Acute toxic effects of club drugs

Potential effect of ketamine in treatment for dextromethorphan use disorder exploding in Japanese young population

In Japan, the landscape of clinical practice for substance use disorder is changing significantly, primarily due to an increase in patients using over-the-counter drugs. A major concern is the rising number of patients misusing dextromethorphan (DXM). These patients with DXM use disorders often have severe trauma-related and mood symptoms, and therefore try to cope with those symptoms by self-medicating with DXM. In this article, we propose that ketamine, which has similar psychopharmacological effects to DXM, may be a useful alternative pharmacological treatment for these patients.

Narrative Review: Low-Dose Ketamine for Pain Management

Pain is the leading cause of medical consultations and occurs in 50-70% of emergency department visits. To date, several drugs have been used to manage pain. The clinical use of ketamine began in the 1960s and it immediately emerged as a manageable and safe drug for sedation and anesthesia. The analgesic properties of this drug were first reported shortly after its use; however, its psychomimetic effects have limited its use in emergency departments. Owing to the misuse and abuse of opioids in some countries worldwide, ketamine has become a versatile tool for sedation and analgesia. In this narrative review, ketamine's role as an analgesic is discussed, with both known and new applications in various contexts (acute, chronic, and neuropathic pain), along with its strengths and weaknesses, especially in terms of psychomimetic, cardiovascular, and hepatic effects. Moreover, new scientific evidence has been reviewed on the use of additional drugs with ketamine, such as magnesium infusion for improving analgesia and clonidine for treating psychomimetic symptoms. Finally, this narrative review was refined by the experience of the Pain Group of the Italian Society of Emergency Medicine (SIMEU) in treating acute and chronic pain with acute manifestations in Italian Emergency Departments.

ERAS Protocol Options for Perioperative Pain Management of Substance Use Disorder in the Ambulatory Surgical Setting

Even prior to the COVID-19 pandemic, rates of ambulatory surgeries and ambulatory patients presenting with substance use disorder were increasing, and the end of lockdown has further catalyzed the increasing rates of ambulatory patients presenting for surgery with substance use disorder (SUD). Certain subspecialty groups of ambulatory procedures have already established protocols to optimize early recovery after surgery (ERAS), and these groups have subsequently enjoyed improved efficiency and reduced adverse outcomes as a result. In this present investigation, we review the literature as it relates to substance use disorder patients, with a particular focus on pharmacokinetic and pharmacodynamic profiles, and their resulting impact on the acute- or chronic user ambulatory patient. The systematic literature review findings are organized and summarized. We conclude by identifying areas of opportunity for further study, specifically with the aim of developing a dedicated ERAS protocol for substance use disorder patients in the ambulatory surgery setting. - Healthcare in the USA has seen an increase in rates of both substance use disorder patients and separately in ambulatory surgery cases. - Specific perioperative protocols to optimize outcomes for patients who suffer from substance use disorder have been described in recent years. - Agents of interest like opioids, cannabis, and amphetamines are the top three most abused substances in North America. - A protocol and recommend further work should be done to integrate with concrete clinical data, in which strategies should be employed to confer benefits to patient outcomes and hospital quality metrics like those enjoyed by ERAS protocol in other settings.

Hofmann vs. Paracelsus: Do Psychedelics Defy the Basics of Toxicology?-A Systematic Review of the Main Ergolamines, Simple Tryptamines, and Phenylethylamines

Psychedelics are experiencing a strong renaissance and will soon be incorporated into clinical practice. However, there is uncertainty about how much harm they can cause at what doses. This review aimed to collect information on the health-hazardous doses of psychedelic substances, to be aware of the risks to which patients may be subjected. We focused on ergolamines, simple tryptamines, and phenylethylamines. We reviewed articles published in major medical and scientific databases. Studies reporting toxic or lethal doses in humans and animals were included. We followed PRISMA criteria for revisions. We identified 3032 manuscripts for inclusion. Of these, 33 were ultimately useful and gave relevant information about effects associated with high psychedelics doses. Despite having different molecular structures and different mechanisms of action, psychedelics are effective at very low doses, are not addictive, and are harmful at extremely high doses. For LSD and psilocybin, no dose has been established above which the lives of users are endangered. In contrast, MDMA appears to be the most dangerous substance, although reports are biased by recreational missuses. It seems that it is not only the dose that makes the poison. In the case of psychedelics, the set and setting make the poison.

Psychedelic assisted therapy for major depressive disorder: Recent work and clinical directions

Psychedelic substances such as psilocybin and ketamine may represent the future of antidepressant treatment, due to their rapid and prolonged effects on mood and cognition. The current body of psychedelic research has focused on administration and treatment within a psychiatric context. Here, instead, we put to the test the contention that it is necessary to evaluate the current state of this literature from a broader biopsychosocial perspective. Examining these arguably neglected social and psychological aspects of psychedelic treatment can provide a more holistic understanding of the interplay between the interconnected domains. This review of six major clinical trials applies a biopsychosocial model to evaluate the antidepressant effects of psilocybin and ketamine assisted therapy. We conclude that combination psychedelic treatment and psychotherapy facilitate more enduring and profound antidepressant effects than produced by ketamine or psilocybin alone. Emphasising the advantages of therapeutic intervention will encourage those who may attempt to self-medicate with psychedelics to instead seek a framework of psychological support, minimising associated risks of unregulated use.

Ketamine for Bipolar Depression: Biochemical, Psychotherapeutic, and Psychedelic Approaches

Bipolar disorder (type 1) is a serious and chronic psychiatric illness that can be difficult to treat. Many bipolar patients have refractory depressive episodes. Racemic ketamine, a glutamate modulator with prominent dissociate and psychedelic properties, has been demonstrated to have rapid acting antidepressant and anti-obsessional effects which may be useful for treating the symptoms of bipolar depression. Most of the existing research literature on unipolar and bipolar depression has looked at racemic ketamine in the sub-psychedelic dose range given by infusion as a stand-alone treatment (without concurrent psychotherapy). This article expands on the existing research by articulating three different paradigms for ketamine treatment: biochemical, psychotherapeutic, and psychedelic. The authors use composite clinical vignettes to illustrate different ways of working with ketamine to treat bipolar depression, and discuss a variety of clinical considerations for using ketamine with this population, including route, dose, frequency, chemical mitigators, and adverse events. Note that the conceptual paradigms could be applied to any ketamine treatment, with broad applicability beyond bipolar treatment.

