The clinical toxicology of γ-hydroxybutyrate, γ-butyrolactone and 1,4-butanediol

Changes in the rates and characteristics of gamma hydroxybutyrate (GHB)-related death in Australia, 2001-2023

INTRODUCTION

In recent years gamma hydroxybutyrate (GHB) use appears to have increased. This study aimed to determine: (i) population rates of GHB-related death in Australia, 2001-2021; and (ii) whether there have been changes in the characteristics of GHB-related death in Australia over the period 2001-2023.

METHODS

Retrospective study of all Australian cases in which GHB was a mechanism contributory to death retrieved from the National Coronial Information System (n = 217). Joinpoint regression models were used to analyse trends in overall rates.

RESULTS

Death rates were stable between 2001 and 2015 ('stable period') (annual percent change [APC] = 3.7) but showed marked acceleration between 2016 and 2021 ('accelerated period') (APC = 44.4). Circumstances of death were: unintentional toxicity (81.6%), intentional toxicity (5.1%), self-harm (6.0%), traumatic injury (7.4%). Compared to the stable period, later cases were slightly older (34.2 vs. 30.7 years, p < 0.05), less likely to be employed (odds ratio [OR] 0.4), but more likely to have substance use problems (OR 3.9), a history of injecting drug use (OR 3.5), mental health problems (OR 3.6), and to have present in their blood at toxicological screening opioids (OR 3.2) and hypnosedatives (OR 3.7). The median blood GHB concentration was 170 mg/L, (range 0-3210), which did not change significantly. There were no differences in major organ pathology, but the proportion with aspiration pneumonia declined (OR 0.4).

DISCUSSION AND CONCLUSIONS

GHB-related death rates increased from 2016, accompanied by changes in case characteristics. In recent years GHB use appears to have extended to a population more likely to have substance use problems and use other respiratory depressants.

Trends in reported GHB-related presentations to Sydney emergency departments between 2012 and 2021

OBJECTIVES

In overdose, gamma-hydroxybutyrate (GHB) and its precursors can cause decreased levels of consciousness, coma and death. Here, we aim to describe reported exposure to GHB at four EDs in Sydney, New South Wales (NSW), Australia.

METHODS

We searched the ED databases of four Sydney metropolitan hospitals for presentations relating to GHB exposure between 2012 and 2021. We calculated annual number of presentations stratified by hospital, age, sex, mode of arrival and triage category.

RESULTS

A total of 3510 GHB-related presentations to ED were recorded across the four hospitals. Data for all hospitals were only available from 2015 onwards and between 2015 and 2021; there was a 114% increase in annual presentations (from 228 to 487). Males represented 68.7% of all presentations and the median age was 31 years (range 16-74 years). There was an increase in the proportion of female presentations between 2012 and 2021 (from 27.9% to 37.9%) along with the severity of presentation over the same period, with the proportion of presentations with a triage category 1 increasing from 19.7% to 34.5%.

CONCLUSIONS

Increases in recorded absolute number and severity of GHB-related presentations to Sydney EDs are a major public health concern. There may also be shifts in the demographics of those with GHB-related presentations. Renewed efforts are required to understand the drivers of these increases to optimally target harm reduction approaches.

Growing burden of gamma-hydroxybutyrate intoxication on emergency department resource utilisation

OBJECTIVE

Recreational gamma-hydroxybutyrate (GHB) use is rising in Australia. We aimed to describe ED presentation patterns related to GHB over time and the impact this has on ED resource use.

METHODS

Retrospective review of prospective data collection from two clinical toxicology units based in Queensland and New South Wales.

RESULTS

There were 751 GHB-related presentations to the two units (Newcastle, 127; Princess Alexandria, 624), with marked increases in presentations occurring in 2019 and 2023. The major intervention was intubation, with 95 (13%) patients intubated.

CONCLUSION

GHB presentations to ED are rising and the impact on acute bed space and clinical resources is significant.

A case of severe and prolonged γ-hydroxybutyrate (GHB) withdrawal syndrome successfully managed with a slow benzodiazepine and baclofen taper

INTRODUCTION

γ-hydroxybutyrate (GHB) is a GABA-B agonist that rapidly produces effects that are likened to both alcohol and MDMA/ecstasy. GHB use can lead to neuroadaptation with a characteristic withdrawal syndrome. There is currently a paucity of data on the progression of GHB withdrawal, however, due to the drug's short half-life it is generally considered to be typically 5-7 days, although some cases can be severe and complicated by life threatening delirium. Here, we present a case of severe GHB withdrawal, which recurred on multiple occasions over 56 days, despite initial clinical stabilisation on each occasion and toxicological evidence of abstinence from GHB between episodes.

CASE PRESENTATION

A male patient in his 30s presented with agitated delirium on a background of severe GHB use disorder with a 15-year history of daily high dose GHB use. Following 3 hospital admissions over 8 weeks, all requiring intravenous sedation and tracheal intubation, the patient's withdrawal delirium was successfully treated with a slow benzodiazepine and baclofen wean over a period of 6 months. Relapse to GHB use between hospitalisations was excluded toxicologically via blood analysis performed at an institute of forensic pathology.

DISCUSSION AND CONCLUSIONS

This case highlights that GHB withdrawal can be more prolonged than previously reported in the literature and in some cases may require slow and prolonged tapering of treatment to prevent re-emergence of delirium. Similar to previous case reports, benzodiazepines and GABA-B receptor agonists appear to be appropriate drug classes to manage GHB withdrawal.

Drugs in blood and urine samples from victims of suspected exposure to drink spiking: A prospective observational study from Oslo, Norway

OBJECTIVE

People regularly contact emergency medicine services concerned that they have been exposed to drink spiking, i.e., exposure to drugs without their knowledge or permission. We identified drugs in blood and urine samples from patients suspecting exposure to drink spiking, with special consideration for drugs not reported taken by the patient (unreported drugs).

METHODS

From September 2018 to May 2019, we collected blood and urine samples from patients 16 years or older presenting at an emergency clinic in Oslo, Norway, within 48 hours of suspected exposure to drink spiking. We also collected information on ethanol ingestion and drugs taken. Blood samples were analyzed for 20 classical recreational drugs using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and an automated enzymatic method for ethanol. Urine samples were analyzed using immunoassay methods and a specific gas chromatography mass spectrometry (GCMS) method for gammahydroxybutyrate (GHB).

RESULTS

From 100 included patients (median age 24 years, 62 females), we collected 100 blood samples and 72 urine samples. Median time since exposure was 5 hours. Unreported drugs were found in 15 patients. Unreported drugs in the blood samples were clonazepam in 3, methylenedioxymethamphetamine (MDMA) in 3, amphetamine in 2, tetrahydrocannabinol (THC) in 2, tramadol in 1, cocaine in 1, and methamphetamine in 1. Unreported drugs in the urine samples were cocaine in 5, amphetamine in 4, ecstasy in 3, and cannabis in 2. Ethanol was found in 69 patients, all reporting ethanol ingestion. Median blood ethanol concentration was higher in patients with no unreported drugs detected, 1.00‰ (interquartile range (IQR) 0-1.52) vs. 0‰ (IQR 0-0.46) (p<0.001). GHB was not detected.

CONCLUSION

Unreported drugs, possibly used for drink spiking, were found in 15% of patients. Blood ethanol concentration was higher when no unreported drugs were found. GHB was not detected in any patient.

