5-Year trends in use of hallucinogens and other adjunct drugs among UK dance drug users

Safety and effectiveness of NMDA receptor antagonists for depression: A multidisciplinary review

Ketamine, an anesthetic available since 1970, and esketamine, its newer S-enantiomer, provide a novel approach for the treatment of depression and other psychiatric disorders. At subanesthetic doses, the two drugs, along with their older congener, phencyclidine (PCP), induce a transient, altered mental state by blocking the N-methyl-D-aspartate (NMDA) receptor for glutamate, the primary excitatory neurotransmitter in the mammalian central nervous system. This multidisciplinary review examines the pharmacology/direct effects on consciousness, effectiveness in depression and acute suicidality, and safety of these fast-acting NMDA antagonists. To capture the essence of 60 years of peer-reviewed literature, we used a semi-structured approach to the subtopics, each of which required a different search strategy. We review the evidence for the three primary reported benefits of the two clinical drugs when used for depression: success in difficult-to-treat patients, rapid onset of action within a day, and immediate effects on suicidality. Key safety issues include the evidence-and lack thereof-for the effects of repeatedly inducing this altered mental state, and whether an adequate safety margin exists to rule out the neurotoxic effects seen in animal studies. This review includes evidence from multiple sources that raise substantial questions about both safety and effectiveness of ketamine and esketamine for psychiatric disorders.

Ketamine: from prescription anaesthetic to New Psychoactive Substance

Discovered in the United States of America (USA) in the 1960s, ketamine was introduced as an anaesthetic drug to specifically replace phencyclidine. Briefly, the substance moved from the medical world to recreational users, since it was discovered that intense psychedelic experiences were obtained with dosages lower than those prescribed for anesthesia. At the end of the 90's, circulated in London nightclubs as a drug itself and as counterfeit 3,4-methylenedioxymethamphetamine tablets. In 1997, the Drug Enforcement Administration (DEA) alerted the United States (US) government to the increasing diffusion of ketamine in American 'clubs', and in 1999, the substance was added to Schedule III of drugs controlled by federal authorities. In 2002, ketamine epidemics moved to Europe, and the European Monitoring Centre for Drugs and Drug Addiction carried out a risk assessment monitoring of the phenomenon. An estimated ninety-nine percent of all global ketamine seizures occurred in Asia. Its growing popularity is due to the fact that this new psychoactive substance is cheaper than other stimulants such as MDMA that the amount used for recreational purposes does not cause respiratory depression and its legal use as a drug makes it widely available for a diversion towards illicit markets. Nevertheless, acute intoxication and several deaths have been related to exclusive ketamine use both in Europe and internationally. Since 2015, there has been and increasing rise of the illicit ketamine market and currently the drug is being used with unprecedented peaks and a consequent significant increase in seizures and clinical cases worldwide.

Past-Year Ketamine Use: Evidence from a United States Population, 2015-2019

Ketamine is an analgesic that has gained notoriety in nightclub scenes. Yet, a paucity of research exists on the prevalence and associated factors in the United States (US). The present study estimated the prevalence of past-year ketamine use among a national sample of US adults and investigated sociodemographic characteristics and past-year use of other substances associated with past-year ketamine use. Data from the 2015-2019 National Survey on Drug Use and Health was conducted among 210,392 adults over the ages of 18 years old. An estimated 0.13% of adults used ketamine in the past year, with males more likely to use. Significant risk factors included past-year drug use and sexual minority status, with sexual minority males reporting more than use of one substance at highest risk for ketamine use. Findings from the present study may inform harm reduction efforts and policy initiatives.

Recreational ketamine-related deaths notified to the National Programme on Substance Abuse Deaths, England, 1997-2019

BACKGROUND

Ketamine is a phencyclidine derivative with dissociative anaesthetic properties. Increasing numbers of individuals in England take ketamine recreationally. Information on deaths arising from such use in England is presented.

METHODS

Cases were extracted on 31 January 2020 from the National Programme on Substance Abuse Deaths database, based on text searches of the cause of death, coroner's verdict and positive toxicology results for the terms 'ketamine' or 'norketamine'.

FINDINGS

During 1997-2005, there were <5 deaths p.a. in which ketamine was implicated. Numbers increased until 2009 (21), plateauing until 2016; thereafter, deaths have risen to about 30 p.a. Decedents' characteristics (N = 283): male 84.1%, mean age 31.2 (SD 10.0) years, employed 56.5%, drug use history 79.6% and living with others 60.3%. Ketamine was detected with other substances in most cases. Main (74.6%) underlying cause of death was accidental poisoning. Ketamine may have impaired judgement in other cases.

CONCLUSIONS

Although controlled, recreational ketamine use and related fatalities continue to increase. Consumers need to be more aware of the potentially fatal risks they face.

Investigation of the Structure-Activity Relationships of Psilocybin Analogues

The 5-HT_2A receptor is thought to be the primary target for psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) and other serotonergic hallucinogens (psychedelic drugs). Although a large amount of experimental work has been conducted to characterize the pharmacology of psilocybin and its dephosphorylated metabolite psilocin (4-hydroxy-N,N-dimethyltryptamine), there has been little systematic investigation of the structure-activity relationships (SAR) of 4-substituted tryptamine derivatives. In addition, structural analogs of psilocybin containing a 4-acetoxy group, such as 4-acetoxy-N,N-dimethyltryptamine (4-AcO-DMT), have appeared as new designer drugs, but almost nothing is known about their pharmacological effects. To address the gap of information, studies were conducted with 17 tryptamines containing a variety of symmetrical and asymmetrical N,N-dialkyl substituents and either a 4-hydroxy or 4-acetoxy group. Calcium mobilization assays were conducted to assess functional activity at human and mouse 5-HT₂ subtypes. Head-twitch response (HTR) studies were conducted in C57BL/6J mice to assess 5-HT_2A activation in vivo. All of the compounds acted as full or partial agonists at 5-HT₂ subtypes, displaying similar potencies at 5-HT_2A and 5-HT_2B receptors, but some tryptamines with bulkier N-alkyl groups had lower potency at 5-HT_2C receptors and higher 5-HT_2B receptor efficacy. In addition, O-acetylation reduced the in vitro 5-HT_2A potency of 4-hydroxy-N,N-dialkyltryptamines by about 10- to 20-fold but did not alter agonist efficacy. All of the compounds induce head twitches in mice, consistent with an LSD-like behavioral profile. In contrast to the functional data, acetylation of the 4-hydroxy group had little effect on HTR potency, suggesting that O-acetylated tryptamines may be deacetylated in vivo, acting as prodrugs. In summary, the tryptamine derivatives have psilocybin-like pharmacological properties, supporting their classification as psychedelic drugs.

