The epidemiology of GHB and ketamine use in an Australian household survey

Prenatal ketamine exposure impairs prepulse inhibition via arginine vasopressin receptor 1A-mediated GABAergic neuronal dysfunction in the striatum

Ketamine is a widely used anesthetic with N-methyl-D-aspartate (NMDA) receptor antagonism. Exposure to ketamine and NMDA receptor antagonists may induce psychosis. However, the mechanism underlying the effects of ketamine on the immature brain remains unclear. In this study, NMDA receptor antagonists, ketamine and methoxetamine, were administered to pregnant F344 rats (E17). These regimens induce psychosis-like behaviors in the offspring, such as hyperlocomotion induced by MK-801, a non-competitive NMDA receptor antagonist. We also observed that prepulse inhibition (PPI) was significantly reduced. Interestingly, ketamine administration increased the arginine vasopressin receptor 1A (Avpr1a) expression levels in the striatum of offspring with abnormal behaviors. Methoxetamine, another NMDA receptor antagonist, also showed similar results. In addition, we demonstrated a viral vector-induced Avpr1a overexpression in the striatum-inhibited PPI. In the striatum of offspring, ketamine or methoxetamine treatment increased glutamate decarboxylase 67 (GAD67) and δ-aminobutyric acid (GABA) levels. These results show that prenatal NMDA receptor antagonist treatment induces GABAergic neuronal dysfunction and abnormalities in sensorimotor gating via regulating Avpr1a expression in the striatum.

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.

Variations in Sexual Behaviors by Use of Specific Substances Among Vancouver Gay, Bisexual, and Other Men Who Have Sex with Men: An Event-Level Analysis

Event-level studies measure substance use and sexual behaviors happening during a specific sexual encounter, ensuring that both variables are temporally paired. This study explored the event-level associations between a range of sexual behaviors (masturbation, anal sex, oral sex, rimming, fisting, sex toys, and group sex) and five sexualized substances (poppers, methamphetamine, GHB, ecstasy/MDMA, and ketamine) used during 11,582 sexual events reported by 762 gay, bisexual, and other men who have sex with men (GBMSM) in Vancouver, Canada. Data were obtained from a prospective cohort of GBMSM who self-reported their behaviors via computer-based questionnaires on their last sexual encounter with up to five of their most recent partners in the past six months. These clustered data were analyzed with multivariable generalized linear mixed models. Participants reported popper use in 16.1% of sexual encounters, methamphetamine in 8.6%, gamma-hydroxybutyrate (GHB) in 4.1%, ecstasy/3,4-methylenedioxymethamphetamine (MDMA) in 3.3%, and ketamine in 1.5%. Condomless receptive anal sex (25.0% of events) was associated with increased odds of using poppers, methamphetamine, GHB, and ecstasy/MDMA. Group sex (13.1% of events) and sharing sex toys (2.0% of events) were more likely with the use of all five substances. Receiving money/drugs/goods in exchange for sex (2.5% of events) was associated with increased odds of poppers, methamphetamine, GHB, and ecstasy/MDMA use. GBMSM living with HIV (29.9% of participants) had higher odds of using poppers, methamphetamine, and GHB, but lower odds of using ecstasy/MDMA. In conclusion, these event-level results suggest public health strategies are needed to address the possible negative impacts of sexualized substance use among GBMSM.

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.

Characteristics and circumstances of death related to the self-administration of ketamine

BACKGROUND AND AIMS

Ketamine is used for anaesthesia, sedation and the treatment of mood disorders, but is also widely used for non-medical purposes. This study aimed to: (1) determine the characteristics and circumstances of all recorded cases of self-administered ketamine-related death in Australia, 2000-19 and (2) determine the toxicology and major organ pathology of cases.

DESIGN

Retrospective study of all Australian cases in which self-administered ketamine was a mechanism contributory to death, retrieved from the National Coronial Information System.

SETTING

Australia-wide.

CASES

Sixty-eight cases, with a mean age of 35.2 years (standard deviation = 11.5, range = 16-63), 76.5% male.

MEASUREMENTS

Information was collected on cause of death, demographics, circumstances of death, toxicology and major organ pathology.

FINDINGS

Death was attributed to toxicity in 82.3% of cases (accidental, 58.8%; deliberate, 23.5%), suicide by violent means (8.8%) and traumatic accident (8.8%). In six cases the decedent had been prescribed ketamine. In 32.4% the final route of ketamine administration was by injection. The fatal incident predominantly occurred in a private environment (72.1%). Ketamine was present in the blood of 90.1% and other biomarkers in the remainder. The median blood ketamine concentration was 0.2 mg/l (0.02-6.9 mg/l). Other drugs were detected in 95.5% of cases: opioids (59.1%), hypnosedatives (57.6%), psychostimulants (50.0%), alcohol (27.3%), Δ-9-tetrahydrocannabinol (18.2%), antidepressants (28.8%) and antipsychotics (9.1%). Pulmonary oedema was present in 82.2% of cases that underwent autopsy and pneumonia in 26.7%.

