ng/mL. Two of these cases had low concentrations of methamphetamine and/or amphetamine, and in the third case tetrahydrocannabinol (THC) was detected. Flubromazolam was detected in nine cases; in all cases, at least one other drug was detected, with THC being the most prevalent. The mean blood concentration of flubromazolam was 16.3 ng/mL and had a median concentration of 17.0 ng/mL, ranging from 7.0 to 31 ng/mL. The low concentrations of designer benzodiazepines that produce pharmacological effects may allow many of these drugs to go undetected using routine testing in laboratories; therefore, it is necessary to include these novel compounds within validated analytical methods to reduce the chance of reporting false negative results. The prevalence in which laboratories are detecting the presence of novel benzodiazepines in impaired drivers illustrates the increased threat to public safety. These case studies demonstrate the importance of investigating agencies and forensic laboratories to be vigilant in monitoring the emerging novel psychoactive substances in their region., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

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., (© The Author(s) 2020. Published by Oxford University Press on behalf of The International Association of Forensic Toxicologists, Inc.)

An analytical method for the detection of 40 benzodiazepines, (±)-zopiclone, zaleplon and zolpidem in blood and urine by solid-phase extraction liquid chromatography-tandem mass spectrometry was developed and validated. Twenty-nine of 43 analytes were quantified in 0.5 mL whole blood for investigating postmortem, drug-facilitated sexual assault (DFSA) and driving under the influence of drugs cases (DUID). The four different dynamic ranges of the seven-point, linear, 1/x weighted calibration curves with lower limits of quantification of 2, 5, 10 and 20 μg/L across the analytes encompassed the majority of our casework encountered in postmortem, DFSA and DUID samples. Reference materials were available for all analytes except α-hydroxyflualprazolam, a hydroxylated metabolite of flualprazolam. The fragmentation of α-hydroxyflualprazolam was predicted from the fragmentation pattern of α-hydroxyalprazolam, and the appropriate transitions were added to the method to enable monitoring for this analyte. Urine samples were hydrolyzed at 55°C for 30 min with a genetically modified β-glucuronidase enzyme, which resulted in >95% efficiency measured by oxazepam glucuronide. Extensive sample preparation included combining osmotic lysing and protein precipitation with methanol/acetonitrile mixture followed by freezing and centrifugation resulted in exceptionally high signal-to-noise ratios. Bias and between-and within-day imprecision for quality controls (QCs) were all within ±15%, except for clonazolam and etizolam that were within ±20%. All 29 of the 43 analytes tested for QC performance met quantitative reporting criteria within the dynamic ranges of the calibration curves, and 14 analytes, present only in the calibrator solution, were qualitatively reported. Twenty-five analytes met all quantitative reporting criteria including dilution integrity. The ability to analyze quantitative blood and qualitative urine samples in the same batch is one of the most useful elements of this procedure. This sensitive, specific and robust analytical method was routinely employed in the analysis of >300 samples in our laboratory over the last 6 months., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Several indole derivatives have been disclosed by our research groups that have been collaborating for nearly 25 years. The results of our investigations led to a variety of molecules binding selectively to different pharmacological targets, specifically the type A γ-aminobutyric acid (GABA A ) chloride channel, the translocator protein (TSPO), the murine double minute 2 (MDM2) protein, the A 2B adenosine receptor (A 2B AR) and the Kelch-like ECH-associated protein 1 (Keap1). Herein, we describe how these works were conceived and carried out thanks to the versatility of indole nucleus to be exploited in the design and synthesis of drug-like molecules.

Issues: Etizolam is a thienodiazepine derivative, with high affinity for the benzodiazepine site of GABA A receptors. It is often referred to as a new (or novel) psychoactive substance, a 'designer' benzodiazepine or a 'street benzodiazepine'. Increasing reports of non-medical use, identification of etizolam as an ingredient in counterfeit medications and the common identification of etizolam in drug-related deaths, highlight the need for a greater understanding of etizolam., Approach: A rapid narrative review was conducted using PubMed and Google Scholar to synthesise what is known about etizolam to answer two research questions: (i) Does the pharmacological or toxicological profile of etizolam differ from other benzodiazepines?; and (ii) What is the nature and context of non-medical use and harms related to etizolam?, Key Findings: Etizolam has a higher potency as an anxiolytic but lower lethality compared with diazepam. Few harms are documented with the therapeutic use of pharmaceutical products. Harms appear to be predominantly related to the use of etizolam in illicitly manufactured pills and occur almost exclusively in the context of mixed-drug toxicity., Conclusion: In therapeutic doses, there is little to suggest that etizolam is more harmful than other benzodiazepines. Most harms with etizolam appear to be related to the wide availability of illicitly manufactured pills, which are taken in unknown doses and combined with other substances. Current harm reduction advice, including avoiding combining opioids and benzodiazepines, remains relevant and increasingly important within an emerging culture of non-medical use., (© 2020 Australasian Professional Society on Alcohol and other Drugs.)

