Powerful behavioral interactions between methamphetamine and morphine

Explaining the high mortality among opioid-cocaine co-users compared to opioid-only users. A systematic review

RATIONALE

The opioid crisis in North America has recently seen a fourth wave, which is dominated by drug-related deaths due to the combined use of illicitly manufactured fentanyl [IMF] and stimulants such as cocaine and methamphetamine.

OBJECTIVES

A systematic review addressing the question why drug users combine opioids and stimulants and why the combination results in such a high overdose mortality: from specific and dangerous pharmacokinetic or pharmacodynamic interactions or from accidental poisoning?

RESULTS

Motives for the combined use include a more intensive high or rush when used at the same time, and some users have the unfounded and dangerous belief that co-use of stimulants will counteract opioid-induced respiratory depression. Overdose deaths due to combined (intravenous) use of opioids and stimulants are not likely to be caused by specific pharmacokinetic or pharmacodynamic interactions between the two drugs and it is unlikely that the main cause of overdose deaths is due to accidental poisoning.

CONCLUSION

The unexpectedly high overdose rates in this population could not be attributed to accidental overdosing or pharmacokinetic/pharmacodynamic interactions. The most likely explanation for the high rate of drug-related deaths in opioid-cocaine co-users is careless overdosing with either cocaine, opioid(s) or both, probably facilitated by the high level of preexisting impulsivity in these co-users and a further acute increase in impulsivity following cocaine use. The primary corollary is that cocaine users should avoid IMF use in the same time window. In addition, IMF users should refrain from cocaine use to avoid impulsive IMF overdosing.

Effects of fentanyl and the adulterant levamisole on the rewarding and locomotor effects of methamphetamine in rats

BACKGROUND

People who use psychostimulant substances can be exposed to unknown adulterants, such as the synthetic opioid fentanyl (FEN) and the anthelmintic cholinergic agent levamisole (LEV). This work explores the rewarding and locomotor effects of methamphetamine (METH) in combination with FEN or LEV.

METHODS

We used adult male Wistar rats in the conditioned-place preference (CPP) paradigm (conditioning, extinction, and reinstatement phases) and in the open field test to study effective doses of METH, FEN, or LEV, or ineffective doses of METH+FEN or METH+LEV in combination.

RESULTS

METH and LEV, at 1mg/kg METH each, and 30µg/kg FEN produced CPP. Extinction to METH- or LEV-induced CPP occurred after eight saline injections, but it took 8-26 sessions to extinguish FEN-induced CPP. A challenge dose of 0.5mg/kg METH reinstated CPP. The same occurred with 15µg/kg FEN but not with 0.5 or 1mg/kg LEV. Training animals with ineffective doses of METH (0.01mg/kg) combined with either FEN (0.3µg/kg) or LEV (0.01mg/kg) produced CPP. Sub-effective doses of METH or FEN alone did not induce reinstatement after extinction. However, animals challenged with LEV, METH+FEN, or METH+LEV mixtures did it. Combining FEN (3µg/kg) with 0.1mg/kg METH increased locomotor activity.

CONCLUSION

Ineffective FEN and LEV doses mixed with METH produce effects larger than would be expected based on the effects of either drug alone. This outcome suggests a supra-additive interaction, which could increase the risk of developing a METH use disorder.

Hyperactivity in Mice Induced by Opioid Agonists with Partial Intrinsic Efficacy and Biased Agonism Administered Alone and in Combination with Morphine

Opioid analgesics such as morphine and fentanyl induce mu-opioid receptor (MOR)-mediated hyperactivity in mice. Herein, we show that morphine, fentanyl, SR-17018, and oliceridine have submaximal intrinsic efficacy in the mouse striatum using ³⁵S-GTPγS binding assays. While all of the agonists act as partial agonists for stimulating G protein coupling in striatum, morphine, fentanyl, and oliceridine are fully efficacious in stimulating locomotor activity; meanwhile, the noncompetitive biased agonists SR-17018 and SR-15099 produce submaximal hyperactivity. Moreover, the combination of SR-17018 and morphine attenuates hyperactivity while antinociceptive efficacy is increased. The combination of oliceridine with morphine increases hyperactivity, which is maintained over time. These findings provide evidence that noncompetitive agonists at MOR can be used to suppress morphine-induced hyperactivity while enhancing antinociceptive efficacy; moreover, they demonstrate that intrinsic efficacy measured at the receptor level is not directly proportional to drug efficacy in the locomotor activity assay.

Long-term wastewater-based surveillance and impacts of the COVID-19 pandemic on drug use trends in a U.S. Northeast rural town

Herein we discuss the findings of a two-year wastewater-based drug use surveillance from September 2018 to August 2020 and present objective evidence on the impacts of the COVID-19 pandemic on drug use in a rural community. 24-h composite wastewater samples were collected twice each month from a university town in Northeastern United States and were analyzed for ten priority opioids and stimulants: morphine, codeine, hydrocodone, methadone, fentanyl cocaine, methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxy-N-ethylamphetamine (MDEA). All target drugs were detected at 100 % frequency in wastewater samples. On a mass basis, the average estimated per capita drug consumption were highest for cocaine, morphine, and amphetamine, and lowest for MDMA, MDEA, and hydrocodone. Furthermore, the estimated per capita consumption of fentanyl was higher than previous reports from rural and university settings in the U.S. Generally, drug consumption was higher during the spring semesters, with year-on-year semester increases also noted over the 2-y study period. Except for methadone and cocaine, the estimated average per capita consumption of drugs increased over the pandemic period, with the highest increase noted for MDMA (286 % increase compared to baseline, p = 0.016). Estimated average consumption of methadone and cocaine decreased slightly by 6 % and 7 %, respectively. These results demonstrate the utility and strength of wastewater-based approaches in capturing long-term and evolving trends in drug use within communities. Our study findings reflect the regionwide problem with opioid-related overdoses and increasing stimulant prescription rates. Our findings also provide objective data and insights for health policymakers on the effects of the pandemic period on community drug use in a rural U.S. town.

Polysubstance use in young people accessing residential and day-treatment services for substance use: substance use profiles, psychiatric comorbidity and treatment completion

BACKGROUND AND AIMS

People with substance use disorders (SUDs) frequently present to treatment with polysubstance use and mental health comorbidities. Different combinations of substance use and mental health problems require different treatment approaches. Our study aimed to: (i) identify the shared substance use classes among young people at treatment admission, (ii) determine which mental health symptoms, quality of life (QoL) and service types were associated with the identified substance use classes, and (iii) prospectively determine which substance use classes and service types were more likely to complete treatment.