Potential drug-drug interactions in acute poisonings managed in the intensive care unit: Occurrence, risk factors and relationship to patient severity on admission

Beyond the direct toxicity resulting from each drug in the poisoned patient, additional toxicities may result from drug-drug interactions (DDIs). We aimed to determine the frequency of potential DDIs in the poisoned patient and investigate whether DDIs are associated with severity. We conducted a 1-year cohort study in a toxicological ICU. DDIs were identified using an electronic interaction-checker tool. Among our 354 ICU poisoned patients, 134 (38%) presented at least one potential DDI between acute poisoning drugs and 180 (51%) at least one potential DDI between acute poisoning and long-term treatment drugs. Using multivariate analyses, previous suicide attempt was associated with the presence of potential DDIs between acute poisoning drugs in suicide attempt patients (P = 0.014). Chronic alcoholism (P = 0.005) and tobacco smoking (P = 0.022) were associated with the presence of potential DDIs between acute poisoning and long-term treatment drugs in recreational drug users. Presence of potential DDIs between acute poisoning and long-term treatment drugs was associated with catecholamine infusion (P = 0.022) in suicidal self-exposure patients. Presence of potential pharmacodynamic DDIs between acute poisoning and long-term treatment drugs was associated with aspiration pneumonia onset in recreational drug users (P = 0.03). ICU poisoned patients present a high rate of potential DDIs that may influence the outcome.

Long-term ketamine administration induces bladder damage and upregulates autophagy-associated proteins in bladder smooth muscle tissue

Long-term ketamine abuse can cause significant lower urinary tract symptoms in humans, termed ketamine-associated cystitis (KC). Here, we established a model of long-term (6 months) ketamine administration in wild-type (C57BL/6) mice. We elucidated the pathological effects of ketamine in the bladder and investigated changes in autophagy-associated protein expression (i.e., LC3, Beclin-1, and P62) and inflammatory cytokines (i.e., IL-6 and IL-1β) in the bladder smooth muscle tissue. Long-term ketamine administration reduced the number of layers in the bladder mucosal epithelial cells (4-5 layers in the saline group vs. 2-3 layers in the ketamine groups), but increased the number of mast cells and collagen fibers. LC3-II/LC3-I, Beclin-1, IL-6, and IL-1β protein expression in the bladder smooth muscle tissues of ketamine-treated mice was significantly increased. The mRNA and protein levels of P62 in the Ket-60 mg/kg group were also significantly increased, but not the Ket-30 mg/kg group. Our results reveal that long-term ketamine administration can cause cystitis-like pathological changes in mice, and the disordered autophagy in the bladder tissue may be involved in the persistent bladder damage following long-term administration of ketamine at 60 mg/kg.

Ketamine-New Possibilities in the Treatment of Depression: A Narrative Review

The SARS-CoV-2 coronavirus epidemic has led to an increase in the number of people with depression. Symptoms related to the mental sphere (mainly depression and anxiety) may be experienced by one third of the worldwide population. This entails the need for the effective and rapid treatment of depressive episodes. An effective drug seems to be s-ketamine, which was accepted in March 2019 by the Food and Drug Administration (FDA) for the treatment of drug-resistant depression. This drug provides a quick antidepressant effect with maximum effectiveness achieved after 24 h. It also appears to reduce the occurrence of suicidal thoughts. However, research into undesirable effects, especially in groups of people susceptible to psychotic episodes or those who use alcohol or psychoactive substances, is necessary.

Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder: A Randomized Clinical Trial

IMPORTANCE

Major depressive disorder (MDD) is a substantial public health burden, but current treatments have limited effectiveness and adherence. Recent evidence suggests that 1 or 2 administrations of psilocybin with psychological support produces antidepressant effects in patients with cancer and in those with treatment-resistant depression.

OBJECTIVE

To investigate the effect of psilocybin therapy in patients with MDD.

DESIGN, SETTING, AND PARTICIPANTS

This randomized, waiting list-controlled clinical trial was conducted at the Center for Psychedelic and Consciousness Research at Johns Hopkins Bayview Medical Center in Baltimore, Maryland. Adults aged 21 to 75 years with an MDD diagnosis, not currently using antidepressant medications, and without histories of psychotic disorder, serious suicide attempt, or hospitalization were eligible to participate. Enrollment occurred between August 2017 and April 2019, and the 4-week primary outcome assessments were completed in July 2019. A total of 27 participants were randomized to an immediate treatment condition group (n = 15) or delayed treatment condition group (waiting list control condition; n = 12). Data analysis was conducted from July 1, 2019, to July 31, 2020, and included participants who completed the intervention (evaluable population).

INTERVENTIONS

Two psilocybin sessions (session 1: 20 mg/70 kg; session 2: 30 mg/70 kg) were given (administered in opaque gelatin capsules with approximately 100 mL of water) in the context of supportive psychotherapy (approximately 11 hours). Participants were randomized to begin treatment immediately or after an 8-week delay.

MAIN OUTCOMES AND MEASURES

The primary outcome, depression severity was assessed with the GRID-Hamilton Depression Rating Scale (GRID-HAMD) scores at baseline (score of ≥17 required for enrollment) and weeks 5 and 8 after enrollment for the delayed treatment group, which corresponded to weeks 1 and 4 after the intervention for the immediate treatment group. Secondary outcomes included the Quick Inventory of Depressive Symptomatology-Self Rated (QIDS-SR).

