Co-exposure to gamma-hydroxybutyrate is associated with attenuated neuropsychiatric and stimulant effects of metamfetamine.

INTRODUCTION: Acute metamfetamine toxicity is characterized by stimulant effects and neuropsychiatric disturbance, which is attenuated by gamma-aminobutyric acid type A receptor agonists including benzodiazepines. We utilized clinical registry data to examine the effect of co-exposure to a gamma-aminobutyric acid type B receptor agonist (gamma-hydroxybutyrate) in illicit drug cases with analytically confirmed exposure to metamfetamine. METHODS: The Emerging Drugs Network of Australia Victoria is an ethics board-approved prospective registry collecting clinical and analytical data (utilising blood samples) on emergency department illicit drug presentations. Comparison groups were defined by analytically confirmed exposure: lone metamfetamine, metamfetamine plus gamma-hydroxybutyrate, metamfetamine plus benzodiazepine, metamfetamine plus gamma-hydroxybutyrate plus benzodiazepine. Cases with co-exposure to other stimulants or sedatives were excluded. RESULTS: Median metamfetamine blood concentrations were significantly greater in metamfetamine plus gamma-hydroxybutyrate (n = 153, median = 0.20 mg/L, interquartile range: 0.10-0.32 mg/L, 95 per cent confidence interval: 0.20-0.23 mg/L) and metamfetamine plus gamma-hydroxybutyrate plus benzodiazepine (n = 160, median = 0.20 mg/L, interquartile range: 0.10-0.30 mg/L, 95 per cent confidence interval: 0.20-0.30 mg/L) positive groups compared to gamma-hydroxybutyrate negative groups including metamfetamine (n = 81, median = 0.10 mg/L, interquartile range: 0.05-0.21 mg/L, 95 per cent confidence interval: 0.09-0.18 mg/L) and metamfetamine plus benzodiazepine (n = 73, median = 0.10 mg/L, interquartile range: 0.06-0.20 mg/L, 95 per cent confidence interval: 0.09-0.20 mg/L) groups (P < 0.0004). Presenting heart rate in metamfetamine plus gamma-hydroxybutyrate cases (n = 153, median = 72 beats per minute, interquartile range: 63-86 beats per minute, 95 per cent confidence interval: 70-78 beats per minute) was significantly lower than metamfetamine plus benzodiazepine cases (n = 73, median = 84 beats per minute, interquartile range: 73-98 beats per minute, 95 per cent confidence interval: 80-90 beats per minute, P < 0.0001), and lone metamfetamine cases (n = 81, median = 110 beats per minute, interquartile range: 87-131 beats per minute, 95 per cent confidence interval: 93-120 beats per minute, P < 0.0001). Presenting temperature in metamfetamine plus gamma-hydroxybutyrate cases (median = 35.8 °C, interquartile range: 35.0-36.2 °C, 95 per cent confidence interval 35.6-35.9 °C) was significantly lower than metamfetamine plus benzodiazepine cases (median 36.2 °C, interquartile range 35.7-36.6 °C, 95 per cent confidence interval, 36.0-36.4 °C, P = 0.017), and lone metamfetamine cases (median = 36.5 °C, interquartile range: 35.8-37.1 °C, 95 per cent confidence interval: 36.2-36.7 °C, P < 0.0001). Median presenting systolic blood pressure was significantly (P ≤ 0.001) lower in benzodiazepine positive groups (metamfetamine plus benzodiazepine median = 120 mmHg, interquartile range: 109-132 mmHg, 95 per cent confidence interval: 116-124 mmHg and metamfetamine plus benzodiazepine plus gamma-hydroxybutyrate median = 124 mmHg, interquartile range: 110-137 mmHg, 95 per cent confidence interval: 120-129 mmHg). Incidence of sedation (Glasgow Coma Scale less than 9) was significantly greater in metamfetamine plus gamma-hydroxybutyrate cases (63 per cent) compared to metamfetamine plus benzodiazepine cases (27 per cent, P < 0.0001) and lone metamfetamine cases (15 per cent, P < 0.0001). Incidence of agitation was significantly lower in metamfetamine plus gamma-hydroxybutyrate plus benzodiazepine cases (17 per cent, P < 0.0001) and metamfetamine plus gamma-hydroxybutyrate cases (34 per cent, P = 0.0004) compared to lone metamfetamine cases (58 per cent). DISCUSSION: Differences in gamma-aminobutyric acid type A and B receptor physiology may offer a gamma-aminobutyric acid type B agonist-facilitated alternative pharmacodynamic mechanism able to attenuate metamfetamine stimulant and neuropsychiatric toxicity. CONCLUSION: Metamfetamine intoxicated patients with analytically confirmed co-exposure to gamma-hydroxybutyrate had significantly reduced heart rate, body temperature and incidence of agitation compared to patients with lone metamfetamine exposure. Metamfetamine intoxicated patients with analytically confirmed co-exposure to a benzodiazepine had significantly reduced systolic blood pressure compared to patients with lone metamfetamine exposure. We hypothesize that gamma-aminobutyric acid type B receptor agonists may be beneficial in the management of acute metamfetamine toxicity.