DESIGN

Cross-sectional and prospective study using service and outcome data.

SETTING

Substance use treatment services in Queensland and New South Wales, Australia.

PARTICIPANTS

De-identified service and outcome measure data were extracted from the files of 744 clients aged 18-35 years (48% male) admitted into seven residential and four day-treatment programmes.

MEASUREMENTS

Substance use and severity among tobacco, alcohol, cannabis, cocaine, amphetamine-type stimulants, opioids, sedatives and inhalants. Other variables included: depression, anxiety, post-traumatic stress and psychotic symptoms, as well as QoL.

FINDINGS

Latent class analysis identified three polysubstance use classes: wide-ranging polysubstance users (WRPU; 22.45%), primary amphetamine users (56.45%) and alcohol and cannabis users (21.10%). The WRPU class had higher odds of psychotic symptoms than the alcohol and cannabis use class [odds ratio (OR) = 1.30; 95% confidence interval (CI) = 1.11-1.11]; and double the odds of residential programme enrolment than those in the amphetamine use class (OR = 2.35; 95% CI = 1.50-3.68). No other class differences on mental health or QoL variables were found. Clients enrolled in day-programmes had higher odds of completing treatment.

CONCLUSIONS

There appear to be high levels of polysubstance use among young people entering substance use treatment in Australia. Wide-ranging polysubstance users were more likely to report psychotic symptoms and be enrolled into a residential programme than primary amphetamine users and alcohol and cannabis users.

The Prevalence and Psychosocial Correlates of Ketum (Mitragyna speciosa) Use among Individuals on Methadone Maintenance Therapy Programme in Hospital Taiping, Malaysia

Ketum use is significantly prevalent amongst individuals in the northern states of Peninsular Malaysia. This study aims to investigate the prevalence and psychosocial correlates of Ketum use in individuals who are in the Methadone Maintenance Therapy (MMT) Programme at the Hospital Taiping. This is a cross-sectional study conducted in the methadone clinic at the Hospital Taiping. The study instruments used were Subjective Opiate Withdrawal Scale (SOWS), Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) questionnaire, and Kratom Dependence Scale (KDS). A total of 215 subjects were recruited for this study. The prevalence of ketum users was 49.3% (n = 106). Chinese and Indian ethnicity had a lower tendency to use ketum compared to Malay ethnicity, with OR = 0.386 (95% CI 0.134, 1.113) and 0.119 (95% CI 0.035, 0.408), respectively. Individuals who used other illicit drugs had a higher tendency to use ketum with the adjusted OR = 9.914 (95% CI: 1.109, 88.602). Every one unit increase in SOWS increased the odds of being a ketum user by 1.340 (95% CI: 1.070, 1.677), whereas every one unit increase in duration in the MMT programme reduced the odds of being a ketum user by 0.990 (95% CI: 0.982, 0.998). Ketum use is prevalent amongst those in the MMT programme in this study. The high prevalence of ketum use is of concern and further interventions should be carried out to address this.

Goofballing of Opioid and Methamphetamine: The Science Behind the Deadly Cocktail

Globally, millions of people suffer from various substance use disorders (SUD), including mono-and polydrug use of opioids and methamphetamine. Brain regions such as the cingulate cortex, infralimbic cortex, dorsal striatum, nucleus accumbens, basolateral and central amygdala have been shown to play important roles in addiction-related behavioral changes. Clinical and pre-clinical studies have characterized these brain regions and their corresponding neurochemical changes in numerous phases of drug dependence such as acute drug use, intoxication, craving, withdrawal, and relapse. At present, many studies have reported the individual effects of opioids and methamphetamine. However, little is known about their combined effects. Co-use of these drugs produces effects greater than either drug alone, where one decreases the side effects of the other, and the combination produces a prolonged intoxication period or a more desirable intoxication effect. An increasing number of studies have associated polydrug abuse with poorer treatment outcomes, drug-related deaths, and more severe psychopathologies. To date, the pharmacological treatment efficacy for polydrug abuse is vague, and still at the experimental stage. This present review discusses the human and animal behavioral, neuroanatomical, and neurochemical changes underlying both morphine and methamphetamine dependence separately, as well as its combination. This narrative review also delineates the recent advances in the pharmacotherapy of mono- and poly drug-use of opioids and methamphetamine at clinical and preclinical stages.

Modeling Stimulant and Opioid Co-use in Rats Provided Concurrent Access to Methamphetamine and Fentanyl

Concurrent use of stimulants (e.g., methamphetamine) and opioids (e.g., fentanyl) has become increasingly common in recent years and continues to pose an enormous health burden, worldwide. Despite the prevalence, relatively little is known about interactions between the reinforcing effects of stimulants and opioids in this pattern of polysubstance use. The goals of the current study were to evaluate the relative reinforcing and relapse-related effects of methamphetamine and fentanyl using a concurrent access, drug-vs.-drug choice procedure. Male Sprague-Dawley rats were first allowed to acquire self-administration for either 0.1 mg/kg/infusion methamphetamine or 0.0032 mg/kg/infusion fentanyl, independently, after which concurrent access to both drugs was provided. When training doses of methamphetamine and fentanyl were concurrently available, a subset of rats self-administered both drugs, either within a session or alternating across sessions, whereas the remaining rats responded exclusively for one drug. When the cost of the preferred drug was increased (i.e., unit dose reduced), or the cost of the non-preferred drug was decreased (i.e., unit dose increased), choice was largely allocated toward the cheaper alternative. Following extinction of responding, methamphetamine- and fentanyl-paired cues reinstated responding on both levers. Responding reinstated by a priming injection of methamphetamine or fentanyl allocated more responding to the lever previously reinforced by the priming drug. The current studies suggest that choice of methamphetamine and fentanyl is largely allocated to the cheaper alternative, although more co-use was observed than would be expected for economic substitutes. Moreover, they lay the groundwork for more fully evaluating interactions between commonly co-abused drugs (e.g., stimulants and opioids) in order to better understand the determinants of polysubstance use and develop effective treatment strategies for individuals suffering from a polysubstance use disorder.

