Acute physiological and behavioral effects of intranasal methamphetamine in humans

The influence of drug class on reward in substance use disorders

In the United States, the societal costs associated with drug use surpass $500 billion annually. The rewarding and reinforcing properties that drive the use of these addictive substances are typically examined concerning the neurobiological effects responsible for their abuse potential. In this review, terms such as "abuse potential," "drug," and "addictive properties" are used due to their relevance to the methodological, theoretical, and conceptual framework for understanding the phenomenon of drug-taking behavior and the associated body of preclinical and clinical literature. The use of these terms is not intended to cast aspersions on individuals with substance use disorders (SUD). Understanding what motivates substance use has been a focus of SUD research for decades. Much of this corpus of work has focused on the shared effects of each drug class to increase dopaminergic transmission within the central reward pathways of the brain, or the "reward center." However, the precise influence of each drug class on dopamine signaling, and the extent thereof, differs considerably. Furthermore, the aforementioned substances have effects on several neurobiological targets that mediate and modulate their addictive properties. The current manuscript sought to review the influence of drug class on the rewarding effects of each of the major pharmacological classes of addictive drugs (i.e., psychostimulants, opioids, nicotine, alcohol, and cannabinoids). Our review suggests that even subtle differences in drug effects can result in significant variability in the subjective experience of the drug, altering rewarding and other reinforcing effects. Additionally, this review will argue that reward (i.e., the attractive and motivational property of a stimulus) alone is not sufficient to explain the abuse liability of these substances. Instead, abuse potential is best examined as a function of both positive and negative reinforcing drug effects (i.e., stimuli that the subject will work to attain and stimuli that the subject will work to end or avoid, respectively). Though reward is central to drug use, the factors that motivate and maintain drug taking are varied and complex, with much to be elucidated.

Trait anger as a predictor of dangerous driving behaviour amongst people who use methamphetamine

INTRODUCTION

Despite increased prevalence of methamphetamine in road trauma, it remains unclear how its use translates to an increased risk of traffic-related harm. Exploration of psychosocial factors may thus help identify relevant predictors of dangerous driving behaviour among people who regularly consume methamphetamine.

METHODS

Licenced individuals who report predominant and sustained methamphetamine use (at least 1-time/month for 6 months at heaviest use) were recruited from the Australian community and via targeted campaign (Eastern Health). Psychosocial, substance use and driving behaviour data (Dula Dangerous Driving Index, DDDI) were collected via a secure anonymous online forced-entry survey platform (Qualtrics).

RESULTS

Seventy-seven individuals (65.5 % male) aged between 20-50 years [mean = 29.7, ± Standard Deviation (SD) 6.1] were included. Most (90 %) respondents met criteria for problematic methamphetamine use [Severity of Dependency Scale (SDS) score ≥ 5], and 75 % were high-risk alcohol consumers [Alcohol Use Disorders Identification Test (AUDIT-C) score ≥ 4 for men and ≥ 3 for women]. On average, age of first methamphetamine use occurred at 23.3 years (±5.2). A best-possible subset's regression selection method with dangerous driving behaviour as the dependent variable determined the model with three predictors (alcohol use, substance dependence severity and trait anger) as most parsimonious. After controlling for substance use, trait anger strongly and positively predicted dangerous driving behaviour as measured by the DDDI ([F(3,74) = 26.06, p < .001, adjusted R2 = 0.50, Cohens f2 = 0.42).

DISCUSSION AND CONCLUSIONS

Trait anger is a strong predictor of risky driving among road users who use methamphetamine. Interactions between stable negative-emotional and situational traffic and driving-related factors may increase risk of harm through greater engagement in risk-taking behaviour.

Cardiomyopathy in Patients With Acute Ischemic Stroke and Methamphetamine Use: Relevance for Cardioembolic Stroke and Outcome

BACKGROUND

Methamphetamine use has emerged as a major risk factor for cardiovascular and cerebrovascular disease in young adults. The aim of this study was to investigate a possible association of methamphetamine use with cardioembolic stroke.

METHODS AND RESULTS

We performed a retrospective study of patients with acute ischemic stroke admitted at our medical center between 2019 and 2022. All patients were screened for methamphetamine use and cardiomyopathy, defined as left ventricular ejection fraction ≤45%. Among 938 consecutive patients, 46 (4.9%) were identified as using methamphetamine. Compared with the nonmethamphetamine group (n=892), the methamphetamine group was significantly younger (52.8±9.6 versus 69.7±15.2 years; P<0.001), included more men (78.3% versus 52.8%; P<0.001), and had a significantly higher rate of cardiomyopathy (30.4% versus 14.0%; P<0.01). They were also less likely to have a history of atrial fibrillation (8.7% versus 33.4%; P<0.01) or hyperlipidemia (28.3% versus 51.7%; P<0.01). Compared with patients with cardiomyopathy without methamphetamine use, the patients with cardiomyopathy with methamphetamine use had significantly lower left ventricular ejection fraction (26.0±9.59% versus 32.47±9.52%; P<0.01) but better functional outcome at 3 months, likely attributable to significantly younger age and fewer comorbidities. In the logistic regression model of clinical variables, methamphetamine-associated cardiomyopathy was found to be significantly associated with cardioembolic stroke (odds ratio, 1.79 [95% CI, 1.04-3.06]; P<0.05).

CONCLUSIONS

We demonstrate that methamphetamine use is significantly associated with cardiomyopathy and cardioembolic stroke in young adults.

A systematic review and meta-analysis of health, functional, and cognitive outcomes in young people who use methamphetamine

Methamphetamine use typically starts in adolescence, and early onset is associated with worse outcomes. Yet, health, functional, and cognitive outcomes associated with methamphetamine use in young people are not well understood. The aim of this study was to comprehensively assess the evidence on health, functional, and cognitive outcomes in young people (10-25 years-old) who use methamphetamine. Sixty-six studies were included. The strongest association observed was with conduct disorder, with young people who use methamphetamine some 13 times more likely to meet conduct disorder criteria than controls. They were also more likely to have justice system involvement and to perpetrate violence against others. Educational problems were consistently associated with youth methamphetamine use. The cognitive domain most reliably implicated was inhibitory control. Key limitations in the literature were identified, including heterogenous measurement of exposure and outcomes, lack of adequate controls, and limited longitudinal evidence. Outcomes identified in the present review - suggesting complex and clinically significant behavioural issues in this population - are informative for the development of future research and targeted treatments.

Serum Methamphetamine Positivity in Trauma Patients Undergoing Surgery has No Negative Effect on Postoperative Morbidity and Mortality

Introduction

The link between methamphetamine (METH) use and mortality or morbidity, particularly perioperative complications, associated with trauma surgery are not well characterized. This study aims to address this by performing a comparison of surgical outcomes between METH-negative (METH-) and METH-positive (METH+) trauma patients.

Methods

An Institutional Review Board-approved retrospective chart review was performed on all trauma patients admitted to our Level 1 trauma center who underwent surgical operations between 2015 and 2020. Patients were categorized into METH- and METH+ groups. Patient characteristics such as age, sex, race, Injury Severity Score (ISS), presence of peri-operative complications, and mortality, amongst others, were used to perform univariate comparisons. Additional multi-variate comparisons were performed across both the whole cohort and with age, sex, and ISS-matched groups.

Results

Of 571 patients who met the final inclusion criteria, 421 were METH- and 150 METH+. The METH+ group also possessed a lower median ISS (P = 0.0478) and did not possess significantly different mortality or morbidity than their METH- counterparts in univariate analysis. Multivariate analysis in whole-group and matched-group cohorts indicated that METH was not a positive predictor of mortality or morbidity. Instead, ISS predicted mortality (P = 0.048) and morbidity (P < 0.001).