Striatal and white matter volumes in chronic ketamine users with or without recent regular stimulant use

BACKGROUND

Previous studies found enlarged striatum and white matter in those with stimulants use disorders. Whether primarily ketamine users (Primarily-K) and ketamine users who co-used stimulants and other substances (K+PolyS) have abnormal brain volumes is unknown. This study aims to evaluate possible brain structural abnormalities, cognitive function and depressive symptoms, between Primarily-K and K+PolyS users.

METHODS

Striatal and white matter volumes were automatically segmented in 39 Primarily-K users, 41 K+PolyS users and 46 non-drug users (ND). Cognitive performance in 7 neurocognitive domains and depressive symptoms were also evaluated.

RESULTS

Ketamine users had larger caudates than ND-controls (Right: 1-way-ANCOVA-p=0.035; K+PolyS vs. ND, p=0.030; Linear trend for K+PolyS>Primarily-K>ND, p=0.011; Left: 1-way-ANCOVA-p=0.047, Primarily-K vs. ND p=0.051) and larger total white matter (1-way ANCOVA-p=0.009, Poly+K vs. Primarily-K, p=0.05; Poly+K vs. ND p=0.011; Linear trend for K+PolyS>Primarily-K >ND, p=0.004). Across all ketamine users, they performed poorer on Arithmetic, learning and memory tasks, and were more depressed than Non-users (p<0.001 to p=0.001). Greater lifetime ketamine usage correlated with more depressive symptoms (r=0.27, p=0.008). Larger white matter correlated with better learning across all participants (r=0.21, p=0.019), while larger right caudate correlated with lower depression scores in ketamine users (r=-0.28, p=0.013).

CONCLUSION

Ketamine users had larger caudates and total white matter than ND-controls. The even larger white matter in K+PolyS users suggests additive effects from co-use of ketamine and stimulants. However, across the ketamine users, since greater volumes were associated with better learning and less depressive symptom, the enlarged caudates and white matter might represent a compensatory response.

Exogenous GM1 Ganglioside Attenuates Ketamine-Induced Neurocognitive Impairment in the Developing Rat Brain

BACKGROUND

A prolonged exposure to ketamine triggers significant neurodegeneration and long-term neurocognitive deficits in the developing brain. Monosialotetrahexosylganglioside (GM1) can limit the neuronal damage from necrosis and apoptosis in neurodegenerative conditions. We aimed to assess whether GM1 can prevent ketamine-induced developmental neurotoxicity.

METHODS

Postnatal day 7 (P7) rat pups received 5 doses of intraperitoneal ketamine (20 mg/kg per dose) at 90-minute intervals for 6 hours. Cognitive functions, determined by using Morris water maze (MWM) including escape latency (at P32-36) and platform crossing (at P37), were compared among the ketamine-exposed pups treated with or without exogenous GM1 (30 mg/kg; n = 12/group). The effect of GM1 on apoptosis in hippocampus was determined by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) staining and activated caspase 3 measurement. The hippocampal expression of brain-derived neurotrophic factor (BDNF), along with the phosphorylation of protein kinase B (AKT) and extracellular signal-related kinases 1 and 2 (ERK1/2), was detected by western blotting (n = 6/group). Anti-BDNF antibody (2 μg per rat) administered before GM1 treatment was applied to determine the neuroprotective mechanisms of GM1.

RESULTS

The rats receiving ketamine exposure experinced cognitive impairment in MWM test compared to the control rats, indicated by prolonged escape latency at P34 (P = .006), P35 (P = .002), and P36 (P = .005). However, in GM1-pretreated rats, ketamine exposure did not induce prolonged escape latency. The exogenous GM1 increased the platform-crossing times at P37 (3.00 ± 2.22 times vs 5.40 ± 1.53 times, mean ± standard deviation; P = .041) and reduced the hippocampal TUNEL-positive cells and cleaved-caspase 3 expression in ketamine-exposed young rats. Ketamine decreased BDNF expression and phosphorylation of AKT and ERK in the hippocampus, whereas exogenous GM1 blocked these ketamine-caused effects. However, for the ketamine-exposed rat pups receiving exogenous GM1, compared to immunoglobulin Y (IgY) isotype control, the BDNF-neutralizing antibody treatment counteracted the exogenous GM1-induced improvement of the escape latency at P36 (41.32 ± 12.37 seconds vs 25.14 ± 8.97 seconds, mean ± standard deviation; P = .036), platform-crossing times at P37 (2.16 ± 1.12 times vs 3.92 ± 1.97 times, mean ± standard deviation; P < .036), apoptotic activity, as well as AKT and ERK1/2 phosphorylation in the hippocampus of ketamine-challenged young rats.

CONCLUSIONS

Our data suggest that the exogenous GM1 acts on BDNF signaling pathway to ameliorate the cognitive impairment and hippocampal apoptosis induced by ketamine in young rats. Our study may indicate a potential use of GM1 in preventing the cognitive deficits induced by ketamine in the young per se.

Ketamine as a rapid antidepressant: the debate and implications

Ketamine, a synthetic derivative of phencyclidine, is a commonly misused party drug that is restricted in high-income countries because of its addictive potential. Ketamine is also used as an anaesthetic in human and veterinary medicine. In the 1990s, research using ketamine to study the pathophysiology of schizophrenia was terminated owing to ethical concerns. Recently, controversy surrounding the drug has returned, as researchers have demonstrated that intravenous ketamine infusion has a rapid antidepressant effect and have therefore proposed ketamine as a novel antidepressant. This article debates the question of ketamine as an antidepressant, considering the drug's addictive potential, ethical concerns about prescribing a hallucinogen, the evidence base and motives behind ketamine trials.