CONCLUSIONS

The typical case of self-administered ketamine-related death in Australia, 2000-19, was a male in his mid-30s who had used multiple drugs, with the fatal incident most commonly occurring in a private setting. Death due to accidental drug toxicity was the most common manner of death, but suicide was highly prevalent.

Overlap in the neural circuitry and molecular mechanisms underlying ketamine abuse and its use as an antidepressant

Ketamine, a dissociative anesthetic and psychedelic compound, has revolutionized the field of psychopharmacology by showing robust, and rapid-acting antidepressant activity in patients suffering from major depressive disorder (MDD), suicidal tendencies, and treatment-resistant depression (TRD). Ketamine's efficacy, however, is transient, and patients must return to the clinic for repeated treatment as they experience relapse. This is cause for concern because ketamine is known for its abuse liability, and repeated exposure to drugs of abuse often leads to drug abuse/dependence. Though the mechanism(s) underlying its antidepressant activity is an area of current intense research, both clinical and preclinical evidence shows that ketamine's effects are mediated, at least in part, by molecular adaptations resulting in long-lasting synaptic changes in mesolimbic brain regions known to regulate natural and drug reward. This review outlines our limited knowledge of ketamine's neurobiological and biochemical underpinnings mediating its antidepressant effects and correlates them to its abuse potential. Depression and addiction share overlapping neural circuitry and molecular mechanisms, and though speculative, repeated use of ketamine for the treatment of depression could lead to the development of substance use disorder/addiction, and thus should be tempered with caution. There is much that remains to be known about the long-term effects of ketamine, and our lack of understanding of neurobiological mechanisms underlying its antidepressant effects is a clear limiting factor that needs to be addressed systematically before using repeated ketamine in the treatment of depressed patients.

Mini review: Ketamine and the urinary tract

The use of ketamine as a recreational drug has become increasingly widespread, particularly amongst teenagers and young men. Its side-effects on the central nervous system and cardiovascular are well established and documented, although it is now clear that ketamine also has significant toxic effects on the genitourinary system. Increasing numbers of patients are presenting to urologists and healthcare professionals with debilitating symptoms attributable to ketamine use, with many clinicians having very little experience of managing patients with this condition. This mini-review aims to provide a contemporary outline of the clinical aspects of ketamine-associated genitourinary toxicity and a summary of management options for treating patients with this often chronic and debilitating condition.

The association between alcohol abstinence, drinking or binge drinking and drug use: is alcohol abstinence that safe?

Purpose

The purpose of this paper is to investigate the association between alcohol abstinence and illicit drug use during early adulthood, and compares abstinence to moderate drinking and binge drinking, regrouped in different frequencies.

Design/methodology/approach

A total of 5,968 young male adults who completed the questionnaires were selected for the analyses. Alcohol abstinent participants were compared to moderate drinkers (who did not experience binge drinking during the previous 12 months), and casual, monthly, weekly and daily binge drinkers in terms of prevalence of drug use during early adulthood.

Findings

Alcohol abstinence was associated with higher risks of drug use than moderate drinking (odds ratio (OR)>3) for most of drugs, especially last-stage drugs: crystal meth, solvents, spice and heroin (6.50<OR<13.50). Such findings encourage rethinking prevention among alcohol abstainers who were so far considered at low risk of drug use.

Research limitations/implications

The main limitations of the study are the fact that it is cross-sectional, gender-blind and focussing on Swiss native who are less vulnerable than migrants.

Practical implications

High-risk subjects should be identified among young people who do not drink in order to develop specific preventive interventions.

Originality/value

This study is one of the first that compare alcohol abstinence, moderate drinking and binge drinking. Separate results covering 15 different drugs are presented.

A REVIEW OF KETAMINE ABUSE AND DIVERSION

Ketamine was discovered in the 1960s and released for public use in 1970. Originally developed as a safer alternative to phencyclidine, ketamine is primarily used in clinical settings for analgesia and sedation. In recent years, other uses have been developed, including pain management and treatment of asthma and depression. Clinical use of ketamine causes dissociation and emergence delirium. These effects have led to recreational abuse. Although death from direct pharmacologic effects appears rare, the disinhibition and altered sensory perceptions caused by ketamine puts users at risk of environmental harm. Ketamine has also been implicated in nonconsensual sexual intercourse. Data continue to build that chronic ketamine use may lead to morbidity. Impairment of memory and persistent dissociative, depressive, and delusional thinking has also been reported with long-term use. Lower urinary tract symptoms, including cystitis have been described. Gastric and hepatic pathology have also been noted, including abnormal liver function tests, choledochal cysts and dilations of the common bile duct. S-ketamine, an enantiomer in racemic ketamine, has been shown to be hepatotoxic in vitro. Abstinence from ketamine may reduce the adverse effects of chronic use and is considered the mainstay of treatment. Specialized urine drug testing may be required to detect use, as not all point of care urine drug screens include ketamine.

