Benzodiazepine Metabolism: An Analytical Perspective

The cutting edge of surveillance: Exploring high-resolution mass spectrometry in wastewater-based epidemiology for monitoring forensic samples

Criminal activity has always been detected through forensic evidence. However, the potential for using such evidence to stop crimes in their tracks or slow them down has not yet been completely realized. There is a lot of potential for assessing trace quantities of chemicals in wastewater systems to provide effective forensic information. Wastewater-based epidemiology (WBE) has emerged in the last decades as a crucial epidemiological information source for collecting data on community-wide health. It can add important knowledge about illicit drug consumption and/or disposal, exposure to pathogens, infectious diseases, industrial pollutants, and antibiotic resistance. The use of high-resolution mass spectrometry (HRMS) in WBE has revolutionized the field by enabling the detection and quantification of these compounds. This review article explores the cutting edge of surveillance in WBE through applying HRMS techniques for forensic sample monitoring. It delves into the most recent WBE applications, examining their advantages and disadvantages. It also explores the potential for obtaining a more comprehensive evaluation of forensic samples. Furthermore, the application of these approaches to generate "forensic intelligence" for surveillance and criminal interruption is discussed, with examples of how this data can be integrated into future work.

A novel LC-MS/MS method for simultaneous estimation of chlordiazepoxide and clidinium in human plasma and its application to pharmacokinetic assessment

A highly sensitive and selective LC-MS/MS assay was developed and validated for the simultaneous quantification of Chlordiazepoxide and Clidinium in human plasma for the first time, employing solid-phase extraction. Chromatographic separation of the analytes and their deuterated internal standards was performed on a reversed-phase Kinetex XB-C18 (150 × 4.6 mm, 5 μm) column with a gradient mobile phase. Mass spectrometric detection was achieved using electrospray ionization in positive ion mode, employing the ion transitions: m/z 300.0 → 227.1 for Chlordiazepoxide, m/z 352.1 → 142.1 for Clidinium, m/z 305.1 → 232.1 for Chlordiazepoxide D5, and m/z 357.2 → 142.2 for Clidinium D5. The assay demonstrated a linear calibration range of 504.0-500,198.3 pg/mL for Chlordiazepoxide and 5.0-3,004.7 pg/mL for Clidinium, ensuring precise pharmacokinetic evaluation. The method was validated with a lower limit of quantification (LLOQ) of 504.0 pg/mL for Chlordiazepoxide and 5.0 pg/mL for Clidinium, precision within 15% RSD, and accuracy within 85-115% of the nominal values. No matrix interference from haemolysed or lipemic plasma was observed, and recovery exceeded 90%. This study presents a novel LC-MS/MS method with significant improvements in sensitivity and specificity, facilitating its direct application in pharmacokinetic and bioequivalence studies.

Midazolam - A diazepam replacement for the management of nerve agent-induced seizures

A benzodiazepine, diazepam, has been the leading antidote for seizures caused by nerve agents, the most toxic chemical weapons of mass destruction, since the 1960s. However, its limitations have often brought questions about its usefulness. Extensive effort has been devoted into exploring alternatives, such as other benzodiazepines, anticholinergics, or glutamate antagonists. However, only few showed clear clinical benefit. The only two options to ultimately reach clinical milestones are Avizafone, a water-soluble prodrug of diazepam adopted by the French and UK armed forces, and intramuscular midazolam, adopted by the US Army. The recently FDA-approved new intramuscular application of midazolam brought several advantages, such as rapid onset of action, short duration with predictable pharmacokinetics, increased water solubility for aqueous injectable solutions, and prolonged storage stability. Herein, we discuss the pitfalls and prospects of using midazolam as a substitute in anticonvulsant therapy with a particular focus on military purposes in combat casualty care. We have also considered and discussed several other alternatives that are currently at the experimental level. Recent studies have shown the superiority of midazolam over other benzodiazepines in the medical management of poisoned casualties. While its use in emergency care is straightforward, the proper dose for soldiers under battlefield conditions is questionable due to its sedative effects.

Low-dose diazepam improves cognitive function in APP/PS1 mouse models: Involvement of AMPA receptors

Previous studies have indicated a close association between cognitive impairment in patients with neurodegenerative diseases, such as Alzheimer's disease (AD), and synaptic damage. Diazepam (DZP), a benzodiazepine class drug, is used to control symptoms such as seizures, anxiety, and sleep disorders. These symptoms can potentially manifest throughout the entire course of AD. Therefore, DZP may be utilized in the treatment of AD to manage these symptoms. However, the specific role and mechanisms of DZP in AD remain unclear. In this study, we discovered that long-term administration of a low dose of DZP (0.5  mg/kg) improved cognitive function and protected neurons from damage in APP/PS1 mice. Mechanistic investigations revealed that DZP exerted its neuroprotective effects and reduced Aβ deposition by modulating GluA1 (glutamate AMPA receptor subunit) to influence synaptic function. In conclusion, these findings highlight the potential benefits of DZP as a novel therapeutic approach, suggesting that long-term use of low-dose DZP in early-stage AD patients may be advantageous in slowing disease progression.

Insights into the Silylation of Benzodiazepines Using N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA): In Search of Optimal Conditions for Forensic Analysis by GC-MS

Silylation is a widely used derivatization technique for the gas chromatographic analysis of benzodiazepines, a class of psychoactive drugs commonly encountered in forensic and biological samples. This study investigated the optimal experimental conditions for the silylation of benzodiazepines using N,O-bis(trimethylsilyl)trifluoroacetamide containing 1% trimethylchlorosilane (BSTFA + 1% TMCS), a widely employed silylating agent. Ten structurally different benzodiazepines, including variations within the classic 1,4-benzodiazepine core and triazolo ring derivatives, were selected to address the effect of structural diversity on silylation. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to optimize the silylation of benzodiazepines by means of GC-MS analysis. PCA identified key experimental factors influencing silylation efficiency and distinct response patterns of different benzodiazepines. HCA further categorized the benzodiazepines based on their silylation behavior, highlighting the need for tailored derivatization strategies. The results indicated that the BSTFA + 1% TMCS concentration and solvent volume were pivotal for achieving high silylation efficiency, whereas the temperature, reaction time, and catalyst were less critical. The optimized method was successfully applied to 30 real forensic samples, demonstrating its efficacy in detecting and identifying various benzodiazepines, including designer drugs like etizolam. This study provides a foundation for improving drug detection methodologies in forensic toxicology and provides useful insights into the dynamics of benzodiazepine silylation and the use of individualized analysis parameters.

