A fluorine turns a medicinal benzodiazepine into NPS: the case of flualprazolam

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

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

Development and validation of a liquid chromatography tandem mass spectrometry method for the analysis of 53 benzodiazepines in illicit drug samples

An LC-MS/MS method for the analysis of 53 benzodiazepines, including various designer benzodiazepines, was developed. The developed method was applied to a total of 79 illicit street drug samples collected in Chicago, IL. Of these samples, 68 (84%) had detectable amounts of at least one benzodiazepine. Further, of the 53 benzodiazepines included in the developed method just 14 were measured in samples. Clonazolam, a potent designer benzodiazepine and derivative of clonazepam, was the most frequently measured benzodiazepine in 63% of samples and was measured in the highest concentrations. Other benzodiazepines measured in more than 10% of samples included clonazepam, alprazolam, flualprazolam, and oxazepam. Mixtures of benzodiazepines were frequently measured in samples, with just 24% of samples containing just one benzodiazepine. To determine the response of benzodiazepines on a rapid, point-of-use drug checking tool, all 53 benzodiazepine standards were screened on a lateral flow immunoassay benzodiazepine test strip. Sixty eight percent of standards gave a positive BTS response at a concentration of 20 μg/mL, demonstrating BTS have response to a wide variety of benzodiazepines, including many designer benzodiazepines. A comparison of this data to previous data reported for the same samples demonstrated all samples containing a benzodiazepine also had an opioid present, with fentanyl being present in 94% of benzodiazepine samples. These results highlight high rates of polysubstance drug presence in Chicago, IL illicit drug samples, posing an increased risk of drug overdoses in people who use drugs.

Fast and Sensitive Method for the Determination of 17 Designer Benzodiazepines in Hair by Liquid Chromatography-Tandem Mass Spectrometry

In recent years, identification and analysis of designer benzodiazepines have become a challenge in forensic toxicology. These substances are analogues of the classic benzodiazepines, but their pharmacology is not well known, and many of them have been associated with overdoses and deaths. As a result, there has been a surge in efforts to develop analytical methods to determine these compounds in different biological samples. Our aim was to develop and validate a fast, sensitive, and specific method for determining 17 designer benzodiazepines (adinazolam, clobazam, clonazolam, delorazepam, deschloroetizolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam, flunitrazolam, N-desmethylclobazam, nifoxipam, nitrazolam, meclonazepam, pyrazolam and zolazepam) in hair by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Hair samples were decontaminated, pulverized, and a 20-mg aliquot was incubated in methanol in an ultrasound bath (1h, 25ºC). The supernatant was evaporated and reconstituted in 200 µL of mobile phase, and the extracts were filtered (nano-filter vials) before injection into LC-MS-MS. All analytes eluted from the chromatographic column in 8 min, and two multiple-reaction monitoring (MRM) transitions were used to identify each compound. The limits of quantification were 5 or 25 pg/mg, depending on the analyte, and calibration functions were linear to 200 pg/mg. Imprecision was <19.2% (n = 15) and bias was from -13.7 up to 18.3% (n = 15). All the analytes yielded high extraction efficiencies >70%, and displayed ion suppression between -62.8% and -23.9% (n = 10). The method was applied to 19 authentic cases. Five samples were positive for flualprazolam (<LOQ - >200 pg/mg) and/or etizolam (47.4-88.5 pg/mg). In conclusion, the present validated method has proven to be fast, sensitive, specific, and capable of determining 17 designer benzodiazepines in hair using LC-MS-MS.

Reports of Adverse Events Associated with Use of Novel Psychoactive Substances, 2017-2020: A Review

An important role of modern forensic and clinical toxicologists is to monitor the adverse events of novel psychoactive substances (NPS). Following a prior review from 2013 to 2016, this critical literature review analyzes and evaluates published case reports for NPS from January 2017 through December 2020. The primary objective of this study is to assist in the assessment and interpretation of these cases as well as provide references for confirmation methods. Chemistry, pharmacology, adverse events and user profiles (e.g., polypharmacy) for NPS are provided including case history, clinical symptoms, autopsy findings and analytical results. Literature reviews were performed in PubMed and Google Scholar for publications using search terms such as NPS specific names, general terms (e.g., ‘designer drugs’ and ‘novel psychoactive substances’), drug classes (e.g., ‘designer stimulants’) and outcome-based terms (e.g., ‘overdose’ and ‘death’). Government and website drug surveillance databases and abstracts published by professional forensic science organizations were also searched. Toxicological data and detailed case information were extracted, tabulated, analyzed and organized by drug category. Case reports included overdose fatalities (378 cases), clinical treatment and hospitalization (771 cases) and driving under the influence of drugs (170 cases) for a total of 1,319 cases providing details of adverse events associated with NPS. Confirmed adverse events with associated toxidromes of more than 60 NPS were reported including synthetic cannabinoid, NPS stimulant, NPS hallucinogen, NPS benzodiazepine and NPS opioid cases. Fifty of these NPS were reported for the first time in January 2017 through December 2020 as compared to the previous 4 years surveyed. This study provides insight and context of case findings described in the literature and in digital government surveillance databases and websites during a recent 4-year period. This review will increase the awareness of adverse events associated with NPS use to better characterize international emerging drug threats.