Prenatal ketamine exposure causes abnormal development of prefrontal cortex in rat

Ketamine is commonly used for anesthesia and as a recreational drug. In pregnant users, a potential neurotoxicity in offspring has been noted. Our previous work demonstrated that ketamine exposure of pregnant rats induces affective disorders and cognitive impairments in offspring. As the prefrontal cortex (PFC) is critically involved in emotional and cognitive processes, here we studied whether maternal ketamine exposure influences the development of the PFC in offspring. Pregnant rats on gestational day 14 were treated with ketamine at a sedative dose for 2 hrs, and pups were studied at postnatal day 0 (P0) or P30. We found that maternal ketamine exposure resulted in cell apoptosis and neuronal loss in fetal brain. Upon ketamine exposure in utero, PFC neurons at P30 showed more dendritic branching, while cultured neurons from P0 PFC extended shorter neurites than controls. In addition, maternal ketamine exposure postponed the switch of NR2B/2A expression, and perturbed pre- and postsynaptic protein expression in the PFC. These data suggest that prenatal ketamine exposure impairs neuronal development of the PFC, which may be associated with abnormal behavior in offsprings.

The behavioural profile of gamma-hydroxybutyrate, gamma-butyrolactone and 1,4-butanediol in humans

Gamma-hydroxybutyrate (GHB) is a putative neurotransmitter, a drug of abuse, and a medical treatment for narcolepsy and other neuropsychiatric disorders. Its precursors gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) are endogenously converted to GHB and thereby exert their psychobehavioural effects. In humans, GHB has a wide spectrum of properties ranging from stimulation and euphoria in lower doses, to sedation, deep sleep, and coma after ingestion of high doses. However, behavioural studies in healthy volunteers remain scarce and are usually limited to psychomotor performance testing. Most available data arise from either qualitative studies with illicit users or clinical trials examining therapeutic properties of GHB (then usually termed sodium oxybate). Here, we present an overview of the behavioural effects of GHB, GBL, and 1,4-BD in these three populations. GHB and its precursors strongly influence behaviours related to core human autonomic functions such as control of food intake, sexual behaviour, and sleep-wake regulation. These effects are instrumentalised by illicit users and clinically utilised in neuropsychiatric disorders such as narcolepsy, fibromyalgia, and binge-eating syndrome. Considering the industry withdrawal from psychopharmacology development, repurposing of drugs according to their behavioural and clinical profiles has gained increasing relevance. As such, GHB seems to be an attractive candidate as an experimental therapeutic in depression.

Mechanisms for the Specific Properties of γ-Hydroxybutyrate in Brain

γ-Hydroxybutyrate (GHB) is both a natural brain compound with neuromodulatory properties at central GABAergic synapses (micromolar concentration range) and also a drug (Xyrem(R) ) clinically used for the treatment of various neurological symptoms (millimolar dose range). However, this drug has abuse potential and can be addictive for some patients. Here, we review the basic mechanistic role of endogenous GHB in brain as well as the properties and mechanisms of action for therapeutic clinical doses of exogenous GHB. Several hypotheses are discussed with a preference for a molecular mechanism that conciliates most of the findings available. This conciliatory model may help for the design of GHB-like drugs active at lower doses and devoid of major side effects.

Steroid users and the unique challenge they pose to needle and syringe program workers

INTRODUCTION AND AIMS

Needle and syringe programs (NSP), which provide sterile injecting equipment, are a cornerstone of Australia's drug harm reduction strategy and assist in reducing the spread of blood-borne virus infections, such as HIV and hepatitis C, among people who inject drugs. Some reports suggest that steroid users are an increasing proportion of clientele at NSPs. In this research, we investigate the experience of NSP workers who come into contact with people who use steroids and other performance- and image-enhancing drugs (PIED).

DESIGN AND METHOD

Thirteen NSP workers were recruited using purposive sampling strategies. Participants were interviewed using a semi-structured interview guide. Interviews were recorded, transcribed and coded for themes.

