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Background: Intrathecal diamorphine is believed to provide postoperative analgesia but is associated with adverse effects such as nausea and vomiting. There is little evidence of synthesis regarding intrathecal diamorphine in the contemporary literature. We performed a systematic review, meta-analysis with meta-regression and trial sequential analysis to determine the magnitude of intrathecal diamorphine efficacy and safety., Methods: We systematically searched the literature for trials comparing intrathecal diamorphine with a control group in patients undergoing all types of surgery. The primary efficacy and safety outcomes were intravenous morphine consumption and incidence of postoperative nausea and vomiting at 24 h following surgery, respectively., Results: Twelve trials were identified, which included data for 712 patients. Intrathecal doses of diamorphine ranged from 100 μg to 2500 μg. Intravenous morphine consumption at 24 h postoperatively was significantly reduced in the intrathecal diamorphine group, with a mean difference (95%CI) of -8 mg (-11 to -6), I 2  = 93%, p < 0.001. There was a significant difference between three intrathecal diamorphine dosing subgroups but without correlation: mean differences (95%CI) -1 mg (-3-0), -26 mg (-40 to -11) and -6 mg (-15-4) in patients receiving doses of 0-200 μg, 201-400 μg and > 400 μg, respectively (p = 0.003). Intrathecal diamorphine increased postoperative nausea and vomiting with a risk ratio (95%CI) of 1.37 (1.19-1.58), I 2  = 7%, p < 0.001. There were no differences in postoperative nausea and vomiting between the three intrathecal diamorphine dosing subgroups. There was no correlation observed with meta-regression of the primary efficacy and safety outcomes. The quality of evidence for all outcomes was very low., Conclusion: There is very low level of evidence that intrathecal diamorphine provides effective analgesia after surgery, while increasing postoperative nausea and vomiting with doses > 200 μg., (© 2024 The Author(s). Anaesthesia published by John Wiley & Sons Ltd on behalf of Association of Anaesthetists.)

Introduction: Opioid use during pregnancy and subsequent neonatal opioid withdrawal syndrome (NOWS) have been associated with poor developmental outcomes including cognitive functioning. Less is known about the underlying molecular effects of prenatal opioid exposure and subsequent withdrawal; however, given the recent increase in NOWS cases, there is a pressing need to better understand these effects, which may partially explain cognitive deficits that have been observed in both preclinical NOWS models and patients with NOWS. This study evaluated the effects of prenatal heroin exposure and subsequent precipitated withdrawal symptoms on microglial reactivity in the nucleus accumbens (NAc), dorsal hippocampus (HC), and ventral tegmental area (VTA) in rat neonates, as well as cognitive functioning at three developmental time points using the Morris Water Maze (MWM) task., Methods: Heroin or saline (2 mg/kg) was randomly assigned and administered to six pregnant Sprague Dawley rat dams via osmotic minipump. A total of 63 rat neonates underwent naloxone-precipitated (5 mg/kg, subcutaneous injection) withdrawal testing at postnatal day 10 (PN10). Following withdrawal testing, neonates were randomly assigned to undergo perfusion and subsequent immunohistochemistry experiments to fluoresce Iba-1 for microglia detection, or to undergo the MWM task at three separate developmental time points (PN21-23; PN37; PN60) for cognitive testing., Results: Results suggest that in-utero heroin exposure led to an increase in ultrasonic vocalizations during naloxone-precipitated withdrawal; a sensitive index of withdrawal in rat neonates. Additional results suggest increased microglial reactivity in the HC and VTA, but not the NAc, as well as reduced performance during the MWM in the group exposed to heroin in-utero., Discussion: Together, these data suggest that in-utero opioid exposure is associated with microglial reactivity in brain regions associated with learning and memory, and may be associated with later cognitive deficits. Further research is needed to characterize these findings, which may inform future therapeutic strategies for this vulnerable population., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Sara L. Mills-Huffnagle, MS reports financial support was provided by National Institutes of Health. Jennifer E. Nyland, PhD reports financial support was provided by National Institute of Health. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Sexual health is a key element to the well-being and quality of life of individuals. However, it is rarely incorporated into care delivery for women with an addictive condition. Female with severe dependence to opiate have their medical and social conditions improved by diacetylmorphine treatment. Which allows them to escape situations of high-risk of sexual violence. However, this pharmacotherapy can also induce adverse effects on the sexual sphere. This paper describes the relevance of integrating psycho-socio-sexological counselling into the care provision for the opiate dependence. The counselling should be oriented to respond to the specific relational and sexual issues faced by these female patients and empowering them on their lives and in recovering a better quality of life., Competing Interests: Les auteurs n’ont déclaré aucun conflit d’intérêts en relation avec cet article.

In opioid use disorder (OUD) patients, a decrease in brain grey matter volume (GMV) has been reported. It is unclear whether this is the consequence of prolonged exposure to opioids or is a predisposing causal factor in OUD development. To investigate this, we conducted a structural MRI longitudinal study in NIH Heterogeneous Stock rats exposed to heroin self-administration and age-matched naïve controls housed in the same controlled environment. Structural MRI scans were acquired before (MRI 1 ) and after (MRI 2 ) a prolonged period of long access heroin self-administration resulting in escalation of drug intake. Heroin intake resulted in reduced GMV in various cortical and sub-cortical brain regions. In drug-naïve controls no difference was found between MRI 1 and MRI 2 . Notably, the degree of GMV reduction in the medial prefrontal cortex (mPFC) and the insula positively correlated with the amount of heroin consumed and the escalation of heroin use. In a preliminary gene expression analysis, we identified a number of transcripts linked to immune response and neuroinflammation. This prompted us to hypothesize a link between changes in microglia homeostasis and loss of GMV. For this reason, we analyzed the number and morphology of microglial cells in the mPFC and insula. The number of neurons and their morphology was also evaluated. The primary motor cortex, where no GMV change was observed, was used as negative control. We found no differences in the number of neurons and microglia cells following heroin. However, in the same regions where reduced GMV was detected, we observed a shift towards a rounder shape and size reduction in microglia, suggestive of their homeostatic change towards a reactive state. Altogether these findings suggest that escalation of heroin intake correlates with loss of GMV in specific brain regions and that this phenomenon is linked to changes in microglial morphology., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: More than 60 million people use opioids each year, and many countries have declared an opioid overdose crisis. Heroin, one of the most commonly used opioids, has depressant effects on autonomic functioning; however, few studies have been able to examine the effects of heroin or its pharmaceutically prepared equivalent, diamorphine, in human clinical populations. The present study examined heart rate and oxygen saturation in the minutes immediately after acute diamorphine administration in outpatients with heroin dependence., Methods: The sample was a subset of participants (N = 36) in the German Project of Heroin Assisted Treatment of Opiate Dependent Patients Trial in Bonn, Germany. Patients were given 3 daily doses of intravenous diamorphine. Doses were determined on an individual basis by study physicians. Pulse oximetry was recorded at baseline and at 30-second intervals from 0 to 450 seconds after diamorphine administration., Results: Heart rate was significantly higher than baseline at 30 seconds after diamorphine administration and significantly lower than baseline at 270 seconds onward. Oxygen saturation was significantly lower than baseline at 60 seconds onward., Conclusions: Results are consistent with other studies in which depressant effects of opioids were observed. Our findings suggest that even therapeutic doses of diamorphine may have rapid and significant-predominantly depressant-effects on oxygenation and heart rate in populations that frequently use opioids. Monitoring of potential adverse opioid effects would be beneficial even in populations presumed to have developed physiological tolerance., (Copyright © 2023 American Society of Addiction Medicine.)

