Global patterns of methamphetamine use

Short-chain fatty acids mitigate Methamphetamine-induced hepatic injuries in a Sigma-1 receptor-dependent manner

Methamphetamine (Meth) is a potent psychostimulant with well-established hepatotoxicity. Gut microbiota-derived short-chain fatty acids (SCFAs) have been reported to yield beneficial effects on the liver. In this study, we aim to further reveal the mechanisms of Meth-induced hepatic injuries and investigate the potential protective effects of SCFAs. Herein, mice were intraperitoneally injected with 15 mg/kg Meth to induce hepatic injuries. The composition of fecal microbiota and SCFAs was profiled using 16 S rRNA sequencing and Gas Chromatography/Mass Spectrometry (GC/MS) analysis, respectively. Subsequently, SCFAs supplementation was performed to evaluate the protective effects against hepatic injuries. Additionally, Sigma-1 receptor knockout (S1R-/-) mice and fluvoxamine (Flu), an agonist of S1R, were introduced to investigate the mechanisms underlying the protective effects of SCFAs. Our results showed that Meth activated S1R and induced hepatic autophagy, inflammation, and oxidative stress by stimulating the MAPK/ERK pathway. Meanwhile, Meth disrupted SCFAs product-related microbiota, leading to a reduction in fecal SCFAs (especially Acetic acid and Propanoic acid). Accompanied by the optimization of gut microbiota, SCFAs supplementation normalized S1R expression and ameliorated Meth-induced hepatic injuries by repressing the MAPK/ERK pathway. Effectively, S1R knockout repressed Meth-induced activation of the MAPK/ERK pathway and further ameliorated hepatic injuries. Finally, the overexpression of S1R stimulated the MAPK/ERK pathway and yielded comparable adverse phenotypes to Meth administration. These findings suggest that Meth-induced hepatic injuries relied on the activation of S1R, which could be alleviated by SCFAs supplementation. Our study confirms the crucial role of S1R in Meth-induced hepatic injuries for the first time and provides a potential preemptive therapy.

Evaluation of methamphetamine assist packs: As-needed antipsychotics for self-management of methamphetamine-associated psychiatric toxicity

BACKGROUND

Methamphetamine frequently causes substance-induced psychosis and related symptoms. There are currently no interventions to prevent or assist in self-management of these symptoms.

METHODS

We evaluated a program providing "Methamphetamine Assist Packs" to patients who were seen in a psychiatric emergency services program for methamphetamine-induced psychosis. Methamphetamine Assist Packs included a small number of tablets of an antipsychotic medication (olanzapine), administration instructions, and referral information. We reviewed medical charts of patients who received Methamphetamine Assist Packs from January 2022 through May 2023 for sociodemographic and emergency visit characteristics. We assessed the changes between the number of psychiatric emergency visits before and after Methamphetamine Assist Pack receipt at two, six, and 12 months using generalized estimating equations.

RESULTS

Ninety-two patients received a Methamphetamine Assist Pack, with a mean age of 40 years; 79 % were male and 49 % Black/African American; 77 % experienced housing instability or homelessness. The most common symptoms were suicidal ideation (54 %), paranoia or delusions (45 %), and hallucinations (40 %); 55 % were on involuntary psychiatric hold, 38 % required medications for agitation, and 18 % required seclusion or physical restraints. The rate of psychiatric emergency visits after Methamphetamine Assist Pack receipt was 0.68 and 0.87 times the rate prior to receipt at two and six months, respectively (p < 0.001). There was no difference at 12 months.

CONCLUSIONS

Methamphetamine Assist Packs were associated with fewer psychiatric emergency visits for six months after receipt, and represent a promising intervention to address acute psychiatric toxicity from methamphetamine in need of further research.

Spectrum of Kidney Biopsy Findings Associated With Methamphetamine Use

Introduction

Methamphetamine (METH) is one of the most used drugs of abuse worldwide. However, there are few reports and series examining the toxic kidney effects of METH, and associated histopathological changes are not well-described.

Methods

We retrospectively identified 112 patients with a history significant for METH abuse, of whom 62 were using METH-only and 60 were using METH plus other drugs of abuse.

Results

In the METH-only cohort, the mean age was 41 years (interquartile range [IQR]: 33-49) and most (76%) were male. Almost all cases (97%) showed evidence of kidney dysfunction at the time of biopsy. Of the cases, 65% had proteinuria, of which 53% were nephrotic range and 10% had nephrotic syndrome. The most common biopsy diagnosis was acute tubular necrosis (ATN) (66%), of which 19% had myoglobin casts; followed by focal segmental glomerulosclerosis (FSGS) in 53% (not otherwise specified [NOS] in 76% and collapsing FSGS [cFSGS] in 18%). Biopsy findings also include tubulointerstitial nephritis (TIN) (37%), thrombotic microangiopathy (TMA) (24%), and diabetic glomerulosclerosis (DG) (31%). Glomerulonephritis (GN) was identified in one-third of cases, the most common of which were infection-related GN (IRGN) (15%) and IgA nephropathy (IgAN) (11%). Of those with GN, 64% had underlying infection. Of interest, there was increased association for myoglobinuric ATN in those with concurrent ethanol-abuse (P = 0.002). Moreover, the METH-only patients were more likely to have DG compared to those with multiple substance-use (P = 0.01). More than half of the patients demonstrated at least moderate to severe tubulointerstitial scarring and marked hypertensive vascular disease.

Conclusion

Most patients with METH-use present with acute kidney injury (AKI) and often have proteinuria associated with a wide spectrum of renal pathology.

Distinct roles of excitatory and inhibitory neurons in the medial prefrontal cortex in the expression and reconsolidation of methamphetamine-associated memory in male mice

Methamphetamine, a commonly abused drug, is known for its high relapse rate. The persistence of addictive memories associated with methamphetamine poses a significant challenge in preventing relapse. Memory retrieval and subsequent reconsolidation provide an opportunity to disrupt addictive memories. However, the key node in the brain network involved in methamphetamine-associated memory retrieval has not been clearly defined. In this study, using the conditioned place preference in male mice, whole brain c-FOS mapping and functional connectivity analysis, together with chemogenetic manipulations of neural circuits, we identified the medial prefrontal cortex (mPFC) as a critical hub that integrates inputs from the retrosplenial cortex and the ventral tegmental area to support both the expression and reconsolidation of methamphetamine-associated memory during its retrieval. Surprisingly, with further cell-type specific analysis and manipulation, we also observed that methamphetamine-associated memory retrieval activated inhibitory neurons in the mPFC to facilitate memory reconsolidation, while suppressing excitatory neurons to aid memory expression. These findings provide novel insights into the neural circuits and cellular mechanisms involved in the retrieval process of addictive memories. They suggest that targeting the balance between excitation and inhibition in the mPFC during memory retrieval could be a promising treatment strategy to prevent relapse in methamphetamine addiction.

Methamphetamine intoxication and suicidal ideation/behavior in the emergency department

BACKGROUND

This study investigates the association between Methamphetamine (MA) intoxication and suicidal ideation/behavior in patients presenting to emergency departments. Amidst rising MA use and co-use with opioids, this "twin epidemic" has manifested in increasing admissions for MA intoxication, often accompanied by psychiatric symptoms that can escalate to suicidal behaviors.

METHOD

This retrospective study utilized patient records and analyzed data from 629 patients admitted to a Texas emergency department in 2020, with MA intoxication confirmed via urine tests and patient interviews. The suicidal tendencies were assessed using the Columbia-Suicide Severity Scale. The 629 patients were divided into three groups for analysis: Group I (n = 188), MA positive with suicidal ideation (SI) (MA + SI+); Group II (n = 202), MA-positive without SI (MA + SI-); and Group III (n = 239), MA-negative with SI (MA- SI+). Multiple regression analysis was used to elicit clinical features predicting patients presenting to the emergency department with acute MA intoxication.

RESULTS

Results reveal that approximately half of patients with acute MA intoxication reported suicidal thoughts, indicating a significant association between MA use and suicidal tendencies. Females exhibited higher rates of suicidal thoughts, behavior, and subsequent medical attention compared to males. Sociodemographic characteristics and clinical features differed among MA-positive patients with and without SI. Multivariable regression analysis identified factors influencing MA use, including cannabis use, male gender, agitation, and an inverse association with alcohol use. Notably, the severity and potential lethality of suicidal behavior in MA-intoxicated patients paralleled those observed in psychiatric patients without MA use.