Dopamine Circuit Mechanisms of Addiction-Like Behaviors

Addiction is a complex disease that impacts millions of people around the world. Clinically, addiction is formalized as substance use disorder (SUD), with three primary symptom categories: exaggerated substance use, social or lifestyle impairment, and risky substance use. Considerable efforts have been made to model features of these criteria in non-human animal research subjects, for insight into the underlying neurobiological mechanisms. Here we review evidence from rodent models of SUD-inspired criteria, focusing on the role of the striatal dopamine system. We identify distinct mesostriatal and nigrostriatal dopamine circuit functions in behavioral outcomes that are relevant to addictions and SUDs. This work suggests that striatal dopamine is essential for not only positive symptom features of SUDs, such as elevated intake and craving, but also for impairments in decision making that underlie compulsive behavior, reduced sociality, and risk taking. Understanding the functional heterogeneity of the dopamine system and related networks can offer insight into this complex symptomatology and may lead to more targeted treatments.

Adult-Attention Deficit Hyperactive Disorder Symptoms Seem Not to Influence the Outcome of an Enhanced Agonist Opioid Treatment: A 30-Year Follow-Up

The role of opioids and opioid medications in ADHD symptoms is still largely understudied. We tested the hypothesis that, in Heroin Use Disorder (HUD), when patients are treated with Agonist Opioid medications (AOT), treatment outcome is associated with the presence of Adult Attention-Deficit/Hyperactive Disorder (A-ADHD) symptomatology. A retrospective cohort study of 130 HUD patients in Castelfranco Veneto, Italy, covering 30 years, was divided into two groups according to the Adult ADHD Self-Report Scale (ASRS) score and compared them using demographic, clinical and pharmacological factors. Survival in treatment was studied by utilizing the available data for leaving treatment and relapsing into addictive behavior and for mortality during treatment as poor primary outcomes. Thirty-five HUD subjects (26.9%) were unlikely to have A-ADHD symptomatology, and 95 (73.1%) were likely to have it. Only current age and co-substance use at treatment entry differed significantly between groups. Censored patients were 29 (82.9%) for HUD patients and 70 (73.9%) for A-ADHD/HUD patients (Mantel-Cox test = 0.66 p = 0.415). There were no significant linear trends indicative of a poorer outcome with the presence of A-ADHD after adjustment for demographic, clinical and pharmacological factors. Conclusions: ADHD symptomatology does not seem to exert any influence on the retention in AOT of HUD patients.

Cognitive Impairment in Opium Use Disorder

This cross-sectional study is aimed at assessing the effects of opium use disorder (OUD) on attention, working memory, and information-processing speed. Thirty outpatients with OUD and 20 healthy controls (HCs) were assessed using a neuropsychological battery consisted of Auditory Verbal Learning Test-Revised (AVLT-R), Brief Visuospatial Memory Test-Revised (BVMT-R), Digit Forward and Backward Tests (DFT and DBT), and WAIS-R Digit Symbol Substitution Test (DSST). The most affected cognitive functions in patients with OUD were detected by DBT and DSST. However, we found no significant difference between patients according to the route of administration. Within patients with OUD, DBT score was associated with opium use quantity (OUQ) (r = −0.385), and DBT (r = 0.483) and DSST (r = 0.542) scores were correlated with duration of use. Our findings indicated that working memory and information-processing speed are the most affected domains of cognitive functioning. DBT and DSST could be used as brief assessments in clinical settings to screen for cognitive deficits in patients with OUD.

The dopaminergic alterations induced by 4-F-PCP and 4-Keto-PCP may enhance their drug-induced rewarding and reinforcing effects: Implications for abuse

Novel psychoactive substances remain the popular recreational drugs of use over the years. They continue to bypass government restrictions due to their synthesis and modifications. Recent additions to the lists are the 4-F-PCP and 4-Keto-PCP, analogs of the drug phencyclidine (PCP) known to induce adverse effects and abuse potential. However, studies on the abuse potential of 4-F-PCP and 4-Keto-PCP remain scarce. The rewarding and reinforcing effects of the drugs were assessed using conditioned place preference (CPP), self-administration, and locomotor sensitization tests. Dopamine (DA) receptor antagonists (SCH23390 and haloperidol) were administered during CPP to evaluate the involvement of the mesolimbic dopaminergic system. DA-related protein expression in the nucleus accumbens (NAcc) and ventral tegmental area (VTA) was measured. Additionally, phosphorylated cyclic-adenosine monophosphate-activated protein (AMP) response element-binding (p-CREB) protein, deltaFosB (∆FosB), and brain-derived neurotrophic factor (BDNF) protein levels in the NAcc were measured to assess the addiction neural plasticity effect of the drugs. Both 4-F-PCP and 4-Keto-PCP-induced CPP and self-administration; however, only 4-F-PCP elicited locomotor sensitization. Treatment with DA receptor antagonists (SH23390 and haloperidol) inhibited the 4-F- and 4-Keto-induced CPP. Both substances altered the levels of DA receptor D1 (DRD1), thyroxine hydroxylase (TH), DA receptor D2 (DRD2), p-CREB, ∆FosB, and BDNF. The results suggest that 4-F-PCP and 4-Keto-PCP may induce abuse potential in rodents via alterations in dopaminergic system accompanied by addiction neural plasticity.

Impact of Morphine Dependence and Withdrawal on the Reinforcing Effectiveness of Fentanyl, Cocaine, and Methamphetamine in Rats

Recent estimates suggest increased popularity of the concurrent use of opioids and stimulants, with over 50% of treatment-seeking opioid users reporting regular stimulant use. The goal of the current study was to determine how opioid dependence and withdrawal affect the reinforcing effects of fentanyl, cocaine, and methamphetamine. Male Sprague-Dawley rats were allowed to self-administer fentanyl under a progressive ratio (PR) schedule of reinforcement. Baseline evaluations of reinforcing effectiveness of fentanyl, cocaine, and methamphetamine were determined. Opioid dependence was then established by administering escalating doses of morphine (10–40 mg/kg) twice-daily for four days and subsequently maintained by once-daily injections of 40 mg/kg morphine. To evaluate the impact of opioid dependence and withdrawal on the self-administration of fentanyl, cocaine, and methamphetamine, sessions occurred either 12 or 20 h after the morphine, respectively. During opioid withdrawal, the fentanyl dose-response curve was shifted rightward with an increase in maximal effectiveness, whereas it was shifted rightward with a reduction in maximal effectiveness when evaluated in rats currently dependent on opioids, relative to baseline. The reinforcing effects of cocaine and methamphetamine were unchanged by either condition. The current studies provide direct evidence that the reinforcing effects of fentanyl are increased in opioid-withdrawn rats and reduced in opioid-dependent rats, relative to rats that are not physically dependent on opioids. These findings suggest that motivations to use opioids are dependent on the state of the individual whereas stimulants retain their reinforcing effects regardless of whether the individual is in an opioid-dependent or withdrawn state.