Rhabdomyolysis is a potentially life-threatening condition induced by diverse mechanisms including drugs and toxins. We aimed to investigate the incidence of rhabdomyolysis occurrence in intoxicated patients with psychoactive substances. In this review, three databases (PubMed, Scopus, Web of Science) and search engine (Google Scholar) were searched by various keywords. After the screening of retrieved documents, related data of included studies were extracted and analyzed with weighted mean difference (WMD) in random effect model. The highest incidence of rhabdomyolysis was observed in intoxication with heroin (57.2 [95% CI 22.6-91.8]), amphetamines (30.5 [95% CI 22.6-38.5]), and cocaine (26.6 [95% CI 11.1-42.1]). The pooled effect size for blood urea nitrogen (WMD = 8.78, p = 0.002), creatinine (WMD = 0.44, p < 0.001), and creatinine phosphokinase (WMD = 2590.9, p < 0.001) was high in patients with rhabdomyolysis compared to patients without rhabdomyolysis. Our results showed a high incidence of rhabdomyolysis induced by psychoactive substance intoxication in ICU patients when compared to total wards. Also, the incidence of rhabdomyolysis occurrence was high in ICU patients with heroin and amphetamine intoxication. Therefore, clinicians should anticipate this complication, monitor for rhabdomyolysis, and institute appropriate treatment protocols early in the patient's clinical course., (© 2023. Springer Nature Limited.)

Opioid use disorder (OUD) looms as one of the most severe medical crises facing society. More effective therapeutics will require a deeper understanding of molecular changes supporting drug-taking and relapse. Here, we develop a brain reward circuit-wide atlas of opioid-induced transcriptional regulation by combining RNA sequencing (RNA-seq) and heroin self-administration in male mice modeling multiple OUD-relevant conditions: acute heroin exposure, chronic heroin intake, context-induced drug-seeking following abstinence, and relapse. Bioinformatics analysis of this rich dataset identified numerous patterns of transcriptional regulation, with both region-specific and pan-circuit biological domains affected by heroin. Integration of RNA-seq data with OUD-relevant behavioral outcomes uncovered region-specific molecular changes and biological processes that predispose to OUD vulnerability. Comparisons with human OUD RNA-seq and genome-wide association study data revealed convergent molecular abnormalities and gene candidates with high therapeutic potential. These studies outline molecular reprogramming underlying OUD and provide a foundational resource for future investigations into mechanisms and treatment strategies.

Heroin is an opioid agonist commonly abused for its rewarding effects. Since its synthesis at the end of the nineteenth century, its popularity as a recreational drug has ebbed and flowed. In the last three decades, heroin use has increased again, and yet the pharmacology of heroin is still poorly understood. After entering the body, heroin is rapidly deacetylated to 6-monoacetylmorphine (6-MAM), which is then deacetylated to morphine. Thus, drug addiction literature has long settled on the notion that heroin is little more than a pro-drug. In contrast to these former views, we will argue for a more complex interplay among heroin and its active metabolites: 6-MAM, morphine, and morphine-6-glucuronide (M6G). In particular, we propose that the complex temporal pattern of heroin effects results from the sequential, only partially overlapping, actions not only of 6-MAM, morphine, and M6G, but also of heroin per se, which, therefore, should not be seen as a mere brain-delivery system for its active metabolites. We will first review the literature concerning the pharmacokinetics and pharmacodynamics of heroin and its metabolites, then examine their neural and behavioral effects, and finally discuss the possible implications of these data for a better understanding of opioid reward and heroin addiction. By so doing we hope to highlight research topics to be investigated by future clinical and pre-clinical studies., (© 2023. The Author(s).)

Heroin-induced toxic leukoencephalopathy (TLE) is an uncommon condition that presents with nonspecific and variable neuropsychiatric findings. It may result in satisfactory recovery or death. Traditionally referred to as "chasing the dragon" syndrome and associated with inhalation of pyrolyzed heroin, recent publications have reported forms of the syndrome associated with noninhaled heroin. We report 2 cases of heroin-induced TLE associated with noninhaled routes of administration and a well-documented history of opioid use disorder. The patient in the first case presented with moderate to severe symptoms. Magnetic resonance imaging of the brain revealed increased T2 and fluid-attenuated inversion recovery signals bilaterally throughout subcortical and periventricular white matter. She survived with significant cognitive issues at discharge from which she adequately recovered by 11-month follow up. The patient in the second case presented with severe symptoms. Magnetic resonance imaging of the brain showed diffuse abnormal increased T2 and fluid-attenuated inversion recovery signals in the white matter of the centrum semiovale and corona radiata. The patient died within 3 weeks of presentation. Both cases illustrate the underrecognition of the form of TLE associated with noninhaled heroin and the difficulties involved in confirming recent heroin use that likely delayed the diagnosis. Further, noninhaled heroin-induced TLE can present with specific signs and symptoms that may help clinicians delineate it from the inhaled form. Given the ongoing opioid epidemic, early and accurate recognition of this condition is of paramount importance., Competing Interests: A.J.R. has received consulting fees from Akili Brain Resource Inc., Compass Inc., Curbstone Consultant LLC., Emmes Corp., Holmusk, Janssen (USA); Liva-Nova, Neurocrine, Otsuka-US, Sunovion; speaking fees from Liva-Nova; and royalties from Guilford Press and the University of Texas Southwestern Medical Center, Dallas, TX (for the Inventory of Depressive Symptoms and its derivatives). He is also named co-inventor on 2 patents: US Patent No. 7,795,033: Methods to Predict the Outcome of Treatment with Antidepressant Medication, Inventors: McMahon F.J., Laje G., Manji H., Rush A.J., Paddock S., Wilson A.S.; and US Patent No. 7,906,283: Methods to Identify Patients at Risk of Developing Adverse Events During Treatment with Antidepressant Medication, Inventors: McMahon F.J., Laje G., Manji H., Rush A.J., Paddock S. The remaining authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Administration of heroin results in the engagement of multiple brain regions and the rewarding and addictive effects are mediated, at least partially, through activation of the mesolimbic dopamine system. However, less is known about dopamine system function following chronic exposure to heroin. Withdrawal from chronic heroin exposure is likely to drive a state of low dopamine in the nucleus accumbens (NAc), as previously observed during withdrawal from other drug classes. Thus, we aimed to investigate alterations in NAc dopamine terminal function following chronic heroin self-administration to identify a mechanism for dopaminergic adaptations. Adult male Long Evans rats were trained to self-administer heroin (0.05 mg/kg/inf, IV) and then placed on a long access (FR1, 6-h, unlimited inf, 0.05 mg/kg/inf) protocol to induce escalation of intake. Following heroin self-administration, rats had decreased basal extracellular levels of dopamine and blunted dopamine response following a heroin challenge (0.1 mg/kg/inf, IV) in the NAc compared to saline controls. FSCV revealed that heroin-exposed rats exhibited reduced stimulated dopamine release during tonic-like, single-pulse stimulations, but increased phasic-like dopamine release during multi-pulse stimulation trains (5 pulses, 5-100 Hz) in addition to an altered dynamic range of release stimulation intensities when compared to controls. Further, we found that presynaptic D3 autoreceptor and kappa-opioid receptor agonist responsivity were increased following heroin self-administration. These results reveal a marked low dopamine state following heroin exposure and suggest the combination of altered dopamine release dynamics may contribute to increased heroin seeking.