Conclusion

Our results suggest that METH use does not exert a positive effect on mortality or morbidity in the acute trauma surgery setting and that ISS may be a more significant contributor, suggesting severity, and etiology of injury are also important considerations for trauma surgery evaluation.

Methamphetamine use increases the risk of cerebral small vessel disease in young patients with acute ischemic stroke

Methamphetamine use causes spikes in blood pressure. Chronic hypertension is a major risk factor for cerebral small vessel disease (cSVD). The aim of this study is to investigate whether methamphetamine use increases the risk of cSVD. Consecutive patients with acute ischemic stroke at our medical center were screened for methamphetamine use and evidence of cSVD on MRI of the brain. Methamphetamine use was identified by self-reported history and/or positive urine drug screen. Propensity score matching was used to select non-methamphetamine controls. Sensitivity analysis was performed to assess the effect of methamphetamine use on cSVD. Among 1369 eligible patients, 61 (4.5%) were identified to have a history of methamphetamine use and/or positive urine drug screen. Compared with the non-methamphetamine group (n = 1306), the patients with methamphetamine abuse were significantly younger (54.5 ± 9.7 vs. 70.5 ± 12.4, p < 0.001), male (78.7% vs. 54.0%, p < 0.001) and White (78.7% vs. 50.4%, p < 0.001). Sensitivity analysis showed that methamphetamine use was associated with increased white matter hyperintensities, lacunes, and total burden of cSVD. The association was independent of age, sex, concomitant cocaine use, hyperlipidemia, acute hypertension, and stroke severity. Our findings suggest that methamphetamine use increases the risk of cSVD in young patients with acute ischemic stroke.

Acupuncture for protracted amphetamine abstinence syndrome: study protocol for a systematic review and meta-analysis

INTRODUCTION

Amphetamine-type stimulants (ATSs) are presenting a great challenge to global public health along with its worldwide abuse in recent years. Protracted amphetamine abstinence syndrome (PAAS) is one of the primary causes of relapse for ATS abusers during withdrawal. However, different conclusions are reached by previous trials. This study is designed to evaluate the efficacy and safety of acupuncture in treating PAAS.

METHODS AND ANALYSIS

Cochrane Central Register of Controlled Trials, PubMed, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, ProQuest Dissertation and Theses, Allied and Complementary Medicine Database (AMED), ClinicalTrials.gov and who.int/trialsearch will be searched from the inception to February 2023 and language will be restricted to English and Chinese. Eligible randomised controlled trials will be included. The primary outcome is the intensity of withdrawal syndrome. The secondary outcomes include: (1) intensity of pain, anxiety, depression and other associated symptoms; (2) number of participants with relapse; (3) retention of treatment and (4) nature and rate of adverse effects. Data synthesis will be performed by using RevMan (V.5.4). The quality of evidence will be evaluated by the Grading of Recommendations, Assessment, Development and Evaluation approach. This study will strictly adhere to the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines.

ETHICS AND DISSEMINATION

Ethical approval is not required as this is a systematic review and meta-analysis based on previously published studies that do not involve patients' privacy. The results of this study will be disseminated in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022297761.

Neurocognitive Functions Related to Parietal Lobe in Patients with Schizophrenia and Methamphetamine Induced Psychotic Disorder and Healthy Individuals: A Comparative Study

BACKGROUND

There are some inconsistent findings about neurocognitive functions in schizophrenia and methamphetamine induced psychosis (MIP). This study aimed to compare these two disorders in terms of neurocognitive functions related to parietal lobe.

METHODS

This was a cross-sectional study in which 30 patients with schizophrenia, 30 patients with MIP, and 32 healthy individuals were compared. The two groups of patients were selected through convenience sampling from among patients hospitalized in Shahid Beheshti hospital in Kerman, Iran and healthy individuals were selected via convenience sampling from among the employees of Kerman University of Medical Sciences. The three groups were administered clock-drawing test (CDT), Rey-Osterrieth complex figure (ROCF) copying test, and interlocking finger test (IFT) and their demographic and clinical data were collected. The one-way analysis of variance (ANOVA) was used to investigate the differences between the groups. Multivariate analysis of covariance was also used to examine the effects of confounding factors. Besides, follow-up pairwise comparisons were performed after adjustment for multiple testing.

FINDINGS

The group with schizophrenia had significantly more impairment than the group with MIP with reference to the results of IFT and the ROCF test. However, the scores of patients with MIP on these two tests were not different from those of the normal controls. With regard to the CDT, the only significant difference was observed between the group with schizophrenia and controls.

CONCLUSION

On the condition that the results are replicated in other studies, some parietal lobe neurocognitive tests might be used when it is difficult to differentially diagnose schizophrenia and MIP.

Atypical presentation and diagnosis of AIDS-related CMV encephalitis

We report a case of man in his 40s with a medical history of post-traumatic stress disorder who presented to the emergency department with altered mental status, ataxia, headache and dizziness a few hours after snorting amphetamines and mushrooms. Twenty-four hours after presentation, while no longer abusing amphetamines or mushrooms, he remained ataxic and dizzy. A CT scan of the head showed periventricular hypodensities. MRI of the brain revealed extensive confluent T2 hyperintense signal throughout the cerebral white matter, brainstem and cerebellar white matter. Given these findings and persistent ataxia, lumbar puncture was performed, and cerebrospinal fluid (CSF) meningoencephalitis panel was positive for cytomegalovirus (CMV), prompting a diagnosis of CMV encephalitis. Since CMV almost always occurs in the setting of immunocompromise, the patient was screened for HIV and found to be positive with a CD4 count of 22. He was treated with ganciclovir 5 mg/kg/dose intravenously every 12 hours, with resolution of all symptoms.

Methamphetamine induces transcriptional changes in cultured HIV-infected mature monocytes that may contribute to HIV neuropathogenesis

HIV-associated neurocognitive impairment (HIV-NCI) persists in 15-40% of people with HIV (PWH) despite effective antiretroviral therapy. HIV-NCI significantly impacts quality of life, and there is currently no effective treatment for it. The development of HIV-NCI is complex and is mediated, in part, by the entry of HIV-infected mature monocytes into the central nervous system (CNS). Once in the CNS, these cells release inflammatory mediators that lead to neuroinflammation, and subsequent neuronal damage. Infected monocytes may infect other CNS cells as well as differentiate into macrophages, thus contributing to viral reservoirs and chronic neuroinflammation. Substance use disorders in PWH, including the use of methamphetamine (meth), can exacerbate HIV neuropathogenesis. We characterized the effects of meth on the transcriptional profile of HIV-infected mature monocytes using RNA-sequencing. We found that meth mediated an upregulation of gene transcripts related to viral infection, cell adhesion, cytoskeletal arrangement, and extracellular matrix remodeling. We also identified downregulation of several gene transcripts involved in pathogen recognition, antigen presentation, and oxidative phosphorylation pathways. These transcriptomic changes suggest that meth increases the infiltration of mature monocytes that have a migratory phenotype into the CNS, contributing to dysregulated inflammatory responses and viral reservoir establishment and persistence, both of which contribute to neuronal damage. Overall, our results highlight potential molecules that may be targeted for therapy to limit the effects of meth on HIV neuropathogenesis.