CONCLUSION

These results underscore the urgent need for targeted interventions to address the complex interplay between MA use and suicidal risks in the emergency department setting, as well as broader public health strategies to combat the increasing prevalence of MA use.

An Investigation into the Prevalence of Methamphetamine Related Enquiries to Local Government Environmental Health Officers

Methamphetamine contamination of residential properties remains a serious public health concern for members of the public. External stakeholders including Environmental Health Officers (EHOs) and testing and remediation technicians are engaged on investigating whether contamination has occurred from manufacturing or smoking processes. More specifically, local council EHOs are responsible for managing clandestine drug laboratories when notified by police and also for responding to public enquiries. However, the full scope of these contaminated properties is not seen by any single stakeholder, making it very challenging to quantify these situations. To evaluate the prevalence of methamphetamine related enquiries from the general public to EHOs, this study surveyed and interviewed officers from around Australia. It was found that public enquiries were infrequent with only 6% of respondents having received enquiries in the last month, which indicates that people are seeking information from other sources. Interestingly, there were case study scenarios that also mentioned issues with awareness and the flow of information. Concerns regarding difficult cases, police notifications, and site visits were also highlighted. The results of this study provide a benchmark of how methamphetamine related cases are managed and highlight the need for trustworthy information that is available to EHOs, governments, industry members, and the public in a unified location.

Dog and cat exposures to drugs of abuse identified by the California animal health and food safety laboratory system 2013-2023

Introduction

While known animal exposures to human "drugs of abuse" (DA) were previously considered relatively uncommon in veterinary medicine, the trends are changing. Marijuana and amphetamines are among the 20 toxicants most frequently consulted about with the Pet Poison Helpline. When such exposures occur, they are typically considered emergencies.

Methods

This retrospective study describes confirmed cases of DA exposure in pets from the California Animal Health and Food Safety Laboratory System (CAHFS), 2013-2023.

Results

Fifty-seven samples tested positive for DA through liquid chromatography with tandem mass spectrometry analysis (qualitative method). In 75% (43/57) of the DA screen tests, the detected drugs included amphetamine-type stimulants and metabolites (methamphetamine, amphetamine, or both). In 47% (27/57) of cases, a combination of more than one drug group was found. Most cases were diagnosed from a urine specimen. In at least 32% (18/57) of cases, the samples were submitted due to suspicions of animal cruelty, and at least 41% (23/57) of the patients were deceased when the samples were submitted.

Discussion

More studies on the prevalence of illicit drugs in small animals, using confirmatory testing, are warranted to fully understand the significance of this emerging toxicological hazard in veterinary medicine.

Prenatal and postnatal methamphetamine exposure alters prefrontal cortical gene expression and behavior in mice

Methamphetamine is a highly abused psychostimulant that substantially impacts public health. Prenatal and postnatal methamphetamine exposure alters gene expression, brain development, and behavior in the offspring, although the underlying mechanisms are not fully defined. To assess these adverse outcomes in the offspring, we employed a mouse model of prenatal and postnatal methamphetamine exposure. Juvenile offspring were behaviorally assessed on the open field, novel object recognition, Y-maze, and forced swim tests. In addition, RNA sequencing was used to explore potential alterations in prefrontal cortical gene expression. We found that methamphetamine-exposed mice exhibited decreased locomotor activity and impaired cognitive performance. In addition, differential expression of genes involved in neurotransmission, synaptic plasticity, and neuroinflammation were found with notable changes in dopaminergic signaling pathways. These data suggest potential neural and molecular mechanisms underlying methamphetamine-exposed behavioral changes. The altered expression of genes involved in dopaminergic signaling and synaptic plasticity highlights potential targets for therapeutic interventions for substance abuse disorders and related psychiatric complications.

Predictive role of impulsivity, anxiety, and depression in the efficacy of intermittent theta burst transcranial magnetic stimulation modalities for treating methamphetamine use disorder: A randomized clinical trial

INTRODUCTION

Methamphetamine use disorder (MUD) can cause impulsive behavior, anxiety, and depression. Stimulation of the left dorsolateral prefrontal cortex in MUD patients by intermittent theta burst repetitive transcranial magnetic stimulation (iTBS-rTMS) is effective in reducing cravings, impulsive behavior, anxiety, and depression. The purpose of this study was to explore whether these psychological factors helped to predict MUD patients' responses to iTBS-rTMS treatment.

METHODS

Fifty MUD patients and sixty healthy subjects matched for general conditions were used as study subjects. The study randomly divided MUD patients into iTBS-rTMS and sham stimulation groups and received 20 sessions of real or sham iTBS-rTMS treatment, and the study collected cue-related evoked craving data before and after treatment. All subjects completed the Barratt Impulsiveness Scale (BIS-11), Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS).

RESULTS

The MUD patients showed significantly higher levels of impulsivity, anxiety, and depression than the healthy subjects. The MUD patients who received the real treatment had significantly lower impulsivity, anxiety, and depression scores, and better treatment effects on cravings than the sham stimulation group. The Spearman rank correlation and stepwise multiple regression analyses showed that the baseline BIS-11 and the reduction rate (RR) of BIS-11 and RR of SDS were positively correlated with the decrease in cravings in the iTBS-rTMS group. ROC curve analysis showed that RR of SDS (AUC = 91.6 %; 95 % CI = 0.804-1.000) had predictive power to iTBS- rTMS therapeutic efficacy, the cutoff value is 15.102 %.

CONCLUSIONS

iTBS-rTMS had a good therapeutic effect in MUD patients and the baseline impulsivity, the improved depression and impulsivity were associated with therapeutic effect of iTBS-rTMS. The improved depression had the potential to predict the efficacy of the iTBS-rTMS modality for MUD treatment.

Enhanced methamphetamine sensitisation in a rat model of the brain-derived neurotrophic factor Val66Met variant: Sex differences and dopamine receptor gene expression

Brain-derived neurotrophic factor (BDNF) and the Val66Met polymorphism may play a role in the development of psychosis and schizophrenia. The aim of this study was to investigate long-term effects of methamphetamine (Meth) on psychosis-like behaviour and dopamine receptor and dopamine transporter gene expression in a novel rat model of the BDNF Val66Met polymorphism. At the end of a 7-day subchronic Meth treatment, female rats with the Met/Met genotype selectively showed locomotor hyperactivity sensitisation to the acute effect of Meth. Male rats showed tolerance to Meth irrespective of Val66Met genotype. Two weeks later, female Met/Met rats showed increased locomotor activity following both saline treatment or a low dose of Meth, a hyperactivity which was not observed in other genotypes or in males. Baseline PPI did not differ between the groups but the disruption of PPI by acute treatment with apomorphine was absent in Meth-pretreated Met/Met rats. Female Met/Met rats selectively showed down-regulation of dopamine D2 receptor gene expression in striatum. Behavioural effects of MK-801 or its locomotor sensitisation by prior Meth pretreatment were not influenced by genotype. These data suggest a selective vulnerability of female Met/Met rats to short-term and long-term effects of Meth, which could model increased vulnerability to psychosis development associated with the BDNF Val66Met polymorphism.

Elevated C-reactive protein/albumin ratio in patients with methamphetamine use disorder

BACKGROUND

Methamphetamine use disorder causes significant crises, which have individual, familial, and social consequences. Identifying inflammatory biomarkers for methamphetamine use disorder may be useful for following the inflammatory status of patients in clinical assessment. In this study, we aimed to investigate whether neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), C-reactive protein/albumin ratio (CAR) and neutrophil/albumin ratio (NAR) levels can be used as inflammatory biomarkers in methamphetamine use disorder.

METHODS

The sample comprised 139 treatment-seeking participants who met the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for methamphetamine use disorder and 139 sociodemographically matched controls. Only hospitalised patients were included. An independent sample t-test, Pearson's correlation test, and binominal logistic regression analysis were performed.

RESULTS

CAR (p = 0.016) and NAR (p = 0.048) levels were significantly higher in individuals with methamphetamine use disorder when compared with healthy controls. The CAR level was found to be a significant predictor of group membership in regression analysis for methamphetamine use disorder.