Background and Aims: This qualitative study aimed to explore how the development of tolerance to both the psychoactive and respiratory depressant effects of heroin on re-exposure are experienced by people who use heroin., Methods: Semi-structured one-to-one interviews were conducted with 20 adults who currently or previously used heroin (for at least 6 months), with any type of administration (injected, smoked) and experience of abstinence (at least 2 weeks) and relapse. Topic guides explored the participants understanding of tolerance, their experience of developing tolerance to heroin and of tolerance following relapse. Interviews were audio-recorded and transcribed. Thematic analysis was used to generate salient themes., Results: The analysis produced three broad themes: lay understanding of tolerance; tolerating tolerance; and rapid tolerance development following relapse. Tolerance was defined as the body adapting to regular drug use, so that the drug no longer produced the same level of effect. Tolerance was experienced as interacting and co-developing with physical dependence and the symptoms of withdrawal. Indeed, several participants did not differentiate between tolerance and dependence. Most participants did not notice tolerance to respiratory depression. Tolerance levels fluctuated-increasing over periods of regular use and reducing when abstinent. Using more drug was the most common response to increasing tolerance to the desired effects. On re-use following abstinence, tolerance was experienced as developing more quickly in the most recent relapse compared to the first. Tolerance was also perceived to return more quickly with each abstinence-relapse cycle., Conclusions: Qualitative accounts of tolerance report that tolerance returns more quickly with each relapse episode. By elucidating the mechanism(s) involved and potentially discovering how they could be switched on prior to relapse occurring we might be able to develop a beneficial harm reduction treatment for people in abstinence that would protect against overdose occurring on subsequent relapse., Competing Interests: The authors have declared that no competing interests exist.

This commentary discusses the novelty of the preclinical opioid choice model published in Heinsbroek et al., Nat Commun, 2021, and the potential influence of altitude on the reported findings. The studies were performed in the Mile High City of Denver, Colorado, where a unique subpopulation of heroin-choosing rats were noted., (© 2022 Wiley Periodicals LLC.)

The incidence of chronic heroin use disorder, including overdose deaths, has reached epidemic proportions. Here we summarise and evaluate our knowledge of the relationship between chronic heroin use disorder and the brain through a narrative review. A broad range of areas was considered including causal mechanisms, cognitive and neurological consequences of chronic heroin use and novel neuroscience-based clinical interventions. Chronic heroin use is associated with limited or very limited evidence of impairments in memory, cognitive impulsivity, non-planning impulsivity, compulsivity and decision-making. Additionally, there is some evidence for certain neurological disorders being caused by chronic heroin use, including toxic leukoencephalopathy and neurodegeneration. However, there is insufficient evidence on whether these impairments and disorders recover after abstinence. Whilst there is a high prevalence of comorbid psychiatric disorders, there is no clear evidence that chronic heroin use per se causes depression, bipolar disorder, PTSD and/or psychosis. Despite the growing burden on society from heroin use, knowledge of the long-term effects of chronic heroin use disorder on the brain remains limited. Nevertheless, there is evidence for progress in neuroscience-based interventions being made in two areas: assessment (cognitive assessment and neuroimaging) and interventions (cognitive training/remediation and neuromodulation). Longitudinal studies are needed to unravel addiction and neurotoxic mechanisms and clarify the role of pre-existing psychiatric symptoms and cognitive impairments., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Clinical trials have indicated that a vaccine must be immunogenic in genetically diverse human populations and that immunogenicity and protective efficacy in animal models are two key indices required for the approval of a new vaccine. Additionally, the immune response (immunogenicity) and immunoprotection are dependent on the mouse strain. Therefore, the objective of the present study was to determine the immune response (immunogenicity) and the protective efficacy (behavioral response) in three inbred mouse strains immunized with the M 6 TT vaccine. Female BALB/c, C57Bl/6, and DBA/2 inbred mice were immunized with the M 6 -TT vaccine. A solid-phase antibody-capture ELISA was used to monitor antibody titer responses after each booster dose in vaccinated animals. The study used tail-flick testing to evaluate the antinociceptive effects induced by heroin. Additionally, heroin-induced locomotor activity and place preference were evaluated. The M 6 -TT vaccine was able to generate a specific antibody titer in the three inbred mouse strains evaluated. The antibodies reduced the antinociceptive effect of different doses of heroin. In addition, they decreased the heroin-induced locomotor activity and place preference. These findings suggest that the M 6 -TT vaccine generates a powerful immunogenic response capable of reducing the antinociceptive and reinforcing effects of heroin in different inbred mouse strains, which supports its possible future use in clinical trials in genetically diverse human populations., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Patients with opioid use disorder experience high rates of relapse during recovery, despite successful completion of rehabilitation programs. A key factor contributing to this problem is the long-lasting nature of drug-seeking behavior associated with opioid use. We modeled this behavior in a rat drug self-administration paradigm in which drug-seeking is higher after extended abstinence than during the acute abstinence phase. The goal of this study was to determine the contribution of discrete or discriminative drug cues and drug dosage to time-dependent increases in drug-seeking. We examined heroin-seeking after 2 or 21 days of abstinence from two different self-administration cue-context environments using high or low doses of heroin and matched animals for their drug intake history. When lower dosages of heroin are used in discriminative or discrete cue protocols, drug intake history contributed to drug-seeking after abstinence, regardless of abstinence length. Incubation of opioid craving at higher dosages paired with discrete drug cues was not dependent on drug intake. Thus, interactions between drug cues and drug dosage uniquely determined conditions permissible for incubation of heroin craving. Understanding factors that contribute to long-lasting opioid-seeking can provide essential insight into environmental stimuli and drug-taking patterns that promote relapse after periods of successful abstinence., (© 2021. The Author(s).)

Unintentional overdose deaths related to opioids and psychostimulants have increased in prevalence due to the adulteration of these drugs with fentanyl. Synergistic effects between illicit compounds and fentanyl cause aggravated respiratory depression, leading to inadvertent fatalities. Traditional small-molecule therapies implemented in the expanding opioid epidemic present numerous problems since they interact with the same opioid receptors in the brain as the abused drugs. In this study, we report an optimized dual hapten for use as an immunopharmacotherapeutic tool in order to develop antibodies capable of binding to fentanyl-contaminated heroin in the periphery, thus impeding the drugs' psychoactive effects on the central nervous system. This vaccine produced antibodies with nanomolar affinities and effectively blocked opioid analgesic effects elicited by adulterated heroin. These findings provide further insight into the development of chemically contiguous haptens for broad-spectrum immunopharmacotherapies against opioid use disorders., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

There is significant comorbidity of opioid use disorder (OUD) and post-traumatic stress disorder (PTSD) in clinical populations. However, the neurobiological mechanisms underlying the relationship between chronic opioid use and withdrawal and development of PTSD are poorly understood. Our previous work identified that chronic escalating heroin administration and withdrawal can produce enhanced fear learning, an animal model of hyperarousal, and is associated with an increase in dorsal hippocampal (DH) interleukin-1β (IL-1β). However, other cytokines, such as TNF-α, work synergistically with IL-1β and may have a role in the development of enhanced fear learning. Based on both translational rodent and clinical studies, TNF-α has been implicated in hyperarousal states of PTSD, and has an established role in hippocampal-dependent learning and memory. The first set of experiments tested the hypothesis that chronic heroin administration followed by withdrawal is capable of inducing alterations in DH TNF-α expression. The second set of experiments examined whether DH TNF-α expression is functionally relevant to the development of enhanced fear learning. We identified an increase of TNF-α immunoreactivity and positive cells at 0, 24, and 48 h into withdrawal in the dentate gyrus DH subregion. Interestingly, intra-DH infusions of etanercept (TNF-α inhibitor) 0, 24, and 48 h into heroin withdrawal prevented the development of enhanced fear learning and mitigated withdrawal-induced weight loss. Overall, these findings provide insight into the role of TNF-α in opioid withdrawal and the development of anxiety disorders such as PTSD.