Methamphetamine, amphetamine, and aggression in humans: A systematic review of drug administration studies

The relationship between amphetamine use and aggressive or violent behaviour is unclear. This review examined laboratory data collected in humans, who were administered an acute dose of amphetamine or methamphetamine, in order to investigate the link between amphetamines and aggression. It is registered with PROSPERO (CRD42019127711). Included in the analysis are data from twenty-eight studies. Behavioural and/or subjective measures of aggression were assessed in one thousand and sixty-nine research participants, with limited amphetamine-use histories, following a single amphetamine dose (0-35mg). The available published evidence indicates that neither amphetamine nor methamphetamine acutely increased aggression as assessed by traditional laboratory measures. Future research should assess supratherapeutic amphetamine doses as well as include a broader range of multiple aggression measures, facilitating simultaneous assessment of the various components that comprise this complex, multifaceted construct.

Cardiovascular disease associated with methamphetamine use: a review

Methamphetamine abuse is a global epidemic associated with a wide-ranging array of adverse effects on the cardiovascular system including dilated cardiomyopathy, malignant and benign arrhythmias, coronary vasospasm, and atherosclerotic coronary artery disease. While the acute behavioral manifestations of amphetamine abuse are the most easily clinically identified, cardiovascular toxicity is common in this patient population and should be considered in this setting due to its high morbidity and mortality. The specific mechanisms for amphetamine cardiotoxicity have not been fully established, but new research implicates activation of several cellular targets including Sigma-1 receptors and trace amine-associated receptor 1 (TAAR1) leading to a myriad of negative downstream effects including increased reactive oxygenating species (ROS), mitochondrial dysfunction, and modulations of intracellular calcium. Additional pathologic effects are mediated by increased circulating catecholamines, which when chronically activated have well-established adverse effects on the cardiovascular system. In this article, we present a case report followed by a current review of the epidemiology, pathophysiology, diagnosis, and treatment modalities of amphetamine-induced cardiovascular disease.

The effects of acute oral naltrexone pretreatment on the abuse potential of intranasal methamphetamine, and the relationship between reward/punishment sensitivity and methamphetamine's effects

One potential medication for treating methamphetamine use disorder is the opioid antagonist naltrexone (NLTX). Despite encouraging preclinical findings, the results of clinical studies have been mixed. The primary aim of the current trial was to examine the effects of acute NLTX pretreatment on the subjective and reinforcing effects of intranasal methamphetamine. Nonmedical psychostimulant users completed outpatient testing sessions in which they received oral placebo (0 mg) or NLTX (50 mg) before intranasal methamphetamine (30 mg/70 kg). Primary outcome measures were peak positive subjective effects (e.g. drug 'Liking') assessed on a visual analog scale (0-100), and methamphetamine self-administration using an operant self-administration task. Participants also completed a probabilistic categorization task to assess reward and punishment learning sensitivity. Complete data were available from 13 male and 1 transgender (male-to-female) participant (age: 33.4 ± 7.6 years). Intranasal methamphetamine significantly increased subjective ratings of drug 'Liking', 'Good Effect' and 'High' from baseline (P's < 0.01), but did not significantly vary as a function of placebo or NLTX pretreatment. Similarly, methamphetamine self-administration did not vary between the placebo and NLTX pretreatment conditions. This sample did not demonstrate a significant 'bias' in learning from positive and negative outcomes (i.e. reward and punishment sensitivity), and reward/punishment sensitivity was not correlated with the effects of methamphetamine or the effects of NLTX on methamphetamine. The current study argues against the use of NLTX as a stand-alone medication for treating methamphetamine use disorder.

A Comprehensive Approach to Managing Methamphetamine-Associated Cardiomyopathy

Methamphetamines are illicit drugs of the amphetamine-type stimulant class that have been increasing in popularity, availability, and purity in recent decades. As a result, rates of methamphetamine-associated cardiomyopathy (MAC) are rising globally. MAC is associated with high rates of sudden cardiac arrest, late presentation, and poor outcomes. This review discusses the medical management of MAC, including anticipated challenges specific to methamphetamine users. Not only are patients with MAC more likely to present at a younger age and with multisystem disease than patients with cardiomyopathy of other etiologies, but there may also be significant behavioral, psychosocial, financial, and system-based challenges to providing the best medical care. An individualized treatment plan that emphasizes methamphetamine abstinence as the foundation of therapy, as well as introducing optimal heart failure therapy and providing multidisciplinary support is likely to result in optimal outcomes. Given the potential reversibility of MAC, institution of guideline-directed heart failure therapy and patient support for adherence to therapy and abstinence from methamphetamines should be energetically pursued.

Methamphetamine and Modulation Functionality of the Prelimbic Cortex for Developing a Possible Treatment of Alzheimer's Disease in an Animal Model

Alzheimer’s disease (AD) is a progressive neurodegenerative condition that causes cognitive impairment and other neuropsychiatric symptoms. Previously, little research has thus far investigated whether methamphetamine (MAMPH) can enhance cognitive function or ameliorate AD symptoms. This study examined whether a low dose of MAMPH can induce conditioned taste aversion (CTA) learning, or can increase plasma corticosterone levels, neural activity, and neural plasticity in the medial prefrontal cortex (mPFC) (responsible for cognitive function), the nucleus accumbens (NAc) and the amygdala (related to rewarding and aversive emotion), and the hippocampus (responsible for spatial learning). Furthermore, the excitations or lesions of the prelimbic cortex (PrL) can affect MAMPH-induced CTA learning, plasma corticosterone levels, and neural activity or plasticity in the mPFC [i.e., PrL, infralimbic cortex (IL), cingulate cortex 1 (Cg1)], the NAc, the amygdala [i.e., basolateral amygdala (BLA) and central amygdala (CeA)], and the hippocampus [i.e., CA1, CA2, CA3, and dentate gyrus (DG)]. In the experimental procedure, the rats were administered either saline or NMDA solutions, which were injected into the PrL to excite or destroy PrL neurons. Additionally, rats received 0.1% saccharin solution for 15 min, followed by intraperitoneal injections of either normal saline or 1 mg/kg MAMPH to induce CTA. A one-way ANOVA was performed to analyze the effects of saccharin intake on CTA, plasma corticosterone levels, and the expression of c-Fos and p-ERK. The results showed that the MAMPH induced CTA learning and increased plasma corticosterone levels. The mPFC, and particularly the PrL and IL and the DG of the hippocampus, appeared to show increased neural activity in c-Fos expression or neural plasticity in p-ERK expression. The excitation of the PrL neurons upregulated neural activity in c-Fos expression and neural plasticity in p-ERK expression in the PrL and IL. In summary, MAMPH may be able to improve cognitive and executive function in the brain and reduce AD symptoms. Moreover, the excitatory modulation of the PrL with MAMPH administration can facilitate MAMPH-induced neural activity and plasticity in the PrL and IL of the mPFC. The present data provide clinical implications for developing a possible treatment for AD in an animal model.

Epigenetic Regulatory Dynamics in Models of Methamphetamine-Use Disorder

Methamphetamine (METH)-use disorder (MUD) is a very serious, potentially lethal, biopsychosocial disease. Exposure to METH causes long-term changes to brain regions involved in reward processing and motivation, leading vulnerable individuals to engage in pathological drug-seeking and drug-taking behavior that can remain a lifelong struggle. It is crucial to elucidate underlying mechanisms by which exposure to METH leads to molecular neuroadaptive changes at transcriptional and translational levels. Changes in gene expression are controlled by post-translational modifications via chromatin remodeling. This review article focuses on the brain-region specific combinatorial or distinct epigenetic modifications that lead to METH-induced changes in gene expression.