Protonitazene detection in two cases of opioid toxicity following the use of tetrahydrocannabinol vape products in Australia.

INTRODUCTION: Protonitazene is an opioid belonging to the 2-benzylbenzimidazole structural class. We describe two cases of opioid toxicity involving the reported inhalation of a delta-9-tetrahydrocannabinol vape product in which protonitazene was detected. CASE REPORTS: Case 1 was a young male found unconscious after the reported use of a delta-9-tetrahydrocannabinol vape. He suffered two subsequent apnoeic episodes requiring bag-valve-mask ventilation before eventual recovery. Only protonitazene was detected in blood at a concentration of 0.74 µg/L. Case 2 was a young male who died shortly after being found unresponsive. The postmortem femoral blood concentrations of protonitazene and delta-9-tetrahydrocannabinol were 0.33 µg/L and 2 µg/L, respectively. Analysis of a pod vaping device found in the decedent's hand and a separate e-liquid bottle labelled as delta-9-tetrahydrocannabinol showed a mixture of protonitazene and delta-9-tetrahydrocannabinol. DISCUSSION: The opioid effects of protonitazene are mediated through ß-arrestin2 and mu opioid receptor signalling pathways. Benzimidazole opioids are lipophilic and, when mixed with a suitable solvent, can be used in a vape device. It is anticipated that naloxone would have provided effective reversal of toxicity in our cases. CONCLUSIONS: Novel routes of opioid administration, like vaping, may appear relatively innocuous in comparison to intravenous administration, but opioids may still be absorbed at high concentrations, resulting in severe opioid toxicity or death.

Identification of clobromazolam in Australian emergency department intoxications using data-independent high-resolution mass spectrometry and the HighResNPS.com database.

The proliferation of novel psychoactive substances (NPSs) continues to challenge toxicology laboratories. In particular, the United Nations Office on Drugs and Crime considers designer benzodiazepines to be a current primary threat among all NPSs. Herein, we report detection of a new emerging designer benzodiazepine, clobromazolam, using high-resolution mass spectrometry and untargeted data acquisition in combination with a "suspect screening" method built from the crowd-sourced HighResNPS.com database. Our laboratory first detected clobromazolam in emergency department presenting intoxications included within the Emerging Drugs Network of Australia-Victoria project in the state of Victoria, Australia, from April 2022 to March 2023. Clobromazolam was the most frequent designer benzodiazepine detected in this cohort (100/993 cases, 10%). No patients reported intentional administration of clobromazolam, although over half reported exposure to alprazolam, which was detected in only 7% of cases. Polydrug use was prevalent (98%), with phenazepam (45%), methylamphetamine (71%) and other benzodiazepines (60%) most frequently co-detected. This is the first case series published in the literature concerning clobromazolam in clinical patients. The identification of clobromazolam in patients presenting to emergency departments in Victoria demonstrates how high-resolution mass spectrometry coupled with the HighResNPS.com database can be a valuable tool to assist toxicology laboratories in keeping abreast of emerging psychoactive drug use.

From signal to alert: A cluster of exposures to counterfeit alprazolam tablets containing five novel benzodiazepines.

OBJECTIVE: To illustrate the toxicosurveillance role of the Emerging Drugs Network of Australia - Victoria (EDNAV) project in informing timely harm minimisation interventions. METHODS: Utilisation of an ethics approved clinical registry storing de-identified clinical and analytical data on Victorian ED illicit drug-related presentations. RESULTS: In April 2022, six adults presented to hospital with varying levels of sedation, following the use of counterfeit benzodiazepines. Comprehensive toxicological analysis identified five separate novel benzodiazepines within blood samples from each patient. A public 'Drug Alert' was subsequently issued, and local emergency physicians were notified. CONCLUSION: Toxicosurveillance projects, such as EDNAV, are critical to the continued monitoring and reporting of illicit substance use in the community.