RESULTS

Of the randomized participants, 24 of 27 (89%) completed the intervention and the week 1 and week 4 postsession assessments. This population had a mean (SD) age of 39.8 (12.2) years, was composed of 16 women (67%), and had a mean (SD) baseline GRID-HAMD score of 22.8 (3.9). The mean (SD) GRID-HAMD scores at weeks 1 and 4 (8.0 [7.1] and 8.5 [5.7]) in the immediate treatment group were statistically significantly lower than the scores at the comparable time points of weeks 5 and 8 (23.8 [5.4] and 23.5 [6.0]) in the delayed treatment group. The effect sizes were large at week 5 (Cohen d = 2.5; 95% CI, 1.4-3.5; P < .001) and week 8 (Cohen d = 2.6; 95% CI, 1.5-3.7; P < .001). The QIDS-SR documented a rapid decrease in mean (SD) depression score from baseline to day 1 after session 1 (16.7 [3.5] vs 6.3 [4.4]; Cohen d = 2.6; 95% CI, 1.8-3.5; P < .001), which remained statistically significantly reduced through the week 4 follow-up (6.0 [5.7]; Cohen d = 2.3; 95% CI, 1.5-3.0; P < .001). In the overall sample, 17 participants (71%) at week 1 and 17 (71%) at week 4 had a clinically significant response to the intervention (≥50% reduction in GRID-HAMD score), and 14 participants (58%) at week 1 and 13 participants (54%) at week 4 were in remission (≤7 GRID-HAMD score).

CONCLUSIONS AND RELEVANCE

Findings suggest that psilocybin with therapy is efficacious in treating MDD, thus extending the results of previous studies of this intervention in patients with cancer and depression and of a nonrandomized study in patients with treatment-resistant depression.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03181529.

Metabolic effects of repeated ketamine administration in the rat brain

Ketamine is a popular recreational drug used in club and dance music settings. Evidence suggests that chronic or repeated ketamine use could induce neurological and psychological harm, while the mechanisms underlying ketamine's effects on the nervous system are still unclear. The aim of this study was to explore the metabolic changes that occur in the prefrontal cortex (PFC), hippocampus (Hip) and striatum of rats with repeated ketamine exposure and withdrawal intervention and to identify the potential metabolic pathways influenced by ketamine. An untargeted ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS)-based metabolomics method coupled with multivariate and univariate statistical analysis was applied to analyze the metabolic profiles of the PFC, Hip, and striatum and to identify metabolite alterations. The pathway analysis tool in MetaboAnalyst was subsequently applied for pathway predictions. A total of 79, 54 and 58 changed metabolites were identified in the PFC, Hip and striatum, respectively, after repeated ketamine exposure. Pathway analysis indicated that purine metabolism and glycerophospholipid metabolism were the main pathways disturbed by ketamine in all three brain regions. After one week of withdrawal intervention, most changed metabolites in the Hip and striatum had been restored to control levels, while the metabolite alterations in the PFC were persistent. These results revealed that repeated ketamine exposure significantly changed purine metabolism and glycerophospholipid metabolism in the PFC, Hip and striatum, which might be involved in the neurotoxic effects of ketamine. Additionally, this study also identified that the PFC, rather than the Hip or striatum, was more likely to be the target region of the long-term effects of ketamine.

The effects of sub-anesthetic ketamine plus ethanol on behaviors and apoptosis in the prefrontal cortex and hippocampus of adolescent rats

Ketamine has become increasingly popular in adolescent drug abusers worldwide. Meanwhile, alcohol is usually used by ketamine users. However, little work has been conducted to examine the chronic combined effects of ketamine and ethanol on adolescent brain. Here we probed into the effects of chronic administration of ketamine at recreational doses alone or combined with ethanol on behaviors and neuron damage in an adolescent rat model. 28-day old rats were treated with either 20 or 30 mg/kg ketamine plus or not plus 10% ethanol daily for 21 days. Depressive like behaviors, anxiety like behavior and memory impairment were tested using open field test, forced swimming test, elevated plus maze and Morris water maze. Apoptosis in prefrontal cortex (PFC) and hippocampus (HIP) were determined by the TdT-mediated dUTP Nick-End Labeling (TUNEL) and protein and mRNA levels of caspase-3, Bax and Bcl-2. Results show that co-application of ketamine and ethanol significantly increased immobility time in the forced swimming test, up-regulated TUNEL positive cells and both protein and mRNA expressions of caspase-3 and Bax, compared with the control group and ketamine and ethanol use alone groups in the PFC, but not in the HIP. Our study suggests that chronic co-administration of ketamine and ethanol results in depressive-like behavior and the caspase-dependent apoptosis in the PFC of adolescent rats' brains.

Prelimbic NMDA receptors stimulation mimics the attenuating effects of clozapine on the auditory electrophysiological rebound induced by ketamine withdrawal

Ketamine (KET) is a non-competitive N-Methyl-d-aspartate (NMDA) receptors antagonist that intensifies sensory experiences, prompts hallucinations and delusions, exacerbates previously installed psychosis and disrupts physiological evoked potentials (AEPs). Pharmacologically, KET stimulates glutamate efflux in the medial prefrontal cortex, mainly in the prelimbic (PrL) sub-region. Efferences from this region exert a top-down regulatory control of bottom-up sensory processes either directly or indirectly. In the midbrain, the central nucleus of the inferior colliculus (CIC) plays a fundamental role in the processing of auditory ascending information related to sound localization, sensorimotor gating, and preattentive event-related potentials. Auditory hallucinations elicited during a psychotic outbreak are accompanied by CIC neural activation. Thus, it is possible that NMDA-mediated glutamate neurotransmission in the PrL indirectly modulates CIC neuronal firing. The aim of the present study was to assess the effects of KET on the latency and amplitude of AEPs elicited in the CIC of rats tested during KET effects and following withdrawal from the chronic administration. Changes on emotionally induced by KET treatment were evaluated with the use of the elevated zero maze (EZM). Unlike typical neuroleptics, the atypical antipsychotic clozapine (CLZ) potently blocks the disruption of the sensorimotor gating induced by NMDA antagonists. Therefore, the effects of KET withdrawal on AEPs were challenged with a systemic injection of CLZ. In addition, we further investigated the role of NMDA receptors of the PrL on the AEPs expression recorded in the CIC through intra-PrL infusions of NMDA itself. Our results showed that the processing of sensory information in the CIC is under indirect control of PrL. These data suggest that the long-term KET treatment disrupts the collicular auditory field potentials, possibly through influencing PrL glutamate activity on intrinsic 5-HT mechanisms in the dorsal raphe and CIC.