Purpose: To investigate effect of metabolic syndrome on blood pressure during cataract surgery with topical anesthesia., Design: A single-centered, retrospective case series., Methods: Consecutive patients who were hospitalized and underwent phacoemulsification and insertion of intraocular lens with topical anesthesia in October 2016 were included. Perioperative blood pressure and pulse pressure were compared between patients with metabolic syndrome (metabolic group) and sex- and age-matched patients without metabolic syndrome (nonmetabolic group) at six time points: on admission, in the morning of the operation, 2 hours before the operation, at the point of entering the operation room, during the operation, and after the operation. Perioperative use of etizolam and nicardipine was compared between the two groups., Results: Thirty patients in the metabolic group and 30 in the nonmetabolic group were included. There was no difference in changes compared with the values on admission in systolic pressure and pulse pressure at any examination point between the two groups. There was no difference in changes in diastolic pressure between the two groups, except for at 2 hours before the operation (1.4 ± 9.6 mm Hg in the metabolic group vs -6.2 ± 8.5 mm Hg in the nonmetabolic group; P = 0.044). The number of patients who were administered etizolam was 5/30 (16.7%) in the metabolic group and 2/30 (6.7%) in the nonmetabolic group, showing no significant difference. No patients were administered intravenous nicardipine in either group., Conclusions: Well-controlled metabolic syndrome did not affect the changes in perioperative blood pressure during cataract surgery with topical anesthesia.