Intoxications in an Australian Emergency Department Involving 'Nitazene' Benzylbenzimidazole Synthetic Opioids (Etodesnitazene, Butonitazene and Protonitazene).

Benzimidazole synthetic opioids are highly potent µ-opioid receptor agonists with heroin-like effects, including dose-dependent respiratory depression and a high risk of abuse and toxicity. Benzimidazoles were first detected in 2019 in Europe and Canada, with analytical confirmation of etodesnitazene, protonitazene and butonitazene in 2021. We report the first detections of these compounds in Australia, in two patients presenting with drug toxicity to Emergency Departments (EDs) in the state of Victoria. Case 1 was a female in her 20s who rectally administered etodesnitazene and was found unconscious with respiratory depression and hypotension. Case 2 was a female in her 30s who presented to the ED in a sedated state after taking a formulation of protonitazene that also contained butonitazene, in addition to methylamphetamine. She responded positively to naloxone. Novel synthetic opioids were used with prior experience of the formulations purchased; however, the unpredictability of their effects was demonstrated by the acute toxicity experienced with this occasion of use. Toxicosurveillance of ED presentations with analytical confirmation of drugs is crucial in identifying emerging drugs in the community and informing harm reduction strategies.

A risk-based approach to community illicit drug toxicosurveillance: operationalisation of the Emerging Drugs Network of Australia - Victoria (EDNAV) project.

INTRODUCTION: The Emerging Drugs Network of Australia - Victoria (EDNAV) project is a newly established toxicosurveillance network that collates clinical and toxicological data from patients presenting to emergency departments with illicit drug related toxicity in a centralised clinical registry. Data are obtained from a network of sixteen public hospital emergency departments across Victoria, Australia (13 metropolitan and three regional). Comprehensive toxicological analysis of a purposive sample of 22 patients is conducted each week, with reporting of results to key alcohol and other drug stakeholders. This paper describes the overarching framework and risk-based approach developed within Victoria to assess drug intelligence from EDNAV toxicosurveillance. METHODS: Risk management principles from other spheres of public health surveillance and healthcare clinical governance have been adapted to the EDNAV framework with the aim of facilitating a consistent and evidence-based approach to assessing weekly drug intelligence. The EDNAV Risk Register was reviewed over the first two years of EDNAV project operation (September 2020 - August 2022), with examples of eight risk assessments detailed to demonstrate the process from signal detection to public health intervention. RESULTS: A total of 1112 patient presentations were documented in the EDNAV Clinical Registry, with 95 signals of concern entered into the EDNAV Risk Register over the two-year study period. The eight examples examined in further detail included suspected drug adulteration (novel opioid adulterated heroin, para-methoxymethamphetamine adulterated 3,4-methylenedioxymethamphetamine (MDMA)), drug substitution (25B-NBOH sold as lysergic acid diethylamide, five benzodiazepine-type new psychoactive substances in a single tablet, protonitazene sold as ketamine), new drug detection (N,N-dimethylpentylone), contamination (unreported acetylfentanyl) and a fatality subsequent to MDMA use. A total of four public Drug Alerts were issued over this period. CONCLUSIONS: Continued toxicosurveillance efforts are paramount to characterising the changing landscape of illicit drug use. This work demonstrates a functional model for risk assessment of illicit drug toxicosurveillance, underpinned by analytical confirmation and evidence-based decision-making.

Non-fatal intoxications involving the novel benzodiazepine clonazolam: case series from the Emerging Drugs Network of Australia - Victoria project.