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.

Safety Assessment of Alkane Diols as Used in Cosmetics

The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 10 alkane diol ingredients as used in cosmetics. The alkane diols are structurally related to each other as small diols, and most are reported to function in cosmetics as solvents. The Panel reviewed the relevant data for these ingredients, and concluded that seven alkane diols are safe in cosmetics in the present practices of use and concentration described in this safety assessment, but that the available data are insufficient to make a determination of safety for three ingredients, namely 1,4-Butanediol, 2,3-Butanediol, and Octanediol.

Sex and Cross-Sex Testosterone Treatment Alters Gamma-Hydroxybutyrate Acid Toxicokinetics and Toxicodynamics in Rats

Γ-hydroxybutyric acid (GHB) is widely abused due to its sedative/hypnotic and euphoric effects. In recent years, GHB use has witnessed a notable rise within the LGBTQ+ community. GHB is a substrate of monocarboxylate transporters (MCTs) and exhibits nonlinear toxicokinetics, characterized by saturable metabolism, absorption, and renal reabsorption. This study investigates the impact of exogenous testosterone administration on GHB toxicokinetics and toxicodynamics, exploring the potential of MCT1 inhibition as a strategy to counteract toxicity. Ovariectomized (OVX) females and castrated (CST) male Sprague Dawley rats were treated with testosterone or placebo for 21 days. GHB was administered at two doses (1000 mg/kg or 1500 mg/kg i.v.), and the MCT1 inhibitor AR-C 155858 (1 mg/kg i.v.) was administered 5 min after GHB (1500 mg/kg i.v.) administration. Plasma and urine were collected up to 8 h post-dose, and GHB concentrations were quantified via a validated LC/MS/MS assay. Sleep time (sedative/hypnotic effect) was utilized as the toxicodynamic endpoint. Testosterone treatment significantly affected GHB toxicokinetics and toxicodynamics. Testosterone-treated CST rats exhibited significantly lower renal clearance, higher AUC, and increased sedative effect, while testosterone-treated OVX rats demonstrated higher metabolic clearance. AR-C 155858 treatment led to an increase in GHB renal and total clearance together with an improvement in sedative/hypnotic effect. In conclusion, exogenous testosterone treatment induces significant alterations in GHB toxicokinetics and toxicodynamics, and MCT inhibition can serve as a potential therapeutic strategy for GHB overdose in both cisgender and transgender male populations.

Aromas: Lovely to Smell and Nice Solvents for Polyphenols? Curcumin Solubilisation Power of Fragrances and Flavours

Natural aromas like cinnamaldehyde are suitable solvents to extract curcuminoids, the active ingredients found in the rhizomes of Curcuma longa L. In a pursuit to find other nature-based solvents, capable of solving curcumin, forty fragrances and flavours were investigated in terms of their solubilisation power. Aroma compounds were selected according to their molecular structure and functional groups. Their capabilities of solving curcumin were examined by UV-Vis spectroscopy and COSMO-RS calculations. The trends of these calculations were in accordance with the experimental solubilisation trend of the solubility screening and a list with the respective curcumin concentrations is given; σ-profiles and Gibbs free energy were considered to further investigate the solubilisation process of curcumin, which was found to be based on hydrogen bonding. High curcumin solubility was achieved in the presence of solvent (mixtures) with high hydrogen-bond-acceptor and low hydrogen-bond-donor abilities, like γ- and δ-lactones. The special case of DMSO was also examined, as the highest curcumin solubility was observed with it. Possible specific interactions of selected aroma compounds (citral and δ-hexalactone) with curcumin were investigated via 1H NMR and NOESY experiments. The tested flavours and fragrances were evaluated regarding their potential as green alternative solvents.

Metagenomic Insights into the Taxonomic and Functional Features of Traditional Fermented Milk Products from Russia

Fermented milk products (FMPs) contain probiotics that are live bacteria considered to be beneficial to human health due to the production of various bioactive molecules. In this study, nine artisanal FMPs (kefir, ayran, khurunga, shubat, two cottage cheeses, bryndza, khuruud and suluguni-like cheese) from different regions of Russia were characterized using metagenomics. A metagenomic sequencing of ayran, khurunga, shubat, khuruud and suluguni-like cheese was performed for the first time. The taxonomic profiling of metagenomic reads revealed that Lactococcus species, such as Lc. lactis and Lc. cremoris prevailed in khuruud, bryndza, one sample of cottage cheese and khurunga. The latter one together with suluguni-like cheese microbiome was dominated by bacteria, affiliated to Lactobacillus helveticus (32-35%). In addition, a high proportion of sequences belonging to the genera Lactobacillus, Lactococcus and Streptococcus but not classified at the species level were found in the suluguni-like cheese. Lactobacillus delbrueckii, as well as Streptococcus thermophilus constituted the majority in another cottage cheese, kefir and ayran metagenomes. The microbiome of shubat, produced from camel's milk, was significantly distinctive, and Lentilactobacillus kefiri, Lactobacillus kefiranofaciens and Bifidobacterium mongoliense represented the dominant components (42, 7.4 and 5.6%, respectively). In total, 78 metagenome-assembled genomes with a completeness ≥ 50.2% and a contamination ≤ 8.5% were recovered: 61 genomes were assigned to the Enterococcaceae, Lactobacillaceae and Streptococcaceae families (the Lactobacillales order within Firmicutes), 4 to Bifidobacteriaceae (the Actinobacteriota phylum) and 2 to Acetobacteraceae (the Proteobacteria phylum). A metagenomic analysis revealed numerous genes, from 161 to 1301 in different products, encoding glycoside hydrolases and glycosyltransferases predicted to participate in lactose, alpha-glucans and peptidoglycan hydrolysis as well as exopolysaccharides synthesis. A large number of secondary metabolite biosynthetic gene clusters, such as lanthipeptides, unclassified bacteriocins, nonribosomal peptides and polyketide synthases were also detected. Finally, the genes involved in the synthesis of bioactive compounds like β-lactones, terpenes and furans, nontypical for fermented milk products, were also found. The metagenomes of kefir, ayran and shubat was shown to contain either no or a very low count of antibiotic resistance genes. Altogether, our results show that traditional indigenous fermented products are a promising source of novel probiotic bacteria with beneficial properties for medical and food industries.

Chemical features and biological effects of degradation products of biodegradable plastics in simulated small waterbody environment

A plethora of research has focused on the biosafety of biodegradable plastics (BPs), including their microplastic formation and additives leaching; however, relatively fewer studies have explored biodegradation products. This study aims to investigate the biological effects and chemical features of degradation products from three kinds of BPs, namely polyglycolic acid (PGA), poly (butylene adipate-co-terephthalate) (PBAT), and the blends of PGA/PBAT without the addition of additives, in a simulated small waterbody environment with extracted soil solution for three months. Results showed that exposure to the whole degradation remnants of three BPs had no lethal effects on zebrafish at the current BP environmental concentrations (from 0.24 to 12.72 mg plastic/L) in small waterbodies. However, from the calculated BPs environmental concentrations (from 0.57 to 43.82 mg plastic/L) in 2026, PGA and PGA/PBAT blends may cause adverse effects on the cardiovascular system such as heartbeat rate suppression in zebrafish embryos, and also lead to reduced body length and pericardial edema and spinal curvature in fish larvae. We further qualitatively analyzed the composition of degradation products, and quantitatively measured four dominant degradation monomers (glycolic acid (GA), adipic acid (A), 1,4-butanediol (B), and terephthalic acid (T)) in the degradation remnants. It was found that the observed toxicities were probably due to the presence of GA, A, and T monomers, and their concentrations can reach 0.776, 0.034, and 0.6 mg/L under the calculated future scenario, respectively. It is worth mentioning that either GA or T monomers at the above concentrations were found to cause suppressed heartbeat rate in zebrafish embryos. Collectively, though the degradation products of BPs are temporarily safe at current environmental concentrations, they may lead to non-negligible toxicity with increasing production and continual improper recycling and/or BP waste management.