The misuse of designer benzodiazepines, as an alternative to prescription benzodiazepines and for drug-facilitated sexual assaults, has emerged as a growing threat, due in part to the ease of purchasing these drugs on the internet at low prices. Causing concern for safety is the lack of dosage information resulting in users self-medicating, often leading to unintended overdoses, coma or death at higher doses. With limited published data regarding the quantification of designer benzodiazepines in forensic cases, a method was validated for the determination of 13 designer benzodiazepines in postmortem blood, to add to the in-house method that already included a limited number of common designer benzodiazepines. The developed method included 3-hydroxyphenazepam, clobazam, clonazolam, delorazepam, deschloroetizolam, diclazepam, flualprazolam, flubromazepam, flubromazolam, flunitrazolam, meclonazepam, nifoxipam and pyrazolam in 0.5 mL postmortem blood using liquid chromatography-tandem mass spectrometry. The analytes were treated with solid phase extraction before undergoing separation on a C18 column and analyzed on the mass spectrometer in electrospray positive mode using multiple reaction monitoring. The linear range of the calibration curve was 1-200 ng/mL and up to 500 ng/mL for 3-hydroxyphenazepam, clobazam, flubromazepam and pyrazolam. The limits of detection and quantitation were 0.5 ng/mL (signal-to-noise ratio >3) and 1 ng/mL, respectively. The calculated bias, intra-day imprecision, relative standard deviation (RSD) and inter-day imprecision RSD were ±12%, 3-20% and 4-21%. Matrix effects ranged from -52% to 33% with RSD values ranging from 3-20%, indicating consistent effects throughout multiple sources. Recovery ranged from 35 to 90%, where only two compounds were <50%. Other parameters tested included carryover, stability, interference and dilution integrity, which all yielded acceptable results. With the application of this method to blood specimens from the New York City Office of Chief Medical Examiner, this validated method proved to be simple, reproducible, sensitive and robust., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The organ distribution of 3-fluorophenmetrazine (3-FPM), pyrazolam, diclazepam as well as its main metabolites delorazepam, lormetazepam and lorazepam, was investigated. A solid phase extraction (SPE) and a QuEChERS (acronym for quick, easy, cheap, effective, rugged and safe) - approach were used for the extraction of the analytes from human tissues, body fluids and stomach contents. The detection was performed on a liquid chromatography-tandem mass spectrometry system (LCMS/MS). The analytes of interest were detected in all body fluids and tissues. Results showed femoral blood concentrations of 10 μg/L for 3-FPM, 28 μg/L for pyrazolam, 1 μg/L for diclazepam, 100 μg/L for delorazepam, 6 μg/L for lormetazepam, and 22 μg/L for lorazepam. Tissues (muscle, kidney and liver) and bile exhibited higher concentrations of the mentioned analytes than in blood. Additional positive findings in femoral blood were for 2-fluoroamphetamine (2-FA, approx. 89 μg/L), 2-flourometamphetamine (2-FMA, hint), methiopropamine (approx. 2.2 μg/L), amphetamine (approx. 21 μg/L) and caffeine (positive). Delorazepam showed the highest ratio of heart (C) and femoral blood (P) concentration (C/P ratio = 2.5), supported by the concentrations detected in psoas muscle (430 μg/kg) and stomach content (approx. 210 μg/L, absolute 84 μg). The C/P ratio indicates that delorazepam displays susceptibility for post-mortem redistribution (PMR), supported by the findings in muscle tissue. 3-FPM, pyrazolam, diclazepam, lorazepam and lormetazepam did apparently not exhibit any PMR. The cause of death, in conjunction with autopsy findings was concluded as a positional asphyxia promoted by poly-drug intoxication by arising from designer benzodiazepines and the presence of synthetic stimulants., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Etizolam is a drug from the thienotriazoldiazepine class, widely prescribed as anxiolytic due to its apparently secure toxicological profile. Nevertheless, some recent cases of etizolam dependence, intoxications and fatalities associated to its abuse have been reported in the international literature. For this reason, the drug listed as new psychoactive substance (NPS) by the World Health Organization (WHO) since 2015. Euphoric effect at high dosage is the first cause of its recreational use that has determined a wider distribution in the illicit market. An experimental study was performed to obtain evidence that etizolam at low therapeutic dosages is a drug with negligible influence on the psychomotor performances involved in driving. The psychomotor performance was assessed by performing different tests, such as critical tracking task (CTT), critical flicker fusion (CFF), choice reaction time (CRT), visual vigilance task (VVT), response competition test (RCT) in a group of 16 healthy volunteers after a single administration of etizolam at two different dosages (0.25 mg or 1.00 mg) in comparison to placebo. The test results showed that etizolam at 0.25 mg and 1.00 mg had no significant effect on vigilance, short term memory, psychomotor coordination or speed in decision making. Differently, abuse of etizolam to obtain the euphoric effects at presumably high dosages or in combination with other psychoactive substances could be fatal. The negligible side effects on mental and behavioral function demonstrated by this study, could represent an incitement to abuse, which can be strongly discouraged with correct information on differences between its correct use and its misuse., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Benzodiazepines (BZDs) are widely used for treatment of anxiety and insomnia, however, this class of drugs is also commonly abused. Many different BZDs and analogs have been produced that are not FDA-approved. We tested 15 of these with the ThermoFisher CEDIA® BZD-immunoassay. With the exception of ketazolam, all compounds showed significant reactivity, highlighting the need for mass spectrometry confirmation assays. We developed a liquid-chromatography high-resolution mass spectrometry method for the detection of these 15 non-FDA approved BZDs. The limit of detection for most compounds ranged from 1 to 50 ng/mL, with mostly positive matrix effects observed in urine and negative matrix effects in serum. In a clinical research case, clonazolam and etizolam were detected in serum at 10.2 and 281 ng/mL, with an apparent elimination half-life of 3.6 and 4.8 hours, respectively. Although we did not detect non-FDA approved BZDs in 211 urine samples that were previously determined to be BZD-positive by immunoassay, abuse of these drugs is on the rise and clinical and forensic toxicology laboratories should consider developing methods to detect them., (© The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Importance: Exposures to novel psychoactive substances are reported with increasing frequency in both the medical literature and the lay press. While the majority of reports describe synthetic cannabinoids and cathinones, a lesser understood family is the "designer benzodiazepines". The current literature describing human exposures to these compounds is comprised of case reports and small case series., Objective: The primary objectives of this study are to describe epidemiologic trends and clinical effects of designer benzodiazepine use., Methods: Data regarding single agent exposures to designer benzodiazepines between 1 January 2014 and 31 December 2017 was obtained from the National Poison Data System. Substances queried include: adinazolam, clonazolam, cloniprazepam, diclazepam, etizolam, flubromazepam, flubromazolam, meclonazepam, nifoxipam, norflurazepam, and pyrazolam. Data was summarized descriptively., Results: 234 single agent exposures in 40 states were reported during the study period. The annual number of exposures increased each year, from 26 in 2014 to 112 in 2017, amounting to a 330% increase. The most common exposures were etizolam (n = 162) and clonazolam (n = 50). The most common clinical effects were drowsiness/lethargy (65%), and slurred speech (17%). 3% required intubation, 36% of cases required hospital admission, 22% to the intensive care unit. There was 1 death in the study population., Conclusions: The incidence of exposures to designer benzodiazepines is rising. Clinical effects are generally consistent with a sedative-hypnotic toxidrome. Severe effects, including death, seemed relatively uncommon in the study population.