Alcohol amplifies ketamine-induced apoptosis in primary cultured cortical neurons and PC12 cells through down-regulating CREB-related signaling pathways

Recreational use of ketamine (KET) has been increasing worldwide. Previous studies have demonstrated that KET induced neurotoxicity; however, few studies have examined how alcohol (ALC) affects KET-induced neurotoxicity. In light of the fact that some KET abusers combine KET with ALC, the present study was aimed to investigate the effects of ALC on KET-induced neurotoxicity and the underlying mechanism in vitro. Our data revealed that co-treatment with ALC and KET was more detrimental to cell viability than KET single treatment in both PC12 cells and primary cultured rat cortical neurons. Furthermore, ALC exacerbated KET-induced apoptosis characterized by morphological changes and the sub-G1 phase increase, which were mitigated by the pretreatment of CNQX, a known alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)/kainite (KA) receptor antagonist. In addition, ALC and KET co-treatment led to intracellular Ca²⁺ overload, down-regulation of p-Akt, p-CREB, PKA, CaMK-IV, Bcl-2 and BDNF expression and up-regulation of cleaved caspase-3 and Bax expression, which can be attenuated by CNQX pretreatment. These results indicate that the potentiation of ALC on KET-induced neurotoxicity was related to the down-regulation of CREB-related pathways. Our present study also indicates that ALC and KET co-abuse might cause serious neurotoxicity which should be conveyed to the public and drew enough attention.

Energy drink use frequency among an international sample of people who use drugs: Associations with other substance use and well-being

OBJECTIVE

The study aims were to identify: i.) energy drink (ED), caffeine tablet, and caffeine intranasal spray use amongst a sample who report drug use, and ii.) the association between ED use frequency and demographic profile, drug use, hazardous drinking, and wellbeing.

METHOD

Participants (n=74,864) who reported drug use completed the online 2014 Global Drug Survey. They provided data on demographics, ED use, and alcohol and drug use, completed the Alcohol Use Disorders Identification Test (AUDIT) and Personal Wellbeing Index (PWI), and reported whether they wished to reduce alcohol use.

RESULTS

Lifetime ED, caffeine tablet and intranasal caffeine spray use were reported by 69.2%, 24.5% and 4.9%. Median age of ED initiation was 16 years. For those aged 16-37, median years using EDs increased from 4 to 17 years of consumption, where it declined thereafter. Greater ED use frequency was associated with: being male; under 21 years of age; studying; and past year caffeine tablet/intranasal spray, tobacco, cannabis, amphetamine, MDMA, and cocaine use. Past year, infrequent (1-4days) and frequent (≥5days) past month ED consumers reported higher AUDIT scores and lower PWI scores than lifetime abstainers; past month consumers were less likely to report a desire to reduce alcohol use.

CONCLUSIONS

ED use is part of a complex interplay of drug use, alcohol problems, and poorer personal wellbeing, and ED use frequency may be a flag for current/future problems. Prospective research is required exploring where ED use fits within the trajectory of other alcohol and drug use.

Methamphetamine in the Czech Republic

The Czech Republic has a relatively long tradition in the addictive and problem use of methamphetamine, which is called “pervitin” locally. This paper attempts to provide as complex a picture of this phenomenon as possible by analyzing what is known about the Czech methamphetamine situation through scientific monitoring and research. It begins with a brief historical overview and then utilizes five key indicators (surveys, treatment demand, problem drug use estimates, blood borne diseases, and mortality) and some of the core indicators (namely, drug related crime, price and purity data, and estimates of market value) of drug epidemiology that were developed by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). By summarizing and carefully interpreting this data, the specifics of the Czech pervitin scene are described and future research directions are identified.

An intravenous self-administration procedure for assessing the reinforcing effects of hallucinogens in nonhuman primates

INTRODUCTION

Self-administration procedures are the gold standard for investigating the reinforcing effects of drugs. The notable exception to good correspondence between laboratory self-administration studies and human drug taking behavior has historically been the classic hallucinogens.

METHOD

The present study used a well-established daily access procedure, followed by a novel intermittent access procedure, to investigate the reinforcing effects of LSD in baboons.

RESULTS

Rates of self-injection in the daily access procedure were minimal. One baboon self-administered 0.001mg/kg and a second baboon self-administered 0.0032mg/kg above vehicle levels, though rates of self-injection were clearly low and neither of the two remaining baboons self-administered any LSD dose tested in the daily access procedure. Rates of self-injection using an intermittent access procedure with discriminative stimuli resulted in two doses of LSD being self-administered above vehicle levels in two of three baboons tested (0.01 and 0.032mg/kg in one baboon; 0.0032 and 0.01mg/kg in a second). In addition, the number of self-injections at these doses was higher (range=3-6 injections) in the intermittent access procedure than in the daily access procedure (range=1-2 injections).

DISCUSSION

The present study is the first to demonstrate LSD self-administration in a laboratory animal, and though the results are limited, they indicate intermittent access procedures with discriminative stimuli may provide a reliable and valid method for investigating the reinforcing effects of IV self-administered hallucinogens in laboratory animals. The usefulness of such procedures should be further evaluated in a larger number of subjects.

Up: The rise of nitrous oxide abuse. An international survey of contemporary nitrous oxide use

In recent years the recreational use of inhaled nitrous oxide gas (N2O) is becoming increasingly popular, yet little is known about the characteristics of its users or the effects they experience. This paper presents original research from the 2014 Global Drug Survey (GDS) (n=74,864). GDS runs the largest survey of recreational drug use in the world. The findings confirm N2O as a very common drug of use, in particular in the UK and US (38.6% and 29.4% lifetime prevalence). In the UK N2O was reported to be the eighth most commonly used substance. N2O was generally consumed via gas-filled balloons, at festivals and clubs where use of other substances was common. The vast majority of users use infrequently, and their use is not associated with significant harm. However, there appears to be a subpopulation of heavy users who may be using in a dependent pattern. Analysis of last year N2O users (n=4883), confirms that N2O is associated with hallucinations and confusion (which may be the desired effects) and persistent numbness and accidental injury (27.8%, 23.9%, 4.3% and 1.2% of last year users, respectively). Accidental injury is associated with the highest number of 'hits' per session, suggesting a dose-response relationship. The presence of significant harm is discussed in the light of public education on the risks of N2O use and harm-reduction strategies appropriate to N2O use. Further work needs to be completed to confirm the presence of persistent neurological symptoms in recreational users.