CONCLUSION

CAR may be a potential inflammatory biomarker for patients with methamphetamine use disorder. CAR as a relatively easier-to-measure biomarker could be beneficial to follow the inflammatory status and treatment response of patients.

Impact of long-acting buprenorphine injection on methamphetamine use: A retrospective cohort study

OBJECTIVE

The aim is to assess the impact of long-acting buprenorphine (LAI-BNP) on frequency of methamphetamine (MA) use.

METHODS

We undertook an observational, descriptive, retrospective cohort study of patients of a public, tertiary, community-based Alcohol and Other Drug Service (AODS) with opioid use disorder (OUD) treated with LAI-BNP who are current or past users of MA. We assessed the changes of frequency of use in their MA use at start (baseline), 3 and 6 months of LAI-BNP.

RESULTS

Study included 59 participants. Based on their MA use at the commencement of LAI-BNP, the sample was further sub-grouped as active users (n = 30) and past users (n = 29). At 6 months of LAI-BNP, all the past users remained abstinent from MA use. 70% (n = 21) of participants with active MA use had reduced or ceased their MA use while 17% (n = 5) increased their MA use at 6 months.

CONCLUSIONS

The results favour the use of LAI-BNP as a potential treatment for MA use.

Prescription psychostimulants as a harm reduction and treatment intervention for methamphetamine use disorder and the implications for nursing clinical practice: A scoping review of the literature

The global rise in methamphetamine use and its negative effects warrants the need for research exploring harm reduction and treatment interventions for individuals with methamphetamine use disorder. Agonist medications have been utilized for years for the treatment of heroin and opioid addiction, but have yet to be incorporated into mainstream Canadian practice for methamphetamine dependence. This review aims to provide an overview of the current trends of prescription psychostimulant usage for individuals with methamphetamine use disorder from a Canadian perspective, identifies the barriers to accessing prescription psychostimulants for methamphetamine use disorder and highlights the nursing clinical practice implications in caring for individuals with the disorder. Discourse on the sustained abstinence and harm reduction debate is presented from the perspective of methamphetamine abuse is provided along with the neuropsychiatric complications of chronic methamphetamine use. The impacts of specific prescription psychostimulants on cognition are discussed as is the use of neuroimaging techniques to assess neuronal damage in methamphetamine users. Sign of toxicity, overdose and the contraindications for use of these prescription psychostimulants is also presented. The implications to nursing clinical practice in caring for this population is provided, touching on the clinical presentation of methamphetamine use, completing thorough assessment and screening and patient education. The findings of this review indicate the need for further research in this area exploring the benefits of prescription psychostimulants as a harm reduction and treatment intervention for the global problem of methamphetamine dependence.

Methamphetamine-induced region-specific transcriptomic and epigenetic changes in the brain of male rats

Psychostimulant methamphetamine (METH) is neurotoxic to the brain and, therefore, its misuse leads to neurological and psychiatric disorders. The gene regulatory network (GRN) response to neurotoxic METH binge remains unclear in most brain regions. Here we examined the effects of binge METH on the GRN in the nucleus accumbens, dentate gyrus, Ammon's horn, and subventricular zone in male rats. At 24 h after METH, ~16% of genes displayed altered expression and over a quarter of previously open chromatin regions - parts of the genome where genes are typically active - showed shifts in their accessibility. Intriguingly, most changes were unique to each area studied, and independent regulation between transcriptome and chromatin accessibility was observed. Unexpectedly, METH differentially impacted gene activity and chromatin accessibility within the dentate gyrus and Ammon's horn. Around 70% of the affected chromatin-accessible regions in the rat brain have conserved DNA sequences in the human genome. These regions frequently act as enhancers, ramping up the activity of nearby genes, and contain mutations linked to various neurological conditions. By sketching out the gene regulatory networks associated with binge METH in specific brain regions, our study offers fresh insights into how METH can trigger profound, region-specific molecular shifts.

Species-specific bioaccumulation and risk prioritization of psychoactive substances in cultured fish

Psychoactive substances are becoming new concern in environmental research with their increasing applications and the potential threats to fishery production as these substances could alter the behavior of fish and consequently affect the yield and quality of cultured fish. In this study, the accumulation and risk of twenty psychoactive substances were investigated in five species of cultured fish in Eastern China. The results showed that the total concentrations of these twenty psychoactive substances ranged from 0.15 to 0.92 ng mL^-1 in the plasma among the five species of cultured fish with an order of perch > crucian carp > bighead carp > grass carp > silver carp. Diazepam (DIAZ) and methamphetamine (MAMP) were identified as the most frequently detected compounds, which were found in 100% and 93% of the samples with a median concentration of 0.15 and 0.12 ng mL^-1 in the plasma, respectively. Although all of the psychoactive substances posed low or negligible risk, species-specific analysis of risk prioritization revealed that alprazolam, MAMP, temazepam and DIAZ exhibited the greatest potentials of hazard to all species of the cultured fish but with a species-dependent variation. These findings suggest that the adverse effects of psychoactive substances on fishery production, especially on different species, should be considered.

The D3 receptor antagonist SR 21502 reduces cue-induced reinstatement of methamphetamine-seeking in rats

There is as of yet no FDA-approved medication for methamphetamine use disorder. Although dopamine D3 receptor antagonists have been shown to be useful in reducing methamphetamine seeking in animal models their translation to the clinic has been hindered because currently tested compounds can produce dangerously high blood pressure. Thus, it is important to continue to explore other classes of D3 antagonists. We report here the effects of SR 21502, a selective D3 receptor antagonist, on cue-induced reinstatement (i.e., relapse) of methamphetamine-seeking in rats. In Experiment 1, rats were trained to self-administer methamphetamine under a fixed ratio schedule of reinforcement followed by extinction of the response. Then, animals were tested with one of several doses of SR 21502 on cue-induced reinstatement of responding. SR 21502 significantly reduced cue-induced reinstatement of methamphetamine-seeking. In Experiment 2, animals were trained to lever press for food under a PR schedule and tested with the lowest dose of SR 21502 that caused a significant reduction in Experiment 1. These animals responded on average 8 times more than the vehicle-treated rats in Experiment 1, eliminating the possibility that SR 21502-treated rats in Experiment 1 responded less because they were incapacitated. In summary, these data suggest that SR 21502 may selectively inhibit methamphetamine-seeking and may constitute a promising pharmacotherapeutic agent for methamphetamine or other drug use disorders.

Prevalence and correlates of methamphetamine use in transitional age youth experiencing homelessness or housing instability in San Francisco, CA

INTRODUCTION

Substance use, including methamphetamine use, is a contributing factor in HIV acquisition and treatment. Stimulant use is linked to mental health yet there is limited data from youth in community-based settings.

DESIGN

One hundred marginally housed or homeless transitional age youth (TAY) were recruited at Larkin Street Youth Services and completed a survey on mental health and substance use.

METHODS

We conducted secondary data analysis using multivariable logistic regression models to identify the correlates of methamphetamine use among TAY.

RESULTS

The participants' mean age was 22. Of those who reported methamphetamine use in the past 3 months, 64% were Gay, Bisexual, or Pansexual. Factors independently associated with methamphetamine use were; living with HIV (adjusted odds ratio [aOR] = 3.18, 95% CI = 1.11-9.15), depressive symptoms (aOR = 6.02, 95% CI = 1.46-24.78), symptoms of PTSD (aOR = 13.38, 95% CI = 1.59-112.73), polysubstance use in the past 3 months (aOR = 50.02, 95% CI = 9.72-257.46) and a history of injection drug use (aOR = 8.38, 95% CI = 1.87-37.53).

CONCLUSIONS

Results from this study suggest a need to develop, adapt, and rapidly implement comprehensive interventions that address the combined epidemics of substance use, HIV, and mental health among TAY.

CLINICAL RELEVANCE

This article examines factors associated with methamphetamine use among transitional age youth (TAY) experiencing homelessness or housing instability. Several factors were associated with use, including depression, PTSD, HIV status, polysubstance use, and injection drug use. These findings highlight the need for nurses to assess for methamphetamine use among youth as well as associated mental health and physical health problems. Nurses should link TAY who are using methamphetamine to evidence-based treatment programs to address substance use and comorbid conditions.