Poly-prescription drug misuse across the life course: Prevalence and correlates across different adult age cohorts in the U.S

BACKGROUND

Most research on prescription drug misuse (PDM) focuses on the misuse of specific classes of psychoactive prescription drugs among adolescents or young adults. The current research addressed important gaps in the literature by assessing poly-prescription drug misuse (poly-PDM), the misuse of more than one class of psychoactive prescription drug, across different adult age cohorts.

METHODS

We used the 2015-2018 National Survey on Drug Use and Health to examine the prevalence of past-year poly-PDM and specific combinations of PDM. Multinomial logistic regression was used to identify demographic, health-related factors, and substance use behaviors that were significantly associated with poly-PDM.

RESULTS

The prevalence of poly-PDM decreases with age and is common among individuals who engage in PDM. Slightly more than one in four respondents in age cohorts 18-25 (31.66%, 95% CI = 30.35, 33.00) and 26-34 (29.92%, 95% CI = 25.82, 30.12) who engage in PDM, misused more than one class of prescription drug. Additionally, poly-PDM was identified as a high-risk type of PDM as roughly 60% of adults younger than 65 who endorse poly-PDM reported having a substance use disorder (SUD). While certain characteristics (i.e., race/ethnicity, marital status, depression, suicidal ideation, illegal drug use, and SUD) were consistently associated with poly-PDM across age cohorts, other characteristics (i.e., sexual identity, income, and justice involvement) varied across age cohorts. Finally, a comparison of poly-PDM to single PDM showed, in all age cohorts, that having an SUD was associated with an increased likelihood of poly-PDM, while Black adults were less likely than whites to report poly-PDM.

CONCLUSIONS

By identifying prevalence and correlates of poly-PDM across adult age cohorts, the current research has significant implications. Understanding stability and heterogeneity in the characteristics associated with poly-PDM should inform interventions, identify at-risk groups, and shape public health approaches to dealing with high-risk substance use behavior.

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

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

Exploring the Interactions between Non-Medical Methamphetamine Use and Prescribed Buprenorphine or Naltrexone in Opioid Use Disorder Treatment Retention

OBJECTIVES

Our objectives were to examine the impact of methamphetamine use on opioid use disorder (OUD) treatment retention in patients prescribed either buprenorphine/buprenorphine-naloxone (BUP-NX) or naltrexone/extended-release naltrexone (XR-NTX), while also exploring the role of other risk factors that may modify the impact of methamphetamine use.

METHODS

We conducted an exploratory retrospective study examining OUD treatment retention in 127 patients in Ohio (USA). Patients were prescribed either BUP-NX or naltrexone/XR-NTX. Cox proportional hazard regression was used to compare time to dropout of treatment between patients positive and negative on screening for methamphetamines at intake, estimate the association between other risk factors and time to dropout, and test interactions between risk factors and methamphetamine status.

RESULTS

Among patients prescribed naltrexone/XR-NTX, those positive for methamphetamines had almost three times the risk of treatment dropout (AHR = 2.89, 95% CI =1.11, 7.07), significantly greater (interaction p = .039) than the methamphetamine effect among those prescribed BUP-NX (AHR = 0.94, 95% CI = 0.51, 1.65). Early in treatment, being prescribed BUP-NX was strongly associated with a greater risk of treatment dropout (at baseline: AHR = 2.90, 95% CI = 1.33, 7.15), regardless of baseline methamphetamine use status. However, this effect decreased with time and shifted to greater risk of dropout among those prescribed naltrexone/XR-NTX (non-proportional hazard; interaction with time AHR = 0.66, 95% CI = 0.49, 0.86), with the shift occurring sooner among those positive for methamphetamine at baseline.

CONCLUSIONS

Additional support should be provided to patients who use methamphetamines prior to starting OUD treatment.

Nonopioid Overdose Death Rates Rose Almost As Fast As Those Involving Opioids, 1999-2016

The number of Americans dying from drug overdoses has risen rapidly, but the contribution of nonopioid drugs to this growth is not well understood. Using vital statistics data from the universe of deaths among US residents in the period 1999-2016, I calculated levels of and increases in overall nonopioid fatal overdose rates and those for subgroups stratified by manner of death, sex, race/ethnicity, and age. Mortality rates were also calculated separately for sedatives, stimulants, antidepressants, and cocaine. Recently developed methods were used to correct for the incomplete reporting of drug involvement on death certificates. From 1999 to 2016 the number of nonopioid drug deaths rose 274 percent, and deaths per 100,000 population rose by 223 percent. Over the same period, opioid-involved fatality counts and rates grew by 371 percent and 307 percent, respectively. Fatal overdose rates involving stimulants increased more than tenfold, with slower growth but higher rates for deaths involving sedatives and cocaine. Midlife non-Hispanic whites generally experienced the highest levels and rise in nonopioid death rates, but cocaine fatality rates were particularly common among nonwhite or Hispanic males ages 40-59. Policies designed to curb the opioid epidemic are probably helpful in reducing nonopioid deaths, but targeted interventions may also be needed.

Pain Agreements and Time-to-Event Analysis of Substance Misuse in a Primary Care Chronic Pain Program

BACKGROUND

Types and correlates of pain medication agreement (PMA) violations in the primary care setting have not been analyzed.

METHODS

A retrospective analysis was completed to examine patient characteristics and correlates of PMA violations, a proxy for substance misuse, over a 15-year period in an outpatient General Medicine Pain Service within the Division of General Medicine and Clinical Epidemiology, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill. Patients who signed the PMA were managed for chronic pain from 2002 through 2017 (N = 1,210). The incidence of PMA violations was measured over a 15-year span. Substance misuse was defined a priori in the study as urine toxicology screen positive for illicit or nonprescribed controlled substances, patient engagement in prescription alteration, doctor-shopping, or diversion.

RESULTS

Most patients received a prescription for a controlled substance (77.4%). During enrollment, 488 (40.3%) patients had one or more violations of their PMA. One-third (33.4%) of pain service patients had a violation within 365 days of signing the agreement. Active tobacco smokers had double the incidence of agreement violation within the first 30 days of enrollment. Almost one-half (49.8%) of violations were due to inconsistent use of controlled substances. Patients with any prior DWI/DUI or drug-related offense had a significantly increased rate of substance misuse (P < 0.0001).