Ketamine users have high rates of psychosis and/or depression

Ketamine has been linked to psychosis and used in the treatment of depression. However, no study has examined the prevalence of psychotic and depressive disorders in dependent ketamine users. This study aimed to examine the frequency of various psychopathologies among a series of patients seeking treatment for ketamine use in Hong Kong, China. The case records of 129 patients with a history of ketamine use receiving treatment at three substance use clinics between January 2008 and August 2012 were retrieved for data collection. Patients' demographic data, patterns of substance misuse, and comorbid psychiatric diagnoses were recorded and entered into analyses. The mean age of onset and length of ketamine use were 17.7 ± 4.4 and 8.7 ± 5.7 years, respectively. All patients were dependent on ketamine at the time of data collection. Multiple substance misuse was common. Eighty-four of the 129 (65.1%) patients were found to have comorbid psychiatric disorders, most commonly substance-induced psychotic disorder (31.8%) followed by depressive disorder (27.9%). Psychosis and/or depression were common in ketamine-dependent patients referred to a psychiatric substance use clinic. The findings provide evidence of an association between chronic ketamine use and the presence of psychosis and/or depression. The results raise the issue of safety when using ketamine in the long-term treatment of depression.

Is off-label repeat prescription of ketamine as a rapid antidepressant safe? Controversies, ethical concerns, and legal implications

Background

Depressive disorders are a common form of psychiatric illness and cause significant disability. Regulation authorities, the medical profession and the public require high safety standards for antidepressants to protect vulnerable psychiatric patients. Ketamine is a dissociative anaesthetic and a derivative of a hallucinogen (phencyclidine). Its abuse is a major worldwide public health problem. Ketamine is a scheduled drug and its usage is restricted due to its abuse liability. Recent clinical trials have reported that ketamine use led to rapid antidepressant effects in patients suffering from treatment-resistant depression. However, various flaws in study designs, and possible biased reporting of results, may have influenced those findings. Further analyses of ketamine use are needed to ensure patient safety.

Discussion

The use of ketamine in research and treatment of depressive disorders is controversial. Recently, mental health professionals raised ethical concerns about an ongoing ketamine trial in the UK. Also, a Canadian agency reviewed the existing evidence and did not recommend prescribing ketamine to treat depressive disorders. Findings obtained from tightly controlled research settings cannot be easily translated to clinical practice as substance abuse is commonly comorbid with depressive disorders. An effective antidepressant should reduce severity of depressive symptoms without liability problems. Although the US FDA has not approved the use of ketamine to treat depressive disorders, some psychiatrists offer off-label repeat prescription of ketamine. Prescribing ketamine for treating depressive disorders requires substantial empirical evidence. Clinicians should also consider research findings on ketamine abuse. Depressive disorders can be chronic conditions and the current evidence does not rule out the risk of substance abuse after repeat prescription of ketamine. Off-label ketamine use in treating depressive disorders may breach ethical and moral standards, especially in countries seriously affected by ketamine abuse. This article presents two real-world clinical vignettes which highlight ethical principles and theories, including autonomy, nonmaleficience, fidelity and consequentialism, as related to off-label ketamine use.

Conclusion

We urge clinicians to minimise the risk of harming patients by considering the empirical evidence on ketamine properties and attempting all standard antidepressant therapies before considering the off-label use of ketamine.

Increasing use of 'party drugs' in people living with HIV on antiretrovirals: a concern for patient safety

Use of 'party drugs', a particular set of recreational drugs used in the context of 'ChemSex', is frequent among MSM living with HIV. A recently published observational study showed that more than half of HIV-infected MSM interviewed reported use of illicit substances in the previous 3 months, with frequent concomitant use of three or more drugs. These substances are a combination of 'club drugs' (methylenedioxymethamphetamine, gamma-hydroxybutyrate, ketamine, benzodiazepine) and drugs that are more specifically used in a sexualized context (methamphetamine, mephedrone, poppers and erectile dysfunction agents). Although formal data on pharmacokinetic or pharmacodynamic interactions between recreational drugs and antiretroviral agents are lacking, information regarding potentially toxic interactions can be theorized or sometimes conclusions may be drawn from case studies and cohort observational studies. However, the risk of coadministering party drugs and antiretrovirals should not be overestimated. The major risk for a drug-drug interaction is when using ritonavir-boosting or cobicistat-boosting agents, and maybe some nonnucleoside reverse transcriptase inhibitors. Knowledge of the metabolic pathways of 'party drugs' may help in advising patients on which illicit substances have a high potential for drug-drug interactions, as this is not the case for all.

Clinical Outcome of a Prospective Case Series of Patients With Ketamine Cystitis Who Underwent Standardized Treatment Protocol

OBJECTIVE

To assess the outcome of a prospective cohort of patients with ketamine-associated uropathy after standardized treatment.

METHODS

This is a prospective case series of patients with ketamine-related urologic problems. Management for the patients includes a 4-tier approach, namely anti-inflammatory or anti-cholinergic drugs, opioid analgesics or pregabalin, intravesical hyaluronic acid, and finally, surgical intervention including hydrodistension and augmentation cystoplasty. Outcome was assessed with functional bladder capacity, pelvic pain and urgency or frequency (PUF) symptom scale, and the EuroQol visual analog scale.

RESULTS

Between December 2011 and June 2014, 463 patients presented with ketamine-associated uropathy. All were managed by the same standardized protocol. Among these patients, 319 patients came back for follow-up assessment. Overall mean follow-up duration was 10.7 ± 8.5 months. For those patients who received first-line treatment (290 patients), there was a significant improvement in PUF scores, the EuroQol visual analog scale, and functional bladder capacity. Both abstinence from ketamine usage and the amount of ketamine consumed were factors predicting the improvement of PUF scores. For those patients who required second-line oral therapy (62 patients), 42 patients (67.7%) reported improvement in symptoms. Eight patients have completed intravesical therapy. There was a significant improvement in voided volume for the patients after treatment.