"There's a big tag on my head": exploring barriers to treatment seeking with women who use methamphetamine in Sydney, Australia

BACKGROUND

Australia has a high prevalence of regular use of methamphetamine. While half of people who use methamphetamine regularly are women, they make up only one third of people seeking treatment for methamphetamine use disorder. There is a lack of qualitative research into the facilitators and barriers to treatment for women who use methamphetamine regularly. The study seeks a better understanding of the experiences and treatment preferences of women who use methamphetamine, to inform person-centred changes in practice and policy that break down barriers to treatment.

METHODS

We conducted semi-structured interviews with 11 women who frequently use methamphetamine (at least once a week), and who are not engaged in treatment. Women were recruited from health services surrounding a stimulant treatment centre at an inner-city hospital. Participants were asked about their methapmhetamine use and health service needs and preferences. Thematic analysis was completed using Nvivo® software.

RESULTS

Three themes were developed from participants' responses around experiences of regular methamphetamine use and treatment needs: 1. Resistance of stigmatised identity including dependence; 2. Interpersonal violence; 3. Institutionalised stigma. A fourth set of themes on service delivery preferences were also elicited, including continuity of care, integrated health care, and provision of non-judgmental services.

CONCLUSION

Gender-inclusive health care services for people who use methamphetamine should actively work to address stigma, support a relational approach to assessment and treatment, and seek to provide structurally competent health care that is trauma and violence informed, and integrated with other services. Findings may also have application for substance use disorders other than methamphetamine.

Intoxication of dogs and cats with common stimulating, hallucinogenic and dissociative recreational drugs

Pets can have accidental, intentional, or malicious exposure to illicit drugs. It is a growing concern over the last decade because there is an increase in usage of illicit drugs in humans and diagnosis is difficult. Owners are often not aware of exposure, or they are reluctant to admit possession of recreational drugs in the household due to potential legal consequences. In addition, illicit drugs sold on the black market are often adulterated with other substances resulting in non-specific clinical presentation and aggravation of symptoms. There are affordable onsite diagnostic tests on the market which could facilitate diagnosis of intoxication with illicit drugs, but they give a lot of false positive results due to low specificity of the tests. In this paper we gathered information about the most common recreational drugs such as amphetamines, methamphetamine, 3,4-methylenedioxy-methamphetamine (MDMA), phencyclidine (PCP), lysergic acid diethylamide (LSD), psilocybin mushrooms and cocaine in terms of toxicokinetic properties, mechanism of toxic action, clinical presentation and treatment in dogs and cats.

Influence of fecal microbial transplant (FMT) between male and female rats on methamphetamine-induced hyperthermia

OBJECTIVE

To investigate the effect of bidirectional fecal microbial transplant (FMT) between male and female rats on methamphetamine (MA)-induced hyperthermia.

METHODS

FMT was performed between male and female rats prior to MA (10 mg/kg, sc) treatment. Core body temperature, plasma drug and norepinephrine (NE) levels were measured and compared between treatment groups. 16S rRNA gene sequencing of bacterial communities between male and female rats was performed.

RESULTS

MA treatment resulted in significantly higher core body temperatures in male groups (control and FMT-treated) compared to MA-treated female groups (control and FMT-treated). Plasma concentrations of MA and amphetamine were higher in females than males. Whereas, plasma norepinephrine (NE) levels were not different between male and female rats 90 minutes after MA treatment. At the phyla level, the microbiome of male and female control rats were dominated by Firmicutes and Bacteroidetes. Males had a higher relative abundance of Firmicutes and lower relative abundances of Bacteroidetes than females. The FMT procedure changed the recipient group towards their donor with males getting closer to their donors than females. In the control groups following MA treatment, Firmicutes increased and Bacteroides decreased in females and males. Conversely, in the FMT treatment groups following MA treatment, Firmicutes decreased while Bacteroidetes increased in females and males.

CONCLUSIONS

Although definite differences in the structure and diversity of the gut microbiome were observed using 16S rRNA gene sequencing of bacterial communities between male and female rats, these differences do not seem to contribute to the sex-based differences in MA-induced hyperthermia.

Distinct roles for orexin-1 and orexin-2 receptors in the dentate gyrus of the hippocampus in the methamphetamine-seeking behavior in the rats

Because of the relapsing properties of psychostimulants such as methamphetamine (Meth), there is no established pharmacotherapy for Meth addiction. The orexinergic system is a promising target for treating psychostimulant use disorders and relapse. However, to the best of our knowledge, no investigation regarding the role of orexin receptors in the dentate gyrus (DG) region of the hippocampus has been conducted in the extinction and reinstatement of Meth-seeking behavior. Two stainless-steel guide cannulae were bilaterally implanted into the DG of the rats' brains. The unbiased conditioned place preference (CPP) procedure was conducted to induce Meth conditioning. Following the five days Meth injections (1 mg/kg; sc), animals received intra-DG microinjection of SB334867 or TCS OX2 29, as orexin 1 (OX1) or orexin 2 (OX2) receptor antagonists, respectively (without Meth administration) during extinction phase to elucidate the role of orexin receptors in the latency of the extinction period in the Meth-conditioned rats. To evaluate the role of orexin receptors in the DG region in the reinstatement of Meth-seeking behavior, the extinguished rats received SB334867 or TCS OX2 29 before injecting a priming dose of Meth (0.25 mg/kg; sc). The results indicated two distinct roles for the OX1 and OX2 receptors in the DG region. TCS OX2 29 attenuated the extinction latency, and SB334867 considerably reduced the reinstatement of Meth-seeking behavior in this region. Therefore, the DG region's orexinergic system might be a potential therapeutic target for psychostimulant use disorders.

Biochemical Neuroadaptations in the Rat Striatal Dopaminergic System after Prolonged Exposure to Methamphetamine Self-Administration

Perturbations in striatal dopamine (DA) homeostasis might underlie the behavioral and pathobiological consequences of METH use disorder in humans. To identify potential consequences of long-term METH exposure, we modeled the adverse consequence DSM criterion of substance use disorders by giving footshocks to rats that had escalated their intake of METH during a drug self-administration procedure. Next, DA D1 receptor antagonist, SCH23390 was injected. Thereafter, rats were euthanized to measure several indices of the striatal dopaminergic system. Footshocks split the METH rats into two phenotypes: (i) shock-sensitive that decreased their METH-intake and (ii) shock-resistant that continued their METH intake. SCH23390 caused substantial dose-dependent reduction of METH taking in both groups. Stopping SCH23390 caused re-emergence of compulsive METH taking in shock-resistant rats. Compulsive METH takers also exhibited greater incubation of METH seeking than non-compulsive rats during withdrawal from METH SA. Analyses of DA metabolism revealed non-significant decreases (about 35%) in DA levels in resistant and sensitive rats. However, striatal contents of the deaminated metabolites, DOPAL and DOPAC, were significantly increased in sensitive rats. VMAT2 and DAT protein levels were decreased in both phenotypes. Moreover, protein expression levels of the D1-like DA receptor, D5R, and D2-like DA receptors, D3R and D4R, were significantly decreased in the compulsive METH takers. Our results parallel findings in post-mortem striatal tissues of human METH users who develop Parkinsonism after long-term METH intake and support the use of this model to investigate potential therapeutic interventions for METH use disorder.

Knockdown of Piccolo in the Nucleus Accumbens Suppresses Methamphetamine-Induced Hyperlocomotion and Conditioned Place Preference in Mice

Methamphetamine (METH), the most widely distributed psychostimulant, aberrantly activates the reward system in the brain to induce addictive behaviors. The presynaptic protein "Piccolo", encoded by Pclo, was identified as a METH-responsive protein with enhanced expression in the nucleus accumbens (NAc) in mice. Although the physiological and pathological significance of Piccolo has been identified in dopaminergic signaling, its role in METH-induced behavioral abnormalities and the underlying mechanisms remain unclear. To clarify such functions, mice with Piccolo knockdown in the NAc (NAc-miPiccolo mice) by local injection of an adeno-associated virus vector carrying miRNA targeting Pclo were generated and investigated. NAc-miPiccolo mice exhibited suppressed hyperlocomotion, sensitization, and conditioned place preference behavior induced by systemic administration of METH. The excessive release of dopamine in the NAc was reduced in NAc-miPiccolo mice at baseline and in response to METH. These results suggest that Piccolo in the NAc is involved in METH-induced behavioral alterations and is a candidate therapeutic target for the treatment of drug addiction.