CONCLUSIONS

PMA violations were common among a population of patients managed for chronic nonmalignant pain. Universal opioid prescribing precautions, including PMAs, require further investigation to assess their roles in mitigating the potential patient and societal harms associated with opioid prescribing.

Electrochemical analysis of speedball-like polydrug samples

Increasing global production, trafficking and consumption of drugs of abuse is an emerging threat to people's health and safety. Electrochemical approaches have been proved to be useful for on-site analysis of drugs of abuse. However, less attention has been focused on the analysis of polydrug samples, even though these samples pose severe health concerns, especially when stimulants and depressants are combined, as is the case of speedball, a mixture of cocaine and heroin. In this work, we provide solutions for the selective detection of cocaine (stimulant) in polydrug samples adulterated with heroin and codeine (depressants). The presence of either one of these compounds in cocaine street samples leads to an overlap with the cocaine signal in square-wave voltammetry measurements at unmodified carbon screen-printed electrodes, leading to inconclusive screening results in the field. The provided solutions to this problem consist of two parallel approaches: (i) cathodic pretreatment of the carbon screen-printed electrode surface prior to measurement under both alkaline and neutral conditions and (ii) electropolymerization of orthophenylenediamine on graphene modified carbon screen-printed electrodes prior to measurement under neutral conditions. Both strategies allow simultaneous detection of cocaine and heroin in speedball samples as well as simultaneous detection of cocaine and codeine. Implementing these strategies in portable devices holds great potential for significantly improved accuracy of on-site cocaine screening in polydrug samples.

Estimation of the impact of changing drug-use trend on HIV, hepatitis C and syphilis epidemics among people who use synthetic drug-only, polydrug and heroin-only during 2005-2035 in China: modelling study

OBJECTIVE

The rapid expansion of the recreational drug market becomes a global health concern. It is worrying that the bacterial and viral infection epidemics linking to drug use may worsen accordingly. This study aimed to estimate the impacts of changing trend and behaviours of using heroin only, synthetic drug (SD) only and polydrug (using SD and heroin concurrently) on HIV, hepatitis C virus (HCV) and syphilis epidemics among people who use drugs in China by 2035.

METHODS

We constructed a compartmental model to estimate HIV, HCV and syphilis epidemics in the dynamic drug-use trend by three scenarios: SD-only use, heroin-only use and polydrug use based on Monte Carlo simulations. The parameters for the model were collected from a comprehensive literature search.

RESULTS

Our model estimated that polydrug use led to the highest HIV and HCV prevalence among three drug-use patterns. The prevalences were projected to increase from 10.9% (95% CI 10.2% to 11.5%) and 61.7% (95% CI 59.4% to 62.5%) in 2005 to 19.0% (95% CI 17.3% to 20.7%) and 69.1% (95% CI 67.3% to 69.5%), respectively, in 2035 among people using polydrug. Similarly, HIV and HCV prevalence in the SD-only group were projected to increase from 0.4% (95% CI 0.3% to 0.4%) and 19.5% (95% CI 19.4% to 21.7%) to 1.8% (95% CI 1.4 to 2.1%) and 33.7% (95% CI 33.2% to 34.9%) in 2005-2035. Conversely, HIV prevalence in the heroin-only group was projected to decrease from 8.0% (95% CI 7.6% to 8.1%) to 2.2% (95% CI 2.0% to 2.3%) in 2005-2035. Syphilis prevalence was estimated to remain unchanged in all population groups within this time frame. It was projected that the proportion of HIV transmitted by sexual transmission will increase compared with unsafe injection transmission in all people who use drugs from 2005 to 2035.

CONCLUSION

Our modelling suggests that polydrug use is projected to lead to the highest HIV and HCV disease burden by 2035, and the proportion of HIV transmitted by sexual transmission will increase. Current HIV intervention among people using heroin seems effective according to our estimation.

Polysubstance Use among Patients Enrolling in Methadone Maintenance Treatment Program in a Vietnam Province with Drug-Driven HIV Epidemic

Methadone maintenance treatment (MMT) has been scaled up significantly in recent years. This study aimed to investigate the pattern of polysubstance use in 395 MMT patients and its contextualized associated factors. A cross-sectional study was performed in three outpatient MMT clinics in Nam Dinh Province. Multivariate Poisson regression was used to identify factors associated with polysubstance use status. The mean MMT duration and the current MMT dose was 3.3 years and 69.2 mg, respectively. Among participants, 24.8% reported daily alcohol use, 68.6% smoked regularly, and 6% used illicit drugs. Peer pressure and MMT suboptimal adherence were found to associate with continual usage of drugs (47.8%). Participants who lived with a spouse/partner, were self-employed, and smoked were more likely to drink alcohol. Those who drink were also more likely to smoke, and vice versa. Recommendations for policymakers include community-based education and promotional programs aiming to decrease substance usage in the community as well as encouraging and supporting the private health sector in establishing private MMT services and clinics. Further longitudinal studies on polysubstance usage among MMT patients should also be conducted.

Multi-drug cocktails: Impurities in commonly used illicit drugs seized by police in Queensland, Australia

BACKGROUND

Impurities in commonly used illicit drugs raise concerns for unwitting consumers when pharmacologically active adulterants, especially new psychoactive substances (NPS), are used. This study examines impurities detected in illicit drugs seized in one Australian jurisdiction.

METHODS

Queensland Health Forensic and Scientific Services provided analytical data. Data described the chemical composition of 9346 samples of 11 illicit drugs seized by police during 2015-2016. Impurities present in primary drugs were summarized and tabulated. A systematic search for published evidence reporting similar analyses was conducted.

RESULTS

Methamphetamine was the primary drug in 6608 samples, followed by MDMA (1232 samples) and cocaine (516 samples). Purity of primary drugs ranged from ∼30% for cocaine, 2-CB and GHB to >90% for THC, methamphetamine, heroin and MDMA. Methamphetamine and MDMA contained the largest variety of impurities: 22 and 18 variants, respectively. Drug adulteration patterns were broadly similar to those found elsewhere, including NPS, but in some primary drugs impurities were found which had not been reported elsewhere. Psychostimulants were adulterated with each other. Levamisole was a common impurity in cocaine. Psychedelics were adulterated with methamphetamine and NPS. Opioids were quite pure, but some samples contained methamphetamine and synthetic opioids.