Cocaine and heroin cause impairment of neural plasticity in the brain including striatum. This study aimed to identify genes differentially expressed in the striatum of cynomolgus monkeys in response to cocaine and heroin. After chronic administration of cocaine and heroin in the monkeys, we performed large-scale transcriptome profiling in the striatum using RNA-Seq technology and analysed functional annotation. We found that 547 and 1238 transcripts were more than 1.5-fold up- or down-regulated in cocaine- and heroin-treated groups, respectively, compared to the control group, and 3432 transcripts exhibited differential expression between cocaine- and heroin-treated groups. Functional annotation analysis indicated that genes associated with nervous system development (NAGLU, MOBP and TTL7) and stress granule disassembly (KIF5B and KLC1) were differentially expressed in the cocaine-treated group compared to the control group, whereas gene associated with neuron apoptotic process (ERBB3) was differentially expressed in the heroin-treated group. In addition, IPA network analysis indicated that genes (TRAF6 and TRAF3IP2) associated with inflammation were increased by the chronic administration of cocaine and heroin. These results provide insight into the correlated molecular mechanisms as well as the upregulation and down-regulation of genes in the striatum after chronic exposure to cocaine and heroin., (© 2021 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Heroin use disorder is a chronic relapsing brain disease containing multiple phenotypes. These phenotypes vary among heroin users and might be influenced by genetic factors. Single-nucleotide polymorphisms (SNPs) of catechol-O-methyltransferase (COMT) and alpha-1-adrenergic receptor (ADRA1A) genes are associated with heroin use disorder. However, it has not been clarified which phenotypes of heroin use disorder are related to these genes. To address this question, we recruited 801 unrelated heroin users and divided them into different subgroups according to four important phenotypes of heroin use disorder. Then 7 SNPs in the functional region of these genes were systematically screened and genotyped using a SNaPshot assay. We found that the A allele of ADRA1A rs1048101 was associated with a shorter duration of transition from first use to addiction. Subjects with the C allele of ADRA1A rs3808585 were more susceptible to memory impairment after heroin use disorder. Subjects with the G allele of COMT rs769224 were more likely to take a higher dose of heroin every day. Our study confirmed the association between polymorphisms of COMT and ADRA1A with those specific phenotypes of heroin use disorder, which will be instructive for the precise treatment of the disease., (Copyright © 2021. Published by Elsevier B.V.)

Using two-sensor electrochemical recordings in freely moving rats, we examined the relationship between physiological and drug-induced oxygen fluctuations in the brain and periphery. Animals chronically implanted with oxygen sensors in the nucleus accumbens (NAc) and subcutaneous (SC) space were subjected to several mildly arousing stimuli (sound, tail-pinch and social interaction) and intravenous injections of cocaine and heroin. Arousing stimuli induced rapid increases in NAc oxygen levels followed by and correlated with oxygen decreases in the SC space. Therefore, cerebral vasodilation that increases cerebral blood flow and oxygen entry into brain tissue results from both direct neuronal activation and peripheral vasoconstriction, which redistributes arterial blood from periphery to the brain. The latter factor could also explain a similar pattern of oxygen responses found in the substantia nigra reticulata, suggesting hyperoxia as a global phenomenon with minor structural differences during early time intervals following the stimulus onset. While arousing stimuli and cocaine induced similar oxygen responses in the brain and SC space, heroin induced a biphasic down-up brain oxygen fluctuation associated with a monophasic oxygen decrease in the SC space. Oxygen decreases occurred more rapidly and stronger in the SC space, reflecting a drop in blood oxygen levels due to respiratory depression.

Background: The opioid epidemic has caused an increase in overdose deaths which can be attributed to fentanyl combined with various illicit substances. Drug checking programs have been started by many harm reduction groups to provide tools for users to determine the composition of their street drugs. Immunoassay fentanyl test strips (FTS) allow users to test drugs for fentanyl by either filling a baggie or cooker with water to dissolve the sample and test. The antibody used in FTS is very selective for fentanyl at high dilutions, a characteristic of the traditional use of urine testing. These street sample preparation methods can lead to mg/mL concentrations of several potential interferents. We tested whether these concentrated samples could cause false positive results on a FTS., Methods: 20 ng/mL Rapid Response FTS were obtained from BTNX Inc. and tested against 4 different pharmaceuticals (diphenhydramine, alprazolam, gabapentin, and naloxone buprenorphine) and 3 illicit stimulants [cocaine HCl, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA)] in concentrations from 20 to 0.2 mg/mL. The FTS testing pad is divided into 2 sections: the control area and the test area. Control and test area signal intensities were quantified by ImageJ from photographs of the test strips and compared to a threshold set by fentanyl at the FTS limit of detection., Results: False positive results indicating the presence of fentanyl were obtained from samples of methamphetamine, MDMA, and diphenhydramine at concentrations at or above 1 mg/mL. Diphenhydramine is a common cutting agent in heroin. The street sample preparation protocols for FTS use suggested by many online resources would produce such concentrations of these materials. Street samples need to be diluted more significantly to avoid interference from potential cutting agents and stimulants., Conclusions: Fentanyl test strips are commercially available, successful at detecting fentanyl to the specified limit of detection and can be a valuable tool for harm reduction efforts. Users should be aware that when drugs and adulterants are in high concentrations, FTS can give a false positive result.

Opioid overdose related deaths have increased dramatically in recent years. Combating the opioid epidemic requires better understanding of the epidemiology of opioid poisoning (OP). To discover trends and patterns of opioid poisoning and the demographic and regional disparities, we analyzed large scale patient visits data in New York State (NYS). Demographic, spatial, temporal and correlation analyses were performed for all OP patients extracted from the claims data in the New York Statewide Planning and Research Cooperative System (SPARCS) from 2010 to 2016, along with Decennial US Census and American Community Survey zip code level data. 58,481 patients with at least one OP diagnosis and a valid NYS zip code address were included. Main outcome and measures include OP patient counts and rates per 100,000 population, patient level factors (gender, age, race and ethnicity, residential zip code), and zip code level social demographic factors. The results showed that the OP rate increased by 364.6%, and by 741.5% for the age group > 65 years. There were wide disparities among groups by race and ethnicity on rates and age distributions of OP. Heroin and non-heroin based OP rates demonstrated distinct temporal trends as well as major geospatial variation. The findings highlighted strong demographic disparity of OP patients, evolving patterns and substantial geospatial variation.

Introduction: Nested graft is a surgical technique that allows to manage difficult-to-treat medical conditions such as chronic cutaneous ulcers, thanks to the high efficacy it has in reverting the fibroblasts senescence. Because of its peculiar regenerative property, nested graft is a surgical technique suitable also for the treatment of cutaneous ulcers developing on fibrotic scar tissue., Case Report: We reported the case of a 45-year-old man, drug-addict, with a large ulcer on the back of the right forearm in the context of scar fibrotic tissue. This lesion resulted from a previous heroin extravasation treated with a dermo-epidermal skin graft, that was accidentally scratched away by mechanical trauma. After several therapeutic failures with topical medications, we decided to treat the ulcer performing a skin graft using the nested graft technique. No adverse events were reported by the patient during or after the surgery. At the clinical evaluation performed three years later the wound was completely healed., Conclusions: Nested graft represents a safe and easy-to-use technique that can be successfully used to treat ulcers on scar tissue, ensuring the achievement and the long-term maintenance of optimal resistance and aesthetic results., (Copyright © 2020 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.)