NE contribution to rebooting unconsciousness caused by midazolam

The advent of midazolam holds profound implications for modern clinical practice. The hypnotic and sedative effects of midazolam afford it broad clinical applicability. However, the specific mechanisms underlying the modulation of altered consciousness by midazolam remain elusive. Herein, using pharmacology, optogenetics, chemogenetics, fiber photometry, and gene knockdown, this in vivo research revealed the role of locus coeruleus (LC)-ventrolateral preoptic nucleus noradrenergic neural circuit in regulating midazolam-induced altered consciousness. This effect was mediated by α1 adrenergic receptors. Moreover, gamma-aminobutyric acid receptor type A (GABAA-R) represents a mechanistically crucial binding site in the LC for midazolam. These findings will provide novel insights into the neural circuit mechanisms underlying the recovery of consciousness after midazolam administration and will help guide the timing of clinical dosing and propose effective intervention targets for timely recovery from midazolam-induced loss of consciousness.

Rapid detection of 10 benzodiazepines and metabolites in blood and urine using DART-MS/MS

Benzodiazepines are essential screening targets for common sleeping and sedative drugs used in forensic toxicology. Direct analysis in real-time tandem mass spectrometry was used to rapidly identify 10 benzodiazepines and related metabolites in the blood and urine. The related direct analysis in real-time tandem mass spectrometry parameters were optimized. A liquid-liquid extraction method using ethyl acetate as the extraction solvent was used for sample preparation. The established method was validated and tested on case specimens. The limits of detection of this method ranged from 0.2 to 20 ng/mL and the limits of quantification from 1 to 50 ng/mL. The recoveries ranged from 78.8% to 114%, and the matrix effects were in the range of -21.2% to 17.9%. The precision and repeatability at high and medium concentrations did not exceed 14.6%, and the limit of quantification did not exceed 18.2%, indicating a desirable linear relationship. The established method was used to determine blood and urine specimens from authentic cases, and promising results were obtained.

Herb-drug interactions: A short review on central and peripheral nervous system drugs

Herbal medicines are widely perceived as natural and safe remedies. However, their concomitant use with prescribed drugs is a common practice, often undertaken without full awareness of the potential risks and frequently without medical supervision. This practice introduces a tangible risk of herb-drug interactions, which can manifest as a spectrum of consequences, ranging from acute, self-limited reactions to unpredictable and potentially lethal scenarios. This review offers a comprehensive overview of herb-drug interactions, with a specific focus on medications targeting the Central and Peripheral Nervous Systems. Our work draws upon a broad range of evidence, encompassing preclinical data, animal studies, and clinical case reports. We delve into the intricate pharmacodynamics and pharmacokinetics underpinning each interaction, elucidating the mechanisms through which these interactions occur. One pressing issue that emerges from this analysis is the need for updated guidelines and sustained pharmacovigilance efforts. The topic of herb-drug interactions often escapes the attention of both consumers and healthcare professionals. To ensure patient safety and informed decision-making, it is imperative that we address this knowledge gap and establish a framework for continued monitoring and education. In conclusion, the use of herbal remedies alongside conventional medications is a practice replete with potential hazards. This review not only underscores the real and significant risks associated with herb-drug interactions but also underscores the necessity for greater awareness, research, and vigilant oversight in this often-overlooked domain of healthcare.

Selective Extraction of Diazepam and Its Metabolites from Urine Samples by a Molecularly Imprinted Solid-Phase Extraction (MISPE) Method

In this research, a molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using oxazepam (OZ) as a template molecule and was subsequently applied as a selective sorbent for the extraction of diazepam (DZP) and its metabolites in urine samples using an SPE cartridge. OZ, temazepam (TZ), nordiazepam (NZ) and DZP were analyzed in the final extracts by high-performance liquid chromatography with diode array detection (HPLC-DAD). The SPE extraction steps were optimized, and the evaluation of an imprinting factor was carried out. The selectivity of the method for OZ versus structurally related benzodiazepines (BZDs), such as bromazepam (BRZ), tetrazepam (TTZ) and halazepam (HZ), was investigated. Under the optimum conditions, the proposed methodology provided good linearity in the range of 10-1500 ng/mL, with limit of detection values between 13.5 and 21.1 ng/mL and recovery levels for DZP and its metabolites from 89.0 to 93.9% (RSD ≤ 8%) at a concentration level of 1000 ng/mL. The proposed method exhibited good selectivity, precision and accuracy and was applied to the analysis of urine samples from a real case of DZP intake.

Innovative analysis of diazepam, zolpidem and their main metabolites in human urine by micelle-to-solvent stacking in capillary electrophoresis

Diazepam and zolpidem are the most widely used medications for managing insomnia. However, significant concerns regarding the potential risks of misuse and abuse problems arose in many literatures. While urine analysis is a valuable diagnostic tool, a challenge arises from the fact that some parent drugs may remain undetectable in urine. This necessitates concurrent monitoring of their metabolites. Here, we described an innovative on-line sample preconcentration technique known as micelle to solvent stacking (MSS) for the analysis of diazepam, zolpidem, and their main metabolites in urine. Several key parameters warrant further discussion to optimize the MSS model, enhancing its performance in terms of sensitivity and resolution. After optimizing the conditions, we conducted a validation test, achieving high correlation coefficients (greater than 0.9977) for intra-day and inter-day regression lines. Additionally, both the relative standard deviation (RSD) and relative error (RE) remained below 6.10% and 12.55%, respectively. The limits of detection (LODs, S/N = 3) for all five analytes ranged from 2.0 to 56 ng/mL. Compared to the conventional capillary zone electrophoresis method, this new approach exhibited remarkable sensitivity enhancements, ranging from 123 to 235-fold. Upon applying this method to actual urine samples from patients, we successfully detected nordiazepam, zolpidem, and its metabolites. This simple and sensitive approach has promising applications in supporting patient medication safety and bolstering forensic investigations.