Drugs of Abuse: Sympathomimetics

Sympathomimetic drugs comprise a broad category of substances including both illicit and prescribed drugs that have deleterious effects when ingested or abused. The clinical syndromes that result from overstimulation of the sympathetic nervous system by reuptake inhibition of biogenic amines, such as norepinephrine and dopamine, carry significant morbidity. Recognition and awareness of the appropriate supportive measures are required to mitigate life-threatening complications of multiple organ systems. The sympathomimetic toxidrome is recognized by a constellation of symptoms including agitation, hyperthermia, tachycardia, and hypertension, and the primary treatment involves supportive care, including the liberal use of benzodiazepines.

Patterns of smoking and injecting methamphetamine and their association with health and social outcomes

Introduction

We examine how smoking and injecting methamphetamine change over time and correlate with specific health and social outcomes.

Methods

Panel data from a longitudinal cohort dependent on methamphetamine (N = 444; 891 months). Random effects regression models examined the relationship between smoking and/or injecting methamphetamine and past month outcomes (substance use, ≥daily injection, needle/syringe sharing, psychological distress, poor mental and physical health, sexual behaviour, psychotic symptoms, violent behaviour and crime). Effects were adjusted for between‐group differences at baseline.

Results

At baseline, 56% of participants only injected methamphetamine in the past month, 18% only smoked and 26% both injected and smoked (concurrent injecting and smoking). Compared to injecting only, concurrent injecting and smoking was associated with more days of methamphetamine use (b = 1.3, P < 0.001; adjusted [A] b = 1.2, P < 0.001), more frequent injection [odds ratio (OR) 1.8, P = 0.013; adjusted OR (AOR) 1.6, P = 0.042], violent behaviour (OR 2.1, P = 0.001; AOR 1.8, P = 0.013] and crime (OR 3.1, P < 0.001; AOR 2.5, P < 0.001). Non‐injecting related outcomes did not differ significantly for only smoking versus only injecting. There was no significant transition from injecting methamphetamine at baseline to non‐injecting methamphetamine use at follow up, or from exclusively smoking methamphetamine at baseline to any methamphetamine injection at follow up.

Discussion and Conclusion

Efforts are needed to address heavier methamphetamine use, more frequent drug injection and elevated violent behaviour and crime among people who concurrently smoke and inject methamphetamine.

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.

Acute Pharmacological Effects of Oral and Intranasal Mephedrone: An Observational Study in Humans

Mephedrone (4-methylmethcathinone) is a synthetic cathinone with psychostimulant properties which remains one of the most popular new psychoactive substances (NPS). It is frequently used orally and/or intranasally. To date, no studies have evaluated the acute effects and pharmacokinetics after self-administration of mephedrone orally (ingestion) and intranasally (insufflation) in naturalistic conditions. An observational study was conducted to assess and compare the acute pharmacological effects, as well as the oral fluid (saliva) concentrations of mephedrone self-administered orally and intranasally. Ten healthy experienced drug users (4 females and 6 males) self-administered a single dose of mephedrone, orally (n = 5, 100–200 mg; mean 150 mg) or intranasally (n = 5, 50–100 mg, mean 70 mg). Vital signs (blood pressure, heart rate, and cutaneous temperature) were measured at baseline (0), 1, 2, and 4 h after self-administration. Each participant completed subjective effects questionnaires: A set of Visual Analogue Scales (VAS), the 49-item Addiction Research Centre Inventory (ARCI), and Evaluation of the Subjective Effects of Substances with Abuse Potential (VESSPA-SSE) at baseline, 1, 2, and 4 h after self-administration. Oral fluid and urine were collected during 4 h. Both routes of mephedrone self-administration enhanced ratings of euphoria and well-being effects and increased cardiovascular effects in humans. Although it was at times assessed that the oral route produced greater and larger effects than the intranasal one, concentrations of mephedrone in oral fluid and also the total amount of mephedrone and metabolites in urine showed that concentrations of mephedrone are considerably higher when self-administered intranasally in comparison to orally. Controlled clinical trials are needed to confirm our observational results.

Neurobiology, Clinical Presentation, and Treatment of Methamphetamine Use Disorder: A Review

IMPORTANCE

The prevalence of and mortality associated with methamphetamine use has doubled during the past 10 years. There is evidence suggesting that methamphetamine use disorder could be the next substance use crisis in the United States and possibly worldwide.

OBSERVATION

The neurobiology of methamphetamine use disorder extends beyond the acute effect of the drug as a monoaminergic modulator and includes intracellular pathways focused on oxidative stress, neurotoxic and excitotoxic effects, and neuroinflammation. Similarly, the clinical picture extends beyond the acute psychostimulatory symptoms to include complex cardiovascular and cerebrovascular signs and symptoms that need to be identified by the clinician. Although there are no pharmacologic treatments for methamphetamine use disorder, cognitive behavioral therapy, behavioral activation, and contingency management show modest effectiveness.

CONCLUSIONS AND RELEVANCE

There is a need to better understand the complex neurobiology of methamphetamine use disorder and to develop interventions aimed at novel biological targets. Parsing the disorder into different processes (eg, craving or mood-associated alterations) and targeting the neural systems and biological pathways underlying these processes may lead to greater success in identifying disease-modifying interventions. Finally, mental health professionals need to be trained in recognizing early cardiovascular and cerebrovascular warning signs to mitigate the mortality associated with methamphetamine use disorder.

Exaggerating Harmful Drug Effects on the Brain Is Killing Black People

Exaggerations of the detrimental impact of recreational drug use on the human brain have bolstered support for draconian drug policies and have been used to justify police brutality against Black people. This situation has led to disproportionately high Black incarceration rates and countless Black deaths. Here, I offer solutions to remedy this multi-century maltreatment of Black people.

Clinical Characteristics and Management of Methamphetamine-Associated Cardiomyopathy: State-of-the-Art Review

Methamphetamine‐associated cardiomyopathy (MACM) is an increasingly recognized disease entity in the context of a rapidly spreading methamphetamine epidemic. MACM may afflict individuals with a wide range of ages and socioeconomic backgrounds. Presentations can vary greatly and may involve several complications unique to the disease. Given the public health significance of this disease, there is a relative dearth of consensus material to guide clinicians in understanding, diagnosing, and managing MACM. This review therefore aims to: (1) describe pathologic mechanisms of methamphetamine as they pertain to the development, progression, and prognosis of MACM, and the potential to recover cardiac function; (2) summarize existing data from epidemiologic studies and case series in an effort to improve recognition and diagnosis of the disease; (3) guide short‐ and long‐term management of MACM with special attention to expected or potential sequelae of the disease; and (4) highlight pivotal unanswered questions in need of urgent investigation from a public health perspective.

Clinical characteristics and outcomes of methamphetamine-associated versus non-methamphetamine intracerebral hemorrhage

Methamphetamine use has emerged as a risk factor for intracerebral hemorrhage (ICH). We aim to investigate the clinical characteristics and outcomes of methamphetamine-associated ICH (Meth-ICH) versus Non-Meth-ICH. Patients with ICH between January 2011 and December 2017 were studied. Meth-ICH and Non-Meth-ICH were defined by history of abuse and urine drug screen (UDS). The clinical features of the 2 groups were explored. Among the 677 consecutive patients, 61 (9.0%) were identified as Meth-ICH and 350 as Non-Meth ICH. Meth-ICH was more common in Hispanics (14.6%) and Whites (10.1%) as compared to Asians (1.2%). Patients with Meth-ICH were more often younger (51.2 vs. 62.2 years, p < 0.001), male (77.0% vs. 61.4.0%, p < 0.05), and smokers (44.3% vs. 13.4%, p < 0.001). Non-Meth-ICH was more likely to have history of hypertension (72.61% v. 59%, p < 0.05) or antithrombotic use (10.9% vs. 1.6%, p < 0.05). There was no significant difference in clinical severity, hospital length of stay (LOS), rate of functional independence (29.5% vs. 25.7%, p = 0.534), or mortality (18.0% vs. 24.6%, p = 0.267) between the 2 groups. Methamphetamine use was not an independent predictor of poor outcome. Despite difference in demographics, Meth-ICH is similar to Non-Meth ICH in hospital course and outcome.