CONCLUSIONS

Impurities detected were mostly pharmacologically active adulterants probably added to enhance desired effects or for active bulking. Given the designer nature of these drug cocktails, the effects of the adulterated drugs on users from possible complex multi-drug interactions is unpredictable. Awareness-raising among users, research into complex multi-drug effects and ongoing monitoring is required.

Methamphetamine-related post-mortem cases in Bangkok, Thailand

Introduction

This study investigated variables associated with methamphetamine-related deaths in Thailand.

Methods

This study used data obtained from methamphetamine-related autopsy cases over a six-year period from 2011 to 2016. From the data available during this period, considered variables included: demographic, toxicological and histopathological profiles. Methamphetamine blood concentration calculations and myoglobin immunostainings in kidney samples were also carried out. Statistical analysis and tests of significance were conducted using a paired-sample t-test, adopting a p-value of 0.05.

Results

A total of 61 methamphetamine-related cases were reviewed. Of several pathological findings, cardiovascular pathological findings were the most common. Cases were divided into a non-trauma group ( n = 19; 31.15%) and a trauma group ( n  =  42; 68.85%), and it was found that methamphetamine blood concentrations of non-trauma cases were largely in therapeutic ranges. The differences between methamphetamine concentrations of trauma and non-trauma groups were not statistically significant ( p > 0.05). Immunostainings for myoglobin in kidney samples were positive in two non-trauma cases, which is suggestive of methamphetamine-induced rhabdomyolysis.

Conclusions

Methamphetamine intoxication causes cardiac toxicity and can cause death. However, methamphetamine quantitation, autopsy findings and scene investigations are considered altogether in determination of cause of death due to many factors such as drug tolerances. Myoglobin immunostaining was found to be a useful tool in determining cause of death.

Estimates of the national trend of drugs use during 2000-2030 in China: A population-based mathematical model

BACKGROUND

The use of synthetic drugs has exceeded heroin to become a major public health concern in China. We aimed to estimate the trend of heroin-only, synthetic drug-only and poly-drug (heroin and synthetic drug) use during 2000-2030 period in China using existing data.

METHODS

We used data from the Annual Report on Drug Control in China and peer-reviewed publications. We constructed a mathematical model to estimate the drug use trend based on Monte Carlo simulations.

RESULTS

The best calibrated model estimated that the number of drug users would increase from 0.86 million to 3,120,059 (95% CI 2,669,214-3,570,904) during 2000-2030 period. The proportion of heroin-only users among the total drug users will decrease from 96.8% (95% CI, 96.6-97.1%) in 2000 to 36.9% (30.1-40.8%) in 2030, while the proportion of synthetic drug-only users will increase from 1.1% (0.9-1.3%) in 2000 to 57.7% (51.7-65.6%) in 2030. In contrast, the proportion of poly-drug users shared an increasing trend during 2000-2016 (from 2.1% (1.5-2.8%) to 15.1 (13.8-17.1%)) but declined to 5.5% (3.4-7.2%) in 2030. Estimated 46,370 (41,634-51,106) heroin-only users and 3767 (3481-4053) synthetic drug only users initiated poly-drug use in 2000. We observed a cross-over in 2012 where more synthetic drug-only users were initiating heroin use than heroin-only users initiating synthetic drug use. There will be estimated 2,094,052 (1,819,830-2,368,274) synthetic drug-only users and poly-drug users 211,407 (177,150-245,664) in 2030.

CONCLUSIONS

Synthetic drug use will become dominant in drug users in China, but poly-drug use of both heroin and synthetic drugs will remain substantial.

Polydrug use disorders in individuals with opioid use disorder

BACKGROUND

Understanding the association of polydrug use disorders (PUD) with psychosocial and clinical factors is essential for the treatment of individuals with opioid use disorder (OUD). The aim of this study is to examine whether there is an association between childhood maltreatment, mood disorders, anxiety disorders, personality disorders, or posttraumatic stress disorder (PTSD) and PUD in individuals with OUD.

METHODS

We used data from 356 individuals with OUD in the past 12 months from a nationally representative database in the United States. PUD patients were classified into two groups: a group with additional one substance disorder (OUD + 1) and that with two or more additional substance disorders (OUD + 2). We conducted multivariate logistic regression to predict the PUD status, after adjustment for confounders including childhood maltreatment.

RESULTS

Among all individuals, 57.3% were polydrug users (n = 204) and 42.7% were not (n = 152). There was a high prevalence of childhood maltreatment in both groups, ranging from 16.1% to 59.5%, but the difference was not statistically significant. After adjustment for confounders, we found an association between past-year PTSD and OUD + 2 (odds ratio: 3.98; 95% confidence interval: 1.15-13.72; p = 0.03) but not with OUD + 1.

CONCLUSION

PTSD is highly prevalent in individuals with OUD using multiple substances and could influence PUD. We recommend screening for PTSD in cases of PUD. Future studies should evaluate the effect of PTSD treatment on PUD.

Prescription opioid misuse among middle-aged and older adults in the United States, 2015-2016

Adults ≥50 years of age have high rates of prescription opioid use. The purpose of this study is to estimate the prevalence and correlates of prescription opioid misuse among middle-aged and older adults in the United States who use prescription opioids. Data from adults age ≥ 50 from the two most recent cohorts (2015 and 2016) of the National Survey of Drug Use and Health were examined (N = 17,608). Characteristics of past-year prescription opioid misusers, including demographics, substance use, depression, chronic disease, and emergency department (ED) use, were compared to adults who used prescription opioids as prescribed in the past year and non-users. We used multivariable logistic regression to determine correlates of prescription opioid misuse among adults who used prescription opioids. Among the entire sample, 61.4% reported no past-year prescription opioid use, 36.0% reported past-year prescription opioid use without misuse, and 2.5% reported past-year prescription opioid misuse. Among past-year prescription opioid users, 6.6% reported misuse. Past-year misuse was higher among males, adults age 50-64, misusers of prescription sedatives, stimulants, and tranquilizers, users of other substances (i.e., tobacco, marijuana, cocaine), and those with alcohol use disorder. Past-year misuse was lower among adults with 2 or more chronic diseases. Past-year prescription misuse of sedatives (AOR 4.08 [95% CI 2.05-8.12]), stimulants (AOR 3.88 [95% CI 2.00-7.53]), and tranquilizers (AOR 10.02 [95% CI 6.48-15.50]) were all associated with past-year opioid misuse. Characteristics of opioid misusers determined in this study-particularly misuse of other substances-may help determine middle-aged and older adults at risk for prescription opioid misuse.