The number of new psychoactive substances (NPS) available is constantly increasing, making it difficult for toxicology laboratories to keep screening methods up to date. Full scan high-resolution mass spectrometry (HRMS) is a versatile technique which allows for progressive updating of spectral databases to increase the scope of screening. It also allows for retrospective screening of data-specifically, reprocessing of data files using an updated spectral database without the need for re-extraction or reanalysis.The coronial case reported here illustrates the application of retrospective processing of HRMS data in the detection of emerging NPS. A 28-year-old male with a history of illicit drug use was found deceased at home. Initial routine screening of the post-mortem peripheral blood identified only methylamphetamine, amphetamine and trace amounts of lorazepam. A compound with an accurate mass and isotope ratio consistent with the opioid AH-7921 was also detected in the liquid chromatography (LC)-HRMS screen; however; the retention time and mass spectrum did not match the library. Further investigation confirmed the compound to be U-47700, another opioid and structural isomer of AH-7921. Several months later, after additional NPS had been added to the in-house HRMS database, retrospective screening of the HRMS data was performed, revealing the presence of designer benzodiazepines, diclazepam and flubromazepam as well as the psychedelic drug 2,5-dimethoxy-4-chloroamphetamine (DOC). Quantitative analysis gave the following results in peripheral post-mortem blood: U-47700 (330 μg/L), diclazepam (70 μg/L), flubromazepam (10 μg/L), methylamphetamine (290 μg/L) and amphetamine (150 μg/L) (DOC not quantitated). These substances, along with lorazepam and etizolam, were also confirmed in the post-mortem urine and an investigation into blood and urinary metabolites was carried out. All analyses were performed using the same LC-quadrupole-time of flight method. The cause of death was aspiration (of gastric content into airways and lungs) due to mixed drug toxicity.

Though illegal in the UK, in many countries novel psychoactive substances are quasi-legal synthetic compounds that are widely available online under the guise of research chemicals. These substances are relatively cheap and are often undetectable in standard drug screens. Nearly 200 such compounds are introduced yearly, and little is usually known about their metabolism or physiological effects. Consequently, managing patients in overdose situations on largely unknown substances usually involves supportive care, however anticipating and managing atypical side effects are challenging in the absence of knowledge of these compounds. In this report, we discuss our encounter with a 33-year-old unconscious man presenting with coingestion of a novel stimulant 3-fluorophenmetrazine with a rarely used benzodiazepine etizolam. This patient developed seizure-like activity and delayed widespread T-wave inversions, both of which ultimately resolved without sequelae., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Introduction: There has been increasing interest in the availability of non-prescription benzodiazepines and their sale as new psychoactive substances. We wanted to determine UK availability from Internet suppliers and motivations for use of three benzodiazepines (diclazepam, flubromazepam, and pyrazolam)., Methods: In November 2014 and March 2016, using the European Monitoring Centre for Drugs and Drug Addiction Snapshot Methodology, Internet search engines ( google.co.uk , uk. yahoo.com and ask.com.uk ) were searched using the terms 'buy diclazepam', 'buy flubromazepam' and 'buy pyrazolam'. Threads from drug-user forums ( bluelight.org , drugs-forum.com , erowid.org , legalhighsforum.com ) were analysed using a general inductive approach. Data were converted into price per gram/pellet to allow cost comparisons and to determine motivations for use., Results: There was an increase in websites selling these benzodiazepines between 2014 and 2016: diclazepam (49 in 2014 to 55 in 2016), pyrazolam (33 to 35), and flubromazepam (39 to 45). Thirty-eight (63.3%) sites were based in the UK/Europe. Drugs were sold as pellets (49 websites, 81.7%), powder (19, 31.7%), and blotters (1, 1.7%). Pill forms were not available, and one (1.7%) website sold diclazepam/flubromazepam in liquid form. The cost reduced with increasing purchase quantities. Main motivations for use included anxiolysis, management of benzodiazepine withdrawal, sedation/sleep aid, and management of stimulant withdrawal., Conclusions: These three benzodiazepines are widely available online, most commonly as pellets, and are (mis)used for a number of reasons. This study could be used to support triangulation of data from other sources to inform harm minimisation strategies.

Anxiety- and stress-related disorders can be debilitating psychiatric conditions in humans. To prevent or ameliorate these conditions, reliable animal models are needed to evaluate the effects of anxiolytic drugs. Previously, we found that a mixture of three pyrazine analogues (P-mix) that were present at high levels in wolf urine induced fear-related responses in mice, rats and deer. A change in cutaneous temperature was shown to be induced by acute stress simultaneously with changes in heart rate, arterial pressure and freezing behavior, raising the possibility that cutaneous temperature could be used as an index of stress. In the present study, using infrared thermography, we showed that exposure of mice to P-mix induced a decrease in cutaneous temperature. We then examined the dose-dependent effects of an anxiolytic drug, etizolam (0-20 mg/kg), on the temperature decrease. Pre-administration of etizolam (5 mg/kg or higher) inhibited the P-mix-induced decrease in cutaneous temperature. Exposure to P-mix induced Fos-immunoreactivity, a marker of neuronal excitation, at the mouse amygdala and hypothalamus, and etizolam (5 mg/kg) attenuated that immunoreactivity. The present results suggested that the measurement of cutaneous P-mix-induced temperature changes in mice could be used as an animal model for evaluating the effects of anxiolytic drugs., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this study, impact of a polymorphism of CYP2C19 on drug-drug interaction (DDI) was examined for etizolam. The effect of itraconazole (a strong CYP3A inhibitor) on the pharmacokinetics of etizolam (a substrate of CYP2C19 and CYP3A) was assessed in both extensive metabolizers (EMs) and poor metabolizers (PMs) of CYP2C19. Sixteen participants (8 EMs and 8 PMs) received a single oral dose of etizolam (0.25 mg) on day 1. The participants ingested itraconazole (200 mg twice a day) on days 2-5. On day 5, participants received an oral dose of etizolam (0.25 mg) again. Before coadministration of itraconazole (day 1), the area under the time-plasma concentration curve from time zero to infinity (AUC ∞ ) of etizolam was higher in PMs than in EMs (2.65-fold, P < .01). Coadministration of itraconazole increased the AUC ∞ of etizolam 1.66-fold and 2.34-fold in EMs and PMs, respectively (day 5). Consequently, AUC ∞ was 6.18-fold higher in PMs with itraconazole than that in EMs without itraconazole. The increase by itraconazole was larger in PMs (P < .01). In heterozygous EMs (hEMs), AUC ∞ was simulated to be 2.56-fold higher with itraconazole than that in EMs without itraconazole. We found that in vitro measurements of fraction metabolized (f m ) using the liver microsome prepared from PM donors would be helpful to predict polymorphism-dependent DDIs. These results suggest that the PMs and hEMs of a polymorphic CYP would be at higher risk of DDIs relative to EMs for drugs metabolized by both polymorphic and nonpolymorphic CYPs such as etizolam., (© 2017, The American College of Clinical Pharmacology.)