INTRODUCTION: Clonazolam is an unregistered novel benzodiazepine which emerged in global illicit drug markets in 2014. We describe the clinical features of four cases of non-fatal clonazolam mono-intoxications from patients presenting to emergency departments in Australia. CASES: Four patients aged between 16 and 19 years presented to hospital with a sedative toxidrome (Glasgow Coma Scale range 8-13) and elevated heart rate (median heart rate 100 beats per minute, range 92-105) following reported benzodiazepine exposure. Three patients reported the use of a large quantity (7-20 tablets) of Xanax®, a brand of alprazolam not commercially available in Australia. Two patients required nasopharyngeal airway insertion following the development of airway obstruction. The median time to return of a normal conscious state (Glasgow Coma Scale 15) was 23 h (range 5-30 h). Clonazolam (range 0.2-2.1 µg/L) and its main metabolite 8-aminoclonazolam (range 5.9-19.1 µg/L) were the only substances detected by liquid chromatography-tandem mass spectrometry in blood samples of all patients. CONCLUSION: Clonazolam intoxication resulted in sedation with mild sinus tachycardia. Three patients who reported multiple tablet exposures experienced prolonged sedation, and two of these patients developed airway obstruction. In this series, clonazolam was unknowingly ingested through possible illicit substitution within an unregulated counterfeit benzodiazepine product.

The Emerging Drugs Network of Australia - Victoria Clinical Registry: A state-wide illicit substance surveillance and alert network.

OBJECTIVES: With an increasingly dynamic global illicit drug market, including the emergence of novel psychoactive substances, many jurisdictions have moved to establish toxicosurveillance systems to enable timely detection of harmful substances in the community. This paper describes the methodology for the Emerging Drugs Network of Australia - Victoria (EDNAV) project, a clinical registry focused on the collection of high-quality clinical and analytical data from ED presentations involving illicit drug intoxications. Drug intelligence collected from the project is utilised by local health authorities with the aim to identify patterns of drug use and emerging drugs of concern. METHODS: The project involves 10 public hospital EDs in Victoria, Australia. Patients 16 years and over, presenting to a network ED with a suspected illicit drug-related toxicity and a requirement for venepuncture are eligible for inclusion in the study under a waiver of consent. Clinical and demographic parameters are documented by site-based clinicians and comprehensive toxicological analysis is conducted on patient blood samples via specialised forensic services. All data are then deidentified and compiled in a project specific database. RESULTS: Cases are discussed in weekly multidisciplinary team meetings, with a view to identify potentially harmful substances circulating in the community. High-risk signals are escalated to key stakeholders to produce timely and proportionate public health alerts with a focus on harm minimisation. CONCLUSIONS: The EDNAV project represents the first centralised system providing near real-time monitoring of community drug use in Victoria and is fundamental in facilitating evidence-based public health intervention.

Characteristics and time course of benzodiazepine-type new psychoactive substance detections in Australia: results from the Emerging Drugs Network of Australia - Victoria project 2020-2022.

INTRODUCTION: The emergence of benzodiazepine-type new psychoactive substances (NPSs) are a growing international public health concern, with increasing detections in drug seizures and clinical and coronial casework. This study describes the patterns and nature of benzodiazepine-type NPS detections extracted from the Emerging Drugs Network of Australia - Victoria (EDNAV) project, to better characterise benzodiazepine-type NPS exposures within an Australian context. METHODS: EDNAV is a state-wide illicit drug toxicosurveillance project collecting data from patients presenting to an emergency department with illicit drug-related toxicity. Patient blood samples were screened for illicit, pharmaceutical and NPSs utilising liquid chromatography-tandem mass spectrometry. Demographic, clinical, and analytical data was extracted from the centralised registry for cases with an analytical confirmation of a benzodiazepine-type NPS(s) between September 2020-August 2022. RESULTS: A benzodiazepine-type NPS was detected in 16.5 % of the EDNAV cohort (n = 183/1112). Benzodiazepine-type NPS positive patients were predominately male (69.4 %, n = 127), with a median age of 24 (range 16-68) years. Twelve different benzodiazepine-type NPSs were detected over the two-year period, most commonly clonazolam (n = 82, 44.8 %), etizolam (n = 62, 33.9 %), clobromazolam (n = 43, 23.5 %), flualprazolam (n = 42, 23.0 %), and phenazepam (n = 31, 16.9 %). Two or more benzodiazepine-type NPSs were detected in 47.0 % of benzodiazepine-type NPS positive patients. No patient referenced the use of a benzodiazepine-type NPS by name or reported the possibility of heterogenous product content. CONCLUSION: Non-prescription benzodiazepine use may be an emerging concern in Australia, particularly amongst young males. The large variety of benzodiazepine-type NPS combinations suggest that consumers may not be aware of product heterogeneity upon purchase or use. Continued monitoring efforts are paramount to inform harm reduction opportunities.