Activation of mGluR5 and NMDA Receptor Pathways in the Rostral Ventrolateral Medulla as a Central Mechanism for Methamphetamine-Induced Pressor Effect in Rats

Acute hypertension produced by methamphetamine (MA) is well known, mainly by the enhancement of catecholamine release from sympathetic terminals. However, the central pressor mechanism of the blood-brain-barrier-penetrating molecule remains unclear. We used radio-telemetry and femoral artery cannulation to monitor the mean arterial pressure (MAP) in conscious free-moving and urethane-anesthetized rats, respectively. Expression of Fos protein (Fos) and phosphorylation of N-methyl-D-aspartate receptor subunit GluN1 in the rostral ventrolateral medulla (RVLM) were detected using Western blot analysis. ELISA was carried out for detection of protein kinase C (PKC) activity in the RVLM. MA-induced glutamate release in the RVLM was assayed using in vivo microdialysis and HPLC. Systemic or intracerebroventricular (i.c.v.) administration of MA augments the MAP and increases Fos expression, PKC activity, and phosphorylated GluN1-ser 896 (pGluN1-ser 896) in the RVLM. However, direct microinjection of MA into the RVLM did not change the MAP. Unilateral microinjection of a PKC inhibitor or a metabotropic glutamate receptor 5 (mGluR5) antagonist into the RVLM dose-dependently attenuated the i.c.v. MA-induced increase in MAP and pGluN1-ser 896. Our data suggested that MA may give rise to glutamate release in the RVLM further to the activation of mGluR5-PKC pathways, which would serve as a central mechanism for the MA-induced pressor effect.

Wild at heart: 34-year-old male with new onset dyspnea, heart failure and history of amphetamine use; a case report

Background

Spontaneous coronary artery dissection (SCAD) is a rather rare cause of acute coronary syndrome with a preponderance for young female patients. Amphetamines are now the second most widely used substance drugs in the world and they are associated with a myriad of cardiac diseases including cardiomyopathies and SCADs. There is much uncertainty regarding the best treatment strategy in such cases and decision-making remains mostly individualized and based on expert opinions.

Case presentation

A 34-year-old male with an unremarkable past medical history presented to a cardiologist with prominent dyspnea and orthopnea. He reported occasional methamphetamine use from 3 years before the presentation. An echocardiogram showed an enlarged left ventricle and severe systolic dysfunction with an ejection fraction of 10–15%. Coronary angiography revealed multiple linear dissections in both left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX). The patient’s right coronary artery (RCA) showed occlusion in the proximal segment. The patient was diagnosed with amphetamine-induced spontaneous coronary artery dissection and resultant ischemic cardiomyopathy. After thorough evaluation, medical treatment ensued.

Conclusions

Methamphetamine abusers have a 3.7 fold risk of developing some form of a cardiomyopathy in comparison to individuals without amphetamine abuse. Coronary artery dissection and increased thrombus burden are some of the mechanisms responsible for ischemic cardiomyopathy in these groups of patients.

Combination of acute intravenous methamphetamine injection and LPS challenge facilitate leukocyte infiltration into the central nervous system of C57BL/6 mice

Methamphetamine (METH) is a stimulant of the central nervous system (CNS) that causes behavioral changes in users. METH is slowly cleared from brain tissue and its chronic use is neurotoxic. METH also alters the cellular and chemical components of inflammation. However, little is known about the effect of a single intravenous dose of METH followed by bacterial lipopolysaccharide (LPS) injection on cellular infiltration and cytokine release in brain tissue. Using a murine model of acute METH administration and flow cytometry, we found that combination of METH and LPS stimulate the infiltration of macrophages (F4/80⁺cells) and neutrophils (Ly-6G⁺cells) into the CNS. Histological sections of the brainstem of METH-treated and LPS-challenged C57BL/6 mice demonstrated considerable leukocyte infiltration relative to untreated, LPS, and METH groups. Moreover, rodents treated with LPS alone or combined with METH showed elevated levels of pro-inflammatory cytokines mRNA in brain tissue. Our observations are important because recognizing neuroinflammatory changes after acute METH administration might help us to understand METH-induced neurotoxicity in users.

Identification of cytotoxic markers in methamphetamine treated rat C6 astroglia-like cells

Methamphetamine (METH) is a powerfully addictive psychostimulant that has a pronounced effect on the central nervous system (CNS). The present study aimed to assess METH toxicity in differentiated C6 astroglia-like cells through biochemical and toxicity markers with acute (1 h) and chronic (48 h) treatments. In the absence of external stimulants, cellular differentiation of neuronal morphology was achieved through reduced serum (2.5%) in the medium. The cells displayed branched neurite-like processes with extensive intercellular connections. Results indicated that acute METH treatment neither altered the cell morphology nor killed the cells, which echoed with lack of consequence on reactive oxygen species (ROS), nitric oxide (NO) or inhibition of any cell cycle phases except induction of cytoplasmic vacuoles. On the other hand, chronic treatment at 1 mM or above destroyed the neurite-like processors and decreased the cell viability that paralleled with increased levels of ROS, lipid peroxidation and lactate, depletion in glutathione (GSH) level and inhibition at G0/G1 phase of cell cycle, leading to apoptosis. Pre-treatment of cells with N-acetyl cysteine (NAC, 2.5 mM for 1 h) followed by METH co-treatment for 48 h rescued the cells completely from toxicity by decreasing ROS through increased GSH. Our results provide evidence that increased ROS and GSH depletion underlie the cytotoxic effects of METH in the cells. Since loss in neurite connections and intracellular changes can lead to psychiatric illnesses in drug users, the evidence that we show in our study suggests that these are also contributing factors for psychiatric-illnesses in METH addicts.

Stimulant Use in Pregnancy: An Under-recognized Epidemic Among Pregnant Women

Stimulant use, including cocaine, methamphetamines, ecstasy, and prescription stimulants, in pregnancy is increasingly common. In the United States, stimulants are the second most widely used and abused substances during pregnancy and pregnant women using stimulants in pregnancy are at increased risk of adverse perinatal, neonatal, and childhood outcomes. In this review, we describe the pharmacology, pathophysiology, and epidemiology of stimulants, summarize the maternal and neonatal effects of perinatal stimulant use, and outline treatment options for stimulant use disorders among pregnant women. Development of effective treatment strategies for stimulant use disorders identified among pregnant women are urgently needed.

DARK Classics in Chemical Neuroscience: Methamphetamine

Methamphetamine has the second highest prevalence of drug abuse after cannabis, with estimates of 35 million users worldwide. The ( S)-(+)-enantiomer is the illicit drug, active neurostimulant, and eutomer, while the ( R)-(-)-enantiomer is contained in over the counter decongestants. While designated a schedule II drug in 1970, ( S)-(+)-methamphetamine is available by prescription for the treatment of attention-deficit disorder and obesity. The illicit use of ( S)-(+)-methamphetamine results in the sudden "rush" of stimulation to the motivation, movement, pleasure, and reward centers in the brain, caused by rapid release of dopamine. In this review, we will provide an overview of the synthesis, pharmacology, adverse effects, and drug metabolism of this widely abused psychostimulant that distinguish it as a DARK classic in Chemical Neuroscience.