A novel microextraction technique based on ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction (UA-LDS-DLLME) had been applied for the determination of 4 designer benzodiazepines (phenazepam, diclazepam, flubromazepam and etizolam) in urine samples by gas chromatography- triple quadrupole mass spectrometry (GC-QQQ-MS). Ethyl acetate (168μL) was added into the urine samples after adjusting pH to 11.3. The samples were sonicated in an ultrasonic bath for 5.5min to form a cloudy suspension. After centrifugation at 10000rpm for 3min, the supernatant extractant was withdrawn and injected into the GC-QQQ-MS for analysis. Parameters affecting the extraction efficiency have been investigated and optimized by means of single factor experiment and response surface methodology (Box-Behnken design). Under the optimum extraction conditions, a recovery of 73.8-85.5% were obtained for all analytes. The analytical method was linear for all analytes in the range from 0.003 to 10μg/mL with the correlation coefficient ranging from 0.9978 to 0.9990. The LODs were estimated to be 1-3ng/mL. The accuracy (expressed as mean relative error MRE) was within ±5.8% and the precision (expressed as relative standard error RSD) was less than 5.9%. UA-LDS-DLLME technique has the advantages of shorter extraction time and is suitable for simultaneous pretreatment of samples in batches. The combination of UA-LDS-DLLME with GC-QQQ-MS offers an alternative analytical approach for the sensitive detection of these designer benzodiazepines in urine matrix for clinical and medico-legal purposes., (Copyright © 2017 Elsevier B.V. All rights reserved.)

We have synthesized and characterized MP-III-022 ((R)-8-ethynyl-6-(2-fluorophenyl)-N,4-dimethyl-4H-benzo[f]imidazo[1,5-a][1,4]diazepine-3-carboxamide) in vitro and in vivo as a binding- and efficacy-selective positive allosteric modulator of GABA A receptors containing the α5 subunit (α5GABA A Rs). By approximation of the electrophysiological responses which the estimated free rat brain concentrations can induce, we demonstrated that convenient systemic administration of MP-III-022 in the dose range 1-10mg/kg may result in a selective potentiation, over a wide range from mild to moderate to strong, of α5βγ2 GABA A receptors. For eliciting a comparable range of potentiation, the widely studied parent ligand SH-053-2'F-R-CH3 containing an ester moiety needs to be administered over a much wider dose range (10-200mg/kg), but at the price of activating non-α5 GABA A Rs as well as the desired α5GABA A Rs at the highest dose. At the dose of 10mg/kg, which elicits a strong positive modulation of α5GABA A Rs, MP-III-022 caused mild, but significant muscle relaxation, while at doses 1-10mg/kg was devoid of ataxia, sedation or an influence on the anxiety level, characteristic for non-selective benzodiazepines. As an amide compound with improved stability and kinetic properties, MP-III-022 may represent an optimized tool to study the influence of α5GABA A Rs on the neuronal pathways related to CNS disorders such as schizophrenia, Alzheimer's disease, Down syndrome or autism., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Research on drug metabolism and pharmacokinetics in large animal species including the horse is scarce because of the challenges in conducting in vivo studies. The metabolic reactions catalyzed by cytochrome P450s (CYPs) are central to drug pharmacokinetics. This study elucidated the characteristics of equine CYPs using diazepam (DZP) as a model compound as this drug is widely used as an anesthetic and sedative in horses, and is principally metabolized by CYPs. Diazepam metabolic activities were measured in vitro using horse and rat liver microsomes to clarify the species differences in enzyme kinetic parameters of each metabolite (temazepam [TMZ], nordiazepam [NDZ], p-hydroxydiazepam [p-OH-DZP], and oxazepam [OXZ]). In both species microsomes, TMZ was the major metabolite, but the formation rate of p-OH-DZP was significantly less in the horse. Inhibition assays with a CYP-specific inhibitors and antibody suggested that CYP3A was the main enzyme responsible for DZP metabolism in horse. Four recombinant equine CYP3A isoforms expressed in Cos-7 cells showed that CYP3A96, CYP3A94, and CYP3A89 were important for TMZ formation, whereas CYP3A97 exhibited more limited activity. Phylogenetic analysis suggested diversification of CYP3As in each mammalian order. Further study is needed to elucidate functional characteristics of each equine CYP3A isoform for effective use of diazepam in horses., (© 2016 John Wiley & Sons Ltd.)