Local efficiency analysis of restingstate functional brain network in methamphetamine users

This study set out to assess restingstate functional connectivity (rs-FN) and graph theorybased local efficiency within the left and right hemispheres of methamphetamine (MA) abusers. Functional brain networks of 19 MA abusers and 21 control participants were analyzed using restingstate fMRI. Graph edges in functional networks of the brain were defined and recurrence plot was used. We found that MA abuse may be accompanied by alterations of rs-FN within the defaultmode network (DMN), executive control network (ECN), and the salience network (SN) in both hemispheres of the brain. We also observed that such effects of MA may be correlated with duration of MA abuse and abstinence in many components of the DMN and SN. The results would seem to suggest that MAinduced alterations of local efficiency may, in part, account for maladaptive decision making, deficits in executive function and control over drug seeking/taking, and relapse.

Gut microbiota mediates methamphetamine-induced hepatic inflammation via the impairment of bile acid homeostasis

Methamphetamine (Meth), an addictive psychostimulant of abuse worldwide, has been a common cause of acute toxic hepatitis in adults. Gut microbiota has emerged as a modulator of host immunity via metabolic pathways. However, the microbial mechanism of Meth-induced hepatic inflammation and effective therapeutic strategies remain unknown. Here, mice were intraperitoneally (i.p.) injected with Meth to induce hepatotoxicity. Cecal microbiome and bile acids (BAs) composition were analyzed after Meth administration. Fecal microbiota transplantation (FMT) technology was utilized to investigate the role of microbiota. Additionally, the protective effects of obeticholic acid (OCA), an agonist of farnesoid X receptor (FXR), were evaluated. Results indicated that Meth administration induced hepatic cholestasis, dysfunction and aroused hepatic inflammation by stimulating the TLR4/MyD88/NF-κB pathway in mice. Meanwhile, Meth disturbed the cecal microbiome and impaired the homeostasis of BAs. Interestingly, FMT from Meth administered mice resulted in serum and hepatic BA accumulation and transferred similar phenotypic changes into the healthy recipient mice. Finally, OCA normalized Meth-induced BA accumulation in both serum and the liver, and effectively protected against Meth-induced hepatic dysfunction and inflammation by suppressing the TLR4/MyD88/NF-κB pathway. This study established the importance of microbial mechanism and its inhibition as a potential therapeutic target to treat Meth-related hepatotoxicity.

Related Effects of Methamphetamine on the Intestinal Barrier via Cytokines, and Potential Mechanisms by Which Methamphetamine May Occur on the Brain-Gut Axis

Methamphetamine (METH) is an illegal drug widely abused in many countries. Methamphetamine abuse is a major health and social problem all over the world. However, the effects of METH on the digestive system have rarely been reported. Previous studies and clinical cases have shown that METH use can lead to the impaired intestinal barrier function and severe digestive diseases. METH can cause multiple organ dysfunction, especially in the central nervous system (CNS). The gut microbiota are involved in the development of various CNS-related diseases via the gut-brain axis (GBA). Here, we describe the related effects of METH on the intestinal barrier via cytokines and the underlying mechanisms by which METH may occur in the brain-gut axis.

Methamphetamine Disturbs Gut Homeostasis and Reshapes Serum Metabolome, Inducing Neurotoxicity and Abnormal Behaviors in Mice

As an illicit psychostimulant, repeated methamphetamine (MA) exposure results in addiction and causes severe neurotoxicity. Studies have revealed complex interactions among gut homeostasis, metabolism, and the central nervous system (CNS). To investigate the disturbance of gut homeostasis and metabolism in MA-induced neurotoxicity, 2 mg/kg MA or equal volume saline was intraperitoneally (i.p.) injected into C57BL/6 mice. Behavioral tests and western blotting were used to evaluate neurotoxicity. To determine alterations of colonic dysbiosis, 16s rRNA gene sequencing was performed to analyze the status of gut microbiota, while RNA-sequencing (RNA-seq) and Western Blot analysis were performed to detect colonic damage. Serum metabolome was profiled by LC–MS analysis. We found that MA induced locomotor sensitization, depression-, and anxiety-like behaviors in mice, along with dysfunction of the dopaminergic system and stimulation of autophagy as well as apoptosis in the striatum. Notably, MA significantly decreased microbial diversity and altered the component of microbiota. Moreover, findings from RNA-seq implied stimulation of the inflammation-related pathway after MA treatment. Western blotting confirmed that MA mediated colonic inflammation by activating the TLR4-MyD88-NF-κB pathway and impaired colonic barrier. In addition, serum metabolome was reshaped after MA treatment. Specifically, bacteroides-derived sphingolipids and serotonin were obviously altered, which were closely correlated with locomotor sensitization, depression-, and anxiety-like behaviors. These findings suggest that MA disrupts gut homeostasis by altering its microbiome and arousing inflammation, and reshapes serum metabolome, which provide new insights into understanding the interactions between gut homeostasis and MA-induced neurotoxicity.

Thirdhand smoke from tobacco, e-cigarettes, cannabis, methamphetamine and cocaine: Partitioning, reactive fate, and human exposure in indoor environments

A source of chemical exposure to humans, thirdhand smoke (THS) refers to the contamination that persists indoors following the cessation of a smoking event. The composition of thirdhand smoke depends on the type of substance from which it originates. Although past studies have investigated the effects of tobacco THS on indoor air quality and human health, few have focused on the chemical composition and health impacts of other sources and components of THS. Here we review the state of knowledge of the composition and partitioning behavior of various types of indoor THS, with a focus on THS from tobacco, e-cigarettes, cannabis, and illicit substances (methamphetamine and cocaine). The discussion is supplemented by estimates of human exposure to THS components made with a chemical fate and exposure model. The modeling results show that while very volatile THS compounds (i.e., aromatics) are likely to be taken up by inhalation, highly water-soluble compounds tended to be dermally absorbed. Conversely, minimally volatile THS compounds with low solubility are predicted to be ingested through hand-to-mouth and object-to-mouth contact.

Substance abuse and neurotransmission

The number of people who suffer from a substance abuse disorder has continued to rise over the last decade; particularly, the number of drug-related overdose deaths has sharply increased during the COVID-19 pandemic. Converging lines of clinical observations, supported by imaging and neuropsychological performance testing, have demonstrated that substance abuse-induced dysregulation of neurotransmissions in the brain is critical for development and expression of the addictive properties of abused substances. Recent scientific advances have allowed for better understanding of the neurobiological processes that mediates drugs of abuse and addiction. This chapter presents the past classic concepts and the recent advances in our knowledge about how cocaine, amphetamines, opioids, alcohol, and nicotine alter multiple neurotransmitter systems, which contribute to the behaviors associated with each drug. Additionally, we discuss the interactive effects of HIV-1 or COVID-19 and substance abuse on neurotransmission and neurobiological pathways. Finally, we introduce therapeutic strategies for development of pharmacotherapies for substance abuse disorders.

DFT-D4 Insight into the Inclusion of Amphetamine and Methamphetamine in Cucurbit[7]uril: Energetic, Structural and Biosensing Properties

The host-guest interactions of cucurbit[7]uril (CB[7]) as host and amphetamine (AMP), methamphetamine (MET) and their enantiomeric forms (S-form and R-form) as guests were computationally investigated using density functional theory calculations with the recent D4 atomic-charge dependent dispersion corrections. The analysis of energetic, structural and electronic properties with the aid of frontier molecular orbital analysis, charge decomposition analysis (CDA), extended charge decomposition analysis (ECDA) and independent gradient model (IGM) approach allowed to characterize the host-guest interactions in the studied systems. Energetic results indicate the formation of stable non-covalent complexes where R-AMP@CB[7] and S-AMP@CB[7] are more stable thermodynamically than R-MET@CB[7] and S-MET@CB[7] in gas phase while the reverse is true in water solvent. Based on structural analysis, a recognition mechanism is proposed, which suggests that the synergistic effect of van der Waals forces, ion-dipole interactions, intermolecular charge transfer interactions and intermolecular hydrogen bonding is responsible for the stabilization of the complexes. The geometries of the complexes obtained theoretically are in good agreement with the X-ray experimental structures and indicate that the phenyl ring of amphetamine and methamphetamine is deeply buried into the cavity of CB[7] through hydrophobic interactions while the ammonium group remains outside the cavity to establish hydrogen bonds with the portal oxygen atoms of CB[7].