GHB toxicokinetics and renal monocarboxylate transporter expression are influenced by the estrus cycle in rats

BACKGROUND

The illicit use and abuse of gamma-hydroxybutyric acid (GHB) occurs due to its sedative/hypnotic and euphoric effects. Currently, there are no clinically available therapies to treat GHB overdose, and care focuses on symptom treatment until the drug is eliminated from the body. Proton- and sodium-dependent monocarboxylate transporters (MCTs (SLC16A) and SMCTs (SLC5A)) transport and mediate the renal clearance and distribution of GHB. Previously, it has been shown that MCT expression is regulated by sex hormones in the liver, skeletal muscle and Sertoli cells. The focus of the current study is to evaluate GHB toxicokinetics and renal monocarboxylate transporter expression over the estrus cycle in females, and in the absence of male and female sex hormones.

METHODS

GHB toxicokinetics and renal transporter expression of MCT1, SMCT1 and CD147 were evaluated in females over the estrus cycle, and in ovariectomized (OVX) female, male and castrated (CST) male rats. GHB was administered iv bolus (600 and 1000 mg/kg) and plasma and urine samples were collected for six hours post-dose. GHB concentrations were quantified using a validated LC/MS/MS assay. Transporter mRNA and protein expression was quantified by qPCR and Western Blot.

RESULTS

GHB renal clearance and AUC varied between sexes and over the estrus cycle in females with higher renal clearance and a lower AUC in proestrus females as compared to males (intact and CST), and OVX females. We demonstrated that renal MCT1 membrane expression varies over the estrus cycle, with the lowest expression observed in proestrus females, which is consistent with the observed changes in GHB renal clearance.

CONCLUSIONS

Our results suggest that females may be less susceptible to GHB-induced toxicity due to decreased exposure resulting from increased renal clearance, as a result of decreased renal MCT1 expression.

Determinants of Admission to Critical Care Following Acute Recreational Drug Toxicity: A Euro-DEN Plus Study

This study aimed to characterize patients admitted to critical care following Emergency Department (ED) presentation with acute recreational drug toxicity and to identify determinants of admission to critical care. A retrospective multicenter matched case-control study was conducted by the European Drug Emergency Network Plus (Euro-DEN Plus) over the period 2014-2021. The cases were ED presentations with acute recreational drug toxicity admitted to critical care, the controls consisted of ED presentations with acute recreational drug toxicity medically discharged directly from the ED. The potential determinants of admission to critical care were assessed through multivariable conditional stepwise logistic regression analysis and multiple imputation was used to account for the missing data. From 2014 to 2021, 3448 Euro-DEN Plus presentations involved patients admitted to critical care (76.9% males; mean age 33.2 years; SD 10.9 years). Patient age ≥35 years (as compared to ≤18 years) was a determinant of admission to critical care following acute recreational drug toxicity (adjusted odds ratio, aOR, 1.51, 95% confidence interval, CI, 1.15-1.99), along with polydrug use (aOR 1.39, 95% CI 1.22-1.59), ethanol co-ingestion (aOR 1.44, 95% CI 1.26-1.64), and the use of gamma-hydroxybutyrate/gamma-butyrolactone (GHB/GBL, aOR 3.08, 95% CI 2.66-3.57). Conversely, lower odds of admission to critical care were associated with the use of cocaine (aOR 0.85, 95% CI 0.74-0.99), cannabis (aOR 0.44, 95% CI 0.37-0.52), heroin (aOR 0.80, 95% CI 0.69-0.93), and amphetamine (aOR 0.65, 95% CI 0.54-0.78), as was the arrival to the ED during the night (8 p.m.-8 a.m., aOR 0.88, 95% CI 0.79-0.98). These findings, which deserve confirmation and further investigation, could contribute to a more complete understanding of the decision-making process underlying the admission to critical care of patients with acute recreational drug toxicity.

Understandings, attitudes, practices and responses to GHB overdose among GHB consumers

BACKGROUND

Gamma-hydroxybutyrate (GHB) is used at disproportionately high rates within sexuality and gender diverse communities and carries a high risk of overdose. GHB overdose can result in death. Internationally, recent increases in GHB overdoses have been observed. Coronial reviews of GHB-related death highlight the pivotal roles that bystanders to GHB overdose play in preventing fatality. No research has examined, in detail, how bystanders respond to GHB overdose. This qualitative study was conducted among people who use GHB and explored how they responded upon witnessing a GHB overdose experienced by someone else.

METHODS

Interviews were conducted with 31 sexuality and gender diverse Australian residents reporting three or more occasions of GHB use in the previous 12 months. Participants were asked questions about witnessed GHB overdose, their actions and decision-making processes throughout overdose. Data were analysed thematically.

RESULTS

Participants described witnessing GHB overdose, commonly in private settings involving sexualized GHB use. Variable definitions of GHB overdose were reported, ranging from GHB-induced symptoms of distress to comatose intoxication. Drastic actions to keep someone alert and responsive post-GHB ingestion were reported; these included the administration of stimulant substances and citrus. Decisions to call or not call for emergency medical services (EMS) were influenced by many circumstantial variables. In most instances, an EMS call was resisted and response practices deviated from established first aid protocols.

CONCLUSIONS

GHB overdose prevention and response training programs targeting people who use GHB are urgently required. These education interventions ought to address inaccuracies that inform street remedies for GHB overdose, teach people how to safely check breathing and response, promote basic first aid principles and address barriers to contacting EMS.

Characteristics of analytically confirmed gamma-hydroxybutyrate (GHB) positive patients in the emergency department: presentation, poly-drug use, disposition and impact on intensive care resource utilisation

BACKGROUND

Gamma-hydroxybutyrate is a potent central nervous system depressant with a narrow recreational dose window and analytical detection time. We describe data relating to intoxicated patients presenting to emergency departments across metropolitan Adelaide who tested positive for gamma-hydroxybutyrate. This work was part of the Emergency Department Admission Blood Psychoactive Testing study.

METHODS

Over a 15-month period, patients presenting to four metropolitan emergency departments with symptoms of drug intoxication were enrolled in the study. The methodology involved the collection of demographic and clinical data and a de-identified blood sample which underwent comprehensive toxicological analysis. Gamma-hydroxybutyrate was determined using an acid-catalysed cyclisation followed by liquid-liquid extraction and gas chromatography-mass spectrometry. Data relating to samples positive for gamma-hydroxybutyrate were examined.