MT-45 (1-cyclohexyl-4-(1,2-diphenylethyl)piperazine) is just one of the many novel psychoactive substances (NPS) to have reached the recreational drug market in the twenty-first century; it is however, one of the first designer opioids to achieve some degree of popularity, in a market currently dominated by synthetic cannabinoids and designer stimulants. A single fatality involving MT-45 and etizolam is described. A method for the quantitation of MT-45 in whole blood using liquid chromatography-tandem mass spectrometry was developed and validated. The linear range was determined to be 1.0-100 ng/mL with a detection limit of 1.0 ng/mL, and the method met the requirements for acceptable linearity, precision and accuracy. After analyzing the sample on dilution and by standard addition, the concentration of MT-45 in the decedent's blood was determined to be 520 ng/mL, consistent with other concentrations of MT-45 reported in drug-related fatalities. Etizolam was present at a concentration of 35 ng/mL. This case illustrates the importance of considering non-traditional drugs in unexplained apparent drug-related deaths., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Phenazepam and etizolam were the first uncontrolled benzodiazepines available for sale in the UK. Pyrazolam, flubromazepam and diclazepam are not used medicinally anywhere in the world; they are produced exclusively for the uncontrolled, recreational market. It is important to know whether potentially abused drugs like these can be detected in routine toxicological screening tests. The purpose of this study was to evaluate whether the Immunalysis® Benzodiazepines ELISA kit could detect phenazepam, etizolam, pyrazolam, flubromazepam, diclazepam and its metabolite delorazepam. Their cross-reactivity was assessed by comparing the absorbance of the drug with that of oxazepam, the reference standard. This study found that these uncontrolled benzodiazepines cross-react sufficiently to produce a positive result with the Immunalysis® Benzodiazepine ELISA kit. Cross-reactivity ranged from 79 to 107% for phenazepam, etizolam, pyrazolam, flubromazepam, diclazepam and delorazepam fortified into blood. The results show that it is possible to detect these newer benzodiazepines with traditional forensic toxicology laboratory tools and it is important to include these benzodiazepines in the confirmation tests., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The clinical need for novel bronchodilators for the treatment of bronchoconstrictive diseases remains a major medical issue. Modulation of airway smooth muscle (ASM) chloride via GABAA receptor activation to achieve relaxation of precontracted ASM represents a potentially beneficial therapeutic option. Since human ASM GABAA receptors express only the α4- and α5-subunits, there is an opportunity to selectively target ASM GABAA receptors to improve drug efficacy and minimize side effects. Recently, a novel compound (R)-ethyl8-ethynyl-6-(2-fluorophenyl)-4-methyl-4H-benzo[f]imidazo[1,5-a][1,4] diazepine-3-carboxylate (SH-053-2'F-R-CH3) with allosteric selectivity for α5-subunit containing GABAA receptors has become available. We questioned whether this novel GABAA α5-selective ligand relaxes ASM and affects intracellular calcium concentration ([Ca(2+)]i) regulation. Immunohistochemical staining localized the GABAA α5-subunit to human ASM. The selective GABAA α5 ligand SH-053-2'F-R-CH3 relaxes precontracted intact ASM; increases GABA-activated chloride currents in human ASM cells in voltage-clamp electrophysiology studies; and attenuates bradykinin-induced increases in [Ca(2+)]i, store-operated Ca(2+) entry, and methacholine-induced Ca(2+) oscillations in peripheral murine lung slices. In conclusion, selective subunit targeting of endogenous α5-subunit containing GABAA receptors on ASM may represent a novel therapeutic option to treat severe bronchospasm., (Copyright © 2015 the American Physiological Society.)