Drug Interactions With New Synthetic Opioids

Fentanyl, fentanyl analogs, and other new synthetic opioids (NSO) have burst onto the illegal drug market as new psychoactive substances (NPS). They are often sold as heroin to unsuspecting users and produce euphoria through their agonist action on μ- opioid receptors. Their high consumption, often combined with other substances, has led to multiple intoxications during recent years. In some countries, such as the United States, the consumption of opioids, whether for medical or recreational purposes, has become epidemic and is considered a public health problem. Fentanyl analogs are more potent than fentanyl which in turn is 50 times more potent than morphine. Furthermore, some fentanyl analogs have longer duration of action and therefore interactions with other substances and medicines can be more serious. This review is focused on the potentially most frequent interactions of opioid NPS taking into account the drugs present in the reported cases of poly-intoxication, including other illegal drugs of abuse and medication. Substances involved are mainly antidepressants, antihistamines, antipsychotics, benzodiazepines, analgesics, anesthetics, psychostimulants, other opioids, alcohol, and illegal drugs of abuse. The interactions can be produced due to pharmacokinetic and pharmacodynamic mechanisms. Naloxone can be used as an antidote, although required doses might be higher than for traditional opioid intoxications. It is crucial that doctors who habitually prescribe opioids, which are often misused by patients and NPS users, be aware of designer opioids' potentially life-threatening drug-drug interactions in order to prevent new cases of intoxication.

The role of nonmuscle myosin II in polydrug memories and memory reconsolidation

Using pharmacologic and genetic approaches targeting actin or the actin-driving molecular motor, nonmuscle myosin II (NMII), we previously discovered an immediate, retrieval-independent, and long-lasting disruption of methamphetamine- (METH-) and amphetamine-associated memories. A single intrabasolateral amygdala complex infusion or systemic administration of the NMII inhibitor Blebbistatin (Blebb) is sufficient to produce this disruption, which is selective, having no retrieval-independent effect on memories for fear, food reward, cocaine, or morphine. However, it was unclear if Blebb treatment would disrupt memories of other stimulants and amphetamine class drugs, such as nicotine (NIC) or mephedrone (MEPH; bath salts). Moreover, many individuals abuse multiple drugs, but it was unknown if Blebb could disrupt polydrug memories, or if the inclusion of another substance would render Blebb no longer able to disrupt METH-associated memories. Therefore, the present study had two primary goals: (1) to determine the ability of Blebb to disrupt NIC- or MEPH-associated memories, and (2) to determine the ability of METH to modify other unconditioned stimulus (US) associations’ susceptibility to Blebb. To this end, using the conditional place preference model, mice were conditioned to NIC and MEPH alone or METH in combination with NIC, morphine, or foot shock. We report that, unlike METH, there was no retrieval-independent effect of Blebb on NIC- or MEPH-associated memories. However, similar to cocaine, reconsolidation of the memory for both drugs was disrupted. Further, when combined with METH administration, NIC- and morphine-, but not fear-, associated memories were rendered susceptible to disruption by Blebb. Given the high rate of polydrug use and the resurgence of METH use, these results have important implications for the treatment of substance use disorder.

Prevalence of and Factors Associated With Long-term Concurrent Use of Stimulants and Opioids Among Adults With Attention-Deficit/Hyperactivity Disorder

IMPORTANCE

There exist limited data on the long-term concurrent use of stimulants and opioids among adults with attention-deficit/hyperactivity disorder (ADHD), a population at risk for prescription drug abuse.

OBJECTIVE

To assess the prevalence and secular trends of and the factors associated with long-term concurrent use of stimulants and opioids among adults with ADHD.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study assessed Medicaid Analytic eXtract data from 29 states between 1999 and 2010. Medicaid fee-for-service enrollees aged 20 to 64 years with ADHD who were continuously enrolled for more than 12 months after receiving an ADHD diagnosis were included. One 12-month continuous enrollment period was randomly selected as an observation unit for each enrollee. Multivariable regression models were used to determine secular trends in the prevalence of and the potential risk factors associated with long-term concurrent stimulant-opioid use. Analyses were conducted between January 1 and December 31, 2017.

EXPOSURES

Risk factors measured during the first half of the 12-month observation unit.

MAIN OUTCOMES AND MEASURES

Prevalence of long-term use of stimulants and opioids overlapping for at least 30 consecutive days was measured during the second half of the randomly selected 12-month observation unit.

RESULTS

Of the 66 406 Medicaid-enrolled adults with ADHD who were identified as eligible, 35 670 (53.7%) were 20 to 30 years old, 37 155 (56.0%) were women, and 52 551 (79.1%) were non-Hispanic white individuals. Of these 66 406 adults with ADHD, 21 723 (32.7%) used stimulants, and 3590 (5.4%) were long-term users of stimulants and opioids. Long-term opioid use was more common among adults with ADHD who used stimulants (3590 of 21 723 [16.5%]) than among those with ADHD who did not use stimulants (5826 of 44 683 [13.0%]). Long-term concurrent stimulant-opioid use increased between 1999 and 2010 (adjusted prevalence relative ratio [PRR], 1.12; 95% CI, 1.10-1.14). Compared with patients aged 20 to 30 years, the prevalence of long-term concurrent stimulant-opioid use was higher among patients in their 30s (PRR, 1.07; 95% CI, 1.07-1.08) and was further increased among patients in their 40s (PRR, 1.14; 95% CI, 1.12-1.15) and 50s (PRR, 1.17; 95% CI, 1.16-1.19). Other strongly associated risk factors included being non-Hispanic white (black PRR, 0.93; 95% CI, 0.92-0.93; other PRR, 0.97; 95% CI, 0.97-0.98; vs white), living in the southern United States (Midwest PRR, 0.98; 95% CI, 0.97-0.98; Northeast PRR, 0.94; 95% CI, 0.93-0.94; West PRR, 0.95; 95% CI, 0.94-0.96; vs South), and receiving a diagnosis of substance abuse disorder (PRR, 1.04; 95% CI, 1.03-1.05), depression (PRR, 1.02; 95% CI, 1.01-1.03), anxiety disorder (PRR, 1.05; 95% CI, 1.04-1.07), chronic pain (PRR, 1.10; 95% CI, 1.07-1.13), chronic obstructive pulmonary disease (PRR, 1.05; 95% CI, 1.04-1.07), or cardiovascular disease (PRR, 1.02; 95% CI, 1.01-1.03).