RESULTS AND DISCUSSION

A total of 1120 patients were enrolled between March 2019 and May 2020, 309 of whom were positive for gamma-hydroxybutyrate (27.6%). Of these, 256 (83%) were also positive for metamfetamine (methamphetamine). The most common clinical observation in gamma-hydroxybutyrate-positive patients was central nervous system depression (89%). There was a significant relationship between gamma-hydroxybutyrate status and sex; although males outnumbered females in absolute terms, a higher proportion of females (32%) tested positive for gamma-hydroxybutyrate than males (25%, P = 0.0155). Blood gamma-hydroxybutyrate concentrations ranged from 10 to 651 mg/L (0.096-6.2 mmol/L) and increasing gamma-hydroxybutyrate concentration correlated with severe toxicity. The presence of gamma-hydroxybutyrate had a significant impact on the patient discharge destination: the majority (69.2%) of gamma-hydroxybutyrate-positive patients were managed and discharged from the emergency department or their attached short stay wards. A significantly higher proportion of gamma-hydroxybutyrate-positive patients were admitted to the intensive care unit (28.2%) compared with gamma-hydroxybutyrate-negative patients (12.7%, chi-squared = 36.85, P <0 .001). Gamma-hydroxybutyrate positive cases accounted for 45.8% of all study-related intensive care unit admissions.

CONCLUSIONS

Gamma-hydroxybutyrate is commonly detected in illicit drug-related emergency department presentations and is detected disproportionately in the patient cohort who require intensive care unit level care.

Environmental and health risks of perovskite solar modules: Case for better test standards and risk mitigation solutions

Perovskite solar cells (PSCs) promise high efficiencies and low manufacturing costs. Most formulations, however, contain lead, which raises health and environmental concerns. In this review, we use a risk assessment approach to identify and evaluate the technology risks to the environment and human health. We analyze the risks by following the technology from production to transportation to installation to disposal and examine existing environmental and safety regulations in each context. We review published data from leaching and air emissions testing and highlight gaps in current knowledge and a need for more standardization. Methods to avoid lead release through introduction of absorbing materials or use of alternative PSC formulations are reviewed. We conclude with the recommendation to develop recycling programs for PSCs and further standardized testing to understand risks related to leaching and fires.

Inpatient GHB withdrawal management in an inner-city hospital in Sydney, Australia: a retrospective medical record review

RATIONALE

Regular consumption of gamma-hydroxybutyrate (GHB) may result in a dependence syndrome that can lead to withdrawal symptoms. There are limited data on medications to manage GHB withdrawal.

OBJECTIVES

To examine characteristics associated with delirium and discharge against medical advice (DAMA), in the context of implementing a GHB withdrawal management protocol at an inner-city hospital in 2020.

METHODS

We retrospectively reviewed records (01 January 2017-31 March 2021), and included admissions that were ≥ 18 years of age, admitted for GHB withdrawal, and with documented recent GHB use. Admissions were assessed for demographics, medications administered, features of delirium, ICU admission, and DAMA. Exploratory analyses were conducted to examine factors associated (p < 0.2) with features of delirium and DAMA.

RESULTS

We identified 135 admissions amongst 91 patients. Medications administered included diazepam (133 admissions, 98.5%), antipsychotics (olanzapine [70 admissions, 51.9%]), baclofen (114 admissions, 84%), and phenobarbital (8 admissions, 5.9%). Features of delirium were diagnosed in 21 (16%) admissions. Delirium was associated with higher daily GHB consumption prior to admission, while duration of GHB use, time from presentation to first dose of diazepam, and concomitant methamphetamine use were inversely associated with delirium. DAMA occurred amongst 41 (30%) admissions, and was associated with a longer time from presentation to first dose of baclofen, while being female and receiving a loading dose of diazepam were inversely associated.

CONCLUSIONS

This study adds to the literature in support of the safety and feasibility of diazepam and baclofen for the management of GHB withdrawal. Prospective, randomised trials are required.

Phenobarbital to manage severe gamma-hydroxybutyrate withdrawal: A case series

INTRODUCTION

Management of a withdrawal syndrome following cessation of regular gamma-hydroxybutyrate (GHB) use, and its precursors, can represent a clinical challenge due to rapid onset delirium and/or seizures. Severe GHB withdrawal can be characterised by persistent or worsening features despite increasing benzodiazepine doses and regular baclofen. Barbiturates, such as phenobarbital, are an appealing option in this context due to their unique GABA-A receptor action.

CASE SERIES

This series describes the use of phenobarbital in 13 cases, 12 patients, across two hospitals in Sydney, Australia, with persistent or progressive GHB withdrawal despite benzodiazepine-based management. A median cumulative dose of oral diazepam prior to commencing phenobarbital was 120 mg (range 80-255 mg). The median time from the last GHB use to the first dose of phenobarbital was 24 h (range 7-57 h). Eight cases received phenobarbital orally on a general ward and 5 intravenously in intensive care units. An improvement in GHB withdrawal symptoms was observed after phenobarbital in all cases and there were no adverse events related to phenobarbital.

DISCUSSION AND CONCLUSION

This case series suggests that phenobarbital for the management of benzodiazepine-resistant GHB withdrawal can be safe, even in general inpatient settings, and may avert the progression of delirium. Most data on the management of GHB withdrawal comes from case reports or series, such as this one. This highlights the need for prospective trials to establish an evidence base for therapeutic approaches, including validated measures of withdrawal severity and more information relating to the safe and effective dosing of phenobarbital.

Off-label and investigational drugs in the treatment of alcohol use disorder: A critical review

Compounds known to be successful in the treatment of alcohol use disorder include the aversive agent, Disulfiram, the glutamatergic NMDA receptor antagonist, Acamprosate, and the opioid receptor antagonists, Naltrexone and Nalmefene. Although all four are effective in maintaining abstinence or reduction of alcohol consumption, only a small percentage of patients receive pharmacological treatment. In addition, many other medications have been investigated for their therapeutic potential in the treatment of alcohol use disorder. In this review we summarize and compare Baclofen, Gabapentin, Topiramate, Ondansetron, Varenicline, Aripiprazole, Quetiapine, Clozapine, Antidepressants, Lithium, Neuropeptide Y, Neuropeptide S, Corticotropin-releasing factor antagonists, Oxytocin, PF-05190457, Memantine, Ifenprodil, Samidorphan, Ondelopran, ABT-436, SSR149415, Mifepristone, Ibudilast, Citicoline, Rimonabant, Surinabant, AM4113 and Gamma-hydroxybutyrate While some have shown promising results in the treatment of alcohol use disorder, others have disappointed and should be excluded from further investigation. Here we discuss the most promising results and highlight medications that deserve further preclinical or clinical study. Effective, patient-tailored treatment will require greater understanding provided by many more preclinical and clinical studies.