RESULTS

There are three key findings of this study. Firstly, NSP workers do not feel well informed about the substances that PIED users are injecting. Secondly, they were unsure what equipment PIED users required. Thirdly, PIED users were perceived to differ from other client groups, and these differences impacted upon the level of rapport staff could build with this group.

DISCUSSION AND CONCLUSION

PIED users pose unique challenges for NSP workers compared with other NSP client groups. The PIEDs used and the way in which they are used are substantially different compared with other NSP clients, and there appears to be a lack of knowledge within the workforce about these substances. This study highlights the need to engage in workforce training, but also the need to more effectively engage with PIED users in relation to effective harm reduction strategies.

Effect of intubation for gamma-hydroxybutyric acid overdose on emergency department length of stay and hospital admission

OBJECTIVES

The objective was to examine the effect of endotracheal intubation on emergency department (ED) length of stay (LOS) and admission rates for patients with gamma-hydroxybutyrate (GHB) overdose.

METHODS

A 3-year retrospective electronic and paper audit of recreational drug presentations was carried out at two major inner-city EDs in Melbourne, Australia. Different GHB overdose management strategies exist at the respective audit sites, namely: 1) all patients with a Glasgow Coma Scale (GCS) score of 8 or less are intubated or 2) uncomplicated patients with GCS scores of 8 or less are managed without intubation (conservative management), unless further complications arise. This difference allows for comparison of the effects of intubation. All suspected GHB-related cases (defined as cases where GHB or its analogs gamma-butyrolactone or 1,4-butanediol were recorded) in which altered consciousness state was noted as a presenting symptom at triage were selected from all recreational drug-related presentations occurring between January 2008 and December 2010. The relationship between intubation and the primary outcome, ED LOS, was examined using robust regression after adjustment for potential confounders. The relationship between intubation and admission status (admission to hospital versus discharge) was also examined using logistic regression.

RESULTS

After adjustment for potential confounders such as GCS score, intubation of GHB-related cases in the ED was associated with an increase in mean LOS of 41% (95% confidence interval [CI] = 19% to 65%) and an increase in the odds of admission to hospital of 9.95 (95% CI = 2.36 to 41.88) at one hospital site, compared to conservative airway management.

CONCLUSIONS

Conservative airway management (no intubation) is associated with shorter ED LOS in cases of uncomplicated GHB-related coma in the ED and may also be associated with lower admission rates for these patients.

Self-reported prevalence of dependence of MDMA compared to cocaine, mephedrone and ketamine among a sample of recreational poly-drug users

BACKGROUND

Evidence regarding MDMA (ecstasy) dependence and the most suitable criteria for its assessment are controversial. This study aimed to assess the prevalence of last year symptoms of dependence upon MDMA compared to cocaine, mephedrone and ketamine among a large global non-treatment seeking sample.

METHODS

A cross-sectional anonymous online survey was promoted by a UK-based dance music website between 15 November 2010 and 1 January 2011. Endorsement of DSM-IV (Diagnostic and Statistical Manual of Mental Disorders) dependence criteria was sought from all last year users of MDMA, cocaine, mephedrone and ketamine. Reporting ≥3 dependence symptoms was indicative of dependence. Logistic regression models with Generalized Estimating Equations were used to compare dependence symptoms between groups.

RESULTS

MDMA users were more likely to report ≥3 DSM-IV dependence symptoms compared to users of cocaine (odds ratio OR 0.81, 95% confidence interval CI 0.71-0.93), mephedrone (OR 0.91, 95%CI 0.78-1.06) and ketamine (OR 0.52, 95%CI 0.44-0.62) (p<0.001). MDMA users were less likely to report desire to use less or get help compared to users of other substances (p<0.001). MDMA got the highest rating of pleasurable high (mean 8.2±1.7) and lowest rating for risk of harm (mean 2.7±2.4).

CONCLUSIONS

Our results highlight the self-reported dependence potential of MDMA but low desire to use less or get help. MDMA's pleasurable effects may compensate for drug-related problems and, therefore, DSM-IV criteria may not be suitable for assessing MDMA dependence. Further research is needed on the ability of DSM-V to assess MDMA dependence.

Cognitive impairments in poly-drug ketamine users

RATIONALE

Cognitive impairment has been found to be reversible in people with substance abuse, particularly those using ketamine. Ketamine users are often poly-substance users. This study compared the cognitive functions of current and former ketamine users who were also abusing other psychoactive substances with those of non-users of illicit drugs as controls.