This article examines injectable Opioid Agonist Treatment (iOAT), in which patients suffering from long-term, treatment refractory opioid use disorder (OUD) are prescribed injectable diacetylmorphine, the active ingredient of heroin. While iOAT is part of the continuum of care for OUD in some European countries and in some parts of Canada, it is not an available treatment in the United States. We suggest that one reason for this situation is the belief that a genuine treatment for substance use disorder cannot prescribe the same substance as that used. We examine possible rationales for this belief by considering four combinations of views on the constitutive causal basis of substance use disorders and the definition of effective treatment. We show that all but one combination counts iOAT as a genuine treatment and that there are good reasons to reject the one that does not. Specifically, we claim that medical interventions, such as iOAT, that significantly reduce the severity of a disorder deserve to be categorized as effective treatments and regarded as such in practice.

Background: Heroin addiction is currently a significant health problem, and information on the electrocardiographic effects of heroin is limited., Objetivo: The aim of the present study is to investigate effects of heroin addiction on electrocardiographic parameters., Methods: A total of 136 individuals, including 66 individuals who smoke heroin as the study group and 70 healthy individuals with no drug addiction as the control group, were included in the study. Individuals who inject heroin were excluded. Electrocardiographic (ECG) evaluation of those using heroin was performed and compared with those of the control group. In addition, pre-treatment and post-treatment ECG of the heroin group were compared. A p-value of <0.05 was accepted as statistically significant., Results: Heart rate (77.2±12.8 versus 71.4±11.2; p=0.02) were found to be higher in the heroin group compared to the control group. QT (341.50±25.80 versus 379.11±45.23; p=0.01), QTc intervals (385.12±29.11 versus 411.3±51.70; p<0.01), and T peak to end time (Tpe) (65.41±10.82 versus 73.3±10.13; p<0.01) were significantly shorter in the heroin group. No difference was observed between the groups with regard to Tpe/QT and Tpe/QTc ratios. In the subgroup analysis of the heroin group, QT (356.81±37.49 versus 381.18±40.03; p<0.01) and QTc (382.06±26.41 versus 396.06±29.80; p<0.01) intervals were significantly shorter in the pre-treatment period., Conclusion: Heroin addiction significantly affects the QT, QTc, and Tpe time intervals. The arrhythmia effects of these parameters are well known. More attention to the electrocardiographic parameters of these individuals should be given. (Arq Bras Cardiol. 2020; 115(6):1135-1141).

Converging evidence suggests opioid abuse can increase the incidence and severity of post-traumatic stress disorder (PTSD) in clinical populations. Interestingly, opioid withdrawal alone can produce symptoms similar to those of PTSD. Despite this association, the neural mechanisms underlying the relationship of opioid abuse, withdrawal, and PTSD is poorly understood. Our laboratory has investigated the neurobiological underpinnings of stress-enhanced fear learning (SEFL), an animal model of PTSD-like symptoms. We have previously shown that, in SEFL, a severe footshock induces an increase in dorsal hippocampal (DH) interleukin-1β (IL-1β), and subsequent fear learning is blocked by DH IL-1 receptor antagonism (IL-1RA). Given that opioids and stress engage similar neuroimmune mechanisms, the present experiments investigate whether the same mechanisms drive heroin withdrawal to induce a PTSD-like phenotype. First, we tested the effect of a chronic escalating heroin dose and withdrawal regimen on fear learning and found it produces enhanced future fear learning. Heroin withdrawal also induces a time-dependent, region-specific increase in IL-1β and glial fibrillary acidic protein (GFAP) immunoreactivity within the dentate gyrus of the DH. IL-1β was significantly colocalized with GFAP, indicating astrocytes may be involved in increased IL-1β. Moreover, intra-DH infusions of IL-1RA 0, 24, and 48 h into heroin withdrawal prevents the development of enhanced fear learning but does not alter withdrawal-induced weight loss. Collectively, our data suggests heroin withdrawal is sufficient to produce enhanced fear learning, astrocytes may play a role in heroin withdrawal-induced IL-1β, and DH IL-1 signaling during withdrawal mediates the development of heroin withdrawal-enhanced fear learning.

Background: Opioid prescribing guidelines recommend reducing or discontinuing opioids for chronic pain if harms of opioid treatment outweigh benefits. As opioid discontinuation becomes more prevalent, it is important to understand whether opioid discontinuation is associated with heroin use. In this study, we sought to assess the association between opioid discontinuation and heroin use documented in the medical record., Methods: A matched nested case-control study was conducted in an integrated health plan and delivery system in Colorado. Patients receiving opioid therapy in the study period (January 2006-June 2018) were included. Opioid discontinuation was defined as ≥45 days with no opioids dispensed after initiating opioid therapy. The heroin use onset date represented the index date. Case patients were matched to up to 20 randomly selected patients without heroin use (control patients) by age, sex, calendar time, and time between initiating opioid therapy and the index date. Conditional logistic regression models estimated matched odds ratios (mOR) for the association between an opioid discontinuation prior to the index date and heroin use., Results: Among 22,962 patients prescribed opioid therapy, 125 patients (0.54%) used heroin after initiating opioid therapy, of which 74 met criteria for inclusion in the analysis. The odds of opioid discontinuation were approximately two times higher in case patients (n = 74) than control patients (n = 1045; mOR = 2.19; 95% CI 1.27-3.78)., Conclusions: Among patients prescribed chronic opioid therapy, the observed increased risk for heroin use associated with opioid discontinuation should be balanced with potential benefits., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Postoperative delirium (POD) is a complication that can occur in patients of any age undergoing major surgery. Due to the high incidence of delirium morbidity and mortality, it is important to identify and treat delirium quickly and successfully. Although many organic, surgical and psychiatric risk factors are recognized as putative causes of delirium, heroin withdrawal is not yet well defined and evaluated in the prevention and treatment of POD. We report a case report of a multi-drug addicted patient, without any other psychiatric comorbidity, suffering from heroin-withdrawal POD after urgent major cardiac surgery, successfully treated with clonazepam orally after conventional therapy failure. At the time of discharge, POD was completely solved and without further complications, psychiatric therapy was further reduced just to a low dose of clonazepam and the patient was referred to a specialized drug abuse center. The reported case suggests that clonazepam may be considered a valid option in case of heroin-withdrawal POD after conventional treatments failure.

We studied mechanisms driving gender differences in HIV incidence among 651 women and men who inject drugs (PWID) in Tijuana, Mexico, hypothesizing that sex work will mediate the association between female gender and HIV incidence. Of 43 HIV seroconversions occurring between 2011 and 2018, 8.8% were among females and 5.2% among males. HIV incidence density was significantly higher among females versus males (1.75 per 100 person years [PY], 95% CI 1.16-2.66, vs. 0.95 per 100 PY, 95% CI 0.62-1.47). Factors significantly associated with HIV seroconversion were: sex work (adjusted hazard ratio [aHR] = 2.25, 95% CI 1.05-4.80); methamphetamine injection (aHR = 2.30, 95% CI 1.12-4.73); and methamphetamine and heroin co-injection in the past six months (aHR = 2.26, 95% CI 1.23-4.15). In mediation analyses, sex work mediated a substantial proportion (84.3%) of the association between female gender and HIV incidence. Interventions should target female PWID who engage in sex work to reduce gender-related disparities in HIV incidence.