Novel Psychoactive Substances-Recent Progress on Neuropharmacological Mechanisms of Action for Selected Drugs

A feature of human culture is that we can learn to consume chemical compounds, derived from natural plants or synthetic fabrication, for their psychoactive effects. These drugs change the mental state and/or the behavioral performance of an individual and can be instrumentalized for various purposes. After the emergence of a novel psychoactive substance (NPS) and a period of experimental consumption, personal and medical benefits and harm potential of the NPS can be estimated on evidence base. This may lead to a legal classification of the NPS, which may range from limited medical use, controlled availability up to a complete ban of the drug form publically accepted use. With these measures, however, a drug does not disappear, but frequently continues to be used, which eventually allows an even better estimate of the drug's properties. Thus, only in rare cases, there is a final verdict that is no more questioned. Instead, the view on a drug can change from tolerable to harmful but may also involve the new establishment of a desired medical application to a previously harmful drug. Here, we provide a summary review on a number of NPS for which the neuropharmacological evaluation has made important progress in recent years. They include mitragynine ("Kratom"), synthetic cannabinoids (e.g., "Spice"), dimethyltryptamine and novel serotonergic hallucinogens, the cathinones mephedrone and methylone, ketamine and novel dissociative drugs, γ-hydroxybutyrate, γ-butyrolactone, and 1,4-butanediol. This review shows not only emerging harm potentials but also some potential medical applications.

Encouraging the Disuse of Illicit Drugs Among At-Risk Youth

Youth at risk of illicit drug abuse and other delinquent acts are the target of social work services. Preventing or discouraging the use of illicit drugs among at-risk youth is a long-standing practical and research concern. For this reason, the preventive function of courage is a research gap the present study seeks to fill. The study collected data from 169 at-risk youths and their social workers with two-wave panel surveys. Results show that courage in Wave 1 presented a strong negative effect on illicit drug use in Wave 2 in the youth, controlling for illicit drug use in Wave 1 and background characteristics. Moreover, the negative effect was stronger when Wave 1 drug use was more likely. These results imply the helpfulness of encouraging at-risk youth to gather courage to resist the temptation to use illicit drugs.

Illicit drug use among rave attendees in a nationally representative sample of US high school seniors

BACKGROUND

The popularity of electronic dance music and rave parties such as dance festivals has increased in recent years. Targeted samples of party-goers suggest high rates of drug use among attendees, but few nationally representative studies have examined these associations.

METHODS

We examined sociodemographic correlates of rave attendance and relationships between rave attendance and recent (12-month) use of various drugs in a representative sample of US high school seniors (modal age: 18) from the Monitoring the Future study (2011-2013; Weighted N=7373).

RESULTS

One out of five students (19.8%) reported ever attending a rave, and 7.7% reported attending at least monthly. Females and highly religious students were less likely to attend raves, and Hispanics, students residing in cities, students with higher income and those who go out for fun multiple times per week were more likely to attend. Rave attendees were more likely than non-attendees to report use of an illicit drug other than marijuana (35.5% vs. 15.6%, p<0.0001). Attendees were more likely to report use of each of the 18 drugs assessed, and attendees were more likely to report more frequent use (≥6 times) of each drug (ps<0.0001). Controlling for sociodemographic covariates, frequent attendance (monthly or more often) was associated with higher odds of use of each drug (ps<0.0001). Frequent attendees were at highest risk for use of "club drugs."

DISCUSSION

Findings from this study can help inform prevention and harm reduction among rave attendees at greatest risk for drug use.

Ketamine: an update on its abuse

Ketamine is a dissociative anesthetic and substance of abuse. Numerous effects can result from the abuse of ketamine. Death from acute direct toxicity is rare. Ketamine can alter numerous functions in the brain including color perception, memory, attention, cognition, reaction time, and sense of time and can produce psychological addiction. Chronic ketamine abuse can produce toxicity to the gastrointestinal and urinary tract. Gastrointestinal changes include epigastric pain, hepatic dysfunction, and impaired gallbladder activity. The most common urological condition from ketamine is cystitis but renal failure has been reported.

Chronic ketamine exposure induces permanent impairment of brain functions in adolescent cynomolgus monkeys

Ketamine, a non-competitive N-methyl-D-aspartic acid receptor antagonist, has emerged as an increasingly popular drug among young drug abusers worldwide. Available evidence suggests that ketamine produces acute impairments of working, episodic and semantic memory along with psychotogenic and dissociative effects when a single dose is given to healthy volunteers. However, understanding of the possible chronic effects of ketamine on behavior, cognitive anomalies and neurochemical homeostasis is still incomplete. Although previous human studies demonstrate that ketamine could impair a range of cognitive skills, investigation using non-human models would permit more precise exploration of the neurochemical mechanisms which may underlie the detrimental effects. The current study examined the abnormalities in behavior (move, walk, jump and climb) and apoptosis of the prefrontal cortex using terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end labeling (TUNEL) and apoptotic markers, including Bax, Bcl-2 and caspase-3 in adolescent male cynomolgus monkeys (Macaca fascicularis) after 1 or 6 months of sub-anesthetic ketamine administration (1 mg/kg, i.v.). Results showed that ketamine decreased locomotor activity and increased cell death in the prefrontal cortex of monkeys with 6 months of ketamine treatment when compared with the control monkeys. Such decreases were not found in the 1-month ketamine-treated group. Our study suggested that ketamine administration of recreational dose in monkeys might produce permanent and irreversible deficits in brain functions due to neurotoxic effects, involving the activation of apoptotic pathways in the prefrontal cortex.