METHODS

One hundred ketamine poly-drug users and 100 controls were recruited. Drug users were divided into current (n = 32) and ex-users (n = 64) according to the duration of abstinence from ketamine (>30 days). The Beck Depression Inventory (BDI), the Hospital Anxiety Depression Scale (HADSA) and the Severity of Dependence Scale (SDS) were used to evaluate depression and anxiety symptoms and the severity of drug use, respectively. The cognitive test battery comprised verbal memory (Wechsler Memory Scale III: Logic Memory and Word List), visual memory (Rey-Osterrieth Complex Figure, ROCF), executive function (Stroop, Wisconsin Card Sorting Test, and Modified Verbal Fluency Test), working memory (Digit Span Backward), and general intelligence (Information, Arithmetic and Digit-Symbol Coding) tests.

RESULTS

Current users had higher BDI and HADSA scores than ex-users (p < 0.001 for BDI and p = 0.022 for HADSA) and controls (p < 0.001 for BDI and p = 0.002 for HADSA). Ex-users had higher BDI (p = 0.006) but equal HADSA scores (p = 1.000) compared to controls. Both current and ex-users had lower scores on Logical Memory delayed recall (p = 0.038 for current users and p = 0.032 for ex-users) and ROCF delayed recall (p = 0.033 for current users and p = 0.014 for ex-users) than controls. Current users also performed worse on ROCF recognition than controls (p = 0.002). No difference was found between the cognitive functions of current and ex-users.

CONCLUSIONS

Ketamine poly-drug users displayed predominantly verbal and visual memory impairments, which persisted in ex-users. The interactive effect of ketamine and poly-drug use on memory needs further investigation.

Individual and peer factors associated with ketamine use among adolescents in Taiwan

The aim of this cross-sectional study was to examine the individual (demographic characteristics, substance-using behaviors, emotional status, and negative outcome expectancy) and peer factors associated with ketamine use in Taiwanese adolescents. A total of 9,860 adolescents completed the self-report questionnaires without omission. Demographic characteristics, substance-using behaviors, emotional status, negative outcome expectancy, and peer factors were compared between the ketamine users and non-users using the Mann-Whitney U test and the Chi-square test, and then significant factors were further selected for stepwise logistic regression analysis to examine the associated factors of ketamine use. Sixty-nine (0.7%) participants reported having used ketamine in the past year. The results of logistic regression analysis indicated that ketamine users were more likely to use marijuana, smoke cigarettes, have peers using illicit drugs, and have a lower level of negative outcome expectancy regarding using ketamine than ketamine non-users. The associated factors found in this study should be taken into consideration when developing prevention and intervention programs for ketamine use in adolescents.

Possible long-term effects of γ-hydroxybutyric acid (GHB) due to neurotoxicity and overdose

In several countries, including the Netherlands, the use of GHB seems to be rising. GHB is regarded by recreational users as an innocent drug without any side effects. Recently, the number of patients in treatment due to GHB addiction sharply increased. In addition, various studies report incidents following risky GHB use or GHB overdosing. Other sedative drugs, like ketamine and alcohol have been shown to result in unintended neurotoxic harm at the level of memory and cognitive function. As outlined in the present review, GHB and ketamine have a common mode of action, which suggests that GHB may also lead to similar neurotoxicity as ketamine. GHB overdosing, as well as binge drinking (and high ketamine doses), induce profound coma which is probably neurotoxic for the brain especially in the maturing brain of young adults. It is therefore advocated to investigate possible long-term neurotoxic effects in recreational GHB users e.g. by studying the residual effects on cognition and memory.

Illicit drug use in the flemish nightlife scene between 2003 and 2009

AIMS

Given the importance of party people as innovators and early adaptors in the diffusion of substance use, and given the lack of longitudinal scope in studies of the nightlife scene, we explored changes in illicit drug use among young people participating in the nightlife scene in Flanders.

METHODS

A survey among party people selected at dance events, rock festivals and clubs was held in the summer of 2003 and repeated in 2005, 2007 and 2009. In total, 2,812 respondents filled in a questionnaire on the use of cannabis, ecstasy, cocaine, amphetamines, GHB and ketamine.

RESULTS

The results of the multiple logistic regression analyses show that in the group of frequent pub visitors, the predicting probability of cannabis use increased over time, while the gap in drug use between dance music lovers and non-lovers of dance music narrowed. For cocaine use during the last year, an increase was found related to the housing situation (alone or with parents) of respondents. While the odds of using ecstasy decreased over the years, the odds of using GHB increased.

CONCLUSION

We can conclude that monitoring emerging trends, which can be quickly observed in the nightlife scene, provides meaningful information for anticipating possible trends.