Gaming under the influence: An exploratory study

Background and aims Association between substance use and excessive play of online games exists both in theory and research. However, no study to date examined playing online games under the influence of licit and illicit drugs. Methods We questioned a convenient online sample of 3,952 Czech online gamers on their experiences and motives of using caffeine, alcohol, tobacco, psychoactive pharmaceuticals, and illicit drugs while playing massive multiplayer online games (MMOGs). Results The results showed low prevalence of illicit drug use while playing online games. Substance use was positively associated with intensity of gaming and both addiction and engagement; psychoactive substances with stimulating effect were linked to higher engagement and gaming intensity, whereas use of sedatives was associated with higher addiction score. Substance use varied slightly with the preference of game genre. Discussion Drug use while playing appears as behavior, which is mostly not related to gaming - it concerns mostly caffeine, tobacco, alcohol, or cannabis. For some users, however, drug use was fueled by motivations toward improving their cognitive enhancement and gaming performance.

Brain Activity during Methamphetamine Anticipation in a Non-Invasive Self-Administration Paradigm in Mice

The ability to sense time and anticipate events is critical for survival. Learned responses that allow anticipation of the availability of food or water have been intensively studied. While anticipatory behaviors also occur prior to availability of regularly available rewards, there has been relatively little work on anticipation of drugs of abuse, specifically methamphetamine (MA). In the present study, we used a protocol that avoided possible CNS effects of stresses of handling or surgery by testing anticipation of MA availability in animals living in their home cages, with daily voluntary access to the drug at a fixed time of day. Anticipation was operationalized as the amount of wheel running prior to MA availability. Mice were divided into four groups given access to either nebulized MA or water, in early or late day. Animals with access to MA, but not water controls, showed anticipatory activity, with more anticipation in early compared to late day and significant interaction effects. Next, we explored the neural basis of the MA anticipation, using c-FOS expression, in animals euthanized at the usual time of nebulization access. In the dorsomedial hypothalamus (DMH) and orbitofrontal cortex (OFC), the pattern of c-FOS expression paralleled that of anticipatory behavior, with significant main and interaction effects of treatment and time of day. The results for the lateral septum (LS) were significant for main effects and marginally significant for interaction effects. These studies suggest that anticipation of MA is associated with activation of brain regions important in circadian timing, emotional regulation, and decision making.

Managing the Patient With Pulmonary Arterial Hypertension and Methamphetamine Use: A Practical Perspective for the Clinician

Pulmonary arterial hypertension (PAH) is a serious, chronic, progressive cardiopulmonary disease. PAH is associated with several concomitant conditions, as well as drugs and toxins.12 Methamphetamine abuse is likely associated with the development of PAH.3 Methamphetamine abuse is epidemic in the United States and abroad, with rates of new users escalating since 2012. There are over 100,000 new users annually as young as 12 years old. Treating a patient with a history of methamphetamine abuse poses many challenges for a clinician, including nonadherence, therapeutic treatment selection, complex psychosocial issues, and relapse or continued drug abuse. Patients with methamphetamine-associated PAH (Meth-APAH) have higher mortality rates when compared to idiopathic PAH.3 Having a better understanding of the complexities of addiction and working with a multidisciplinary team that includes a social worker to provide care and counseling to these patients can improve their trajectory. In this article, we will offer insight and background into methamphetamine abuse and addiction, as well as discuss a practical approach for clinicians in treating a patient with Meth-APAH, based on the literature, as well as our personal experiences at University of California, San Francisco Medical Center.

Molecular, Behavioral, and Physiological Consequences of Methamphetamine Neurotoxicity: Implications for Treatment

Understanding the relationship between the molecular mechanisms underlying neurotoxicity of high-dose methamphetamine (METH) and related clinical manifestations is imperative for providing more effective treatments for human METH users. This article provides an overview of clinical manifestations of METH neurotoxicity to the central nervous system and neurobiology underlying the consequences of administration of neurotoxic METH doses, and discusses implications of METH neurotoxicity for treatment of human abusers of the drug.

Voluntary inhalation of methamphetamine: a novel strategy for studying intake non-invasively

RATIONALE

The abuse of the psychostimulant methamphetamine (MA) is associated with substantial costs and limited treatment options. To understand the mechanisms that lead to abuse, animal models of voluntary drug intake are crucial.

OBJECTIVES

We aimed to develop a protocol to study long-term non-invasive voluntary intake of MA in mice.

METHODS

Mice were maintained in their home cages and allowed daily 1 h access to an attached tunnel leading to a test chamber in which nebulized MA was available. Restated, if they went to the nebulizing chamber, they self-administered MA by inhalation. This protocol was compared to injected and to imposed exposure to nebulized MA, in a series of seven experiments.

RESULTS

We established a concentration of nebulized MA at which motor activity increases following voluntary intake resembled that following MA injection and imposed inhalation. We found that mice regulated their exposure to MA, self-administering for shorter durations when concentrations of nebulized MA were increased. Mice acquire the available MA by repeatedly running in and out of the nebulizing chamber for brief bouts of intake. Such exposure to nebulized MA elevated plasma MA levels. There was limited evidence of sensitization of locomotor activity. Finally, blocking access to the wheel did not affect time spent in the nebulizing chamber.

CONCLUSIONS

We conclude that administration of MA by nebulization is an effective route of self-administration, and our new protocol represents a promising tool for examining the transitions from first intake to long-term use and its behavioral and neural consequences in a non-invasive protocol.

Two Case Studies Illustrating a Shared Decision-Making Approach to Illicit Methamphetamine Use and Breastfeeding

Crystal methamphetamine (MA) is a potent psycho-stimulant that is increasingly used worldwide. It is highly addictive, is often made in clandestine laboratories, and can cause serious health issues in adults. Health professionals caring for women in the perinatal period must counsel women about the health risks to infants if they are exposed to MA in breast milk. Most guidelines recommend that women who have current or recent MA use do not breastfeed. This article explores approaches to breastfeeding advice in the context of MA use. Women who have made lifestyle changes, engaged well with services in the antenatal period, and are committed to drug counseling services after discharge from hospital may be supported to breastfeed if they are assessed as safe to do so. The importance of assessing each woman individually when developing infant feeding plans throughout the perinatal period is advocated.

A Markerless 3D Computerized Motion Capture System Incorporating a Skeleton Model for Monkeys

In this study, we propose a novel markerless motion capture system (MCS) for monkeys, in which 3D surface images of monkeys were reconstructed by integrating data from four depth cameras, and a skeleton model of the monkey was fitted onto 3D images of monkeys in each frame of the video. To validate the MCS, first, estimated 3D positions of body parts were compared between the 3D MCS-assisted estimation and manual estimation based on visual inspection when a monkey performed a shuttling behavior in which it had to avoid obstacles in various positions. The mean estimation error of the positions of body parts (3-14 cm) and of head rotation (35-43°) between the 3D MCS-assisted and manual estimation were comparable to the errors between two different experimenters performing manual estimation. Furthermore, the MCS could identify specific monkey actions, and there was no false positive nor false negative detection of actions compared with those in manual estimation. Second, to check the reproducibility of MCS-assisted estimation, the same analyses of the above experiments were repeated by a different user. The estimation errors of positions of most body parts between the two experimenters were significantly smaller in the MCS-assisted estimation than in the manual estimation. Third, effects of methamphetamine (MAP) administration on the spontaneous behaviors of four monkeys were analyzed using the MCS. MAP significantly increased head movements, tended to decrease locomotion speed, and had no significant effect on total path length. The results were comparable to previous human clinical data. Furthermore, estimated data following MAP injection (total path length, walking speed, and speed of head rotation) correlated significantly between the two experimenters in the MCS-assisted estimation (r = 0.863 to 0.999). The results suggest that the presented MCS in monkeys is useful in investigating neural mechanisms underlying various psychiatric disorders and developing pharmacological interventions.