The antemortem neurobehavior in fatal paramethoxymethamphetamine usage

Paramethoxymethamphetamine (PMMA) is an emerging and prevalent psychoactive drug with a structure analogous to amphetamine and related psychostimulants. However, the neurobehavioral effect is only studied in experimental animals and is barely mentioned in human. The authors report the antemortem neurobehavioral manifestations in 8 patients with PMMA use. There were 2 different antemortem presentations. The first group of patients showed delirium, hypertalkativity, and incoherence speech and then turned into convulsion and death. They did not exhibit the typical hyperdopaminergic movement disorder. The second group of patients gradually fell asleep and then suffered respiratory or cardiovascular collapse. The heart blood PMMA level was higher in the second group than in the first group of patients. Forensic autopsy showed variable findings, ranging from no remarkable change to significant pathological damage similar to serotonin syndrome in both groups of patients. PMMA seems to enhance serotoninergism than dopaminergism, and exerts a concentration-related dual effect on human.

Ketamine prevents seizures and reverses changes in muscarinic receptor induced by bicuculline in rats

The cholinergic system has been implicated in several experimental epilepsy models. In a previous study bicuculline (BIC), known to antagonize GABA-A postsynaptic receptor subtype, was administered to rats at subconvulsant (1mg/kg) and convulsant (7.5mg/kg) doses and quinuclidinyl benzilate ([(3)H]-QNB) binding to CNS membranes was determined. It was observed that ligand binding to cerebellum increases while it decreases in the case of hippocampus. Saturation binding curves showed that changes were due to the modification of receptor affinity for the ligand without alteration of binding site number. The purpose of this study was to assay muscarinic receptors employing other BIC dose (5mg/kg), which induces seizures and allows the analysis of a postseizure stage as well. To study further muscarinic receptor involvement in BIC induced seizures, KET was also employed since it is a well known anticonvulsant in some experimental models. The administration of BIC at 5mg/kg to rats produced a similar pattern of changes in [(3)H]-QNB binding to those recorded with 1.0 and 7.5mg/kg doses. Here again, changes were observed in receptor binding affinity without alteration in binding site number for cerebellum or hippocampus membranes. Pretreatment with KET (40 mg/kg) prevented BIC seizures and reverted [(3)H]-QNB binding changes induced by BIC administration. The single administration of KET invariably resulted in [(3)H]-QNB binding decrease to either cerebellar or hippocampal membranes. KET added in vitro decreased ligand binding likewise. Results of combined treatment with KET plus BIC are hardly attributable to the single reversion of BIC effect since KET alone invariably decreased ligand binding. It is suggested that besides alteration of cholinergic muscarinic receptor other(s) neurotransmitter system(s) may well also be involved.

Teenage toxins: recreational poisoning in the adolescent

Adolescents are experimenting with recreational drugs on a regular basis, particularly at social gatherings such as parties, raves and mass events. A combination of reduced fluid intake, physical activity and drug-induced hyperthermia leads to complications such as heat stroke, delirium and potentially death. The clinician needs to be aware of the variety of pharmacologically active substances available in the recreational marketplace in order to diagnose and manage these patients. Recreational misadventure, because of incorrect dosage or mixing multiple substances, is a common reason for teenagers presenting to hospital with toxidromes. Death from club drug overdose is more likely to be associated with suicidal intent, related risky behaviour and trauma, as well as the inherent toxicity of the drug itself. Although many teenagers are concerned about 'drink spiking' with club drugs, the most common agent causing drink spiking incidents is ethanol.

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.

Permanent deficits in brain functions caused by long-term ketamine treatment in mice

Ketamine, an injectable anesthetic, is also a popular recreational drug used by young adults worldwide. Ketamine is a non-competitive antagonist of N-methyl-d-aspartate receptor, which plays important roles in synaptic plasticity and neuronal learning. Most previous studies have examined the immediate and short-term effects of ketamine, which include learning and cognitive deficits plus impairment of working memory, whereas little is known about the long-term effects of repeated ketamine injections of common or usual recreational doses. Therefore, we aimed to evaluate the deficits in brain functions with behavioral tests, including wire hang, hot plate and water maze tests, plus examine prefrontal cortex apoptotic markers, including Bax, Bcl-2 and caspase-3, in mice treated with 6 months of daily ketamine administration. In our study, following 6 months of ketamine injection, mice showed significant deterioration in neuromuscular strength and nociception 4 hours post-dose, but learning and working memory were not affected nor was there significant apoptosis in the prefrontal cortex. Our research revealed the important clinical finding that long-term ketamine abuse with usual recreational doses can detrimentally affect neuromuscular strength and nociception as part of measurable, stable and persistent deficits in brain function.

Drug poisoning deaths in Sweden show a predominance of ethanol in mono-intoxications, adverse drug-alcohol interactions and poly-drug use

Over a 10-year period (1998-2007) all deaths in Sweden classified by forensic pathologists as fatal drug poisonings (N = 6894) were retrieved from a toxicology database (TOXBASE) belonging to the National Board of Forensic Medicine. The deaths were further classified as suicides N = 2288 (33%), undetermined N = 2260 (33%) and accidental N = 2346 (34%). The average age (± SD) of all victims was 49.1 ± 15.9 years and men 47.4 ± 15.6 years were 5-year younger than women 52.2 ± 15.8 years (p < 0.01). Most of the deceased (78%) were poly-drug users although a single drug (mono-intoxications) was found in 22% of all poisoning deaths (p < 0.001). The number of drugs in blood samples varied from 1 to 12 with a median of 3-4 per case. Mono-intoxication deaths were mostly ethanol-related (N = 976) and the mean and median blood-alcohol concentration (BAC) was 3.06 g/L and 3.10 g/L, respectively. The BAC decreased as the number of additional drugs in blood increased from 2.15 g/L with one drug to 1.25 g/L with 6 or more drugs. The mean (median) concentrations of non-alcohol drugs in mono-intoxication deaths were morphine (N = 93) 0.5mg/L (0.2mg/L), amphetamine (N = 39) 2.0mg/L (1.2mg/L), dextropropoxyphene (N = 33) 3.9 mg/L (2.9 mg/L), dihydro-propiomazine (N = 32) 1.6 mg/L (1.0mg/L) and 7-amino-flunitrazepam (N = 28), 0.4 mg/L (0.3mg/L). Elevated blood morphine in these poisoning deaths mostly reflected abuse of heroin as verified by finding 6-monoacetyl morphine (6-MAM) in the blood samples. When investigating drug poisoning deaths a comprehensive toxicological analysis is essential although the results do not reveal the extent of prior exposure to drugs or the development of pharmacological tolerance. The concentrations of drugs determined in post-mortem blood are one element in the case. The autopsy report, the police investigation, the findings at the scene and eye-witness statements should all be carefully considered when the cause and manner of death are determined.