CONCLUSION

The study demonstrated the efficacy of managing ketamine-associated uropathy using a 4-tier approach. Both anti-inflammatory drugs and analgesics could effectively alleviate symptoms. Being abstinent from ketamine abuse and the amount of ketamine consumed have bearings on treatment response.

Ketamine as a novel treatment for major depressive disorder and bipolar depression: a systematic review and quantitative meta-analysis

OBJECTIVE

Given the significant disability, morbidity and mortality associated with depression, the promising recent trials of ketamine highlight a novel intervention. A meta-analysis was conducted to assess the efficacy of ketamine in comparison with placebo for the reduction of depressive symptoms in patients who meet criteria for a major depressive episode.

METHOD

Two electronic databases were searched in September 2013 for English-language studies that were randomized placebo-controlled trials of ketamine treatment for patients with major depressive disorder or bipolar depression and utilized a standardized rating scale. Studies including participants receiving electroconvulsive therapy and adolescent/child participants were excluded. Five studies were included in the quantitative meta-analysis.

RESULTS

The quantitative meta-analysis showed that ketamine significantly reduced depressive symptoms. The overall effect size at day 1 was large and statistically significant with an overall standardized mean difference of 1.01 (95% confidence interval 0.69-1.34) (P<.001), with the effects sustained at 7 days postinfusion. The heterogeneity of the studies was low and not statistically significant, and the funnel plot showed no publication bias.

CONCLUSIONS

The large and statistically significant effect of ketamine on depressive symptoms supports a promising, new and effective pharmacotherapy with rapid onset, high efficacy and good tolerability.

A brief history of the development of antidepressant drugs: from monoamines to glutamate

Major depressive disorder (MDD) is a chronic, recurring, and debilitating mental illness that is the most common mood disorder in the United States. It has been almost 50 years since the monoamine hypothesis of depression was articulated, and just over 50 years since the first pharmacological treatment for MDD was discovered. Several monoamine-based pharmacological drug classes have been developed and approved for the treatment of MDD; however, remission rates are low (often less than 60%) and there is a delayed onset before remission of depressive symptoms is achieved. As a result of a "proof-of-concept" study in 2000 with the noncompetitive NMDA antagonist ketamine, a number of studies have examined the glutamatergic systems as viable targets for the treatment of MDD. This review will provide a brief history on the development of clinically available antidepressant drugs, and then review the possible role of glutamatergic systems in the pathophysiology of MDD. Specifically, the glutamatergic review will focus on the N-methyl-D-aspartate (NMDA) receptor and the efficacy of drugs that target the NMDA receptor for the treatment of MDD. The noncompetitive NMDA receptor antagonist ketamine, which has consistently produced rapid and sustained antidepressant effects in MDD patients in a number of clinical studies, has shown the most promise as a novel glutamatergic-based treatment for MDD. However, compounds that target other glutamatergic mechanisms, such as GLYX-13 (a glycine-site partial agonist at NMDA receptors) appear promising in early clinical trials. Thus, the clinical findings to date are encouraging and support the continued search for and the development of novel compounds that target glutamatergic mechanisms.

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.

Comparison of antidepressant-like and abuse-related effects of phencyclidine in rats

Preclinical Research N-methyl-D-aspartate (NMDA) receptor antagonists, such as ketamine, have emerged as novel candidate treatments for major depressive disorder, but abuse potential of these agents is a concern. The NMDA antagonist phencyclidine has known abuse liability but undefined efficacy as an antidepressant. To further evaluate the relationship between antidepressant-like and abuse-related effects of NMDA antagonists, this study evaluated the effects of phencyclidine (1.0-10.0 mg/kg) in male Sprague-Dawley rats responding under two procedures that have been used to assess antidepressant-like effects (differential-reinforcement-of-low-rate [DRL] 72 s schedule of food reinforcement; n = 9) and abuse-related drug effects (intracranial self-stimulation [ICSS]; n = 6). Under the DRL 72 s schedule, phencyclidine (10.0 mg/kg) increased reinforcers and decreased responses without shifting the peak location of the interresponse time (IRT) distribution. Ketamine (10.0 mg/kg) also increased reinforcers and decreased responses, but unlike phencyclidine, it produced a rightward shift in the peak location of the IRT distribution. The 10.0 mg/kg phencyclidine dose that decreased DRL 72 s responding also decreased rates of ICSS for 50 min after its administration; however, abuse-related ICSS facilitation was observed at later times (100-300 min) or after a lower phencyclidine dose (3.2 mg/kg). These results suggest that phencyclidine produces weaker antidepressant-like effects, but stronger abuse-related effects than ketamine in these procedures.

Repeated ketamine administration alters N-methyl-D-aspartic acid receptor subunit gene expression: implication of genetic vulnerability for ketamine abuse and ketamine psychosis in humans

For more than 40 years following its approval by the Food and Drug Administration (FDA) as an anesthetic, ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, has been used as a tool of psychiatric research. As a psychedelic drug, ketamine induces psychotic symptoms, cognitive impairment, and mood elevation, which resemble some symptoms of schizophrenia. Recreational use of ketamine has been increasing in recent years. However, little is known of the underlying molecular mechanisms responsible for ketamine-associated psychosis. Recent animal studies have shown that repeated ketamine administration significantly increases NMDA receptor subunit gene expression, in particular subunit 1 (NR1 or GluN1) levels. This results in neurodegeneration, supporting a potential mechanism where up-regulation of NMDA receptors could produce cognitive deficits in chronic ketamine abuse patients. In other studies, NMDA receptor gene variants are associated with addictive behavior. Here, we focus on the roles of NMDA receptor gene subunits in ketamine abuse and ketamine psychosis and propose that full sequencing of NMDA receptor genes may help explain individual vulnerability to ketamine abuse and ketamine-associated psychosis.

The non-medical use of tramadol in the UK: findings from a large community sample

BACKGROUND

Prescription drug misuse has become a public health problem in several developed countries. In the UK, there has been no increase in people seeking treatment for prescription drug dependence, but there has been a progressive rise in fatal overdoses involving tramadol.

OBJECTIVES

To explore the source, motivations for use and patterns of use of tramadol in the UK.