Recent findings and advancements in the detection of designer benzodiazepines: a brief review

This review article takes a closer look at a new class of psychoactive substances called designer benzodiazepines (DBZs) and the challenges of their detection. These are adinazolam, clonazolam, deschloroetizolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam, phenazepam, and pyrazolam. They are central nervous system depressants and sedatives that can cause psychomotor impairment and increase the overdose risk when combined with other sedatives. DBZs undergo phase I and II metabolism similar to traditional benzodiazepines, but their specific metabolic pathways and the influence of genetic polymorphisms are yet to be clarified. Advances in liquid chromatography-tandem mass spectrometry (LC-MS/MS) have enhanced the method's sensitivity for DBZs and their metabolites in biological samples and coupled with improved blood sampling methods require less blood for drug monitoring. Further research should focus on elucidating their pharmacokinetic properties and metabolism in humans, especially in view of genetic polymorphisms and drug interactions that could inform clinical treatment choices. Even though we have witnessed important advances in DBZ detection and measurement, further refinements are needed to expand the scope of detectable DBZs and their metabolites. All this should help toxicological research to better identify and characterise the risks of chronic and polydrug abuse and facilitate clinical, forensic, and regulatory responses to this growing issue.

Characterization of Extended-Release Lorazepam: Pharmacokinetic Results Across Phase 1 Clinical Studies

PURPOSE/BACKGROUND

Once-daily extended-release (ER) lorazepam was developed to reduce fluctuations in plasma levels compared with lorazepam immediate-release (IR) for short-term anxiety relief. Here we report a series of phase 1 randomized, open-label, multiperiod crossover studies characterizing ER lorazepam pharmacokinetics and safety in healthy adults.

METHODS/PROCEDURES

These phase 1 studies assessed the pharmacokinetics of ER lorazepam administered: (study 1) 3 mg once daily versus IR lorazepam 1 mg 3 times a day (TID; every 8 hours), (study 2) with or without food, and (study 3) intact versus sprinkled onto food. Study 3 further evaluated the proportionality of 1 × 4- versus 4 × 1-mg doses. Safety was also monitored.

FINDINGS/RESULTS

There were 43, 27, and 29 subjects who completed studies 1, 2, and 3, respectively. The 90% confidence intervals for Cmax,SS, Cmin, and AUCTAU,SS of once-daily ER lorazepam compared with IR given TID were within 80% to 125% limits establishing steady-state bioequivalence. Maximum mean lorazepam concentrations were achieved at 11 hours compared with 1 hour after dosing for ER versus IR lorazepam, respectively. Pharmacokinetic parameters (Cmax, AUClast or AUC0-t, AUCinf or AUC0-inf) of ER lorazepam were bioequivalent whether taken with or without food, administered intact or sprinkled onto food, or administered as intact 1 × 4- versus 4 × 1-mg capsules. No serious safety concerns were found.

IMPLICATIONS/CONCLUSIONS

Once-daily ER lorazepam provided a pharmacokinetic profile bioequivalent to IR lorazepam given TID and was well tolerated in healthy adults across all phase 1 studies. These data suggest that ER lorazepam could be an alternative for patients currently treated with IR lorazepam.

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.

Concordance between controlled substance receipt and post-mortem toxicology in opioid-detected overdose deaths: A statewide analysis

BACKGROUND

Opioid overdoses are a leading cause of preventable death in the United States. There is limited research linking decedents' receipt of controlled substances and presence of controlled substances on post-mortem toxicology (PMT).

METHODS

We linked data on opioid-detected deaths in Connecticut between May 3, 2016, and December 31, 2017 from the Office of the Chief Medical Examiner, Department of Consumer Protection, and Department of Mental Health and Addiction Services. Exposure was defined as receipt of an opioid or benzodiazepine prescription within 90 days prior to death. Our primary outcome was concordance between medication received and metabolites in PMT.

RESULTS

Our analysis included 1412 opioid-detected overdose deaths. 47 % received an opioid or benzodiazepine 90 days prior to death; 36 % received an opioid and 27 % received a benzodiazepine. Concordance between receipt of an opioid or benzodiazepine and its presence in PMT was observed in 30 % of opioid-detected deaths. Concordance with an opioid was present in 17 % of opioid-detected deaths and concordance with a benzodiazepine was present in 21 % of opioid-detected deaths. Receipt of an opioid or benzodiazepine and concordance with PMT were less common in fentanyl or heroin-detected deaths and more common in pharmaceutical opioid-detected deaths.

DISCUSSION

Our results suggest medically supplied opioids and benzodiazepines potentially contributed to a substantial number, though minority, of opioid-detected deaths during the study period. Efforts to reduce opioid and benzodiazepine prescribing may reduce risk of opioid-detected deaths in this group, but other approaches will be needed to address most opioid-detected deaths that involved non-pharmaceutical opioids.

Eutectic Mixture Formation and Relaxation Dynamics of Coamorphous Mixtures of Two Benzodiazepine Drugs

The formation of coamorphous mixtures of pharmaceuticals is an interesting strategy to improve the solubility and bioavailability of drugs, while at the same time enhancing the kinetic stability of the resulting binary glass and allowing the simultaneous administration of two active principles. In this contribution, we describe kinetically stable amorphous binary mixtures of two commercial active pharmaceutical ingredients, diazepam and nordazepam, of which the latter, besides being administered as a drug on its own, is also the main active metabolite of the other in the human body. We report the eutectic equilibrium-phase diagram of the binary mixture, which is found to be characterized by an experimental eutectic composition of 0.18 molar fraction of nordazepam, with a eutectic melting point of T_e = 395.4 ± 1.2 K. The two compounds are barely miscible in the crystalline phase. The mechanically obtained mixtures were melted and supercooled to study the glass-transition and molecular-relaxation dynamics of amorphous mixtures at the corresponding concentration. The glass-transition temperature was always higher than room temperature and varied linearly with composition. The T_e was lower than the onset of thermal decomposition of either compound (pure nordazepam decomposes upon melting and pure diazepam well above its melting point), thus implying that the eutectic liquid and glass can be obtained without any degradation of the drugs. The eutectic glass was kinetically stable against crystallization for at least a few months. The relaxation processes of the amorphous mixtures were studied by dielectric spectroscopy, which provided evidence for a single structural (α) relaxation, a single Johari-Goldstein (β) relaxation, and a ring-inversion conformational relaxation of the diazepinic ring, occurring on the same timescale in both drugs. We further characterized both the binary mixtures and pure compounds by FTIR spectroscopy and first-principles density functional theory (DFT) simulations to analyze intermolecular interactions. The DFT calculations confirm the presence of strong attractive forces within the heteromolecular dimer, leading to large dimer interaction energies of the order of -0.1 eV.