Effects of cytidine-5'-diphosphate choline on gray matter volumes in methamphetamine-dependent patients: A randomized, double-blind, placebo-controlled study

BACKGROUND

Cytidine-5'-diphosphate choline (CDP-choline) has been suggested to exert neuroprotective and neuroreparative effects and may be beneficial for patients with stimulant dependence. This randomized, double-blind, placebo-controlled study in methamphetamine (MA) dependence investigated effects of CDP-choline on the brain structures and their associations with craving and MA use.

METHODS

MA users (n = 44) were randomized to receive 2 g/day of CDP-choline (n = 22) or placebo (n = 22) for 8 weeks. Patients underwent brain magnetic resonance imaging (MRI) at baseline and 8-week follow-up. Healthy individuals (n = 27) were also examined using brain MRI at the same interval. Voxel-based morphometry analysis was conducted to examine changes in gray matter (GM) volumes and their associations with craving and MA use.

RESULTS

Craving for MA was significantly reduced after the 8 week-treatment with CDP-choline (p = 0.01), but not with the placebo treatment (p = 0.10). There was no significant difference in the total number of MA-negative urine samples between the two groups (p = 0.19). With CDP-choline treatment, GM volumes in the left middle frontal gyrus (p = 0.001), right hippocampus (p = 0.009), and left precuneus (p = 0.001) were significantly increased compared to the placebo and control groups. Increased GM volumes in the left middle frontal gyrus with CDP-choline treatment were associated with reduced craving for MA (Spearman's ρ = -0.56, p = 0.03). In addition, the right hippocampal volume increases were positively associated with the total number of MA-negative urine results in the CDP-choline group (Spearman's ρ = 0.67, p = 0.006).

CONCLUSION

Our findings suggest that CDP-choline may increase GM volumes of MA-dependent patients, which may be related to decreases in MA use and craving.

Increasing emergency department attendances in central London with methamphetamine toxicity and associated harms

BACKGROUND

Methamphetamine is a stimulant drug of abuse with increasing prevalence of use worldwide leading to public health concern. While previous research by our group a decade ago found no evidence of increasing harms associated with methamphetamine use in the UK, there are conflicting data on whether or not this is still the case. This paper aims to identify trends in methamphetamine-related harms and characterise the clinical features of ED presentations involving methamphetamine with gamma-hydroxybutyrate/gamma-butyrolactone (GHB/GBL).

METHODS

We retrospectively interrogated a database of all toxicology-related presentations to two central London EDs, extracting data on drugs involved for presentations relating to methamphetamine between 2005 and 2018 to enable analysis of trends. Further clinical data were extracted for presentations between 2014 and 2018 to give a 4-year case series.

RESULTS

A total of 1244 presentations involving the use of methamphetamine were identified. The number of presentations rose from 4 in 2005 (1.9% of all recreational drug presentations) to 294 (16.2%) in 2018. A total of 850 cases were identified for the 2014-2018 case series, 94.9% were male with a median (range) age of 35.1 (16-67) years. The most common clinical features in the methamphetamine presentations were neuropsychiatric: agitation (41.5%), anxiety (35.2%), hallucinations (16.5%) and psychosis (14.8%). GHB/GBL was co-used in 54.2% of presentations and appeared to attenuate the neuropsychiatric features seen. Use of GHB/GBL was associated with a higher Poisoning Severity Score and requirement for level 2/3 (high dependency unit/intensive care unit (ICU)) care.

CONCLUSION

ED attendances in central London relating to methamphetamine use have risen over the last decade. Combining methamphetamine with GHB/GBL is common and is associated with a higher Poisoning Severity Score and need for ICU level care. Further work is required to establish whether further resources need to be directed at this clinical and public health problem.

Neurotoxicity of methamphetamine: Main effects and mechanisms

Methamphetamine (METH) is an illicit psychostimulant that is abused throughout the world. METH addiction is also a major public health concern and the abuse of large doses of the drug is often associated with serious neuropsychiatric consequences that may include agitation, anxiety, hallucinations, paranoia, and psychosis. Some human methamphetamine users can also suffer from attention, memory, and executive deficits. METH-associated neurological and psychiatric complications might be related, in part, to METH-induced neurotoxic effects. Those include altered dopaminergic and serotonergic functions, neuronal apoptosis, astrocytosis, and microgliosis. Here we have endeavored to discuss some of the main effects of the drug and have presented the evidence supporting certain of the molecular and cellular bases of METH neurotoxicity. The accumulated evidence suggests the involvement of transcription factors, activation of dealth pathways that emanate from mitochondria and endoplasmic reticulum (ER), and a role for neuroinflammatory mechanisms. Understanding the molecular processes involved in METH induced neurotoxicity should help in developing better therapeutic approaches that might also serve to attenuate or block the biological consequences of use of large doses of the drug by some humans who meet criteria for METH use disorder.

Changes in corneal and anterior chamber indices due to methamphetamine abuse

CLINICAL RELEVANCE

Considering the significant relationship between methamphetamine abuse and some anterior segment indices, methamphetamine abuse should be considered in differential diagnosis especially in the case of angle closure glaucoma.

BACKGROUND

To investigate the effect of inhaled methamphetamine (meth) and crystal methamphetamine (crystal meth) on the quantitative indices of the cornea and anterior chamber using pentacam and anterior segment optical coherence tomography.

METHODS

In this cross-sectional study, the participants were (crystal) meth addicts living in Zahedan. The participants were transported to the examination site to undergo imaging and optometric tests. Pentacam and anterior segment optical coherence tomography imaging were then conducted so as to evaluate corneal and anterior chamber quantitative indices.

RESULTS

A total of 42 (crystal) meth addicts and 42 healthy subjects with matching age and gender were examined. Out of 42 subjects in the case group, 6 were female and 36 were male (mean age: 35.7 ± 8.6 years). The mean dose of drug used was 0.0074 ± 0.0034 g, and the mean duration of drug use was 6.9 ± 2.6 years (5-12 years). Based on the images of both devices, corneal curvature was significantly steeper in both meridians of anterior and posterior surfaces compared to the control group (p = 0.01). Among the anterior chamber parameters, the anterior chamber depth and volume were lower in the cases than the controls (p < 0.01). However, the lens rise was higher in addicts than controls (p = 0.01).

CONCLUSION

Quantitative changes in corneal and anterior segment indices including dilated pupils, shallower anterior chamber depth and higher lens rise in addicted cases compared to the control group may precipitate the risk of closed-angle in these individuals.

Overview of Current Practices in the Methamphetamine Testing and Decontamination Industry: An Australian Case Study

To better protect public health from third-hand exposure to methamphetamine, it is important to understand the techniques and current practices used within the methamphetamine testing and decontamination industry in Australia. A survey was conducted focusing on business owners that advertised testing and/or remediation services online. They were also invited to participate in a follow-up phone interview upon completion. The survey demonstrated that testing and decontamination methods were highly varied, which was expected for an industry with no regulation. Most companies offered methamphetamine testing and remediation which could be a conflict of interest. Participants also shared personal experiences, including the conduct of other industry members, demonstrating both poor practice and/or the competitive nature of the business. Participating business owners were following Australian guidelines to the best of their ability, and many are advocates for regulation to be implemented within the industry. This would address the inconsistencies between companies and establish trust for industry members and the public. It would also provide significant public health protection, which is currently lacking. A more consistent approach to the testing and remediation of methamphetamine contamination, aided by regulation, would address the significant risk to public health caused by third-hand exposure to methamphetamine.

Methamphetamine Use, Syphilis, and Specific Online Sex Partner Meeting Venues Are Associated With HIV Status Among Urban Black Gay and Bisexual Men Who Have Sex Men

BACKGROUND

In the context of increasing syphilis rates, particularly among Black men who have sex men (MSM), the objectives were to determine the associations between methamphetamine (meth) use and syphilis and HIV positivity, and to identify sex partner meeting venues as potential intervention access points among Black MSM in a mid-Atlantic US city.

METHODS

This study is an ongoing longitudinal cohort study. Participants were recruited from clinical and nonclinical settings and included sexually active MSM aged 18 to 45 years. The baseline visit included a behavioral survey and testing for syphilis, HIV, gonorrhea, and chlamydia. Logistic regression analyses were used for hypothesis testing.