METHODS

We conducted anonymous online survey of drug use and related behaviours as part of an ongoing drug trend monitoring initiative. We included questions assessing the patterns of use, source and function of tramadol.

RESULTS

UK Survey respondents (n = 7360) were predominantly young (mean age 29), and 90% reported being employed or studying. Less than 1% reported past-year use of heroin or methadone, but about 1/3 reported past-year use of cocaine. 326 (5% of respondents) reported having used tramadol in the preceding year, usually obtained by prescription but in 1/3 of cases from a friend; rarely from a dealer or from the internet. Most used the drug for pain relief, but 163 respondents (44%) reported using tramadol for reasons other than pain relief - particularly, using it to relax, to sleep, to get high or to relieve boredom. Nineteen per cent took doses higher than prescribed, and 10% reported difficulty discontinuing. Twenty-eight per cent combined tramadol with alcohol or other drugs to enhance its effect.

CONCLUSION

Misuse and sharing of tramadol, supplied by prescription, was common.

The NBOMe hallucinogenic drug series: Patterns of use, characteristics of users and self-reported effects in a large international sample

The NBOMe compounds are a novel series of hallucinogenic drugs that are potent agonists of the 5-HT2A receptor, have a short history of human consumption and are available to buy online, in most countries. In this study, we sought to investigate the patterns of use, characteristics of users and self-reported effects. A cross-sectional anonymous online survey exploring the patterns of drug use was conducted in 2012 (n = 22,289), including questions about the use of 25B-NBOMe, 25C-NBOMe, and 25I-NBOMe and comparison drugs. We found that 2.6% of respondents (n = 582) reported having ever tried one of the three NBOMe drugs and that at 2.0%, 25I-NBOMe was the most popular (n = 442). Almost all (93.5%) respondents whose last new drug tried was a NBOMe drug, tried it in 2012, and 81.2% of this group administered the drug orally or sublingually/buccally. Subjective effects were similar to comparison serotonergic hallucinogens, though higher 'negative effects while high' and greater 'value for money' were reported. The most common (41.7%) drug source was via a website. The NBOMe drugs have emerged recently, are frequently bought using the internet and have similar effects to other hallucinogenic drugs; however, they may pose larger risks, due to the limited knowledge about them, their relatively low price and availability via the internet.

Hallucinogen persisting perception disorder and the serotonergic system: a comprehensive review including new MDMA-related clinical cases

Hallucinogen persisting perception disorder (HPPD) is a drug-induced condition associated with inaccurate visual representations. Since the underlying mechanism(s) are largely unknown, this review aims to uncover aspects underlying its etiology. Available evidence on HPPD and drug-related altered visual processing was reviewed and the majority of HPPD cases were attributed to drugs with agonistic effects on serotonergic 5-HT₂A receptors. Moreover, we present 31 new HPPD cases that link HPPD to the use of ecstasy (MDMA), which is known to reverse serotonin reuptake and acts as agonist on 5-HT₂A receptors. The available evidence suggests that HPPD symptoms may be a result from a misbalance of inhibitory-excitatory activity in low-level visual processing and GABA-releasing inhibitory interneurons may be involved. However, high co-morbidities with anxiety, attention problems and derealization symptoms add complexity to the etiology of HPPD. Also, other perceptual disorders that show similarity to HPPD cannot be ruled out in presentations to clinical treatment. Taken together, evidence is still sparse, though low-level visual processing may play an important role. A novel finding of this review study, evidenced by our new cases, is that ecstasy (MDMA) use may also induce symptoms of HPPD.

Dissociable effects of the noncompetitive NMDA receptor antagonists ketamine and MK-801 on intracranial self-stimulation in rats

RATIONALE

The noncompetitive NMDA antagonist ketamine produces rapid antidepressant effects in treatment-resistant patients suffering from major depressive and bipolar disorders. However, abuse liability is a concern.

OBJECTIVES

This study examined abuse-related effects of ketamine using intracranial self-stimulation (ICSS) in rats. The higher-affinity NMDA antagonist MK-801 and the monoamine reuptake inhibitor cocaine were examined for comparison.

METHODS

Male Sprague Dawley rats were implanted with electrodes targeting the medial forebrain bundle and trained to respond to brain stimulation under a frequency-rate ICSS procedure. The first experiment compared the potency and time course of ketamine (3.2-10.0 mg/kg) and MK-801 (0.032-0.32 mg/kg). The second experiment examined effects of repeated dosing with ketamine (3.2-20.0 mg/kg/day) and acute cocaine (10.0 mg/kg).

RESULTS

Following acute administration, ketamine (3.2-10 mg/kg) produced only dose- and time-dependent depressions of ICSS and failed to produce an abuse-related facilitation of ICSS at any dose or pretreatment time. In contrast, MK-801 (0.032-0.32 mg/kg) produced a mixed profile of rate-increasing and rate-decreasing effects; ICSS facilitation was especially prominent at an intermediate dose of 0.18 mg/kg. Repeated dosing with ketamine produced dose-dependent tolerance to the rate-decreasing effects of ketamine (10.0 and 18.0 mg/kg) but failed to unmask expression of ICSS facilitation. Termination of ketamine treatment failed to produce withdrawal-associated decreases in ICSS. As reported previously, 10.0 mg/kg cocaine facilitated ICSS.

CONCLUSIONS

The dissociable effects of ketamine and MK-801 suggest differences in the pharmacology of these nominally similar NMDA antagonists. Failure of ketamine to facilitate ICSS contrasts with other evidence for the abuse liability of ketamine.

Use of Silk Road, the online drug marketplace, in the United Kingdom, Australia and the United States

AIMS

To investigate the prevalence of awareness of the online illicit drug marketplace Silk Road (SR), consumption of drugs purchased from SR and reasons for use and non-use of SR.

DESIGN AND SETTING

Global Drug Survey: purposive sample collected in late 2012.

PARTICIPANTS

The base sample (n = 9470) reported recent drug purchase and resided in the United Kingdom (n = 4315, median age 24, 76% male), Australia (n = 2761, median age 32, 76% male) or the United States (n = 2394, median age 21, 80% male).

MEASUREMENTS

Online questionnaire.