Psychosocial aspects of sports medicine in pediatric athletes: Current concepts in the 21st century

Behavioral aspects of organized sports activity for pediatric athletes are considered in a world consumed with winning at all costs. In the first part of this treatise, we deal with a number of themes faced by our children in their sports play. These concepts include the lure of sports, sports attrition, the mental health of pediatric athletes (i.e., effects of stress, anxiety, depression, suicide in athletes, ADHD and stimulants, coping with injuries, drug use, and eating disorders), violence in sports (i.e., concepts of the abused athlete including sexual abuse), dealing with supervisors (i.e., coaches, parents), peers, the talented athlete, early sports specialization and sports clubs. In the second part of this discussion, we cover ergolytic agents consumed by young athletes in attempts to win at all costs. Sports doping agents covered include anabolic steroids (anabolic-androgenic steroids or AAS), androstenedione, dehydroepiandrostenedione (DHEA), human growth hormone (hGH; also its human recombinant homologue: rhGH), clenbuterol, creatine, gamma hydroxybutyrate (GHB), amphetamines, caffeine and ephedrine. Also considered are blood doping that includes erythropoietin (EPO) and concepts of gene doping. In the last section of this discussion, we look at disabled pediatric athletes that include such concepts as athletes with spinal cord injuries (SCIs), myelomeningocele, cerebral palsy, wheelchair athletes, and amputee athletes; also covered are pediatric athletes with visual impairment, deafness, and those with intellectual disability including Down syndrome. In addition, concepts of autonomic dysreflexia, boosting and atlantoaxial instability are emphasized. We conclude that clinicians and society should protect our precious pediatric athletes who face many challenges in their involvement with organized sports in a world obsessed with winning. There is much we can do to help our young athletes find benefit from sports play while avoiding or blunting negative consequences of organized sport activities.

Repurposing of substances with lactone moiety for the treatment of γ-Hydroxybutyric acid and γ-Butyrolactone intoxication through modulating paraoxonase and PPARγ

GHB and GBL are highly accessible recreational drugs of abuse with a high risk of adverse effects and mortality while no specific antidotes exist. These components can also be found in the clinical setting, beverages, and cosmetic products, leading to unwanted exposures and further intoxications. As the structural analogue of GABA, GHB is suggested as the primary mediator of GHB/GBL effects. We further suggest that GBL might be as critical as GHB in this process, acting through PPARγ as its receptor. Moreover, PPARγ and PON (i.e., the GHB-GBL converting enzyme) can be targeted for GHB/GBL addiction and intoxication, leading to modulation of the GHB-GBL balance and blockage of their effects. We suggest that repurposing substances with lactone moiety such as bacterial lactones, sesquiterpene lactones, and statins might lead to potential therapeutic options as they occupy the active sites of PPARγ and PON and interfere with the GHB-GBL balance. In conclusion, this hypothesis improves the GHB/GBL mechanism of action, suggests potential therapeutic options, and highlights the necessity of classifying GBL as a controlled substance.

Treatment of Poorly Responsive Gamma-Hydroxybutyrate Withdrawal With Baclofen: A Case Report

Gamma-hydroxybutyrate (GHB) is a sedative often abused for its euphoric and relaxant effects. This case report looks to discuss a case of GHB intoxication in a 57-year-old gentleman, which resulted in an 11-day hospitalization due to withdrawal effects of his GHB dependence. His hospitalization and care primarily followed usual supportive care treatments; however, a novel use of baclofen to further expedite patient sedation reversal was done. This case report looks to explore the management of this patient's GHB toxicity and eventual resolution of symptoms using baclofen.

Toxicological Characterization of GHB as a Performance-Enhancing Drug

Performance-enhancing drugs (PEDs) are represented by several compounds used to ameliorate the image, the appearance, or an athletic or non-athletic performance. Gamma-hydroxybutyrate (GHB) is an endogenous molecule first used as anesthetic and then marketed as a nutritional supplement with a wide diffusion in the bodybuilding community. The aim of the present work is to provide a toxicological characterization of the use of GHB as a PED, including the scientific basis for its use, the patterns of use/abuse, and the health risks arising from its consumption in this peculiar recreative setting. A literature search was performed on multiple databases including experimental studies on humans and animals as well as epidemiological reports and forensic case reports/series. Experimental studies demonstrated that the use of GHB as a PED is motivated by the release of growth hormone and the induction of sleep. However, the panel of desired performance-related effects was much wider in real cases and epidemiological studies. Even though the use of GHB among bodybuilders has decreased, its use to enhance some kind of performance, particularly sexual ones or social-communicative ones, as well as means to increase mood and perceived energy, is still common.

Toward Eco-Friendly Dye-Sensitized Solar Cells (DSSCs): Natural Dyes and Aqueous Electrolytes

Due to their low cost, facile fabrication, and high-power conversion efficiency (PCE), dye-sensitized solar cells (DSSCs) have attracted much attention. Ruthenium (Ru) complex dyes and organic solvent-based electrolytes are typically used in high-efficiency DSSCs. However, Ru dyes are expensive and require a complex synthesis process. Organic solvents are toxic, environmentally hazardous, and explosive, and can cause leakage problems due to their low surface tension. This review summarizes and discusses previous works to replace them with natural dyes and water-based electrolytes to fabricate low-cost, safe, biocompatible, and environmentally friendly DSSCs. Although the performance of “eco-friendly DSSCs” remains less than 1%, continuous efforts to improve the PCE can accelerate the development of more practical devices, such as designing novel redox couples and photosensitizers, interfacial engineering of photoanodes and electrolytes, and biomimetic approaches inspired by natural systems.

Sedative-Hypnotic Agents That Impact Gamma-Aminobutyric Acid Receptors: Focus on Flunitrazepam, Gamma-Hydroxybutyric Acid, Phenibut, and Selank

There are many nonopioid central nervous system depressant substances that share a gamma-aminobutyric acid (GABA) receptor-related mechanism of action. These sedatives-hypnotics can be indicated to treat anxiety, seizures, depression, and insomnia but are also used as substances of abuse and used to facilitate sexual assault. Barbiturates, methaqualone, and glutethimide were among the first type A GABA receptor-mediated sedative-hypnotics. Their clinical use was limited for most indications by serious adverse events and strong abuse potential but continue to be used illicitly around the world. The benzodiazepines supplanted barbiturates for most indications because they were less likely to cause severe adverse events in monotherapy. Flunitrazepam is a newer benzodiazepine that is preferentially used recreationally and to facilitate sexual assault. Flunitrazepam has greater potency and higher affinity for the type A GABA receptor than most benzodiazepines. Gamma-hydroxybutyric acid is sought illicitly for its hypnotic, euphoric and anabolic effects as well as to facilitate sexual assault. When any of these GABAergic drugs are used in high doses or with other sedative hypnotic agents, respiratory depression, coma, and death have occurred. Chronic use of these GABAergic drugs can lead to significant withdrawal syndromes. Phenibut and selank are poorly studied Russian drugs with GABAergic mechanisms that are inexplicably sold to US consumers as dietary supplements. Poison control center calls regarding phenibut have increased substantially over the past 5 years. Desired euphoriant effects account for the recreational and illicit use of many GABA-modulating agents. However, illicit use can lead to significant toxicities related to abuse, dependence, and subsequent withdrawal syndromes. Significant evaluation of developing agents with GABA properties should be conducted to determine abuse potential before public access ensues.

Safety of withholding intubation in gamma-hydroxybutyrate- and gamma-butyrolactone-intoxicated coma patients in the emergency department

OBJECTIVE

The objective of this study was to determine if supportive care without endotracheal intubation in the emergency department (ED) was safe in the absence of complications in gamma-hydroxybutyrate (GHB)/gamma-butyrolactone (GBL) intoxicated patients with a decreased Glasgow Coma Scale (GCS) score.