RESULTS

Among 359 MSM completing baseline, 74.4% (268) Black MSM were included; 31% (84) were aged 24 to 29 years, 43.7% (117) reported unprotected anal intercourse at last sex, and 15.3% (41) reported meth use in the past 3 months. Sixteen percent (43) had syphilis, 46.6% (125) were living with HIV, and 19.0% (51) had gonorrhea and/or chlamydia. Meth use was associated with sexual and drug risk behaviors and HIV, but not syphilis. In adjusted analyses, meth use increased the odds of HIV positivity by 6.43 (95% confidence interval, 2.30-17.98) and syphilis positivity by 2.57 (95% confidence interval, 1.23-5.37). Four online sex partner meeting venues were associated with meth use and HIV, whereas syphilis was associated with one.

CONCLUSIONS

Among Black MSM, meth use and syphilis positivity were associated with more than 6-fold and almost 3-fold increased adjusted odds of HIV positivity, respectively. Four specific sex partner meeting venues may be important access points for HIV/sexually transmitted infection and substance use prevention.

Assessment of demand for methamphetamine and cigarettes among individuals with methamphetamine use disorder

Methamphetamine (MA) is a highly addictive stimulant with recent upward trends in prevalence and associated public health problems. Drug demand, as assessed by hypothetical purchasing tasks, has been useful in addictions research and may help our understanding of the factors influencing MA use. However, no studies have assessed MA demand using current models of demand. The purpose of the current study was to assess demand for MA using a hypothetical drug purchasing task. Given high rates of cigarette smoking among MA users, it was of interest also to assess and compare demand for MA relative to cigarettes. Participants consisted of non-treatment-seeking volunteers with MA use disorder (N = 18), of whom 17 reported daily smoking. Results showed the exponentiated demand model provided a good fit to consumption data. Results from Bayesian generalized linear modeling demonstrated multiple positive relationships (posterior probability ≥75%) between self-reported drug use (days MA used in the past 30 days, cigarettes smoked per day) and indices of demand for each drug (Qo, Omax, Pmax, and break point). Comparing MA to cigarettes, results from Bayesian generalized linear mixed modeling revealed greater abuse liability for MA compared to cigarettes (posterior probability ≥99%) based on α and essential value. Overall, the findings of the current study support the feasibility and validity of the exponentiated demand model for assessing demand for drugs among individuals with MA use disorder. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Methamphetamine exposure induces neuronal programmed necrosis by activating the receptor-interacting protein kinase 3 -related signalling pathway

Methamphetamine (METH) is a synthetic drug with severe neurotoxicity, however, the regulation of METH-induced neuronal programmed necrosis remains poorly understood. The aim of this study was to identify the molecular mechanisms of METH-induced neuronal programmed necrosis. We found that neuronal programmed necrosis occurred in the striatum of brain samples from human and mice that were exposed to METH. The receptor-interacting protein kinase 3 (RIP3) was highly expressed in the neurons of human and mice exposed to METH, and RIP3-silenced or RIP1-inhibited protected neurons developed neuronal programmed necrosis in vitro and in vivo following METH exposure. Moreover, the RIP1-RIP3 complex causes cell programmed necrosis by regulating mixed lineage kinase domain-like protein (MLKL)-mediated cell membrane rupture and dynamin-related protein 1 (Drp1)-mediated mitochondrial fission. Together, these data indicate that RIP3 plays an indispensable role in the mechanism of METH-induced neuronal programmed necrosis, which may represent a potential therapeutic target for METH-induced neurotoxicity.

Age-specific treatment effects of orexin/hypocretin-receptor antagonism on methamphetamine-seeking behavior

BACKGROUND

Worldwide methamphetamine (METH) use has increased significantly over the last 10 years, and in the US, METH dependence has sky-rocketed among individuals with opioid use disorder. Of significant concern, METH use is gaining popularity among groups with susceptibility to developing severe substance use disorders, such as women and adolescents. Nevertheless, there is no established pharmacotherapy for METH addiction. Emerging evidence has identified the orexin/hypocretin system as an important modulator of reward-driven behavior and a potential target for the treatment of drug addiction and relapse. However, to date, there have been no investigations into the therapeutic efficacy of orexin/hypocretin receptor antagonists for METH-motivated behavior in adolescents or adults. In the present study, we examined the effects of selective antagonists of the orexin-1 (SB-334867, 20 mg/kg) and orexin-2 (TCS-OX2-29, 20 mg/kg) receptors on the reinstatement of METH seeking in both adolescent and adult male and female rats.

METHODS

Rats were trained to self-administer METH (0.05 mg/kg/inf, iv) during two 2-h sessions/day for 5 days. Following 20 sessions of extinction over 10 days, a within-subjects design was used to test for METH seeking precipitated by METH (1 mg/kg, ip) or METH cues after systemic pretreatment with SB-334867 or TCS-OX2-29.

RESULTS

SB-334867 reduced cue-induced reinstatement in males and females, regardless of age. Additionally, METH-induced METH seeking was attenuated by SB-334867 in adolescents and by TCS-OX2-29 in adults.

CONCLUSION

Selective orexin/hypocretin receptor antagonists have significant therapeutic potential for diminishing METH-seeking behavior, although their treatment efficacy may be influenced by age.

The effects of minocycline in improving of methamphetamine withdrawal syndrome in male mice

Methamphetamine (METH) is a potent psychostimulant drug with an increasing rate of abuse over recent years. Depressive-like behaviors are one of the major symptoms patients in the METH withdrawal period experience. There is limited evidence regarding the METH withdrawal treatment, and conventional managements are not completely effective. Furthermore, extensive promising literature supports minocycline, a well-known antibiotic with anti-oxidant, anti-inflammatory properties, to treat depressive-like behaviors. Therefore, we hypothesized that administration of minocycline might mitigate the methamphetamine (METH) induced depression in male mice. Administration of METH (2 mg/kg) to mice two times a day for 14 constitutive days was done to induce the METH-induced withdrawal syndrome model. Animals were divided into 10 groups (n = 10 in each group), and three doses of minocycline (2.5, 5 and 10 mg/kg) were daily administered to male albino mice for 10 days. Following the behavioral test, the animals were scarified, their hippocampus were dissected to measure oxidative stress parameters. Our data revealed that chronic administration of minocycline provoked antidepressant effects in behavioral tests, such as forced swim test (FST), tail suspension test (TST) and splash test. Additionally, minocycline was able to improve oxidative stresses and neuronal damage in the hippocampus and restore the body's antioxidant system by increasing glutathione (GSH) and the cellular energy (ATP) and reducing the malondialdehyde (MDA) level. According to our promising results of minocycline on targeting mitochondria and its performance, we suggest minocycline as a new therapeutic option in clinical trials of depression treatment.

Methamphetamine in Orthopaedics: Considerations of an At-Risk Population

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Methamphetamine use by orthopaedic trauma patients has risen to epidemic proportions.

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Perioperative methamphetamine use by orthopaedic trauma patients requires physicians to consider both medical and psychosocial factors during treatment.

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Behavioral and psychosocial effects of methamphetamine use present barriers to care.

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Patients who use methamphetamine face elevated rates of complications.

The application of harm reduction to methamphetamine use during pregnancy: a call to arms

Compared with opioid use disorder, methamphetamine use is a public health crisis that has limited evidence-based pharmacologic interventions for long-term treatment. The prevalence of methamphetamine use during pregnancy is growing and contributes to adverse maternal and neonatal outcomes. Because of widespread stigma and social complexities associated with methamphetamine use during pregnancy, these patients often experience limited prenatal care, further contributing to poor outcomes. In public health circles, harm reduction describes a framework for conceptualizing substance use by championing health promotion and the safest use of substances, as opposed to the unachievable goal of abstinence. There is limited evidence supporting the application of harm reduction in this population. We call for action and research to investigate how the progressive concept of harm reduction might be applied to mitigate adverse outcomes for obstetrical patients who use methamphetamine.

Methamphetamine-Induced Keratitis Case Series

ABSTRACT

Methamphetamine-induced keratitis is a recognized but not widely studied cause of corneal stromalysis and infections. These 2 cases describe the presentation and clinical course of keratitis in patients with preceding methamphetamine use.