FINDINGS

A total of 65% of US, 53% of Australian and 40% of UK respondents had heard of SR; 18% of US, 10% of UK and 7% of Australian respondents had consumed drugs purchased through SR. Across the three countries, 3,4-methylenedioxy-N-methylamphetamine (MDMA) was the most commonly purchased drug (53-60%), followed by cannabis (34-51%), lysergic acid diethylamide (LSD) (29-45%) and the 2C family (16%-27%). The most common reasons for purchasing from SR were wider range (75-89%), better quality (72-77%), greater convenience (67-69%) and the use of vendor rating systems (60-65%). The most common reasons for avoiding SR purchase were adequate drug access (63-68%) and fear of being caught (41-53%). Logistic regressions found that, compared with people from the UK, Australians [odds ratio (OR) = 3.37; 95% confidence interval (CI) = 2.29, 4.97) and Americans (OR = 1.46; 95% CI = 1.10, 1.94) were more likely to use SR due to lower prices; and to avoid SR purchase due to fear of being caught (Australia: OR = 1.65; 95% CI = 1.39, 1.96; USA: OR = 1.62; 95% CI = 1.37, 1.92).

CONCLUSIONS

While reasons for Silk Road use accord with broader online commerce trends (range, quality, convenience, ratings), its appeal to drug purchasers is moderated by country-specific deterrents and market characteristics.

Ketamine cystitis: practical considerations in management

OBJECTIVE

The aim of this study was to investigate and report the clinical spectrum and practical problems in the management of a cohort of patients presenting with lower urinary tract symptoms (LUTS) related to abuse of ketamine.

MATERIAL AND METHODS

The clinical presentation, cystoscopic findings, radiological features and outcomes of patients presenting with LUTS related to ketamine abuse between January 2008 and April 2013 were retrospectively reviewed and analysed.

RESULTS

In total, 34 patients were seen during this period. All patients had LUTS, haematuria and abdominal pain to varying degrees. Two patients (7%) had a concomitant urinary tract infection. Upper tract imaging was carried out in 18 out of 34 patients and bilateral hydronephrosis was found in two cases (6%). Cystoscopy showed a small inflamed bladder (capacity 60-350 ml) in 14 out of the 16 cases where this was performed. Bladder biopsies showed denudation of urothelium and infiltration of submucosa with lymphocytes and eosinophils with no increase in mast cells. Fifty-nine per cent of patients did not attend their clinic, imaging and/or cystoscopy appointments. One patient underwent a subtotal cystectomy and bladder reconstruction.

CONCLUSIONS

Ketamine cystitis is a complex problem whose exact pathological mechanism and natural history remain unknown. The only known effective treatment is to abstain from the drug. Urologists need to recognize the condition early and work together with the local substance misuse service, focusing on drug cessation therapy to reduce complications.

Are sexes affected differently by ketamine? An exploratory study in ketamine users

One hundred primary ketamine users and 100 controls were recruited in Hong Kong between December 2009 and December 2011. Cognitive assessment included general intelligence, working, verbal, and visual memory, and executive functions. A Univariate General Linear Model was used to compare cognitive performance between the male and female ketamine users and controls. The female users appeared to have a higher risk of visual memory impairment than their male counterparts. Further studies are warranted to clarify the mechanism of the sex-specific effect of ketamine on cognitive functions.

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.

Dilated common bile duct and deranged liver function tests associated with ketamine use in two HIV-positive MSM

We report here the first two cases of hepatobiliary pathology in HIV-positive men following recreational use of ketamine: >1 g/day over a 12-month period while on ritonavir-based antiretroviral therapy. Presentation in each case was acute with nausea, vomiting and epigastric pain. Alanine aminotransferase was raised at 3.2× and 10.1 × upper limit of normal and alkaline phosphatase was raised at 1.7× and 2.5 × ULN for cases 1 and 2, respectively. Magnetic resonance cholangiopancreatography showed dilatation of the common bile duct; case 1, 18 mm and case 2, 14 mm with no ductal obstruction on endoscopic retrograde cholangiopancreatography. The symptoms resolved, common bile duct dilatation and liver function improved on discontinuation of ketamine use. Time to development of symptoms is shorter than reported in HIV-negative cases (12 months vs. 4 years) which may be explained by an interaction between ketamine and ritonavir.

Synthetic cannabis: a comparison of patterns of use and effect profile with natural cannabis in a large global sample

BACKGROUND

The last decade has seen the appearance of myriad novel psychoactive substances with diverse effect profiles. Synthetic cannabinoids are among the most recently identified but least researched of these substances.

METHODS

An anonymous online survey was conducted in 2011 using a quantitative structured research tool. Missing data (median 2%) were treated by available-case analysis.

RESULTS

Of 14,966 participants, 2513 (17%) reported use of synthetic cannabis. Of these, 980 (41% of 2417) reported its use in the last 12 months. Almost all recent synthetic cannabis users (99% of 975) reported ever use of natural cannabis. Synthetic cannabis reportedly had both a shorter duration of action (z=17.82, p<.001) and quicker time to peak onset of effect (z=-9.44, p<.001) than natural cannabis. Natural cannabis was preferred to synthetic cannabis by 93% of users, with natural cannabis rated as having greater pleasurable effects when high (t(930)=-37.1, p<.001, d=-1.22) and being more able to function after use (t(884)=-13.3, p<.001, d=-0.45). Synthetic cannabis was associated with more negative effects (t(859)=18.7, p<.001, d=0.64), hangover effects (t(854)=6.45, p<.001, d=0.22) and greater paranoia (t(889)=7.91, p<.001, d=0.27).

CONCLUSIONS

Users report a strong preference for natural over synthetic cannabis. The latter has a less desirable effect profile. Further research is required to determine longer term consequences of use and comparative dependence potential.

Effects of chronic ketamine use on frontal and medial temporal cognition

BACKGROUND

Recreational ketamine use has been on the rise worldwide. Previous studies have demonstrated that it disrupts various memory systems, but few studies have examined how it affects learning and frontal functioning. The present study investigates the effects of repeated ketamine self-administration on frontal fluency, attention, learning, and memory along the verbal/nonverbal axis.