Contextual profiles of young adult ecstasy users: A multisite study

These analyses assess contextual profiles of 612 young adult ecstasy users, 18-30 years of age, from St. Louis (USA), Miami (USA) and Sydney (Australia). Bivariate analyses revealed different contextual factors influencing ecstasy use. Friends were the most common sources of ecstasy at all sites and most used with friends. St. Louis and Miami use mostly occurred in residences, whereas in Sydney use was mostly at clubs, bars or restaurants. Ecstasy consumption at public places and in cars, trains or ferries was significantly higher in Miami (89% and 77%) than in St. Louis (67% and 65%) and Sydney (67% and 61%). At all sites, simultaneous use of LSD/mushroom and nitrous oxide with ecstasy was common; concurrent amphetamines predominated in Sydney and heroin/opiates in St. Louis Contextual factors influencing ecstasy use among young adults vary by geographic region. Their inclusion may help tailor effective prevention programs to reduce or ameliorate ecstasy use.

Ketamine self-administration in the rat: evidence for a critical role of setting

RATIONALE

The abuse of ketamine has been reported to be on the rise over the past 15 years, but its abuse appears to be limited almost exclusively to the context of music and dance settings, indicating a major role of context in modulating its reinforcing effects. We have previously reported that amphetamine, cocaine, and heroin self-administration (SA) in the rat are differentially influenced by the setting in which testing takes place. The aim of the present study is to extend this pre-clinical model to ketamine.

MATERIALS AND METHODS

Independent groups of rats with intravenous catheters were given the possibility to self-administer different doses of ketamine (125, 250, and 500 μg/kg per infusion) under two environmental conditions. Some animals were housed in the SA chambers (resident rats) whereas other rats were transported to the SA chambers only for the test sessions (non-resident rats). After training, within-subject dose effect curves (125, 250, 500, and 1,000 μg/kg per infusion) and break-point (during a progressive ratio session) were calculated.

RESULTS

Non-resident rats readily acquired ketamine self-administration. In contrast, resident rats self-administered only the highest dose of ketamine (500 μg/kg), but still four times less than non-resident rats (11.0 ± 6.0 vs 44.4 ± 5.2 infusions during the last training session). No significant differences in break-point were found during the progressive ratio session.

CONCLUSIONS

The present study confirms at a preclinical level the importance of setting for ketamine SA and further validates a previously described animal model of drug-environment interaction.

Reduced dorsal prefrontal gray matter after chronic ketamine use

BACKGROUND

Use of ketamine as a recreational drug is spreading rapidly among young people all over the world. Epidemiological studies have linked chronic ketamine use with a number of problems, including cognitive impairments, bladder dysfunction, and ketamine-related death. However, little is known about the long-term effects of ketamine use on brain structure and function.

METHODS

We used voxel based morphometry in conjunction with statistical parametric mapping on the structural magnetic resonance images of ketamine-dependent (n = 41) and drug-naive control individuals (n = 44) to assess differences in gray matter volume between the two groups.

RESULTS

We observed significant decreases in gray matter volume in bilateral frontal cortex (left superior frontal gyrus and right middle frontal gyrus) of ketamine users in comparison with control subjects (p < .05 corrected for multiple comparisons at cluster-level). Duration of ketamine use was negatively correlated with gray matter volume in bilateral frontal cortex, whereas the estimated total lifetime ketamine consumption was negatively correlated with gray matter volume in left superior frontal gyrus.

CONCLUSIONS

We have demonstrated a reduction in frontal gray matter volume in patients after chronic ketamine use. The link between frontal gray matter attenuation and the duration of ketamine use and cumulative doses of ketamine perhaps suggests a dose-dependent effect of long-term use of the drug. Our results have important connotations for the clinical picture that is likely to emerge with the growing recreational use of ketamine and is also relevant to the status of the drug as a model for schizophrenia.

Ketamine-induced vesicopathy: a literature review

Ketamine consumption in on the increase as a recreational abuse substance. It is reported to cause lower urinary tract symptoms (LUTS), and published accounts of its deleterious effects are increasing. We reviewed the available literature regarding the urological impact of ketamine abuse and its management. Twenty-two publications were found in total after a search of all databases including Pubmed, Medline and Google Scholar using the words 'ketamine', 'bladder' and 'cystitis' with no limits imposed. There are approximately 110 cases reported in the literature in the form of case series, case reports and letters. The effect of ketamine abuse on the bladder is universally similar; however, there is no uniform method adopted in reporting the symptoms, diagnosis and management. Very little is known regarding the pathogenesis of its effects on the urinary tract. Patients with severe irritative LUTS, a positive history of ketamine abuse and the absence of any other aetiology should be considered to have ketamine-induced vesicopathy. Effort must be made to elicit the history of drug abuse in those with no found cause of LUTS, especially in the young. Presently, ketamine cessation is the only effective treatment modality to prevent deterioration of the renal function and indeed offer the possibility of symptom resolution. Management akin to that formulated for interstitial cystitis patients would appear to offer the greatest opportunity for effective treatment.