Quantitation of Methamphetamine and Amphetamine in Postmortem Canine Tissues and Fluids

The production and use of the highly addictive stimulant methamphetamine are a serious public health problem in the United States and globally. Because of its increased popularity with recreational drug users, accidental or intentional poisoning incidents in companion animals have become an unavoidable scenario in veterinary medicine. We describe a case of methamphetamine poisoning in a 4-year-old female German Shepherd with postmortem analytical quantitation of methamphetamine and its metabolite, amphetamine, in bodily tissues and fluids. Many tissues and bodily fluids can be tested to confirm methamphetamine exposure. More importantly, the higher concentrations found in stomach contents, liver, kidney and heart tissue suggest these are the most useful diagnostic specimens for postmortem confirmation of toxicosis in pets especially in cases in which source material is not available for testing or in cases with no postmortem evaluation.

Spinal cord infarction in a young patient with methamphetamine abuse

We report a case of a 20-year-old man who was diagnosed with spontaneous spinal cord infarction after abusing methamphetamine for a year. He presented with sudden onset of bilateral upper and lower limb weakness. His MRI spine showed a long segment of high signal intensity seen predominantly in the anterior spinal cord from medulla to mid thoracic level as well as a pencil-like hyperintensity seen postcontrast suggestive of spinal cord ischaemia or infarct. Thus, he was empirically treated for presumed anterior spinal cord infarction. He then developed autonomic dysfunction and went into respiratory distress, which required invasive mechanical ventilation support. Subsequently, he developed cardiac arrythmia with supraventricular tachycardiac followed by asystole and succumbed to illness on day 9 despite maximal resuscitative efforts. This case report illustrates a rare spinal cord infarction caused by methamphetamine intoxication and the importance of identifying and treating it early.

Prevalence of Amphetamine-Type Stimulant Use and Related Factors among Methadone Maintenance Patients in Ho Chi Minh City Vietnam: A Cross-Sectional Study

The objective of this study was to determine the prevalence of amphetamine-type stimulant use and associated factors among methadone maintenance treatment (MMT) patients. In 2018, a cross-sectional study was conducted on 967 MMT patients at two methadone clinics in Ho Chi Minh City that serve Vietnamese patients. Amphetamine-type stimulant use was assessed by rapid urine test and face-to-face interview using the Alcohol, Smoking, Substance Involvement Screening Test (ASSIST) tool. The prevalence of amphetamine-type stimulant use assessed by urine test was 25.4%. According to ASSIST, the prevalence of moderate and high risk amphetamine-type stimulant use was 15.5% and 1.1%, respectively. Amphetamine-type stimulant use and hazardous use were more prevalent in younger patients, having a part-time job, drug injection, having a lower score of self-health assessment, treated with a higher dose of methadone and missing methadone dose in the past 3 months. By contrast, patients who were HIV positive were less likely to use amphetamine-type stimulants. Cannabis and heroin use were significantly associated with amphetamine-type stimulant use (OR = 1.46; 95% CI: 1.38-8.67; and OR = 1.50; CI: 1.04-2.18, respectively) and hazardous use (OR = 4.07; CI: 1.67-9.92; and OR = 2.38; CI: 1.56-3.63, respectively). Screening and interventions are needed to cope with this issue on time, particularly in young patients, having drug injection and concurrent drugs user groups.

Recent Increase in Methamphetamine Use in a Cohort of Rural People Who Use Drugs: Further Evidence for the Emergence of Twin Epidemics

Appalachian Kentucky was at the epicenter of the prescription opioid epidemic in the early 2000's. As we enter the third decade of the epidemic, patterns have begun to emerge as people who use drugs (PWUD) transition from use of opioids to other drugs. The purpose of this analysis was to examine longitudinal changes in methamphetamine use in an ongoing cohort of rural people who use drugs (PWUD) in Appalachian Kentucky. All but five of the cohort participants (N = 503) reported nonmedical prescription opioid use (NMPOU) at baseline and those 498 are included in this longitudinal analysis encompassing eight waves of data (2008-2020). Past 6-month use of methamphetamine was the dependent variable. Given the correlated nature of the data, mixed effects logistic regression was utilized to examine changes in methamphetamine use over time. Significant increases in methamphetamine use were observed over the past decade in this cohort of PWUD, especially in recent years (2017-2020). Prevalence of recent use at baseline and each of the follow-up visits was as follows: 9.4, 5.6, 5.0, 5.4, 8.1, 6.8, 6.9, and 33.1%, respectively (p < 0.001). On the contrary, significant reductions in NMPO and heroin use were observed in the same time period. The odds of methamphetamine use at the most recent visit were 25.8 times greater than at baseline (95% CI: 14.9, 44.6) and 52.6% of those reporting methamphetamine use reported injecting the drug. These results provide further evidence of "twin epidemics" of methamphetamine use among NMPOU. While problematic on several fronts, of particular concern is the lack of effective treatment options for methamphetamine use disorder. As policies around the opioid epidemic continue to evolve, particular attention should be paid to the surge in stimulant use in opioid-endemic areas.

Role of the central amygdala in acupuncture inhibition of methamphetamine-induced behaviors in rats

Methamphetamine (METH) enhances dopamine (DA) transmission in the mesolimbic system implicated in its reinforcing effects. Our previous studies have shown that acupuncture attenuates drug-seeking behaviors by modulating GABAergic transmission in the ventral tegmental area and DA release in the nucleus accumbens (NAc) of the striatum. The effects of acupuncture on METH-induced behaviors and its mediation by neural pathways remain a relatively understudied area of research. The central amygdala (CeA) plays a critical role in physiological and behavioral responses to somatosensory and drug stimuli and has been implicated in negative reinforcement. Thus, we evaluated the role of the CeA in acupuncture effects on locomotor activity, positive affective states, and DA release in the NAc following acute administration of METH. Acupuncture at acupoint HT7 reduced locomotor activity, 50-kHz ultrasonic vocalizations (USVs), and NAc DA release following systemic injection of METH, which was prevented by electrolytic lesions or optogenetic inhibition of the CeA. Acupuncture alone excited CeA neurons and reversed the suppression of CeA neurons induced by METH. These results suggest that acupuncture can relieve psychomotor responses and positive affective states following METH by inhibiting NAc DA release and this effect is mediated by activation of CeA neurons.

Intestinal mRNA expression profile and bioinformatics analysis in a methamphetamine-induced mouse model of inflammatory bowel disease

Background

Methamphetamine use has become a serious global public health problem and puts increasing burdens on healthcare services. Abdominal complications caused by methamphetamine use are uncommon and often go ignored by clinicians. The exact intestinal pathological alterations and transcriptomic responses associated with methamphetamine use are not well understood. This study sought to investigate the transcriptome in a methamphetamine-induced mouse model of inflammatory bowel disease (IBD) using next-generation RNA sequencing.

Methods

Tissues from the ileum of methamphetamine-treated mice (n=5) and control mice (n=5) were dissected, processed and applied to RNA-sequencing. Bioinformatics and histopathological analysis were then performed. The expression profiles of intestinal tissue samples were analyzed and their expression profiles were integrated to obtain the differentially expressed genes and analyzed using bioinformatics. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the differentially expressed genes were performed using Metascape.

Results

A total of 326 differentially expressed genes were identified; of these genes, 120 were upregulated and 206 were downregulated. The Gene Ontology analysis showed that the biological processes of the differentially expressed genes were focused primarily on the regulation of cellular catabolic processes, endocytosis, and autophagy. The main cellular components included the endoplasmic and endocytic vesicles, cytoskeleton, adherens junctions, focal adhesions, cell body, and lysosomes. Molecular functions included protein transferase, GTPase and proteinase activities, actin-binding, and protein-lipid complex binding. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the differentially expressed genes were mainly involved in bacterial invasion of epithelial cells, protein processing in the endoplasmic reticulum, regulation of the actin cytoskeleton, and T-cell receptor signaling pathways. A set of overlapping genes between IBD and methamphetamine-treated intestinal tissues was discovered.

Conclusions

The present study is the first to analyze intestinal samples from methamphetamine-treated mice using high-throughput RNA sequencing. This study revealed key molecules that might be involved in the pathogenesis of a special type of methamphetamine-induced IBD. These results offer new insights into the relationship between methamphetamine abuse and IBD.