The decreasing age of young people injecting illicit drugs is an under-reported challenge for the prevention of HIV transmission worldwide. Young people aged 15-24 years represent 1 in 5 persons living with HIV in Mauritius where the epidemic is driven by injecting drug use and risky sexual behaviours. We recruited 22 heroin users aged 18-24 and 5 service providers working in harm reduction (HR) for the present study. Qualitative data were collected through unstructured interviews. We adopted an economic framework and an inductive approach to the analysis, which implied revising codes and themes. The risks heroin users described as consumers of illicit drugs and as clients of HR services could not be analyzed in isolation. Polydrug use emerged as a recurrent coping mechanism resulting from the changing dynamics within the heroin market. The risks faced by women went beyond addiction and infection with HIV. How participants viewed the risks and benefits linked to using heroin was greatly influenced by gaps in knowledge that left room for uncertainty and reinforcing mechanisms such as peer influence. The study shows that qualitative research can produce in-depth socio-behavioural insights required to produce more effective services for young people.

Background: People who inject drugs often get bacterial infections. Few longitudinal studies have reported the incidence and treatment costs of these infections., Methods: For a cohort of 2335 people who inject heroin entering treatment for drug dependence between 2006 and 2017 in London, England, we reported the rates of hospitalisation or death with primary causes of cutaneous abscess, cellulitis, phlebitis, septicaemia, osteomyelitis, septic arthritis, endocarditis, or necrotising fasciitis. We compared these rates to the general population. We also used NHS reference costs to calculate the cost of admissions., Results: During a median of 8.0 years of follow-up, 24 % of patients (570/2335) had a severe bacterial infection, most commonly presenting with cutaneous abscesses or cellulitis. Bacterial infections accounted for 13 % of all hospital admissions. The rate was 73 per 1000 person-years (95 % CI 69-77); 50 times the general population, and the rate remained high throughout follow-up. The rate of severe bacterial infections for women was 1.50 (95 % CI 1.32-1.69) times the rate for men. The mean cost per admission was £4980, and we estimate that the annual cost of hospital treatment for people who inject heroin in London is £4.5 million., Conclusions: People who inject heroin have extreme and long-term risk of severe bacterial infections., Competing Interests: Declaration of Competing Interest MK is employed by the South London and Maudsley NHS Trust (SLaM) as clinical lead for Lambeth Addictions Consortium, which provides treatment for the patients included in this study. JS is a clinician and researcher and has worked extensively on clinical trials and wider research. JS’s employer (King’s College London) receives, unconnected to this specific study but connected to his wider work, project grant support and/or honoraria and/or consultancy payments from government agencies, charitable sources and also from pharmaceutical companies related to funding for clinical trials and research studies (for fuller information see www.kcl.ac.uk/ioppn/depts/addictions/people/hod.aspx)., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: There is growing public health concern around the potential impact of the opioid crisis on efforts to eradicate HIV. This secondary analysis seeks to determine if those who report opioids as their primary problem drug compared to those who report other drugs and/or alcohol differ in engagement in HIV primary care among a sample of hospitalized people with HIV (PWH) who use drugs and/or alcohol, a traditionally marginalized and difficult to engage population key to ending the HIV epidemic., Setting and Participants: A total of 801 participants (67% male; 75% Black, non-Hispanic; mean age 44.2) with uncontrolled HIV and reported drug and/or alcohol use were recruited from 11 hospitals around the U.S. in cities with high HIV prevalence from 2012 to 2014 for a multisite clinical trial to improve HIV viral suppression., Methods: A generalized linear model compared those who reported opioids as their primary problem drug to those who reported other problem drugs and/or alcohol on their previous engagement in HIV primary care, controlling for age, sex, race, education, income, any previous drug and/or alcohol treatment, length of time since diagnosis, and study site., Results: A total of 95 (11.9%) participants reported opioids as their primary problem drug. In adjusted models, those who reported opioids were significantly less likely to have ever engaged in HIV primary care than those who reported no problem drug use (adjusted risk ratio, ARR = 0.84, 95% Confidence Interval, CI 0.73, 0.98), stimulants (ARR = 0.84, 95% CI 0.74, 0.95), and polydrug use but no alcohol (ARR = 0.79, 95% CI 0.68, 0.93). While not statistically significant, the trend in the estimates of the remaining drug and/or alcohol categories (alcohol, cannabis, polydrug use with alcohol, and [but excluding the estimate for] other), point to a similar phenomena-those who identify opioids as their primary problem drug are engaging in HIV primary care less., Conclusions: These findings suggest that for hospitalized PWH who use drugs and/or alcohol, tailored and expanded efforts are especially needed to link those who report problem opioid use to HIV primary care. Trial registration This study was funded by National Institutes of Health (NIH) grant: U10-DA01372011 (Project HOPE-Hospital Visit as Opportunity for Prevention and Engagement for HIV-Infected Drug Users; Metsch); which is also a registered clinical trial under the Clinical Trials Network (CTN-0049). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

Covertly using heroin during methadone maintenance treatment (MMT) is very common among heroin-dependent patients, which has posed threats to the physical health of heroin-dependent patients and social safety. Covertly using heroin may be influenced by many factors, especially social capital. Therefore, we aimed to investigate the relationship between behaviors of covertly using heroin during MMT and social capital heroin-dependent patients in Sichuan Province, China. A cross-sectional study was conducted between October and November 2018, with a total of 581 heroin-dependent patients participating in the study. In addition to socio-demographic characteristics and heroin use related behaviors, the questionnaire also included the measures of social capital: social network (SN), social support (SP), community participation (CP) and social trust (ST). Multivariate logistic regression analyses were used to estimate the association between different measures of social capital and heroin use. The prevalence of covertly using heroin of heroin during MMT was 31.0% among our participants in the 6 months before the study. After adjusting for socio-demographic factors and heroin-use related variables, SN (OR = 0.85, 95% CI: 0.76-0.95), SP (OR = 0.89, 95% CI: 0.83-0.95), and ST (OR = 0.88, 95% CI: 0.81-0.95) were significantly associated with heroin use. Results suggest that social capital may have a protective effect on behavior of covertly using heroin during MMT, which should be consider in the interventions for heroin-dependent patients, in order to reduce the incidence of heroin use during MMT as well as improve the compliance of MMT.

Objective: To investigate the manifestations and incidence of headaches caused by heroin in Chinese women., Methods: This was a survey study conducted from 29 June to 3 July 2015 with women attending the Shanxi Drug Rehabilitation Centre for Women (China). All study subjects were newly admitted and had not begun their drug rehabilitation. Demographic characteristics, heroin usage and headache episodes within the previous 3 months were surveyed, especially the presence of a headache within 2 hours of heroin use. Details of the severity, location, premonitory symptoms and characteristics of headaches were recorded., Results: Of the 90 heroin-dependent patients, 74 experienced headache attacks within 2 hours of heroin use, and the headaches subsided within 72 hours of discontinuation of heroin use. Most heroin-induced headaches were similar to migraines and manifested as pulsating pain in 54 patients (51/74, 68.9%); bilateral pain was reported by 46 patients (46/74, 62.2%). Approximately half of the patients with heroin-induced headaches also reported accompanying symptoms of nausea, vomiting, and light and sound sensitivity., Conclusions: Heroin-induced headache may eventually be listed as a new class of headache in the International Classification of Headache Disorders.