A novel strategy for dissecting goal-directed action and arousal components of motivated behavior with a progressive hold-down task

Motivation serves 2 important functions: It guides actions to be goal-directed, and it provides the energy and vigor required to perform the work necessary to meet those goals. Dissociating these 2 processes with existing behavioral assays has been a challenge. In this article, we report a novel experimental strategy to distinguish the 2 processes in mice. First, we characterize a novel motivation assay in which animals must hold down a lever for progressively longer intervals to earn each subsequent reward; we call this the progressive hold-down (PHD) task. We find that performance on the PHD task is sensitive to both food deprivation level and reward value. Next, we use a dose of methamphetamine (METH) 1.0 mg/kg, to evaluate behavior in both the progressive ratio (PR) and PHD tasks. Treatment with METH leads to more persistent lever pressing for food rewards in the PR. In the PHD task, we found that METH increased arousal, which leads to numerous bouts of hyperactive responding but neither increases nor impairs goal-directed action. The results demonstrate that these tools enable a more precise understanding of the underlying processes being altered in manipulations that alter motivated behavior.

Boundary conditions of methamphetamine craving

Methamphetamine use has increased significantly and become a global health concern. Craving is known to predict methamphetamine use and relapse following abstinence. Some have suggested that cravings are automatic, generalized, and uncontrollable, but experimental work addressing these claims is lacking. In 2 exploratory studies, we tested the boundary conditions of methamphetamine craving by asking: (a) is craving specific to users' preferred route of administration?, and (b) can craving be regulated by cognitive strategies? Two groups of methamphetamine users were recruited. In Study 1, participants were grouped by their preferred route of administration (intranasal vs. smoking), and rated their craving in response to photographs and movies depicting methamphetamine use (via the intranasal vs. smoking route). In Study 2, methamphetamine smokers implemented cognitive regulation strategies while viewing photographs depicting methamphetamine smoking. Strategies involved either focusing on the positive aspects of smoking methamphetamine or the negative consequences of doing so-the latter strategy based on treatment protocols for addiction. In Study 1, we found a significant interaction between group and route of administration, such that participants who preferred to smoke methamphetamine reported significantly stronger craving for smoking stimuli, whereas those who preferred the intranasal route reported stronger craving for intranasal stimuli. In Study 2, participants reported significantly lower craving when focusing on the negative consequences associated with methamphetamine use. Taken together, these findings suggest that strength of craving for methamphetamine is moderated by users' route of administration and can be reduced by cognitive strategies. This has important theoretical, methodological, and clinical implications.

The Effects of BDNF Val66Met Gene Polymorphism on Serum BDNF and Cognitive Function in Methamphetamine-Dependent Patients and Normal Controls: A Case-Control Study

Studies suggest that a functional polymorphism of the brain-derived neurotrophic factor gene (BDNF Val66Met) may contribute to methamphetamine dependence. We hypothesized that this polymorphism had a role in cognitive deficits in methamphetamine-dependent patients and in the relationship of serum BDNF with cognitive impairments. We conducted a case-control study by assessing 194 methamphetamine-dependent patients and 378 healthy volunteers without history of drug use on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the presence of the BDNF Val66Met polymorphism and serum BDNF levels. We showed no significant differences in genotype and allele distributions between the methamphetamine-dependent patients and controls. Some aspects of cognitive function significantly differed in the 2 groups. The serum BDNF levels in methamphetamine-dependent patients were significantly higher than those of the healthy controls. In the patients, partial correlation analysis showed a significant positive correlation between serum BDNF and the delayed memory index score. The RBANS scores showed statistically significant BDNF level × genotype interaction. Further regression analyses showed a significant positive association between BDNF levels and the RBANS total score, immediate memory or attention index among Val homozygote patients, whereas a significant negative association of BDNF levels with the RBANS total score, visuospatial/constructional, or language index was found among Met/Val heterozygous patients. We demonstrated significant impairment on some aspects of cognitive function and increased BDNF levels in methamphetamine-dependent patients as well as genotypic differences in the relationships between BDNF levels and RBANS scores on the BDNF Val66Met polymorphism only in these patients.

The Effects of Naltrexone on Subjective Response to Methamphetamine in a Clinical Sample: a Double-Blind, Placebo-Controlled Laboratory Study

Methamphetamine (MA) use disorder is a serious psychiatric condition for which there are no FDA-approved medications. Naltrexone (NTX) is an opioid receptor antagonist with demonstrated efficacy, albeit moderate, for the treatment of alcoholism and opioid dependence. Preclinical and clinical studies suggest that NTX may be useful for the treatment of MA use disorder. To inform treatment development, we conducted a double-blind, randomized, crossover, placebo-controlled human laboratory study of NTX. Non-treatment-seeking individuals meeting DSM-IV criteria for MA abuse or dependence (n=30) completed two separate 5-day inpatient stays. During each admission, participants completed testing sessions comprised of MA cue-reactivity and intravenous MA administration (30 mg) after receiving oral NTX (50 mg) or placebo for 4 days. This study tested the hypotheses that NTX would (a) attenuate cue-induced MA craving, and (b) reduce subjective responses to MA administration. Results largely supported the study hypotheses such that (a) NTX significantly blunted cue-induced craving for MA and (b) attenuated several of the hedonic subjective effects of MA, including craving, during controlled MA administration and as compared with placebo. NTX decreased overall subjective ratings of 'crave drug,' 'stimulated,' and 'would like drug access,' decreased the the post-MA administration timecourse of 'anxious' and increased ratings of 'bad drug effects,' as compared with placebo. These findings support a potential mechanism of action by showing that NTX reduced cue-induced craving and subjective responses to MA. This is consistent with positive treatment studies of NTX for amphetamine dependence, as well as ongoing clinical trials for MA.

The Impact of Illicit Use of Amphetamine on Male Sexual Functions

INTRODUCTION

Data concerning the impact of amphetamine on male sexual functions are limited, although amphetamine has been used as an aphrodisiac.

AIMS

This cross-sectional study was to assess the impact of illicit use of amphetamine on male sexual functions.

METHODS

Male illicit drug users in a Drug Abstention and Treatment Center were recruited to complete a self-administered questionnaire, and data were compared with age-matched controls.

MAIN OUTCOME MEASURES

The International Index of Erectile Function (IIEF) and global assessment questions were used to assess sexual functions.

RESULTS

Of 1,159 amphetamine mono-illicit drug users, the mean age was 31.9 ± 7.5 (18-57) years, and mean duration of drug use was 30.7 ± 52.2 (median 9, range 0.1-252) months. Half of them reported that drug use had no impact on their sexual functions. The other half reported drug impacts as reduced erectile rigidity and sexual life satisfaction, enhanced orgasmic intensity, and prolonged ejaculation latency time more often than the opposite effects, while they reported enhanced or reduced effect equally on sexual desire. Dosing frequency of amphetamine was associated with its impact on sexual functions, but duration of its use had little association with that. Compared with 211 age-matched controls, the amphetamine mono-illicit drug users had lower IIEF scores in the domains of erectile function, orgasmic function, and overall satisfaction, but there are no significant differences in intercourse satisfaction and sexual desire scores. The prevalence of erectile dysfunction (ED) was significantly higher in the drug users than in the controls (29.3% vs. 11.9%). The odds ratio of ED for amphetamine use was 2.1 (95% confidence interval 1.2-3.6) after adjustment for other risk factors.

CONCLUSIONS

The impact of illicit use of amphetamine on male sexual functions varied among users, and their ED prevalence was higher than the controls.