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).

Reactive metabolites of the anticonvulsant drugs and approaches to minimize the adverse drug reaction

Several generations of antiepileptic drugs (AEDs) are available in the market for the treatment of seizures, but these are amalgamated with acute to chronic side effects. The most common side effects of AEDs are dose-related, but some are idiosyncratic adverse drug reactions (ADRs) that transpire due to the formation of reactive metabolite (RM) after the bioactivation process. Because of the adverse reactions patients usually discontinue the medication in between the treatment. The AEDs such as valproic acid, lamotrigine, phenytoin etc., can be categorized under such types because they form the RM which may prevail with life-threatening adverse effects or immune-mediated reactions. Hepatotoxicity, teratogenicity, cutaneous hypersensitivity, dizziness, addiction, serum sickness reaction, renal calculi, metabolic acidosis are associated with the metabolites of drugs such as arene oxide, N-desmethyldiazepam, 2-(1-hydroxyethyl)-2-methylsuccinimide, 2-(sulphamoy1acetyl)-phenol, E-2-en-VPA and 4-en-VPA and carbamazepine-10,11-epoxide, etc. The major toxicities are associated with the moieties that are either capable of forming RM or the functional groups may itself be too reactive prior to the metabolism. These functional groups or fragment structures are typically known as structural alerts or toxicophores. Therefore, minimizing the bioactivation potential of lead structures in the early phases of drug discovery by a modification to low-risk drug molecules is a priority for the pharmaceutical companies. Additionally, excellent potency and pharmacokinetic (PK) behaviour help in ensuring that appropriate (low dose) candidate drugs progress into the development phase. The current review discusses about RMs in the anticonvulsant drugs along with their mechanism vis-a-vis research efforts that have been taken to minimize the toxic effects of AEDs therapy.

Suspicion of driving under the influence of alcohol or drugs: Cross sectional analysis of drug prevalence in the context of the Swiss legislation

Driving under the influence of alcohol and drugs (DUID) is a major field of study to improve road safety. In Switzerland, during controls whether or not they follow an accident, the police can request toxicological analysis targeted either on alcohol only (ALC cases), or on drugs and alcohol (DUID cases). To evaluate both the drugs consumption on the road and whether or not these requests are well correlated with toxicological results, we built a database recording 4003 offenders (3443 males, 550 females) over a two-year period (2018-2019) in Western Switzerland. ALC case samples were then analyzed to target other substances than ethanol. We found one or more psychoactive drugs in 89% of DUID cases and alcohol alone was found in 56% of ALC cases. In ALC cases, alcohol alone was found in 72% of non-accident cases and in 52% of accident cases. This highlights an influence of accident context, inducing a too high suspicion of alcohol after accidents, and therefore an underestimation of the prevalence of other drugs. The most frequently detected drugs in DUID cases were cannabinoids (58%), ethanol (30%), cocaine (21%), benzodiazepines (11%), amphetamines (7%), opiates (6%), and antidepressants (5%). For the ALC cases, the drugs found were ethanol (84%), cannabinoids (13%), benzodiazepines (9%), antidepressants (6%), opiates (5%), cocaine (4%), methadone (3%), and amphetamines (1%). Prescription drugs, such as benzodiazepines, were common in accidents (22%) but rare in non-accidents DUID cases (5%). Thus, these drugs highly impact driving skills while being hard to suspect. This is of first concern as prescription drugs are largely found in poly-drug consumption, especially in combination with alcohol in accident cases. This emphasizes the emerging issue of prescription drugs and should motivate a strategy of prevention focused on the noxious effect of combining alcohol and prescription drugs on driving skills.

Autoinjector - A smart device for emergency cum personal therapy

Autoinjectors are self-injectable devices; they are important class of medical devices which can deliver drugs through subcutaneous or intramuscular route. They enclose prefilled syringes or cartridges which are driven by a spring system. The major benefits of this device are easy self-administration, improved patient compliance, reduced anxiety, and dosage accuracy. Immediate treatment during emergency conditions such as anaphylaxis, migraine, and status epilepticus or for chronic conditions like psoriasis, diabetes, multiple sclerosis, and rheumatoid arthritis, Reformulation of first-generation biologics, technical advancements, innovative designs, patient compliance, overwhelming interest for self-administration all these made entry of more and more autoinjectors into use. In this review, intensive efforts have been made for exploring the different types of currently available autoinjectors for the management of emergency and chronic diseases.

Precisely adjusting the hepatic clearance of highly extracted drugs using the modified well-stirred model

Hepatic clearance has been widely studied for over 50 yr. Many models have been developed using either theoretical or empirical tests to predict drug metabolism. The well-stirred, parallel-tube, and dispersion metabolic models have been extensively discussed. However, to our knowledge, these models cannot fully describe all relevant scenarios in hepatic clearance. We addressed this issue using the isolated perfused rat liver technique with minor modifications. Diazepam was selected to illustrate different levels of drug plasma-protein binding by changing the added concentration of human serum albumin. The free fractions of diazepam at different albumin concentrations were assayed by rapid equilibrium dialysis. The experimental data provide new insights concerning an accepted formula used to describe hepatic clearance. Regarding drug concentrations passing through the liver, the driving force concentration (C_H,ss) in terms of C_in (influx in the liver) or C_out (efflux from the liver) needs to be carefully considered when determining drug hepatic and intrinsic clearances. The newly established model, termed the modified well-stirred model, which was derived from the original formula, successfully estimated hepatic drug metabolism. Using the modified well-stirred model, a theoretical driving force concentration of diazepam passing through the liver was evaluated. The model was further used to assess the predictability of in vitro to in vivo extrapolation. This study was not intended to refute the existing models, but rather to augment them using experimental data. The results stress the importance of proper calculation of dose when the drug clearance deviates from the prediction of the well-stirred model.