Infant with in utero ketamine exposure: quantitative measurement of residual dosage in hair

BACKGROUND

The drug ketamine is frequently abused for recreational use in Asia, but few studies in humans have focused on the effects of ketamine exposure during pregnancy on the health of neonates. Here, we report a neonate whose mother was suspected of ketamine abuse during pregnancy. The case was confirmed by testing hair samples of the neonate.

METHODS

Hair samples of the neonate were taken on the first day of referral. Levels of common drugs of abuse in Asia were measured in the hair sample by gas chromatography-mass spectrometry using our previously reported method with modifications. This method was developed and validated to simultaneously quantify levels of amphetamine, ketamine and opiate in human hair.

RESULTS

The neonate was a female baby, born full term, with a low birth weight of 2250 g. Very high levels of ketamine were detected in the neonate's hair, even though the mother stated that she had stopped abusing ketamine during the early stage of pregnancy. The neonate suffered from general hypotonia; moderate cerebral dysfunction was found by electroencephalography. Fortunately, her hypotonia improved gradually within 21 days.

CONCLUSION

This is the first report of ketamine exposure during late pregnancy detected by hair testing. We noted several clinical features in this case, including the infant being small for gestational age, intrauterine growth retardation, remarkable hypotonia, and poor reflex responses. Although the mother denied the use of ketamine during the late stage of her pregnancy, significant amount of ketamine and norketamine was still found in hair samples (only 2 cm long and 25 mg) from the infant.

The Impact of Gamma Hydroxybutyrate (GHB) Legal Restrictions on Patterns of Use: Results from an International Survey

AIMS: To conduct an Internet-based survey of GHB use, identifying differences by respondent residence. METHODS: We recruited GHB-knowledgeable persons via "social networking Internet sites." Individuals (n=314) or groups (n=66) were approached based on GHB-use testimonials. DATA COLLECTED: location, use, reason for cessation (if applicable). FINDINGS: We recruited 155 GHB users. U.S. respondents (53 of 70; 76%) compared to non-U.S. respondents (38 of 85; 45%) were older and more highly educated (p<0.05) but manifest a 3-fold greater adjusted odds of GHB cessation (Odds Ratio [OR] 3.1; 95% CI 1.4-6.9; p < 0.05). Of the 80 respondents stating reason for cessation, 36 (45%) cited legal risk, price, or access; 44 (55%) cited health or related concerns. U.S. compared to non-U.S. respondents more frequently invoked legal and related concerns (OR 2.5; 95% CI 0.99-6.3; p=0.05). In a nested analysis, narrowly stated legal (n=4/5 U.S.) versus health (n=6/18 U.S.) reasons differed by location (p=0.048, one-tailed). CONCLUSIONS: In the U.S., where GHB has stricter legal penalties, GHB cessation is more likely, with legal and related reasons more commonly invoked for cessation. These findings support a link between declining U.S. GHB abuse and more stringent restrictions; although other un-assessed factors may also explain this association. The Impact of Gamma Hydroxybutyrate (GHB) Legal Restrictions on Patterns of Use: Results from an International Survey.

Comparing probability and non-probability sampling methods in Ecstasy research: implications for the internet as a research tool

The usage of Ecstasy and related drug (ERD) has increasingly been the focus of epidemiological and other public health-related research. One of the more promising methods is the use of the Internet as a recruitment and survey tool. However, there remain methodological concerns and questions about representativeness. Three samples of ERD users in Melbourne, Australia surveyed in 2004 are compared in terms of a number of key demographic and drug use variables. The Internet, face-to-face, and probability sampling methods appear to access similar but not identical groups of ERD users. Implications and limitations of the study are noted and future research is recommended.

A review of tolerability and abuse liability of gamma-hydroxybutyric acid for insomnia in patients with schizophrenia

BACKGROUND

Approved therapeutic uses for gamma-hydroxybutyric acid (GHB) (or sodium oxybate), a gamma-aminobutyric acid type B and GHB receptor agonist, include narcolepsy in the United States and Europe and alcohol abuse treatment in Italy. Possible efficacy of GHB in schizophrenia has also been proposed. A tolerability concern regarding use of GHB is its abuse potential. Given the high comorbidity of substance disorders and schizophrenia, a systematic assessment of the published literature is crucial.

OBJECTIVE

The aim of this review was to assess the tolerability and abuse liability of GHB in the context of future clinical studies as a potential treatment for insomnia in patients with schizophrenia.

METHODS

A literature search in English (inception through April 2009, inclusive) was conducted of MEDLINE, EMBASE, and PsycINFO using the search term GHB. All articles whose abstracts mentioned human use of GHB were read in their entirety. The reference sections of identified articles were reviewed for publications that might have been missed by the initial search.