METHODS

This was a retrospective chart review of patients presenting to a Dutch tertiary urban ED with a reduced level of consciousness related to alleged GHB/GBL intoxication between April 2011-December 2014. Primary endpoint was major adverse events, defined by: upper airway obstruction not resolved with mayo tube or nasopharyngeal airway, hypoxia not resolved with 15 l of oxygen delivered via non-rebreathing mask, bradypnea not resolved after stimulation, intubation, bradycardia not resolved after intravenous atropine bolus, hypotension for which inotropes were started.

RESULTS

Data of 209 patients were retrieved. Major adverse events were reported in five patients (2.4%; 95% CI: 0.8-5.5). Intubation with subsequent ICU admission was required for 1.4% of patients (95% CI: 0.3-4.1). The most frequently seen minor adverse events (N = 209) were: airway obstruction (22%), hypothermia (14.8%), hypoxia (12.9%), bradycardia (8.1%), hypotension (6.7%), bradypnea (5.7%), vomiting (5.3%). There were no deaths. None of the patients had signs of aspiration pneumonia or returned to our ED due to complications.

CONCLUSION

Our study suggests that conservative airway management for patients with a decreased GCS due to suspected GHB intoxication may be safe. Major adverse events were present in 2.4% of patients, only 1.4% of patients required intubation. All minor adverse events were managed effectively with conservative treatment.

GHB related acids are useful in routine casework of suspected GHB intoxication cases

GHB related acids (3,4-dihydroxy butyric acid, 2,4-dihydroxy butyric acid and glycolic acid) are produced through oxidative GHB metabolism. These analytes could be potential biomarkers to ensure the diagnosis of a GHB intoxication and even prolong the detection window. Within this study, forensic routine cases were measured to consider the potential of additional gas chromatographic mass spectrometric analysis on these acids. 17 GHB positive real cases (10 serum samples and 7 urine samples) and 40 cases with suspicion of drugging in DFC cases and negative GHB results (21 serum samples and 19 urine samples) were evaluated. Increased GHB related acid concentrations were detected in all serum and most urine samples positive on GHB. In some GHB negative cases, especially in serum samples, concentrations of GHB related acids gave hints that GHB actually was taken. We recommend to use the following cut-offs for a more reliable interpretation of potential GHB intoxication cases: 3,4-OH-BA:>3 mg/L in serum and>50 mg/L in urine; 2,4-OH-BA:>2 mg/L in serum and>25 mg/L in urine; GA:>5 mg/L in serum and>400 mg/L in urine.

Gamma-Butyrolactone Overdose Potentially Complicated by Co-Ingestion of Industrial Solvent N-Methyl-2-Pyrrolidone

Gamma-hydroxybutyrate (GHB) is misused as an intoxicant, either alone or concurrently with other substances. Because GHB is illegal, the precursor chemicals 1,4-butanediol and gamma-butyrolactone are also misused for the same effect, either through pre-ingestion alteration or endogenous metabolism to GHB. We describe a case of a 50-year-old man with a history of polysubstance misuse who experienced an overdose of GHB from gamma-butyrolactone ingestion. The patient also co-ingested a common industrial solvent, N-methyl-2-pyrrolidone (NMP). This co-ingested substance raised theoretical concern of metabolism to a GHB congener, underscoring that the emergence of new psychoactive substance use patterns requires ongoing vigilance and toxicologic confirmation.

Unity in diversity: A systematic review on the GHB using population

BACKGROUND

Over the past decades gamma-hydroxybutyrate (GHB) has emerged as a popular drug with high potential of (ab)use due to its euphoric and relaxing effects. An overview of different populations using GHB is urgently needed, since this would enable development of adequate prevention and treatment policies to diminish the risks associated with GHB use. We systematically reviewed literature on different GHB using populations, comparing demographic characteristics, GHB use patterns, psychosocial aspects and psychiatric comorbidity.

METHODS

We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using Rayyan software. Original studies published from January 1997 up to October 2019 on GHB use were included. Out of 80 full-text articles, 60 articles of 51 unique studies were included. Most studies included people using GHB 1) presenting at emergency departments (n = 22), 2) recruited from the general population (n = 11), or 3) presenting at addiction care (n = 8).

RESULTS

Three main sub-populations of people using GHB are described in the literature: people using GHB recreationally without adverse effects; people using GHB recreationally with adverse effects, and people with dependence on GHB. These groups show considerable overlap in gender, age range, and comorbid substance use, as well as amount of GHB use per occasion. Differences are related to frequency and function of GHB use, the number of comas experienced, as well as work status, and psychiatric comorbidity.

CONCLUSION

Policy interventions should aim at preventing the transition from recreational substance use to GHB use, as most users are experienced recreational substance users prior to starting GHB use. When people use GHB regularly, interventions should aim at reducing the level of GHB use and preventing GHB use-related harm. Longitudinal studies and population-based probability sampling are required for more insight in the dynamics of GHB use in different sub-populations, and the transition from one group to the other, ultimately leading to dependence on GHB.

Metabolic Alterations Associated with γ-Hydroxybutyric Acid and the Potential of Metabolites as Biomarkers of Its Exposure

γ-Hydroxybutyric acid (GHB) is an endogenous short chain fatty acid that acts as a neurotransmitter and neuromodulator in the mammalian brain. It has often been illegally abused or misused due to its strong anesthetic effect, particularly in drug-facilitated crimes worldwide. However, proving its ingestion is not straightforward because of the difficulty in distinguishing between endogenous and exogenous GHB, as well as its rapid metabolism. Metabolomics and metabolism studies have recently been used to identify potential biomarkers of GHB exposure. This mini-review provides an overview of GHB-associated metabolic alterations and explores the potential of metabolites for application as biomarkers of GHB exposure. For this, we discuss the biosynthesis and metabolism of GHB, analytical issues of GHB in biological samples, alterations in metabolic pathways, and changes in the levels of GHB conjugates in biological samples from animal and human studies. Metabolic alterations in organic acids, amino acids, and polyamines in urine enable discrimination between GHB-ingested animals or humans and controls. The potential of GHB conjugates has been investigated in a variety of clinical settings. Despite the recent growth in the application of metabolomics and metabolism studies associated with GHB exposure, it remains challenging to distinguish between endogenous and exogenous GHB. This review highlights the significance of further metabolomics and metabolism studies for the discovery of practical peripheral biomarkers of GHB exposure.

PBAT biodegradable mulch films: Study of ecotoxicological impacts using Allium cepa, Lactuca sativa and HepG2/C3A cell culture

Biodegradable mulch films are an alternative to polyethylene films used in agriculture for weed control, improving crop productivity. This change could minimize the residue production and costs related to the final disposal. Nevertheless, the environmental safety of these biodegradable products is scarcely investigated. In this work, samples of poly(butylene adipate-co-terephthalate)-PBAT mulch films, with and without UV stabilizer additives, were prepared. Aqueous extracts of soil samples, where mulch films were disposed, were investigated using bioassays with Lactuca sativa, Allium cepa, and cell culture HepG2/C3A. As PBAT is expected to suffer photodegradation and biodegradation, soil samples mixed with films before and after these processes were evaluated. Soil aqueous extracts promoted root grown (mainly hypocotyl) of L. sativa, probably due to presence of nutrients. So, to evaluate toxicity potential, in this case it was necessary to use aqueous extract prepared with soil instead of ultrapure water as the control. After doing this analysis it was observed that no adverse impacts due to PBAT films occurred. No chromosomal abnormalities were observed in A. cepa bioassay for any of tested samples. The absence of genotoxic potential was confirmed by comet assay and micronucleus test using human hepatocarcinoma cell line HepG2/C3A. These results showed that the soil did not induce damage to the tested organisms, before and after degradation of PBAT films.