Objectives: Drug abuse is one of the most severe global social and public health problems, especially in China. However, objective blood biomarkers that are easy to detect are still in great need. This study was aim to explore the expression pattern of circulating microRNAs (miRNAs) in subjects with drug addiction and test the potential of altered serum miRNAs as noninvasive diagnostic tools for drug abuse., Methods: Serum samples were obtained from 42 heroin abusers, 42 methamphetamine (MA) abusers and 42 controls. Microarray-based miRNA analysis was first applied to screen unique serum miRNA profiles in drug abusers on a training set of serum samples from 12 heroin abusers, 12 MA abusers and 12 control subjects. The expression levels of selected candidate miRNAs were subsequently verified in individual samples of the training set and further confirmed independently in a validation set of samples from 30 heroin abusers, 30 MA abusers and 30 controls using real-time quantitative polymerase chain reaction (RT-qPCR)., Results: Microarray analysis identified 116 and 109 significantly altered miRNAs in heroin abusers and MA abusers, respectively. Three miRNAs, including let-7b-5p, miR-206 and miR-486-5p, were verified to be significantly and steadily increased in heroin abusers, and miR-9-3p was significantly increased in MA abusers compared with normal controls. The areas under the curve (AUCs) of the ROC curve of these miRNAs ranged from 0.718 to 0.867., Conclusions: Our study raises the possibility that the altered serum miRNAs could potentially be used as an auxiliary tool to identify individuals in drug abuse and addiction., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Rationale: Deficits in response inhibition associated with heroin use could last several months after abstinence in heroin users, and their response inhibition can also be interfered with task-irrelevant drug-related cues. However, it is unclear whether exposure to drug-related cues affects subsequent response inhibition in heroin users following abstinence., Objectives: The present study aimed to investigate how drug-related cues with different durations between stimulus presentations, referred to as stimulus onset asynchronies (SOAs), affect subsequent response inhibition in heroin abstainers (HAs) with different length of abstinence., Methods: Sixty-seven male HAs performed a modified Go/NoGo task in which a motor response to frequent Go targets and no response to rare NoGo targets were required and a Go or NoGo target was displayed after either a heroin-related or a neutral picture presented for the 200 ms and 600 ms SOAs., Results: The HAs responded significantly faster to Go targets following the neutral pictures for the 600 ms SOA compared to other conditions. They also made more commission errors following heroin-related pictures compared to neutral pictures regardless of the SOAs. The shorter-term HAs made more commission errors compared to the longer-term HAs following the 200 ms SOA, and it was only a trend when the SOA was 600 ms. Additionally, negative correlations between the duration of current abstinence and commission errors were observed following cues with the 200 ms SOA., Conclusions: Impaired response inhibition in HAs can be improved through protracted drug abstinence. However, that effect can be reduced by exposure to drug-related cues, which may increase the risk of relapse.

It is widely reported that drug addiction involves the strengthening of specific reward circuits through N-methyl-d-aspartic acid receptor (NMDAR)-dependent synaptic potentiation, and several lines of evidence strongly implicate NMDA receptor 2 (NR2) subunits in drug abuse. To explore the potential mechanism of heroin dependence, this study examined changes in the expression levels of NR2 subunits NR2A-D in the prelimbic (PL) region of the medial prefrontal cortex (mPFC) after repeated heroin administration and subsequent abstinence. The conditioned place preference (CPP) test confirmed successful induction of heroin dependence and withdrawal. Western blotting and qRT-PCR revealed no differences in NR2A subunit expression among heroin-exposure, heroin-withdrawal, and control group rats; in contrast, expression of NR2B was significantly higher in the heroin-exposure group, whereas expression levels of NR2C and NR2D were significantly higher in the heroin-withdrawal group relative to the controls. Further studies are needed to identify the functional significance based on alterations of NR2 subunits., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

While it is known that opioid receptors (ORs) are densely expressed in both the brain and periphery, it is widely accepted that hypoxic effects of opioids result solely from their direct action in the CNS. To examine the role of peripheral ORs in triggering brain hypoxia, we used oxygen sensors in freely moving rats to examine how naloxone-HCl and naloxone-methiodide, the latter which is commonly believed to be peripherally restricted, affect brain oxygen responses induced by intravenous heroin at low, human-relevant doses. Similar to naloxone-HCl, naloxone-methiodide at a relatively low dose (2 mg/kg) fully blocked heroin-induced decreases in brain oxygen levels. As measured by mass spectrometry, naloxone-methiodide was found to be ~40-fold less permeable than naloxone-HCl across the blood-brain barrier, thus acting as a selective blocker of peripheral ORs. Despite this selectivity, a low but detectable amount of naloxone was found in brain tissue after naloxone-methiodide administration, potentially influencing our results. Therefore, we examined the effects of naloxone-methiodide at a very low dose (0.2 mg/kg; at which naloxone was undetectable in brain tissue) and found that this drug still powerfully attenuates heroin-induced brain oxygen responses. These data demonstrate the role of peripheral ORs in triggering heroin-induced respiratory depression and subsequent brain hypoxia.