RESULTS

GHB is abused by a small percentage of people (<1%) as a "club drug" and is commonly associated with enhanced sexual experiences (65%), euphoria (41%), somnolence (71%), and confusion (24%), according to a recent study. A review of all available emergency room case series suggests that while GHB can be associated with serious coma necessitating intubation, the number of reported fatal cases associated with GHB appears limited. Clarity on the lethality of GHB is complicated by instability of GHB in postmortem samples and frequent concomitant ingestions. Furthermore, formal abuse liability studies do not support high abuse propensity for GHB, mainly because oversedation and dizziness may lead most individuals to find GHB unpleasant at high doses. As supported by 2 large studies, there is limited evidence to suggest widespread use as an agent in sexual assault. Years of clinical use in narcolepsy do not support the development of tolerance or withdrawal in those subjects without substance dependence.

CONCLUSIONS

Tolerability and abuse liability issues, while a concern with GHB given its abuse potential, do not preclude further study of the potential use for insomnia in nondually diagnosed schizophrenia. Full cognizance must be taken of risk/benefit tradeoffs, and to the development of improved formulations with decreased abuse liability.

Illicit gamma-hydroxybutyrate (GHB) and pharmaceutical sodium oxybate (Xyrem): differences in characteristics and misuse

There are distinct differences in the accessibility, purity, dosing, and misuse associated with illicit gamma-hydroxybutyrate (GHB) compared to pharmaceutical sodium oxybate. Gamma-hydroxybutyrate sodium and sodium oxybate are the chemical and drug names, respectively, for the pharmaceutical product Xyrem (sodium oxybate) oral solution. However, the acronym GHB is also used to refer to illicit formulations that are used for non-medical purposes. This review highlights important differences between illicit GHB and sodium oxybate with regard to their relative abuse liability, which includes the likelihood and consequences of abuse. Data are summarized from the scientific literature; from national surveillance systems in the U.S., Europe, and Australia (for illicit GHB); and from clinical trials and post-marketing surveillance with sodium oxybate (Xyrem). In the U.S., the prevalence of illicit GHB use, abuse, intoxication, and overdose has declined from 2000, the year that GHB was scheduled, to the present and is lower than that of most other licit and illicit drugs. Abuse and misuse of the pharmaceutical product, sodium oxybate, has been rare over the 5 years since its introduction to the market, which is likely due in part to the risk management program associated with this product. Differences in the accessibility, purity, dosing, and misuse of illicit GHB and sodium oxybate suggest that risks associated with illicit GHB are greater than those associated with the pharmaceutical product sodium oxybate.

Sedative and hypothermic effects of gamma-hydroxybutyrate (GHB) in rats alone and in combination with other drugs: assessment using biotelemetry

The recreational drug gamma-hydroxybutyrate (GHB) has euphoric effects and can induce sedation and body temperature changes. GHB is frequently combined with other recreational drugs although these interactions are not well characterised. The present study used biotelemetry to provide a fine-grained analysis of the effects of GHB on body temperature and locomotor activity in freely moving rats, and investigated interactions between GHB and 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine (METH) and various antagonist drugs. GHB (1000mg/kg) caused profound sedation for more than 2h and a complex triphasic effect on body temperature: an initial hypothermia (5-40min), followed by hyperthermia (40-140min), followed again by hypothermia (140-360min). A lower GHB dose (500mg/kg) also caused sedation but only a hypothermic effect that lasted up to 6h. The dopamine D(1) receptor antagonist SCH 23390 (1mg/kg), the opioid antagonist naltrexone (1mg/kg), the benzodiazepine antagonist flumazenil (10mg/kg), and the 5-HT(2A/2C) receptor antagonist ritanserin (1mg/kg) did not prevent the overall sedative or body temperature effects of GHB (1000mg/kg). However the GABA(B) antagonist SCH 50911 (50mg/kg) prevented the hyperthermia induced by GHB (1000mg/kg). Repeated daily administration of GHB (1000mg/kg) produced tolerance to the sedative and hyperthermic effects of the drug and cross-tolerance to the sedative effects of the GABA(B) receptor agonist baclofen (10mg/kg). A high ambient temperature of 28 degrees C prevented the hypothermia obtained with GHB (500mg/kg) at 20 degrees C, while GHB (500mg/kg) reduced the hyperthermia and hyperactivity produced by co-administered doses of MDMA (5mg/kg) or METH (1mg/kg) at 28 degrees C. These results further confirm a role for GABA(B) receptors in the hypothermic and sedative effects of GHB and show an interaction between GHB and MDMA, and GHB and METH, that may be relevant to the experience of recreational users who mix these drugs.