Successful Management of Gamma-hydroxybutyrate (GHB) Withdrawal Using Baclofen as a Standalone Therapy: A Case Report

BACKGROUND

Gamma-hydroxybutyrate (GHB)-a GABA-B agonist-can lead to a use disorder, and a withdrawal syndrome similar to that of alcohol. At present, evidence is lacking for how to best manage GHB withdrawal, and often clinicians rely on alcohol withdrawal management approaches, using medications like benzodiazepines (BZD). However, BZD doses needed to control GHB withdrawal symptoms are typically much higher than those required for alcohol, posing significant safety risks. Novel approaches include the use of baclofen as an adjunct to BZD, allowing reductions in BZD requirements. While the use of baclofen as monotherapy may result in even greater risk reductions, research to support this approach is limited.

CASE

We present a case of a 26-year-old female with severe GHB use disorder and history of severe withdrawal symptoms, whose withdrawal was successfully, managed using baclofen alone.

CONCLUSION

In keeping with other case reports, baclofen appears to have potential to be used in the management of GHB withdrawal. Here, we presented a case of severe GHB withdrawal which was managed solely by baclofen. Clinical research is needed to evaluate baclofen's potential as a standalone treatment for GHB withdrawal.

Endogenous GHB in Segmented Hair Part I: Inter-individual Variation for Group Comparisons

While earlier studies have attempted to resolve the challenges encountered when interpreting gamma-hydroxybutyric acid (GHB) concentrations in hair (primarily due to its endogenous presence), few have had large sample sizes. The first objective of this study was to evaluate the inter-individual variation of endogenous GHB concentrations. The second objective, to be detailed in another report, was to assess intra-individual variation and the impact on exogenous GHB discrimination. Over 2,000 hair segments from 141 women and 73 men (all processed hair 3–12 cm long) were analyzed in this study. The raw calculated range of endogenous GHB concentrations was &lt;0.40–5.47 ng/mg with 97.5% of the segmental results calculated less than 2.00 ng/mg. Imputation, assuming a lognormal distribution, was applied to the data to include non-detect (ND) data (&lt;LOQ), which led to an estimated endogenous GHB range of 0.16–5.47 ng/mg. Kruskal–Wallis tests were employed on a segmental basis for group comparisons. This test was applied to the male and female segmental medians and subsequently indicated that these groups were different at the α = 0.05 level of significance. Additionally, female hair samples appeared to have a trend comprising higher endogenous GHB concentrations close to the scalp and a mean net decrease of ~0.2–0.3 ng/mg distally. Male hair samples displayed the opposite trend, with a mean net increase of ~0.5–0.6 ng/mg from the proximal to the distal end of the hair shaft. It was also concluded that differences exist between the median GHB concentrations of the ‘treated’ and ‘untreated’ hair in the female group at the α = 0.05 level of significance. Age groups and races were analyzed, but none of the observed differences in median concentration were significant at α = 0.05. This is the largest endogenous GHB hair population study to date and provides substantial new data on inter-individual variation and chronological trends of GHB concentrations in hair.

Poly(methyl methacrylate)-Assisted Exfoliation of Graphite and Its Use in Acrylonitrile-Butadiene-Styrene Composites

One of the applications of graphene in which its scalable production is of utmost importance is the development of polymer composites. Among the techniques used to produce graphene flakes, the liquid-phase exfoliation (LPE) of graphite stands out due to its versatility and scalability. However, solvents suitable for the LPE process are generally toxic and have a high boiling point, making the processing challenging. The use of low boiling point solvents could be convenient for the processing, due to the easiness of their removal. In this study, the use of poly(methyl methacrylate) (PMMA) as a stabilizing agent is proposed for the production of graphene flakes in a low boiling point solvent, that is, acetone. The graphene dispersions produced in the mixture acetone-PMMA have higher concentration, +175 %, and contain a higher percentage of few-layer graphene flakes (<5 layers), that is, +60 %, compared to the dispersions prepared in acetone. The as-produced graphene dispersions are used to develop graphene/acrylonitrile-butadiene-styrene composites. The mechanical properties of the pristine polymer are improved, that is, +22 % in the Young's modulus, by adding 0.01 wt. % of graphene flakes. Moreover, a decrease of ≈20 % in the oxygen permeability is obtained by using 0.1 wt. % of graphene flakes filler, compared to the unloaded matrix.

Designer drugs: mechanism of action and adverse effects

Psychoactive substances with chemical structures or pharmacological profiles that are similar to traditional drugs of abuse continue to emerge on the recreational drug market. Internet vendors may at least temporarily sell these so-called designer drugs without adhering to legal statutes or facing legal consequences. Overall, the mechanism of action and adverse effects of designer drugs are similar to traditional drugs of abuse. Stimulants, such as amphetamines and cathinones, primarily interact with monoamine transporters and mostly induce sympathomimetic adverse effects. Agonism at μ-opioid receptors and γ-aminobutyric acid-A (GABAA) or GABAB receptors mediates the pharmacological effects of sedatives, which may induce cardiorespiratory depression. Dissociative designer drugs primarily act as N-methyl-D-aspartate receptor antagonists and pose similar health risks as the medically approved dissociative anesthetic ketamine. The cannabinoid type 1 (CB1) receptor is thought to drive the psychoactive effects of synthetic cannabinoids, which are associated with a less desirable effect profile and more severe adverse effects compared with cannabis. Serotonergic 5-hydroxytryptamine-2A (5-HT2A) receptors mediate alterations of perception and cognition that are induced by serotonergic psychedelics. Because of their novelty, designer drugs may remain undetected by routine drug screening, thus hampering evaluations of adverse effects. Intoxication reports suggest that several designer drugs are used concurrently, posing a high risk for severe adverse effects and even death.

Gamma-hydroxybutyrate abuse: pharmacology and poisoning and withdrawal management

Gamma-hydroxybutyrate (GHB) is a central nervous system depressant primarily used as a recreational drug of abuse, but also for the treatment of narcolepsy with cataplexy in adult patients and as an adjuvant for control of alcohol withdrawal syndrome. The main aim of this review is to summarise updated knowledge about GHB pharmacokinetics and pharmacodynamics, acute poisoning, and clinical features of GHB withdrawal syndrome, its diagnosis and medical treatment. The most common clinical signs and symptoms of acute poisoning include sleepiness to deep coma, bradycardia, hypotension, and respiratory failure. Therapy is essentially supportive and based on continuous monitoring of vital signs. GHB withdrawal syndrome shares patterns with other withdrawal syndromes such as alcohol withdrawal and is sometimes difficult to distinguish, especially if toxicological tests are GHB-negative or cannot be performed. There are no official detoxification protocols for GHB withdrawal syndrome, but its therapy is based on benzodiazepine. When benzodiazepine alone is not effective, it can be combined with barbiturates or antipsychotics. Information about abuse and distribution of GHB and its precursors/analogues among the general population is still limited. Their prompt identification is therefore crucial in conventional and non-conventional biological matrices, the latter in particular, to clarify all the issues around this complex molecule.