Benzodiazepines: Drugs with Chemical Skeletons Suitable for the Preparation of Metallacycles with Potential Pharmacological Activity

The synthesis of organometallic compounds with potential pharmacological activity has attracted the attention of many research groups, aiming to take advantage of aspects that the presence of the metal-carbon bond can bring to the design of new pharmaceutical drugs. In this context, we have gathered studies reported in the literature in which psychoactive benzodiazepine drugs were used as ligands in the preparation of organometallic and metal complexes and provide details on some of their biological effects. We also highlight that most commonly known benzodiazepine-based drugs display molecular features that allow the preparation of metallacycles via C-H activation. These organometallic compounds merit further attention regarding their potential biological effects, not only in terms of psychoactive drugs but also in the search for drug replacements, for example, for cancer treatments.

Synthesis and characterization of molecularly imprinted polymers for the selective extraction of oxazepam from complex environmental and biological samples

Oxazepam, one of the most frequently prescribed anxiolytic drugs, is not completely removed from wastewater with conventional treatment processes. It can thus be found at trace levels in environmental water, with human urine constituting the major source of contamination. This study focused on the development and characterization of molecularly imprinted polymers (MIPs) for the selective solid-phase extraction of oxazepam at trace levels from environmental water and human urine samples. Two MIPs were synthesized, and their selectivity in pure organic and aqueous media were assayed. After optimizing the extraction procedure adapted to a large sample volume to reach a high enrichment factor, the most promising MIP was applied to the selective extraction of oxazepam from environmental water. Extraction recoveries of 83 ± 12, 92 ± 4 and 89 ± 10% were obtained using the MIP for tap, mineral and river water, respectively, while a recovery close to 40% was obtained on the corresponding non-imprinted polymer (NIP). Thanks to the high enrichment factors, a limit of quantification (LOQ) of 4.5 ng L^-1 was obtained for river water. A selective extraction procedure was also developed for urine samples and gave rise to extraction recoveries close to 95% for the MIP and only 23% for the NIP. Using the MIP, a LOQ of 357 ng L^-1 was obtained for oxazepam in urine. The use of the MIP also helped to limit the matrix effects encountered for the quantification of oxazepam in environmental samples and in human urine samples after extraction on an Oasis HLB sorbent.

Effects of CYP2C19*2 polymorphisms on the efficacy and safety of phenazepam in patients with anxiety disorder and comorbid alcohol use disorder

Introduction: Phenazepam therapy can often be ineffective and some patients develop dose-related adverse drug reactions. Aim. The purpose of this research was to study the effect of the CYP2C19*2 (681G>A, rs4244285) in patients with anxiety disorders and alcohol dependence taking phenazepam therapy. Materials & methods: Patients (175 males, average age: 37.16 ± 7.84 years) received phenazepam in tablet form for 5 days. Genotyping was performed by real-time polymerase chain reaction. Results: The statistically significant differences in the UKU Side-Effect Rating Scale scores on the fifth day of therapy: (CYP2C19*1/*1) 2.00 [1.00; 2.00), (CYP2C19*1/*2) 7.00 (7.00; 7.00), (CYP2C19*2/*2) 9.00 (8.00; 9.00), p < 0.001. Conclusion: This study demonstrated the different efficacy and safety of phenazepam in patients with different genotypes of CYP2C19*2.

Common and dissociable effects of oxytocin and lorazepam on the neurocircuitry of fear

Benzodiazepines (BZDs) represent the gold standard of anxiolytic pharmacotherapy; however, their clinical benefit is limited by side effects and addictive potential. Consequently, there is an urgent need to develop novel and safe anxiolytics. The peptide hormone oxytocin (OXT) exhibits anxiolytic-like properties in animals and humans, but whether OXT and BZDs share similar effects on the neural circuitry of fear is unclear. Therefore, the rationale of this ultra-high-field functional MRI (fMRI) study was to test OXT against the clinical comparator lorazepam (LZP) with regard to their neuromodulatory effects on local and network responses to fear-related stimuli. One hundred twenty-eight healthy male participants volunteered in this randomized double-blind, placebo-controlled, between-group study. Before scanning using an emotional face-matching paradigm, participants were randomly administered a single dose of OXT (24 IU), LZP (1 mg), or placebo. On the behavioral level, LZP, but not OXT, caused mild sedation, as evidenced by a 19% increase in reaction times. On the neural level, both OXT and LZP inhibited responses to fearful faces vs. neutral faces within the centromedial amygdala (cmA). In contrast, they had different effects on intra-amygdalar connectivity; OXT strengthened the coupling between the cmA and basolateral amygdala, whereas LZP increased the interplay between the cmA and superficial amygdala. Furthermore, OXT, but not LZP, enhanced the coupling between the cmA and the precuneus and dorsomedial prefrontal cortex. These data implicate inhibition of the cmA as a common denominator of anxiolytic action, with only OXT inducing large-scale connectivity changes of potential therapeutic relevance.

Effects of plasma concentration of micro-RNA Mir-27b and CYP3A4*22 on equilibrium concentration of alprazolam in patients with anxiety disorders comorbid with alcohol use disorder

Alprazolam is used in the treatment of patients with anxiety disorders comorbid with alcohol use disorder. Some proportion of these patients does not respond adequately to treatment with alprazolam, while many of them experience dose-dependent adverse drug reactions. Results of the previous studies have shown that CYP3A is involved in the biotransformation of alprazolam, the activity of which is dependent, inter alia, on the polymorphism of the encoding gene.