Case series of 226 γ-hydroxybutyrate-associated deaths: lethal toxicity and trauma

γ-Hydroxybutyrate (GHB) and its prodrugs are drugs of abuse that were also sold as "dietary supplements." Users present to emergency departments with overdose, impaired driving, withdrawal, and associated trauma. We compiled a series of GHB-associated deaths to elucidate lethal risks, GHB concentrations, cointoxicants, products, uses, and medical interventions. Death records were reviewed for toxicology, autopsy findings, and history. Inclusion cutoffs were as follows: 5/10 mg/L of GHB (antemortem blood/urine) and 50/20/7 mg/L of GHB (postmortem blood/urine/vitreous). Of 226 deaths included, 213 had cardiorespiratory arrest and 13 had fatal accidents. Seventy-eight deaths (35%) had no cointoxicants. Sixteen deaths involved "supplements" and 1 involved pharmaceutical GHB (Xyrem, Jazz Pharmaceuticals, Palo Alto, CA). Postmortem blood GHB was 18 to 4400 mg/L (median, 347 mg/L) in deaths negative for cointoxicants. Cardiorespiratory arrest occurred prehospital in 100% of 184 cases with available history. Of 72 cases with antemortem adverse effects reported, medical assistance was delayed or absent in 66; of these, acute GHB ingestion was known in 51, including 40 left to "sleep off" adverse effects. Thirty others were left "sleeping" and found dead. γ-Hydroxybutyrate is lethal even without cointoxicants, directly and through fatal accidents. Medical interventions were frequently delayed or absent despite known GHB ingestion, and witnessed adverse events and cardiorespiratory arrest occurred prehospital. Education is needed about the lethality of GHB and the necessity for prompt medical intervention.

The toxic effect of ketamine on SH-SY5Y neuroblastoma cell line and human neuron

Ketamine used as an injectable anesthetic in human and animal medicine is also a recreational drug used primarily by young adults often at all night dance parties in nightclubs. The percentage of ketamine users has grown very fast in the last 5 years worldwide. However, this leads to the serious question of the long-term adverse effects of ketamine on our nervous system, particularly the brain, because ketamine as an NMDA antagonist could cause neurons to commit apoptosis. Our study therefore aimed to find out the chronic effect of ketamine on neuron using prolonged incubation (48 h) of neuronal cells with ketamine in culture. Our results showed that differentiated neuronal cells were prone to the toxicity of ketamine but probably less susceptible than undifferentiated neuronal cells and fibroblasts. This suggested that the ketamine abuse would be harmful to many other organs as well as the brain. Our results also confirmed that the toxicity of ketamine is related to apoptosis via the Bax/Bcl-2 ratio pathway and caspase-3 in the differentiated neuronal cells. Therefore, long-term ketamine treated cell or animal models should be sought to study this multiorgan effects of ketamine.

Hyperphosphorylated tau in the brains of mice and monkeys with long-term administration of ketamine

Ketamine, a non-competitive antagonist at the glutamatergic N-methyl-d-aspartate (NMDA) receptor, might impair memory function of the brain. Loss of memory is also a characteristic of aging and Alzheimer's disease. Hyperphosphorylation of tau is an early event in the aging process and Alzheimer's disease. Therefore, we aimed to find out whether long-term ketmaine administration is related to hyperphosphorylation of tau or not in the brains of mice and monkeys. Results showed that after 6 months' administration of ketamine, in the prefrontal and entorhinal cortical sections of mouse and monkey brains, there were significant increases of positive sites for the hyperphosphorylated tau protein as compared to the control animals receiving no ketamine administration. Furthermore, about 15% of hyperphosphorylated tau positive cells were also positively labeled by terminal dUTP nick end labeling (TUNEL) indicating there might be a relationship between hyperphosphorylation of tau and apoptosis. Therefore, the long-term ketamine toxicity might involve neurodegenerative process similar to that of aging and/or Alzheimer's disease.

Methylenedioxymethamphetamine (MDMA)-related fatalities in Australia: demographics, circumstances, toxicology and major organ pathology

AIM

To examine the demographic characteristics, circumstances, toxicology and major organ pathology of MDMA-related deaths in Australia.

METHODS

Retrospective review of cases in which MDMA was a cause of death, as identified from the National Coronial Information System.

RESULTS

82 cases over a 5-year period were identified. The majority of decedents were male (83%), with a median age of 26 years. Deaths were predominantly due to drug toxicity (82%), with MDMA the sole drug causing death in 23% of cases, and combined drug toxicity in 59% of cases. The remaining deaths (18%) were primarily due to pathological events/disease or injury, with MDMA a significant contributing condition. Cardiovascular pathology, typically atherosclerosis, was detected in 58% of decedents, with moderate-severe atherosclerosis in 23% of cases. The prevalence of such pathology is higher than that expected among similarly aged members of the general population. Cerebrovascular pathology, primarily cerebral haemorrhage and hypoxic damage, was present in 12% of cases.