Regional depolarization of the mitochondrial network can alter cellular electrical excitability and increase the propensity for reentry, in part, through the opening of sarcolemmal KATP channels. Mitochondrial inner membrane potential (ΔΨm) instability or oscillation can be induced in myocytes by exposure to reactive oxygen species (ROS), laser excitation, or glutathione depletion, and is thought to be a major factor in arrhythmogenesis during ischemia-reperfusion. Nevertheless, the correlation between ΔΨm recovery kinetics and reperfusion-induced arrhythmias has been difficult to demonstrate experimentally. Here, we investigate the relationship between subcellular changes in ΔΨm, cellular glutathione redox potential, electrical excitability, and wave propagation during coverslip-induced ischemia-reperfusion (IR) in neonatal rat ventricular myocyte (NRVM) monolayers. Ischemia led to decreased action potential amplitude and duration followed by electrical inexcitability after ~15min of ischemia. ΔΨm depolarization occurred in two phases during ischemia: in phase 1 (<30min ischemia), mitochondrial clusters within individual NRVMs depolarized, while phase 2 ΔΨm depolarization (30-60min) was characterized by global functional collapse of the mitochondrial network across the whole ischemic region of the monolayer, typically involving a propagating metabolic wave. Oxidation of the glutathione (GSSG:GSH) redox potential occurred during ischemia, followed by recovery upon reperfusion (i.e., lifting the coverslip). ΔΨm recovered in the mitochondria of individual myocytes quite rapidly upon reperfusion (<5min), but was highly unstable, characterized by subcellular oscillations or flickering of clusters of mitochondria in NRVMs across the reperfused region. Electrical excitability also recovered in a heterogeneous manner, providing an arrhythmogenic substrate which led to formation of sustained reentry. Treatment with 4'-chlorodiazepam, a peripheral benzodiazepine receptor ligand, prevented ΔΨm oscillation, improved GSH recovery rate, and prevented reentry during reperfusion, indicating that stabilization of mitochondrial network dynamics is important for preventing post-ischemic arrhythmias. This article is part of a Special Issue entitled "Mitochondria: From Basic Mitochondrial Biology to Cardiovascular Disease"., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Etizolam is a thienodiazepine anxiolytic which is said to have lower dependence potential than other benzodiazepines. We report a case of etizolam dependence in a young male with social anxiety disorder and moderate depression. This case report highlights the fact that the same caution be exercised while prescribing etizolam with respect to its potential to cause dependence as with any other benzodiazepine.

Designer benzodiazepines, first offered in online shops selling 'research chemicals' in 2012, provide an attractive alternative to prescription-only benzodiazepines as they are readily available over the Internet at a low price. However, as data regarding pharmacokinetic parameters, metabolism, and detectability in biological fluids are limited, they present a challenge for forensic laboratories. Most recently, diclazepam (other names: 2-chlorodiazepam, Ro 5-3448 or 7-chloro-5-(2-chlorophenyl)-1-methyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one) emerged as a new compound in this class of drugs. In this paper, this new designer benzodiazepine was characterized utilizing nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS) as well as liquid chromatography tandem mass spectrometry (LC-MS/MS) techniques. Furthermore, a self-experiment was performed to gain preliminary data on pharmacokinetic properties and to identify the main metabolites. For this purpose, one tablet of diclazepam (declared amount: 1 mg) was ingested by one of the authors, and serum as well as urine samples were collected for 14 and 21 days, respectively. Based on this study, diclazepam has an approximate elimination half-life of 42 h and is metabolized into the pharmacologically active benzodiazepines delorazepam, lorazepam, and lormetazepam which can be detected in urine for 6, 19, and 11 days, respectively, when applying the presented LC-MS/MS method. In serum, the consumption could be proven between 99 h post-intake targeting the parent compound and up to 10 days targeting the metabolite delorazepam. As immunochemical assays are applied for screening purposes quite often, detectability using this technique was assessed, especially since detection of low-dosed benzodiazepines can be sometimes problematic. However, only one of the utilized immunochemical assays was capable of detecting the intake of one tablet diclazepam, and the positive results were restricted to a few urine samples showing relatively high creatinine concentrations., (Copyright © 2014 John Wiley & Sons, Ltd.)

Trials of novel compounds for the treatment of schizophrenia are typically tested in patients following brief withdrawal of ongoing medication despite known long-term changes in the dopamine (DA) system following chronic antipsychotic drug therapy. The present study explored the impact of withdrawal from repeated haloperidol (HAL) treatment, as well as the response to a novel α5 gamma-aminobutyric acid (GABA(A)) receptor positive allosteric modulator (α5PAM), on the activity of the DA system in the methylazoxymethanol acetate (MAM) neurodevelopmental model of schizophrenia. Electrophysiological recordings were conducted from DA neurons in the ventral tegmental area of MAM and saline (SAL) rats following 7-day withdrawal from repeated HAL (21 d, 0.6 mg/kg, orally). In separate animals, amphetamine-induced locomotion was measured to assess changes in DA behavioral sensitivity. SAL rats withdrawn from HAL demonstrated reduced spontaneous DA neuron activity along with an enhanced locomotor response to amphetamine, indicative of the development of DA supersensitivity. Both α5PAM treatment and ventral hippocampal (vHPC) inactivation reversed the DA neuron depolarization block following HAL withdrawal in SAL rats. In contrast, MAM rats withdrawn from HAL exhibited reduced spontaneous DA activity and enhanced locomotor response to amphetamine compared with untreated SAL rats; however, this condition was unresponsive to α5PAM treatment or vHPC inactivation. Withdrawal from prior HAL treatment interferes with the therapeutic actions of this novel treatment in the MAM model of schizophrenia. Consequently, testing novel compounds on chronically treated schizophrenia patients may be ineffective.