OBJECTIVE

The objective of our study was to investigate the effect of 99366316G>A polymorphism of the CYP3A4 gene on the concentration/dose indicator of alprazolam in patients with anxiety disorders comorbid with alcohol use disorder, using findings on enzymatic activity of CYP3A (as evaluated by the 6-beta-hydroxy-cortisol/cortisol ratio measurement) and on CYP3A4 expression level obtained by measuring the miR-27b plasma concentration levels in patients with anxiety disorders comorbid with alcoholism.

MATERIAL AND METHODS

Our study enrolled 105 patients with anxiety disorders comorbid with alcohol use disorder (age - 37.8±14.6 years). Therapy included alprazolam in an average daily dose of 5.6±2.4 mg per day. Treatment efficacy was evaluated using the psychometric scales. Therapy safety was assessed using the UKU Side-Effect Rating Scale. For genotyping and estimation of the microRNA (miRNA) plasma levels, we performed the real-time polymerase chain reaction. The activity of CYP3A was evaluated using the HPLC-MS/MS method by the content of the endogenous substrate of the given isoenzyme and its metabolite in urine (6- beta-hydroxy-cortisol/cortisol). Therapeutic drug monitoring (TDM) has been performed using HPLC-MS/MS.

RESULTS

Our study revealed the statistically significant results in terms of the treatment efficacy evaluation (HAMA scores at the end of the treatment course): (GG) 3.0 [2.0; 5.0] and (GA) 4.0 [4.0; 5.0], p = 0.007; at the same time, the statistical significance in the safety profile was not obtained (the UKU scores): (GG) 3.0 [2.0; 3.8] and (GA) 3.0 [1.5; 4.0], p = 0.650. We revealed a statistical significance for concentration/dose indicator of alprazolam in patients with different genotypes: (GG) 1.583 [0.941; 2.301] and (GA) 2.888 [2.305; 4.394], p = 0.001). Analysis of the results of the pharmacotranscriptomic part of the study didn't show the statistically significant difference in the miR-27b plasma levels in patients with different genotypes: (GG) 25.6 [20.4; 28.8], (GA) 25.7 [19.7; 33.1], p = 0.423. At the same time, correlation analysis revealed a statistically significant relationship between the alprazolam efficacy profile evaluated by changes in HAMA scale scores and the miR-27b plasma concentration: rs = 0.20, p = 0.042. Also, we didn't reveal the correlation between the miRNA concentration and safety profile: rs = 0.15, p = 0.127. In addition, we revealed the relationship between the CYP3A enzymatic activity (as evaluated by 6-beta-hydroxycortisol/ cortisol ratio measurement) and the miR-27b plasma concentration: rs = -0.27, p = 0.006. At the same time, correlation analysis revealed a statistically significant relationship between the alprazolam concentration and the miR-27b plasma concentration: rs = 0.28, p = 0.003.

CONCLUSION

The effect of genetic polymorphism of the CYP3A4 gene on the efficacy and safety profiles of alprazolam was demonstrated in a group of 105 patients with anxiety disorders comorbid with alcohol use disorder. At the same time, miR-27b remains a promising biomarker for assessing the level of CYP3A4 expression, because it correlates with the encoded isoenzyme's activity.

Synthesis and anti-H5N1 virus activity of triazole- and oxadiazole-pyrimidine hybrids and their nucleoside analogs

New 1,2,3-triazole glycosides and 1,2,4-thioglycosides incorporating a substituted pyrimidinedione ring system were synthesized via click dipolar cycloaddition and heterocyclization of hydrazine-1-carbodithioate derivatives, respectively. The sugar hydrazine derivatives linked aminodimethyluracil were also prepared. In addition, the oxadiazoline substituted with acyclic sugar moieties linked to the pyrimidinedione as acyclic nucleoside analogs were synthesized. The antiviral activity of the synthesized compounds against avian influenza H5N1 virus was investigated and compounds 18, 13 and 19 showed good activities against the virus strains.

Urine analysis of 28 designer benzodiazepines by liquid chromatography-high-resolution mass spectrometry

Hundreds of new psychoactive substances (NPS) covering most drugs-of-abuse classes have been introduced to the recreational drug market in recent years. One class of NPS drugs that has become more common recently is "designer" benzodiazepines. Due to a close structural resemblance with prescription benzodiazepines, some of these substances may elicit a positive response (i.e. cross react) in immunoassay screening. Consequently, it is increasingly important to include NPS benzodiazepines during method confirmation to ensure accurate identification of closely-related compounds as well as detection of the benzodiazepines themselves. Here, we present our efforts to develop a screening and confirmation method for detection of 28 NPS benzodiazepines in urine using reversed-phase liquid chromatographic separation in combination with high-resolution mass spectrometry (LC-HRMS). MS was performed in positive electrospray mode on a Thermo Fischer Scientific Q Exactive Orbitrap instrument using either full scan (for screening) or parallel reaction monitoring (for confirmation). We found the lower quantification limit of the method to range from 5 to 50 ng/mL. Analytical precision and accuracy were ≤15% for both screening and confirmation for all except one analyte. The method was used to analyze patient urine samples from routine drug testing and samples from acute intoxication cases presenting in emergency wards. Altogether, 16 of the 28 benzodiazepines (i.e., clobazam, clonazolam, deschloroetizolam, diclazepam, estazolam, etizolam, flubromazepam, flubromazolam, flunitrazolam, 3-hydroxyflubromazepam, 3-hydroxyphenazepam, ketazolam, meclonazepam, metizolam, nifoxipam, and pyrazolam) were detected in the urine samples. The results from patient sample analysis indicate a high prevalence of NPS benzodiazepine use, emphasizing the importance of including novel drugs of abuse in drug testing menus.