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

PURPOSE

The number of benzodiazepines appearing as new psychoactive substances (NPS) is continually increasing. Information about the pharmacological parameters of these compounds is required to fully understand their potential effects and harms. One parameter that has yet to be described is the blood-to-plasma ratio. Knowledge of the pharmacodynamics of designer benzodiazepines is also important, and the use of quantitative structure-activity relationship (QSAR) modelling provides a fast and inexpensive method of predicting binding affinity to the GABA_A receptor.

METHODS

In this work, the blood-to-plasma ratios for six designer benzodiazepines (deschloroetizolam, diclazepam, etizolam, meclonazepam, phenazepam, and pyrazolam) were determined. A previously developed QSAR model was used to predict the binding affinity of nine designer benzodiazepines that have recently appeared.

RESULTS

Blood-to-plasma values ranged from 0.57 for phenazepam to 1.18 to pyrazolam. Four designer benzodiazepines appearing since 2017 (fluclotizolam, difludiazepam, flualprazolam, and clobromazolam) had predicted binding affinities to the GABA_A receptor that were greater than previously predicted binding affinities for other designer benzodiazepines.

CONCLUSIONS

This work highlights the diverse nature of the designer benzodiazepines and adds to our understanding of their pharmacology. The greater predicted binding affinities are a potential indication of the increasing potency of designer benzodiazepines appearing on the illicit drugs market.

Selective electrophilic di- and mono-fluorinations for the synthesis of 4-difluoromethyl and 4-fluoromethyl quinazolin(thi)ones by Selectfluor-triggered multi-component reaction

A simple and efficient domino protocol for the selective synthesis of 4-difluoromethyl and 4-fluoromethyl quinazolin(thi)ones was established from readily available 2-aminoacetophenones and iso(thio)cyanates mediated by Selectfluor. The reaction outcomes are...

A case of fatal multidrug intoxication involving flualprazolam: distribution in body fluids and solid tissues

Purpose

Designer benzodiazepines (DBZDs) increasingly emerged on the novel psychoactive substance (NPS) market in the last few years. They are usually sold as readily available alternatives to prescription benzodiazepines (BZDs) or added to counterfeit medicines. BZDs are generally considered relatively safe drugs due to the low risk of serious acute adverse effects in mono-intoxication, though e.g., alprazolam seems to display an elevated risk of respiratory depression. Here we report on a fatal intoxication involving the novel DBZD flualprazolam.

Methods

A complete postmortem examination was performed. General unknown screenings and analysis of drugs of abuse were performed on postmortem samples by immunoassay, gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry. The standard addition method was employed to quantify flualprazolam in postmortem blood and tissues. Finally, a toxicological significance score (TSS) was assigned.

Results

Flualprazolam was detected in heart serum (25.4 ng/mL) and peripheral blood (21.9 ng/mL) as well as in urine, stomach contents, brain, liver and kidney (65.2–323 ng/g). The cause of death was deemed as central nervous system (CNS) and respiratory depression with agonal aspiration of stomach contents, in the setting of a multiple drug intake. Given the concentration levels of the co-consumed CNS depressants, the contribution of flualprazolam to the death was considered likely (TSS of 3).

Conclusions

Our results support that highly potent DBZDs like flualprazolam carry an elevated risk for unintended toxicity, especially in association with other CNS depressants. A multidisciplinary evaluation of fatalities remains mandatory, especially when pharmacological/toxicological data on intoxicating compounds are lacking. To our knowledge this is the first report of flualprazolam concentrations in solid tissues in human.

What's in fake 'Xanax'?: A dosage survey of designer benzodiazepines in counterfeit pharmaceutical tablets

The identification of a range of different drugs within counterfeit benzodiazepine tablets has been widely reported; however, limited information is available on the dosage of these products. A rapid dosage survey of 46 counterfeit benzodiazepine tablets from 20 seizures was conducted over a 6-month period between April and September 2020. Existing methods utilised for the determination of benzodiazepines in toxicology specimens were applied to assess the dosage of four benzodiazepines detected across five different counterfeit benzodiazepine presentations. The highest dosage variation was observed for etizolam with a range of 0.7-8.3 mg per tablet. This report demonstrates the variability in drug content and dosage that can occur between visually similar counterfeit tablets, even when co-packaged within the same seizure, highlighting the potential public harm posed by these counterfeit medications.