Immunoassays are useful methods for the determination of regulated drugs in clinical and forensic laboratories. Although the Instant-View M-1 (IV M-1) immunoassay kit is frequently used to screen drugs in laboratories in Japan, basic information about the IV M-1 such as its specificity and reactivity is not available. In this study, we determined the specificity and cross-reactivity of IV M-1 for the detection of benzodiazepine-related drugs and their metabolites in urine. The IV M-1 could detect triazolobenzodiazepines such as triazolam in urine at concentrations > or = 300 ng/mL. However, thienodiazepines such as etizolam could not be detected because of lack of cross reactivity. A correlation was observed between the structure of the metabolites and the reactivity of the kit; 4-hydroxy metabolites of alprazolam and triazolam were detectable, whereas a-hydroxy metabolites were not. Furthermore, 7-amino metabolites such as nitrazepam could not be detected at any concentration, including high concentrations. The specificity and reactivity of various kits used for detection of drugs in urine are different. Therefore, it is necessary to consider the basic features of the kit used while assessing the results obtained.

Non-selective positive allosteric modulators (PAMs) of GABAA receptors (GABAARs) are known to impair anterograde memory. The role of the various GABAAR subtypes in the memory-impairing effects of non-selective GABAAR PAMs has not been fully elucidated. The current study assessed, in rhesus monkeys, effects of modulation of α1, α2/3, and α5GABAARs on visual recognition and spatial working memory using delayed matching-to-sample (DMTS) and self-ordered spatial search (SOSS) procedures, respectively. The DMTS procedure (n=8) involved selecting a previously presented 'sample' image from a set of multiple images presented after a delay. The SOSS procedure (n=6) involved touching a number of boxes without repeats. The non-selective GABAAR PAM triazolam and the α1GABAA preferential PAMS zolpidem and zaleplon reduced accuracy in both procedures, whereas the α5GABAA preferential PAMs SH-053-2'F-R-CH3 and SH-053-2'F-S-CH3, and the α2/3GABAA preferential PAM TPA023B were without effects on accuracy or trial completion. The low-efficacy α5GABAAR negative allosteric modulator (NAM) PWZ-029 slightly increased only DMTS accuracy, whereas the high-efficacy α5GABAAR NAMs RY-23 and RY-24 did not affect accuracy under either procedure. Finally, the slopes of the accuracy dose-effect curves for triazolam, zolpidem, and zaleplon increased with box number in the SOSS procedure, but were equivalent across DMTS delays. The present results suggest that (1) α1GABAARs, compared with α2/3 and α5GABAARs, are primarily involved in the impairment, by non-selective GABAAR PAMs, of visual recognition and visuospatial working memory in nonhuman primates; and (2) relative cognitive impairment produced by positive modulation of GABAARs increases with number of locations to be remembered, but not with the delay for remembering.

Neocortical neurons mediate the sedative and anticonvulsant properties of benzodiazepines. These agents enhance synaptic inhibition via positive modulation of γ-aminobutyric acid (GABAA) receptors harboring α1-, α2-, α3- or α5-protein subunits. Benzodiazepine-sensitive GABAA receptors containing the α5-subunit are abundant in the neocortex, but their impact in controlling neuronal firing patterns is unknown. Here we studied how the discharge rates of cortical neurons are modified by a positive (SH-053-2'F-R-CH3) and a negative (L 655,708) α5-subunit-preferring allosteric modulator in comparison to diazepam, the classical non-selective benzodiazepine. Drug actions were characterized in slice cultures from wild-type and α5(H105R) knock-in mice by performing extracellular multi-unit-recordings. In knock-in mice, receptors containing the α5 subunit are insensitive to benzodiazepines. The non-selective positive allosteric modulator diazepam decreased the discharge rates of neocortical neurons during episodes of ongoing neuronal activity (up states). In contrast to diazepam, the α5-preferring positive modulator SH-053-2'F-R-CH3 accelerated action potential firing during up states. This promoting action was absent in slices from α5(H105R) mice, confirming that it is mediated by the α5-subunit. Consistent with these observations, the negative α5-selective modulator L 655,708 inhibited up state action potential activity in slices from wild-type mice. The opposing actions of diazepam and SH-053-2'F-R-CH3, which both enhance GABAA receptor function but differ in subtype-selectivity, uncovers contrasting roles of GABAA receptor subtypes in controlling the firing rates of cortical neurons. These findings may have important implications for the design of novel anaesthetic and anticonvulsant benzodiazepines displaying an improved efficacy and fewer side effects., (Copyright © 2013 Elsevier B.V. All rights reserved.)