CONCLUSIONS

MDMA has contributed to a clinically significant number of deaths in Australia. The prevalence of cardiovascular pathology was similar to that among methamphetamine and cocaine fatalities. Whilst cardiovascular pathology may reflect the use of other stimulants, the cardiotoxic properties of MDMA have been well-documented. Future studies examining MDMA-related morbidity and mortality in the context of other risk factors are recommended. Overall, the current study highlights the need to educate users about the potential harms of MDMA use, particularly that in conjunction with other stimulants, opioids and alcohol, which are known to increase overall toxicity.

Modification of ethanol's reinforcing effectiveness in rhesus monkeys by cocaine, flunitrazepam, or gamma-hydroxybutyrate

BACKGROUND

Although ethanol is frequently used in combination with other psychoactive drugs, the behavioral and pharmacological reasons for this form of polydrug abuse have not been well described.

MATERIALS AND METHODS

Rhesus monkeys with indwelling intravenous catheters produced intravenous injections of ethanol (50, 100, or 200 mg/kg/inj), flunitrazepam (0.001-0.03 mg/kg/inj), cocaine (0.01 or 0.03 mg/kg/inj), or combinations of ethanol and these drugs or gammahydroxybutyrate (GHB) (1.0 or 3.2 mg/kg/inj) by lever pressing according to a fixed-ratio schedule. The response requirement for each drug or drug combination was increased across sessions (10, 32, 100, 320, or 1,000). The dependent variables were rates of responding maintained by the drug or drug combination and the elasticity of drug demand when consumption was expressed as a function of price.

RESULTS

Elasticity (P (max)) values for each drug varied among the monkeys but retained the same rank order for the monkeys, suggesting a fundamental difference in the animals' apparent sensitivities to the reinforcing effects of the drugs. Combining ethanol with the other drugs did not increase their reinforcing effectiveness. GHB (ineffective in previous studies) did not modify ethanol's reinforcing effects; demand functions for the combination of ethanol and flunitrazepam were slightly less elastic than for ethanol alone, but no different from that for flunitrazepam alone; adding ethanol to cocaine detracted from the reinforcing effectiveness of cocaine.

CONCLUSIONS

The hypothesis that use of ethanol in combination with sedative and stimulant drugs is due to an ability of ethanol to enhance the reinforcing effects of these drugs is not supported.

High-risk behaviors and hospitalizations among gamma hydroxybutyrate (GHB) users

INTRODUCTION

Little is known about behaviors linked to gamma hydroxybutyrate (GHB) morbidity.

METHODS

We surveyed 131 GHB users, using logistic regression to test the associations between the high risk behaviors and hospital treatment for GHB (26 [20%] of subjects).

RESULTS

Increased risk of GHB hospital treatment was associated with: co-ingestion of ethanol (OR 5.2; 95% CI 1.7-16), driving under the influence of GHB (OR 3.2; 95%, CI 1.3-7.8),use of GHB to treat withdrawal symptoms (OR 2.9; 95% CI 1.1-7.9), and co-ingestion of ketamine (OR 2.7; 95% CI 1.1-6.7).

CONCLUSION

Targeted prevention activities could focus on selected high-risk behaviors.

Risk assessment of ritual use of oral dimethyltryptamine (DMT) and harmala alkaloids

AIM

To extend previous reviews by assessing the acute systemic toxicity and psychological hazards of a dimethyltryptamine and beta-carboline brew (ayahuasca/hoasca) used in religious ceremonies.

METHOD

A systematic literature search, supplemented by interviews with ceremony participants.

RESULTS

No laboratory animal models were located that tested the acute toxicity or the abuse potential of ayahuasca. Separate animal studies of the median lethal dose of dimethyltryptamine (DMT) and of several harmala alkaloids indicated that a lethal dose of these substances in humans is probably greater than 20 times the typical ceremonial dose. Adverse health effects may occur from casual use of ayahuasca, particularly when serotonergic substances are used in conjunction. DMT is capable of inducing aversive psychological reactions or transient psychotic episodes that resolve spontaneously in a few hours. There was no evidence that ayahuasca has substantial or persistent abuse potential. Long-term psychological benefits have been documented when ayahuasca is used in a well-established social context.

CONCLUSION

A decoction of DMT and harmala alkaloids used in religious ceremonies has a safety margin comparable to codeine, mescaline or methadone. The dependence potential of oral DMT and the risk of sustained psychological disturbance are minimal.

Differences in club drug use between heterosexual and lesbian/bisexual females

Although there has been much empirical research documenting current trends in club drug use among gay and bisexual men, little research has addressed the variance among lesbian, bisexual, or heterosexual women. Using data collected through time-space sampling from dance clubs in New York City during 2005 (N=1104), this study explored sexual identity variance among women in the reported use of six club drugs: methamphetamine, cocaine, MDMA, ketamine, GHB, and LSD. Significant differences were found in that younger women were more likely to be active club drug users. Lesbian and bisexual women reported significantly higher lifetime rates of ecstasy, cocaine, methamphetamine, and LSD use compared to heterosexual women. These data suggest a need to better understand the influence of sexual orientation and sexual culture in relation to club drug use and to tailor health promotion efforts to meet the needs of various groups of club drug using women.

Ketamine : from medicine to misuse

This review describes the medical, research and recreational uses of ketamine, an anaesthetic derivative of phencyclidine that has dissociative, analgesic and psychedelic properties. Ketamine has a complex mechanism of action that is further complicated by stereoselectivity; however, antagonism of glutamate NDMA receptors is thought to underlie its analgesic, dissociative and neuroprotective effects. While ketamine use in medical and veterinary settings is well documented and has a good safety record, the increase in its unregulated use outside of such controlled environments is a cause for concern. The impact on higher centres in the brain, particularly altered perception of auditory, visual and painful stimuli, results in a general lack of responsive awareness that puts the recreational user at (often unrecognised) risk of personal harm. The perceptual and mood changes observed in those who have consumed ketamine are highly sensitive to age, dose, route of administration, previous experience and setting. At low doses, stimulant effects predominate and the effect of environmental conditions are significant; with higher doses, psychedelic effects predominate and the effect of the environment diminishes. The potential of ketamine as a novel clinical and research tool is matched by its abuse potential outside medical settings.