METHODS

Twenty-five ketamine users and 30 healthy controls took a battery of neuropsychological tests. Frontal fluency was measured by the Verbal Fluency Test for semantic organization ability and the Figural Fluency Test for nonverbal executive functioning. Learning and memory were measured with the Chinese Auditory-Verbal Learning Test for acquisition and retention abilities of verbal information, as well as with the Continuous Visual Memory Test for nonverbal information. Participants also took several tests tapping subdomains of attention. To test for the potential effects of other drug use, 10 polydrug controls were included for comparison with the ketamine users and healthy controls.

RESULTS

Ketamine users had impaired verbal fluency, cognitive processing speed, and verbal learning. Verbal learning impairment was strongly correlated with estimated lifetime ketamine use. Ketamine users showed no impairments in figural fluency, sustained attention, selective attention, visual learning, or verbal/nonverbal memory. However, heavier lifetime ketamine use was significantly correlated with deficits in verbal memory (both immediate recall and delayed recall) and visual recognition memory. Deficits in cognitive processing speed and verbal learning persisted even after polydrug controls were included in the control group, but their inclusion did make the impairment in verbal fluency barely reach statistical significance.

CONCLUSIONS

This study suggests that repeated ketamine use causes differential impairment to multiple domains of frontal and medial temporal functioning, possibly specific to verbal information processing.

Psychological effects of ketamine: a research note

Purpose

Ketamine intoxication has been mooted as a model of some of the signs and symptoms of psychosis. However, little research has focused on the self‐report experience of ketamine users. The purpose of the current study is to quantify (the frequency of occurrence of) ketamine induced phenomenology in recreational users. The paper also seeks to meaningfully group these experiences into facets and their principal components.

Design/methodology/approach

Respondents completed a checklist of experiences, the Ketamine Experiences Questionnaire (KEQ). Two samples were recruited via opportunity and snowball sampling one in 2009 (n=52) and one in 2010/11 (n=35).

Findings

The “Q‐sort” and principal component analysis (PCA) indicate that there are two factors, factor one representing aversive ketamine experiences (accounting for 48.2 per cent of the variance) and factor two representing appetitive ketamine experiences (accounting for 20.1 per cent of the variance). Ketamine induces a raft of appetitive, aversive and transcendental experiences many of which are illustrated. The data suggest that a decision about whether to continue using ketamine (and if so, how often) depends in part on an intuitive cost‐benefit analysis of the phenomenology that it induces.

Research limitations/implications

There are some notable limitations to the current study; the small sample size to variable ratio necessitated a “Q‐sort” before PCA; the sampling procedure prohibited the generation of a representative sample; and there were no means of independently verifying ketamine use.

Originality/value

This study represents a novel exploration into ketamine phenomenology and the principal components of these experiences.

The prevalence and natural history of urinary symptoms among recreational ketamine users

Study Type--Symptom prevalence (prospective cohort) Level of Evidence 1b. What's known on the subject? and What does the study add? Case series have described lower urinary tract symptoms associated with ketamine use including severe pain, frequency, haematuria and dysuria. Little is known regarding the frequency of symptoms, relationship of symptoms with dose and frequency of use and natural history of symptoms once the ketamine user has stopped. This study describes the prevalence of ketamine use in a population of recreational drug users in a dance music setting. It shows a dose-frequency relationship with ketamine use. It shows that urinary symptoms associated with recreational ketamine use may lead to a considerable demand on health resources in the primary-, secondary- and emergency-care settings. It shows that symptoms may improve once ketamine use is decreased.

OBJECTIVE

• To investigate the prevalence and natural history of urinary symptoms in a cohort of recreational ketamine users.

PATIENTS AND METHODS

• A purposeful sampling technique was used. • Between November 2009 and January 2010 participants were invited to undertake an on-line questionnaire promoted by a national dance music magazine and website. • Data regarding demographics and illicit drug-use were collected. • Among respondents reporting recent ketamine use, additional information detailing their ketamine use, experience of urinary symptoms and use of related healthcare services was obtained.

RESULTS

• In all, 3806 surveys were completed, of which 1285 (33.8%) participants reported ketamine use within the last year. • Of the ketamine users, 17% were found to be dependent on the drug; 26.6% (340) of recent ketamine users reported experiencing urinary symptoms. • Urinary symptoms were significantly related to both dose of ketamine used and frequency of ketamine use. • Of 251 users reporting their experience of symptoms over time in relationship to their use of ketamine, 51% reported improvement in urinary symptoms upon cessation of use with only eight (3.8%) reporting deterioration after stopping use.

CONCLUSIONS

• Urinary tract symptoms are reported in over a quarter of regular ketamine users. • A dose and frequency response relationship has been shown between ketamine use and urinary symptoms. • Both users and primary-care providers need to be educated about urinary symptoms that may arise in ketamine users. A multi-disciplinary approach promoting harm reduction, cessation and early referral is needed to manage individuals with ketamine-associated urinary tract symptoms to avoid progression to severe and irreversible urological pathologies.

Ketamine use: a review

AIMS

Ketamine remains an important medicine in both specialist anaesthesia and aspects of pain management. At the same time, its use as a recreational drug has spread in many parts of the world during the past few years. There are now increasing concerns about the harmful physical and psychological consequences of repeated misuse of this drug. The aim of this review was to survey and integrate the research literature on physical, psychological and social harms of both acute and chronic ketamine use.

METHOD

The literature on ketamine was systematically searched and findings were classified into the matrix of Nutt et al.'s (2007) rational scale for assessing the harms of psychoactive substances.

RESULTS

A major physical harm is ketamine induced ulcerative cystitis which, although its aetiology is unclear, seems particularly associated with chronic, frequent use of the drug. Frequent, daily use is also associated with neurocognitive impairment and, most robustly, deficits in working and episodic memory. Recent studies suggest certain neurological abnormalities which may underpin these cognitive effects. Many frequent users are concerned about addiction and report trying but failing to stop using ketamine.

CONCLUSIONS

The implications of these findings are drawn out for treatment of ketamine-induced ulcerative cystitis in which interventions from urologists and from addiction specialists should be coordinated. Neurocognitive impairment in frequent users can impact negatively upon achievement in education and at work, and also compound addiction problems. Prevention and harm minimization campaigns are needed to alert young people to these harmful and potentially chronic effects of ketamine.

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.