Sorption, plant uptake and metabolism of benzodiazepines

Reuse of treated wastewater for irrigation of crops is growing in arid and semi-arid regions, whilst increasing amounts of biosolids are being applied to fields to improve agricultural outputs. Due to incomplete removal in the wastewater treatment processes, pharmaceuticals present in treated wastewater and biosolids can contaminate soil systems. Benzodiazepines are a widely used class of pharmaceuticals that are released following wastewater treatment. Benzodiazepines are represented by a class of compounds with a range of physicochemical properties and this study was therefore designed to evaluate the influence of soil properties on the sorption behaviour and subsequent uptake of seven benzodiazepines (chlordiazepoxide, clonazepam, diazepam, flurazepam, oxazepam, temazepam and triazolam) in two plant species. The sorption and desorption behaviour of benzodiazepines was strongly influenced by soil type and hydrophobicity of the chemical. The partitioning behaviour of these chemicals in soil was a key controller of the uptake and accumulation of benzodiazepines by radish (Raphanus sativus) and silverbeet (Beta vulgaris). Benzodiazepines such as oxazepam that were neutral, had low sorption coefficients (K_d) or had pH-adjusted log octanol-water partition coefficients (log D_ow, pH6.3) values close to 2 had the greatest extent of uptake. Conversely, benzodiazepines such as flurazepam that had an ionised functional groups and greater K_d values had comparatively limited accumulation in the selected plant species. Results also revealed active in-plant metabolism of benzodiazepines, potentially analogous to the known metabolic transformation pathway of benzodiazepines in humans. Along with this observed biological transformation of benzodiazepines in exposed plants, previously work has established the widespread presence of the plant signalling molecule γ-amino butyric acid (GABA), which is specifically modulated by benzodiazepines in humans. This highlights the need for further assessment of the potential for biological activity of benzodiazepines following their plant uptake.

The pharmacogenetics of medications used in general anesthesia

General anesthesia is a state of unconsciousness, amnesia, analgesia and akinesia induced by drugs including opioids, hypnotic-sedative agents, muscle relaxants and antiemetics. Clinical and genetic factors are reported to influence the efficacy and side effects of these agents. Based on the evidence, clinical action is needed to improve clinical outcomes. This review summarizes the latest knowledge with regards to the pharmacogenetics of anesthetics and general anesthesia related complications.

Improved Clinical Sensitivity of a Reflexive Algorithm to Minimize False-Negative Test Results by a Urine Benzodiazepine Immunoassay Screen

BACKGROUND

Urine drug testing is an essential component of treating patients for chronic pain and/or anxiety and is used to monitor compliance during treatment. A common algorithm is to use an immunoassay as a urine drug screen (UDS), followed by mass spectrometry to confirm all presumptive positive samples. Many UDSs, however, have significant limitations, and false-negative test results can be common due to lack of antibody specificity.

METHODS

Urine samples were screened by a benzodiazepine immunoassay followed by confirmatory testing using LC-MS/MS to determine an initial false-negative test rate for the screen. Attempts to improve the false-negative test rate included hydrolysis before screening and optimization of the absorbance cutoff required for a positive result.

RESULTS

Hydrolysis corrected 41% of false-negative test results in samples containing parent benzodiazepines and/or metabolites but had no effect on samples containing only clonazepam. Of the confirmed false-negative test results, 85% (17 of 20) demonstrated absorbance values between 20 and 100, with 100 being the cutoff for a positive result. Implementing an optimized absorbance cutoff of 20, rather than 100, for a reflexive confirmation testing algorithm decreases the false-negative test rate of detecting benzodiazepine from 47% to 2%.

CONCLUSIONS

Hydrolyzing samples before the benzodiazepine screen provided a modest improvement in the false-negative test rate; however, the screen still missed samples containing clonazepam. Optimization of the absorbance cutoff to reflex samples to LC-MS/MS markedly improved the false-negative test rate for all benzodiazepines.

Stereoselective Synthesis of Benzo[e][1,4]oxazino[4,3-a][1,4]diazepine-6,12-diones with Two Diversity Positions

Herein, we report a stereoselective formation of tetrahydro-6H-benzo[e][1,4]oxazino[4,3-a][1,4]diazepine-6,12(11H)-diones. Their preparation consisted in solid-phase synthesis of linear intermediates starting from polymer-supported Ser(tBu)-OH. Using various 2-nitrobenzoic acids and bromoketones, the key intermediates were obtained in five steps and subjected to trifluoroacetic acid-mediated cleavage from the resin, followed by stereoselective reduction with triethylsilane. Subsequent catalytic hydrogenation of the nitro group and cyclization yielded the target compounds with full retention of the C^12a stereocenter configuration.

Polymer-Supported Stereoselective Synthesis of Benzoxazino[4,3-b][1,2,5]thiadiazepinone 6,6-dioxides

Herein, we report the stereoselective synthesis of trisubstituted benzoxazino[4,3-b][1,2,5]thiadiazepinone 6,6-dioxides from polymer-supported Fmoc-Ser(tBu)-OH and Fmoc-Thr(tBu)-OH. After the solid-phase synthesis of N-alkylated-N-sulfonylated intermediates using various 2-nitrobenzenesulfonyl chlorides and bromoketones, the target compounds were obtained via trifluoroacetic acid (TFA)-mediated cleavage from the resin, followed by cyclization of the diazepinone scaffold. Except for the threonine-based intermediates, the inclusion of triethylsilane (TES) in the cleavage cocktail yielded a specific configuration of the newly formed C³ chiral center. The final cyclization resulted in minor or no inversion of the C^12a stereocenter configuration.

Metabolic profile of oxazepam and related benzodiazepines: clinical and forensic aspects

Anxiolytic drugs, namely benzodiazepines, are the most commonly used psychoactive substances since anxiety disorders are prevalent mental disorders particularly in the Western world. Oxazepam is a short-acting benzodiazepine and one of the most frequently prescribed anxiolytic drugs. It is also the active metabolite of a wide range of other benzodiazepines, such as diazepam, ketazolam, temazepam, chlordiazepoxide, demoxazepam, halazepam, medazepam, prazepam, pinazepam, and chlorazepate. Therefore, relevant clinical and forensic outocomes may arise, namely those related to interference in driving performance. It is clinically available as a racemic formulation, with S-enantiomer being more active than R-enantiomer. In humans, it is mainly polimorphically metabolized by glucuronide conjugation at the 3-carbon hydroxyl group, yielding stable diastereomeric glucuronides (R- and S-oxazepam glucuronide). Relevant metabolic and stereoselective interspecies differences have been reported. In this work, the pharmacokinetics of oxazepam with particular focus on metabolic pathways is fully reviewed. Moreover, the metabolic profile of other prescribed benzodiazepines that produce oxazepam as a metabolite is also discussed. It is aimed that knowing the metabolism of oxazepam and related benzodiazepines may lead to the development of new analytical strategies for its early detection and help in further toxicological and clinical interpretations.