Characteristics and circumstances of death related to gamma hydroxybutyrate (GHB)

Introduction: Gamma hydroxybutyrate (GHB) has gained substantial popularity as an illicit recreational drug. The current study aimed to: (1) determine the characteristics and circumstances of death of all recorded cases of GHB-related death in Australia, 2001-2019; (2) determine the toxicology of cases; and (3) determine major organ pathology.Methods: Retrospective study of all Australian cases in which GHB was a mechanism contributory to death retrieved from the National Coronial Information System (n = 74). Information was collected on cause of death, demographics, circumstances of death, toxicology and major organ pathology.Results: The mean age was 31.5 years and 70.3% were male. The predominant circumstance of death was accidental drug toxicity (79.7%), including five cases attributed to a combination of toxicity and natural disease. Other deaths were due to trauma (12.2%) and suicide (8.2%). The fatal incident overwhelmingly occurred in a home environment (82.4%). In all cases, GHB was consumed orally. The median GHB blood concentration was 210 mg/L (range 13-1350 mg/L), and was significantly higher in toxicity cases than others (258 vs. 98 mg/L, p < .01). Other substances were present in 92.2%, most commonly psychostimulants (64.1%), hypnosedatives (28.2%) and alcohol (20.3%). Resuscitation was attempted in 20.3% of cases. Acute pneumonia (36.7%) and aspiration of vomitus (30.6%) were common.Conclusions: The typical case was a young male, who swallowed GHB and used it with other substances, most commonly at home. While acute drug toxicity was the most common cause of death, there was a substantial minority due to trauma or suicide.

An intoxication mimicking brain death: baclofen

Baclofen is a derivative of gamma-aminobutyric acid, used mainly for the treatment of muscle spasticity. Baclofen overdose can result in severe respiratory depression, autonomic disturbances, seizures and coma. Here we report a 15-year-old girl who was found unresponsive, intubated and admitted to the PICU. On initial presentation, her Glasgow Coma Score was 3, with fixed dilated pupils. EEG revealed cerebral bioelectric activity and ground amplitudes significantly lower than normal. Supportive treatments were administered. On the 2nd PICU day, she regained consciousness and was able to follow commands. She was extubated and discharged on hospital day 3. Conclusively emergency physicians should consider baclofen overdose in children presenting with acute loss of consciousness, flaccidity, and hyporeflexia.

Severe illicit gamma-hydroxybutyric acid withdrawal in a pregnant woman: what to do?

This case report presents the case of a 29 weeks pregnant woman in her late twenties who was seen at the emergency department of a hospital with a seizure of unknown cause. By anamnesis and hetero-anamnesis the use of illicit gamma-hydroxybutyric acid (GHB) was revealed. Examination showed dilated pupils, sweating, tremor, tachycardia and bradyphrenic thinking. Subsequently, the seizure was indicated as a severe illicit GHB withdrawal symptom. Thereafter, treatment had to be decided on in the absence of evidence-based and practiced-based guidelines and treatment options for this specific patient population. Initially diazepam was started, which was later on substituted by sodium oxybate. Despite the critical professional situation the patient gave birth to a healthy daughter after 37 weeks of pregnancy.

Room-temperature direct synthesis of semi-conductive PbS nanocrystal inks for optoelectronic applications

Lead sulphide (PbS) nanocrystals (NCs) are promising materials for low-cost, high-performance optoelectronic devices. So far, PbS NCs have to be first synthesized with long-alkyl chain organic surface ligands and then be ligand-exchanged with shorter ligands (two-steps) to enable charge transport. However, the initial synthesis of insulated PbS NCs show no necessity and the ligand-exchange process is tedious and extravagant. Herein, we have developed a direct one-step, scalable synthetic method for iodide capped PbS (PbS-I) NC inks. The estimated cost for PbS-I NC inks is decreased to less than 6 $·g⁻¹, compared with 16 $·g⁻¹ for conventional methods. Furthermore, based on these PbS-I NCs, photodetector devices show a high detectivity of 1.4 × 10¹¹Jones and solar cells show an air-stable power conversion efficiency (PCE) up to 10%. This scalable and low-cost direct preparation of high-quality PbS-I NC inks may pave a path for the future commercialization of NC based optoelectronics.

Providing large-scale iodide capped semi-conductive PbS nanocrystals inks preparation for high-throughput manufacturing remains a challenge. Here, the authors propose a direct one step and scalable synthesis method enabling cost reduction and promoting its commercial viability for solar cells.

Intensive sex partying with gamma-hydroxybutyrate: factors associated with using gamma-hydroxybutyrate for chemsex among Australian gay and bisexual men - results from the Flux Study

Background Gamma-hydroxybutyrate (GHB) use among gay and bisexual men (GBM) has increased in recent years. It is commonly cited as a sexual-enhancement drug. There is, however, little evidence for factors associated with GHB use or the consequences of its use among GBM.

AIM

Factors associated with GHB use, its relationship to sexual risk behaviour, and the contexts, consequences, and motivations for its use were examined.

METHODS

The Following Lives Undergoing Change (Flux) Study is an online prospective observational study of Australian GBM. At baseline, a total of 3190 GBM provided details about their use of GHB. Data on frequency, methods, pleasures and consequences of their drug use, alongside key demographic variables were collected.

RESULTS

Mean age was 35.0 years. One in five men (19.5%) had a history of GHB use and 5.4% reported use within the past 6 months, with 2.7% having used it monthly or more frequently. Overdose had been experienced by 14.7%, this was more common among men who used GHB at least monthly. Being HIV-positive, having more gay friends, greater social engagement with gay men who use drugs, a greater number of sexual partners, group sex, and condomless anal intercourse with casual partners were independently associated with GHB use in the past 6 months. Greater social engagement with gay men who use drugs and group sex were independently associated with at least monthly use. More frequent GHB use was independently associated with experiencing overdose among GHB users.

CONCLUSION

Most men used GHB infrequently and it was often used explicitly to enhance sexual experiences, often in the context of intensive sex partying. Men who used GHB frequently, were at greater risk of overdose and other negative health outcomes. GHB use should be considered alongside other drugs that have been implicated in sexual risk behaviour and HIV transmission. Harm-reduction interventions need to consider the particular impact of frequent GHB use.

DARK Classics in Chemical Neuroscience: Gamma-Hydroxybutyrate (GHB)

Gamma-hydroxybutyrate (GHB) is a naturally occurring short-chain fatty acid that rose to prominence as a popular club drug in the 1990s. Originally developed as an anesthetic in the early 1960s, it was later sold as an over-the-counter dietary supplement before becoming a rising substance of abuse in the following decades as one of the "date rape" drugs. Despite its abuse potential, there has been a recent surge in therapeutic interest in the drug due to its clinical viability in the treatment of narcolepsy and alcohol abuse/withdrawal. Its interactions with the GABAergic framework of higher mammals has made it the prototypical example for the study of the chief inhibitory mechanism in the human central nervous system. Though relatively obscure in terms of popular culture, it has a storied history with widespread usage in therapeutic, recreational ("Chemsex"), and some disturbingly nefarious contexts. This Review aims to capture its legacy through review of the history, synthesis, pharmacology, drug metabolism, and societal impact of this DARK classic in chemical neuroscience.