Behavioral effects of ketamine and toxic interactions with psychostimulants

Background

The anesthetic drug ketamine (KT) has been reported to be an abused drug and fatal cases have been observed in polydrug users. In the present study, considering the possibility of KT-enhanced toxic effects of other drugs, and KT-induced promotion of an overdose without making the subject aware of the danger due to the attenuation of several painful subjective symptoms, the intraperitoneal (i.p.) KT-induced alterations in behaviors and toxic interactions with popular co-abused drugs, the psychostimulants cocaine (COC) and methamphetamine (MA), were examined in ICR mice.

Results

A single dose of KT caused hyperlocomotion in a low (30 mg/kg, i.p.) dose group, and hypolocomotion followed by hyperlocomotion in a high (100 mg/kg, i.p.) dose group. However, no behavioral alterations derived from enhanced stress-related depression or anxiety were observed in the forced swimming or the elevated plus-maze test. A single non-fatal dose of COC (30 mg/kg, i.p.) or MA (4 mg/kg, i.p.) caused hyperlocomotion, stress-related depression in swimming behaviors in the forced swimming test, and anxiety-related behavioral changes (preference for closed arms) in the elevated plus-maze test. For the COC (30 mg/kg) or MA (4 mg/kg) groups of mice simultaneously co-treated with KT, the psychostimulant-induced hyperlocomotion was suppressed by the high dose KT, and the psychostimulant-induced behavioral alterations in the above tests were reversed by both low and high doses of KT. For the toxic dose COC (70 mg/kg, i.p.)- or MA (15 mg/kg, i.p.)-only group, mortality and severe seizures were observed in some animals. In the toxic dose psychostimulant-KT groups, KT attenuated the severity of seizures dose-dependently. Nevertheless, the mortality rate was significantly increased by co-treatment with the high dose KT.

Conclusion

Our results demonstrated that, in spite of the absence of stress-related depressive and anxiety-related behavioral alterations following a single dose of KT treatment, and in spite of the KT-induced anticonvulsant effects and attenuation of stress- and anxiety-related behaviors caused by COC or MA, the lethal effects of these psychostimulants were increased by KT.

Club drugs as causal risk factors for HIV acquisition among men who have sex with men: a review

We reviewed medical and psychology databases for articles published between January 1980 and August 2005 demonstrating associations between HIV/Sexually Transmitted Infection risk and club drug use. Seventy-four articles were reviewed, of which 30 provided adjusted risk ratios for associations between HIV/sexually transmitted infection risk and club drug use among men who have sex with men. Definitions and lists of club drugs were broad and inconsistent. We constructed a conceptual framework of biologically plausible pathways for causation. Using Hill's criteria to examine club drugs as causal risk factors for HIV, we found the most evidence for methamphetamine and volatile nitrites; however, more studies are needed.

Flunitrazepam: psychomotor impairment, agitation and paradoxical reactions

Benzodiazepines are sedatives used for anxiolysis, hypnosis, muscle relaxation and the treatment of epilepsy. Paradoxical reactions including agitation, talkativeness, confusion, disinhibition, aggression, violent behavior and loss of impulse control may, however, occur in some subjects. It has been claimed that high doses of flunitrazepam may cause aggression on a more regular basis in all individuals. The present study makes use of a Norwegian forensic toxicological database containing analytical results from drivers suspected of driving under the influence and suspects of violent crime to analyze the relationship between behavior and blood flunitrazepam concentration. Four-hundred and fifteen cases of drivers suspected of driving under the influence and seven cases of suspects of violent crime were studied. These selected cases had flunitrazepam as the only drug in blood samples and had been evaluated by a clinical test for impairment (CTI) performed by a police physician at the time of blood sampling. The impaired drivers had higher blood flunitrazepam concentrations than the not impaired drivers. Multivariate analysis revealed that both blood flunitrazepam concentration and age of the suspected drivers had independent impact on impairment, indicating tolerance with age. Most of the effects measured were sedative effects of flunitrazepam and these effects were related to flunitrazepam level. Possible paradoxical reactions were observed in a subgroup of 23 individuals (6%), but these reactions did not relate to blood flunitrazepam concentration. The suspects of violent crime showed similar degree impairment and had not more paradoxical reactions than the suspected drugged drivers. The findings were in agreement with other research that claims paradoxical reactions should be viewed as a reaction in certain individuals, and does not support the notion that flunitrazepam in high concentration produces aggression in all individuals taking the drug.

Ketamina, da anestesia ao uso abusivo

Objetivo. Realizar uma revisão bibliográfica sobre a ketamina, enfocando aspectos químicos e farmacocinéticos, seus mecanismos de ação, efeitos farmacológicos, usos terapêuticos, bem como aborda o uso da ketamina como droga de abuso. Ketamina. Método. Estudo de revisão bibliográfica através das bases de dados Pubmed, SciELO, Lilacs e Medline, na qual foram selecionados estudos clássicos e recentes relevantes para a discussão do tema abordado. Resultados. Após análise dos artigos selecionados, conclui-se que a ketamina apresenta perspectivas promissoras. Alguns estudos demonstraram propriedades analgésicas em relação à dor pós-operatória e outros revelaram uma ação antidepressiva rápida. Além disto, a ketamina também apresentou efeitos neuroprotetores em vários estudos animais. Embora a ketamina seja um campo promissor, essas ações precisam ser melhor investigadas. Atualmente, observou-se que o seu uso não se restringe apenas à prática clínica ou pesquisa, sendo frequentemente utilizada como droga de abuso pelos jovens em festas como um potente alucinógeno. Conclusão. Pesquisas sobre o uso recreacional da ketamina também são necessárias, especialmente no Brasil, assim como dados que mostrem a morbidade e mortalidade pelo uso desta substância como droga de abuso.