LC-MS-MS Method for Analysis of Benzodiazepines in Wastewater During Football Games IV

Continuing our studies for the analyses of drugs of abuse in municipal wastewater, a method was developed for the analysis of benzodiazepines in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Ten benzodiazepines and metabolites were analyzed (structures were found), including alprazolam, α-OH-alprazolam (the primary urinary metabolite of alprazolam), chlordiazepoxide, flurazepam, 2-OH-ethylflurazepam (the primary urinary metabolite of flurazepam), 7-NH2-flunitrazepam, nordiazepam, oxazepam, temazepam and α-OH-triazolam (the primary urinary metabolite of triazolam) (representative chromatograms were found). These drugs were chosen because of their widespread abuse. Wastewater samples were collected at both the Oxford Wastewater Treatment Plant (WWTP) in Oxford, Mississippi (MS) and the University WWTP in University, MS. These wastewater samples were collected on weekends in which the Ole Miss Rebel football team held home games at the Vaught-Hemingway Stadium, University, and one weekend on which there was no game. The collected samples were analyzed using a validated method and found to contain alprazolam, α-OH-alprazolam, nordiazepam, oxazepam and temazepam. None of the samples contained chlordiazepoxide, flurazepam, 2-hydroxyethyl-flurazepam, 7-NH2-flunitrazepam and α-OH-triazolam.

The effect of triazolam premedication on anxiety, sedation, and amnesia in general anesthesia

BACKGROUND

Benzodiazepines have been used preoperatively as part of an anesthesia regimen to attenuate the anxiety of patients. In this study, we aimed to examine the effect of oral triazolam, a short-acting benzodiazepine, on anxiety, sedation, and amnesia.

METHODS

Ninety patients, aged 20-55 years, were randomly assigned to receive no premedication, or to receive triazolam 0.25 mg or 0.375 mg 1 h before anesthesia. Anxiety score, sedation score, blood pressure, heart rate and psychomotor performance were measured on the evening before surgery and on the day of surgery. Additional tests of psychomotor performance were performed in the postanesthesia care unit and on the next day of surgery. The occurrence of amnesia, bispectral index (BIS), recovery profiles and patient satisfaction with overall anesthesia care were also evaluated.

RESULTS

Changes in the anxiety and sedation scores on the day of surgery were not significantly different among groups, whereas the increases in systolic blood pressure and heart rate were significantly less in both triazolam groups. The triazolam groups both showed a higher incidence of high satisfaction scores (≥ 2). The two triazolam groups also showed similar outcomes, except for a dose-dependent increase in the number of patients with amnesia and BIS values < 90. Delayed recovery from general anesthesia and psychomotor impairment were not observed in the triazolam groups.

CONCLUSIONS

Triazolam 0.25 mg or 0.375 mg reduced the hemodynamic changes associated with anxiety, produced potent amnesia, and improved patient satisfaction. We suggest that triazolam can be used effectively as anesthetic premedication in adults.

An ultra-sensitive LC–MS/MS method to determine midazolam levels in human plasma: development, validation and application to a clinical study

Aim: Midazolam is a commonly used marker substrate for the in vivo assessment of CYP3A activity. Reliable pharmacokinetic assessment at sub-pharmacological doses of midazolam requires an ultra-sensitive analytical method. Methods: A new, ultra-sensitive LC–MS/MS method for the determination of midazolam in human plasma using SPE was developed and fully validated. The lowest limit of quantitation is 0.1 pg/ml with a sample volume of 500 μl. Results/conclusion: The following parameters were validated: sensitivity, assay accuracy and precision, linearity, selectivity, and stability of midazolam at pertinent analytical and storage conditions. The validated method was utilized successfully for the sample assay during a midazolam microdosing study for the evaluation of CYP3A4 activity of a clinical candidate.

Metabolites replace the parent drug in the drug arena. The cases of fonazepam and nifoxipam

Fonazepam (desmethylflunitrazepam) and nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives and active metabolites of flunitrazepam. They recently invaded the drug arena as substances of abuse and alerted the forensic community after being seized in powder and tablet forms in Europe between 2014 and 2016. A review of all the existing knowledge of fonazepam and nifoxipam is reported, concerning their chemistry, synthesis, pharmacology and toxicology, prevalence/use, biotransformation and their analysis in biological samples. To our knowledge, fonazepam and nifoxipam-related intoxications, lethal or not, have not been reported in the scientific literature. All the available information was gathered through a detailed search of PubMed and the World Wide Web.

TRPM7 channel inhibition mediates midazolam-induced proliferation loss in human malignant glioma

The melastatin-like transient receptor potential 7 (TRPM7) has been implicated in proliferation or apoptosis of some cancers, indicating the potential of TRPM7 as an anti-anaplastic target. Here, we identified the characteristic TRPM7 channel currents in human malignant glioma MGR2 cells, which could be blocked by a pharmacologic inhibitor Gd³⁺. We mined the clinical sample data from Oncomine Database and found that human malignant glioma tissues expressed higher TRPM7 mRNA than normal brain ones. Importantly, we identified a widely used clinical anesthetic midazolam as a TRPM7 inhibitor. Midazolam treatment for seconds suppressed the TRPM7 currents and calcium influx, and treatment for 48 h inhibited the TRPM7 expression. The inhibitory effect on TRPM7 accounts for the proliferation loss and G₀/G₁ phase cell cycle arrest induced by midazolam. Our data demonstrates that midazolam represses proliferation of human malignant glioma cells through inhibiting TRPM7 currents, which may be further potentiated by suppressing the expression of TRPM7. Our result indicates midazolam as a pharmacologic lead compound with brain-blood barrier permeability for targeting TRPM7 in the glioma.