Simultaneous thrombosis of the left anterior descending artery and the right coronary artery in a 34-year-old crystal methamphetamine abuser

This case report underscores that crystal methamphetamine abuse is an important cause of multivessel coronary thrombosis and raises doubts about the therapeutic options. The patient was a 34-year-old smoker and crystal methamphetamine abuser with no significant medical history, who presented with retrosternal chest pain associated with cold sweats. Twelve-lead electrocardiogram revealed diffuse ST-segment elevation in I, II, AVL, AVF, and V 2-6 leads. He underwent urgent coronary angiography and it showed Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in coronary arteries and presence of a thrombus in the left anterior descending artery (LAD) and the right coronary artery (RCA). The patient underwent medical therapy with antiplatelet agents and anticoagulants. Repeat coronary angiography after three months of dual therapy with warfarin and aspirin did not show any thrombus or any significant lesion in the RCA and the LAD having TIMI grade 3 flow.

Comparison of noradrenaline, dopamine and serotonin in mediating the tachycardic and thermogenic effects of methamphetamine in the ventral medial prefrontal cortex

Methamphetamine (METH) is a psychostimulant that disrupts monoaminergic neurotransmission to evoke profound behavioral and physiological effects. Rapidly distributing to forebrain regions to increase synaptic concentrations of three monoamines (dopamine (DA), serotonin (5-HT) and noradrenaline (NA)), the medial prefrontal cortex (mPFC) is important in METH-altered behavioral and psychological profiles. Activation of the ventral mPFC can modify physiological variables, however, METH-evoked autonomic changes from this region are unknown. Therefore, the aim of this study was to characterize the respiratory, metabolic and cardiovascular effects of microinjection of METH, DA, 5-HT and NA into the ventral mPFC in urethane-anesthetized Sprague-Dawley rats. METH and NA microinjection evoked dose-related increases in heart rate, interscapular brown adipose tissue temperature and expired CO2, a pattern of response characteristic of non-shivering thermogenesis. NA and 5-HT microinjection elicited pressor and depressor responses, respectively, with matching baroreflex adjustments in sympathetic nerve activity while METH and DA evoked no change in vasomotor outflow. Low doses of METH and DA may evoke respiratory depression. These data suggest that METH's actions in the ventral mPFC, likely via adrenergic receptors, evoke non-shivering thermogenesis which may contribute to the increased body temperature and tachycardia seen in those that abuse METH.

Racial disparities in methamphetamine-associated intracerebral hemorrhage

OBJECTIVE

To assess racial disparities in the prevalence of methamphetamine-associated intracerebral hemorrhage (Meth-ICH) among Native Hawaiians and other Pacific Islanders (NHOPI).

METHODS

Prospectively collected data from an ongoing, multiethnic, single-center cohort study were analyzed. The inclusion criteria for the cohort study required that patients be adult (age 18 years or older) residents of Hawaii with nontraumatic spontaneous intracerebral hemorrhage (ICH). Patients of race other than white, Asian, or NHOPI were excluded. Determination of Meth-ICH was made prospectively by positive urine toxicology result and lack of other clinically suspected ICH etiology. Prevalence of Meth-ICH among NHOPI was compared with that of white and Asian patients.

RESULTS

A total of 193 patients (white 16%, Asian 61%, NHOPI 23%) were analyzed. NHOPI were younger than white (54 ± 15 vs 68 ± 15 years, respectively, p = 0.0001) and Asian (vs 65 ± 16 years, p = 0.0001) patients. Overall, 25 (13%) Meth-ICHs (mean age: 49 ± 6 years, range: 33-56 years) were identified. NHOPI had higher prevalence of Meth-ICH compared with white (24% vs 0%, respectively, p = 0.003) and Asian (vs 12%, p = 0.046) patients. The observed age differences between the racial groups persisted even after excluding the Meth-ICH group (p < 0.01 for all comparison).

CONCLUSIONS

NHOPI have higher prevalence of Meth-ICH compared with white and Asian patients. However, the age disparity is not entirely driven by methamphetamine abuse.

Investigation of "bath salts" use patterns within an online sample of users in the United States

"Bath salts" are synthetic stimulant "legal highs" that have recently been banned in the US. Epidemiological data regarding bath salts use are limited. In the present study, 113 individuals in the US reporting use of bath salts completed an anonymous, online survey characterizing demographic, experiential, and psychological variables. Respondents were more often male, 18-24 years old, and Caucasian/White with some college education. Past-year use was typically low (≤ 10 days), but marked by repeated dosing. Intranasal was the most frequently reported administration route and subjective effects were similar to other stimulants (e.g., cocaine, amphetamines). Bath salts use was associated with increased sexual desire and sexual HIV risk behavior, and met DSM-5 diagnostic criteria for disordered use in more than half of respondents. Bath salts use persists in the US despite federal bans of cathinone-like constituents. Self-reported stimulant-like effects of bath salts suggest their use as substitutes for traditional illicit stimulants. Data revealed more normative outcomes vis-à-vis extreme accounts by media and medical case reports. However, indications of product abuse potential and sexual risk remain, suggesting bath salts pose potential public health harm.

Impact of methamphetamine on infection and immunity

The prevalence of methamphetamine (METH) use is estimated at ~35 million people worldwide, with over 10 million users in the United States. METH use elicits a myriad of social consequences and the behavioral impact of the drug is well understood. However, new information has recently emerged detailing the devastating effects of METH on host immunity, increasing the acquisition of diverse pathogens and exacerbating the severity of disease. These outcomes manifest as modifications in protective physical and chemical defenses, pro-inflammatory responses, and the induction of oxidative stress pathways. Through these processes, significant neurotoxicities arise, and, as such, chronic abusers with these conditions are at a higher risk for heightened consequences. METH use also influences the adaptive immune response, permitting the unrestrained development of opportunistic diseases. In this review, we discuss recent literature addressing the impact of METH on infection and immunity, and identify areas ripe for future investigation.

Methamphetamine self-administration in humans during D-amphetamine maintenance

Agonist replacement may be a viable treatment approach for managing stimulant use disorders. This study sought to determine the effects of D-amphetamine maintenance on methamphetamine self-administration in stimulant using human participants. We predicted that D-amphetamine maintenance would reduce methamphetamine self-administration. Eight participants completed the protocol, which tested 2 D-amphetamine maintenance conditions in counterbalanced order (0 and 40 mg/d). Participants completed 4 experimental sessions under each maintenance condition in which they first sampled 1 of 4 doses of intranasal methamphetamine (0, 10, 20, or 30 mg). Participants then had the opportunity to respond on a computerized progressive-ratio task to earn portions of the sampled methamphetamine dose. Subject-rated drug effect and physiological measures were completed at regular intervals prior to and after sampling methamphetamine. Methamphetamine was self-administered as an orderly function of dose regardless of the maintenance condition. Methamphetamine produced prototypical subject-rated effects on 12 items of the drug-effects questionnaires, 8 of which were attenuated by D-amphetamine maintenance (eg, increased ratings were attenuated on items such as Any Effect, Like Drug, and Willing to Take Again on the Drug Effect Questionnaire). Methamphetamine produced significant increases in systolic blood pressure, which were attenuated by D-amphetamine maintenance compared to placebo maintenance. Methamphetamine was well tolerated during D-amphetamine maintenance and no adverse events occurred. Although D-amphetamine attenuated some subject-rated effects of methamphetamine, the self-administration results are concordant with those of clinical trials showing that D-amphetamine did not reduce methamphetamine use. Unique pharmacological approaches may be needed for treating amphetamine use disorders.