Background: The differential utility of neurocognitive impulsivity and externalizing/ internalizing traits as putative endophenotypes for dependence on heroin vs. amphetamine is unclear., Objective: This exploratory study aims to determine: (1) whether neurocognitive impulsivity dimensions and externalizing/internalizing traits are correlated between siblings discordant for heroin and amphetamine dependence; and (2) which of these associations are common across substances and which are substance- specific., Methods: Pearson correlations between individuals with 'pure' heroin and amphetamine dependence and their unaffected biological siblings (n = 37 heroin sibling pairs; n = 30 amphetamine sibling pairs) were run on 10 neurocognitive measures, 6 externalizing measures, and 5 internalizing measures. Sibling pair effects were further examined using regression., Results: Siblings discordant for heroin dependence were significantly correlated on delay aversion on the Cambridge Gambling Task, risk-taking on the Balloon Analogue Risk Task, sensation seeking, and hopelessness. Siblings discordant for amphetamine dependence were significantly correlated on the quality of decision-making on the Cambridge Gambling Task, discriminability on the Immediate Memory Task, commission errors on the Go/No Go Task, trait impulsivity, ADHD and anxiety sensitivity., Conclusion: Dimensions of impulsivity and externalizing/internalizing traits appear to aggregate among siblings discordant for substance dependence. Risk-taking propensity, sensation seeking and hopelessness were specific for heroin sibling pairs. Motor/action impulsivity, trait impulsivity, and anxiety sensitivity were specific to amphetamine sibling pairs. Decisional/choice impulsivity was common across both heroin and amphetamine sibling pairs. These findings provide preliminary evidence for the utility of neurocognitive impulsivity and externalizing/ internalizing traits as candidate endophenotypes for substance dependence in general and for substance-specific dependencies., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Illicit drug use contributes to substantial morbidity and mortality. Drug scheduling, a legal measure in drug enforcement, is often structured as a hierarchy based on addiction tendency, abuse trends, and harm, but may lack data-driven evidence when classifying substances. Our study aims to measure addiction tendency and use trends based on real-world data. We used the open access database of National Police Agency, Ministry of the Interior in Taiwan and analyzed all daily criminal cases of illicit drugs from 2013 to 2017 and monthly illicit drug enforcement data from the same database from 2002 to 2017. We hypothesized that repeat and frequent use despite legal consequence may be a reflection of addictive behavior, and empirical mode decomposition was applied in analysis to calculate addiction tendency indices and intrinsic 15-year use trends. Our analysis showed heroin has the highest addiction index, followed by methamphetamine. 3,4-Methyl enedioxy methamphetamine, marijuana, and ketamine had lower addictive propensities. This result is consistent with most drug scheduling hierarchies. 15-year use trends of substances were consistent with previous epidemiological studies., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: This project offers new epidemiological estimates for DSM-IV cocaine dependence among sub-groups of newly incident cocaine users in the United States (US), including estimated attack rates for 21 dependence-related cocaine side effect problems and experiences occurring <12 months after onset., Method: In 2002-2016, US National Surveys on Drug Use and Health (NSDUH) sampled, recruited, and assessed cocaine experiences of non-institutionalized civilians. Unweighted estimates for year-pairs (2002-3,…,2015-16) are from 3488 cocaine powder-only initiates and 275 powder-then-crack initiates (all evaluated <12 months after onset). Analysis-weighted attack rate estimates are incidence proportions with 95% confidence intervals (CI), summarized via meta-analysis., Results: Evaluated <12 months after onset, meta-analysis summaries show 5% of powder-only initiates developed cocaine dependence (95% CI = 4%, 6%) versus 22% of powder-then-crack initiates (95% CI = 17%, 29%). For several cocaine side effect problems and experiences (e.g., 'loss of control' indicators) there is a statistically robust crack-associated excess risk., Conclusions: Three interpretations of observed crack-associated excess risk are especially cogent and deserving of continued inquiry: (1) Powder-then-crack initiates start with heightened dependence risk susceptibilities (i.e., pre-dating onset); (2) Powder-using initiates become cocaine dependent and then start using crack; (3) The cocaine delivery variant of 'crack-smoking' is more toxic than powder insufflation. For powder-then-crack initiates, the cocaine dependence risk (22%) is modestly lower but statistically undifferentiable from a recently estimated risk of heroin dependence <12 months after heroin onset (30%). Clinicians can use these side effect estimates in an evidence-based diagnostic workup when patients disclose new onsets of cocaine use., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Electroacupuncture (EA) has effective analgesic effects. Our previous study demonstrated that the upregulation of P2X3 receptors in the dorsal root ganglia (DRG) might participate in heroin withdrawal-induced hyperalgesia. The aim of this study is to further explore whether 2 Hz EA reduces heroin relapse associated with its analgesic effect and whether P2X3 receptors in the DRG are involved in this process. 2 Hz EA was adopted to treat the heroin SA rats in the present study. Heroin-seeking and pain sensitivity were evaluated. The expression of P2X3 receptors in the DRG was detected. Our results showed that compared with the control group, the reinstatement, thermal hyperalgesia, and mechanical allodynia of the heroin-addicted group were increased significantly. The expression of P2X3 receptors in the DRG was increased markedly. After being treated using 2 Hz EA, reinstatement was reduced, hyperalgesia was decreased, and the upregulated expression of P2X3 receptors in the DRG had decreased significantly compared to that in the heroin-addicted group. Consequently, our results indicated that 2 Hz EA was an effective method for treating heroin-induced hyperalgesia and helping prevent relapse, and the potential mechanism might be related to the downregulation of P2X3 receptor expression in the DRG., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2019 Lin Chen et al.)

Background: Although much is known about the correlates of heroin overdose, less is known about pharmaceutical opioid (PO) overdose. This study aimed to examine correlates of opioid overdose deaths by opioid and compare correlates between opioids., Methods: Analysis of opioid overdose deaths in Australia between 2000-2015, extracted from the National Coronial Information System (NCIS). The NCIS is an online database of deaths reportable to the coroner, and contains coroner's findings, autopsy and toxicology reports. Deaths were categorized into mutually exclusive groups: 1) Heroin deaths; and 2) PO deaths (excluding heroin). PO deaths were examined by individual opioid., Results: There were 10,795 opioid overdose deaths over the study period. Relative to deaths occurring in major cities, deaths in regional/remote areas had 15.2 (95 % CI: 11.5-20.2) times the risk of being attributed to pharmaceutical fentanyl than heroin. Relative to deaths among people without a recorded history of chronic pain, deaths among people with a recorded history of chronic pain had a 1.9-10.7-fold increased risk of the death being attributed to POs than heroin. Deaths among people with a recorded history of substance use problems where the opioid was injected prior to death had 7.2 and 1.7 times the risk of being attributed to methadone and pharmaceutical fentanyl (respectively) than heroin., Conclusions: Findings suggest the need to: educate PO consumers about the risks of overdose at the time of prescribing; increase coverage and engagement in opioid dependence treatment (particularly in regional/remote areas); and increase uptake of take-home naloxone to reduce opioid overdose mortality., (Copyright © 2019. Published by Elsevier B.V.)

Background: Emerging evidence suggests that non-medical prescription opioid (NMPO) use may be a risk factor for initiating heroin use; however, pathways from PO to heroin use among youth remain underexplored. We sought to examine the association between NMPO use and heroin initiation., Methods: Between September 2005 and June 2017 data were derived from an open prospective cohort of street-involved youth aged 14-28 who use illegal drugs in Vancouver, Canada. The study included 526 youth who had never used non-injection heroin, and 652 youth who had never used injection heroin at baseline. We used Cox proportional hazards regressions to examine the association between NMPO use - in addition to other substance use patterns - and subsequent initiation into non-injection and injection heroin use., Results: Among those who had never used non-injection heroin at baseline, 133 (25.3%) initiated non-injection heroin use during the study period. Among those who had never injected heroin at baseline, 137 (21.0%) initiated heroin injection during the study period. In multivariable analyses, NMPO use, crack use, and crystal methamphetamine use predicted non-injection heroin initiation (all p < 0.05). In separate multivariable analyses, non-injection heroin and crystal methamphetamine predicted heroin injection initiation (all p < 0.05)., Conclusions: Among street-involved youth in this setting, NMPO use predicted initiation into non-injection heroin use but not initiation into heroin injection. Interestingly, crack cocaine and crystal methamphetamine use were stronger predictors of heroin initiation than NMPO use was, suggesting that stimulant use may carry greater risks for heroin initiation than NMPO use., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Opioids have high abuse potential and pose a major public health concern. Yet, a large percentage of individuals exposed to opioids do not develop problematic use. Individual differences in opioid abuse potential are not well understood., Methods: This within-subject (N = 16), double-blind, double-dummy, human laboratory study evaluated individual differences in response to dose (placebo, low, medium, high) following administration of heroin and hydromorphone through intravenous and subcutaneous routes, in opioid-experienced but non physically-dependent participants. Outcomes were self-reported visual analog scale (VAS) ratings (High, Liking, Drug Effect, Good Effect, Rush), pupil diameter change from baseline, and crossover point on the Drug vs. Money questionnaire. The degree to which results were consistent across measures within an individual was assessed using a mixed-effects model from which an intraclass correlation coefficient measure of between and within-subject variance was derived., Results: The mixed effects model fit was significant (p < 0.0001) and revealed that 85.5% of the explainable variance was due to between-subject effects, suggesting the responses within an individual were highly consistent. Visual inspection reveals a myriad response pattern across participants, with some demonstrating classic dose-effect responses and others not differentiating any active doses from placebo., Conclusions: Data suggest the abuse potential of opioids is significantly different between individuals but that the experience within an individual is highly consistent. Research to prospectively characterize and evaluate mechanisms underlying these differences is warranted and may provide a foundation to help identify persons at heightened risk of transitioning from opioid exposure to misuse and/or opioid use disorder., (Copyright © 2019. Published by Elsevier B.V.)