CONCLUSIONS AND RELEVANCE

Long-term concurrent use of stimulants and opioids among adults with ADHD is common. This study suggests that clinical and research priorities should be made toward understanding the benefits and risks of long-term coadministration of stimulants and opioids in the management of ADHD and co-occurring pain conditions.

Influence of social network on drug use among clients of methadone maintenance treatment centers in Kunming, China

AIMS

To examine drug use behavior of clients attending Methadone Maintenance Treatment (MMT) programs and its relationship with the clients' social network characteristics.

DESIGN

Cross-sectional study.

SETTING

Four MMT clinics in Kunming, Yunnan province, China.

PARTICIPANTS

324 consecutive MMT clients.

MEASUREMENTS

A structured, self-completed questionnaire on background characteristics and existing social network. Current drug use was assessed by urine test for opiate metabolites.

ANALYSIS

The association between client's social network characteristics and their own current drug use behavior is analysed using multiple logistic regression adjusting for socio-demographic characteristics. Adjusted odds ratios (AOR) with 95% confidence intervals (CI) are obtained to give the strength of the associations.

FINDINGS

MMT clients were more likely to concurrently use heroin while attending MMT if their social network had any of the following characteristics: more than half of the members were older than them (AOR = 1.03, 95% CI = 1.00,1.06), any member had a high level of influence on them (AOR = 6.47, 95% CI = 2.86,14.65) and any member joined them in using drugs (AOR = 1.94, 95% CI = 1.04,3.63). Having a social network member who could provide emotional support (AOR = 0.11, 95% CI = 0.03,0.35), having a spouse and/or child in their social network (AOR = 0.44, 95% CI = 0.24,0.81) and having a social network member with a high level of closeness (AOR = 0.28, 95% CI = 0.09,0.90) were associated with a decreased odds of heroin use.

CONCLUSION

Social networks who could provide MMT clients with emotional support and a close relationship were significant factors for reducing the risk of concurrent drug use among clients attending MMT clinics in Kunming, China. Behavioral interventions should address the role of family and social network members in providing support to these clients.

APBB2 is associated with amphetamine use and plasma beta-amyloids in patients receiving methadone maintenance treatment

APBB2, amyloid beta (A4) precursor protein-binding family B member 2, has been reported to be associated with opioid dependence. In this study, we reported the first time that the genetic variants in the APBB2 gene were associated with use of amphetamine in opioid dependent patients undergoing methadone maintenance treatment (MMT). 344 heroin-dependent patients undergoing MMT were recruited and assessed for use of amphetamine and opioids by urine toxicology, withdrawal severity, and side effects. DNAs were genome-widely genotyped for all patients. Single nucleotide polymorphisms (SNPs) in APBB2 were selected for association analyses for methadone treatment responses. Gene expression levels of APBB2 were measured by real-time polymerase chain reaction (PCR) in the EBV-transformed lymphoblastoids from patients. MMT patients who used amphetamine showed a significantly higher percentage of positive results in the urine morphine test (P=0.005), and insomnia (P=0.018). In single locus association analyses, SNPs rs3935357 and rs4861075 located at intron 6 were significantly associated with amphetamine use in both genotype and allele type (general linear model (GLM), P=0.0003, and 0.0002 for genotype, and 0.0003, and 0.002 for allele type, respectively). The major allele type carriers had twice risk of amphetamine use compared to the minor allele type carriers. Subjects with the TT genotype of rs4861075 showed significantly higher levels of APBB2 gene expression in both total (P=0.02) and long-form (P=0.037) than those with CC genotype. Detailed mechanisms underlying the association of APBB2 with amphetamine use and level of plasma amyloid beta in MMT patients require further investigation.

Adrenergic Agonists Bind to Adrenergic-Receptor-Like Regions of the Mu Opioid Receptor, Enhancing Morphine and Methionine-Enkephalin Binding: A New Approach to "Biased Opioids"?

Extensive evidence demonstrates functional interactions between the adrenergic and opioid systems in a diversity of tissues and organs. While some effects are due to receptor and second messenger cross-talk, recent research has revealed an extracellular, allosteric opioid binding site on adrenergic receptors that enhances adrenergic activity and its duration. The present research addresses whether opioid receptors may have an equivalent extracellular, allosteric adrenergic binding site that has similar enhancing effects on opioid binding. Comparison of adrenergic and opioid receptor sequences revealed that these receptors share very significant regions of similarity, particularly in some of the extracellular and transmembrane regions associated with adrenergic binding in the adrenergic receptors. Five of these shared regions from the mu opioid receptor (muOPR) were synthesized as peptides and tested for binding to adrenergic, opioid and control compounds using ultraviolet spectroscopy. Adrenergic compounds bound to several of these muOPR peptides with low micromolar affinity while acetylcholine, histamine and various adrenergic antagonists did not. Similar studies were then conducted with purified, intact muOPR with similar results. Combinations of epinephrine with methionine enkephalin or morphine increased the binding of both by about half a log unit. These results suggest that muOPR may be allosterically enhanced by adrenergic agonists.

Transitioning illicit drug preferences and emerging user identities in Ohio: The proliferation of methamphetamine use among African Americans

Understanding the social dynamics of local methamphetamine markets is critical to improving community health and reducing social costs associated with illicit drug use. We examine a local drug market in Summit County, Ohio, wherein methamphetamine users ascribe themselves different ethnic identities from those long associated with the drug elsewhere in the United States. Qualitative interviews with 52 study participants demonstrate that very poor and homeless White males and females are now using methamphetamine; however, even more surprising is that 31 of the participants identified themselves as poor or homeless, male or female African, Native, biracial, or multiracial Americans. The drug use trajectory of these 31 participants in particular involved a transition from a historical preference for crack to a present one for methamphetamine and, in some cases, a preference for concurrent use of methamphetamine and heroin. Many of these methamphetamine users also emphasized their ethnic identity to distinguish themselves as nonproducers of methamphetamine in comparison to Whites, who are commonly associated with methamphetamine production. Findings appear to suggest an emergent means of identity management resulting from the ethnic diversity of users in this methamphetamine market. These findings may have relevance in other communities with similar demographics and drug markets and may hold important implications for drug treatment, policy-making, and law enforcement professionals' work associated with methamphetamine users, producers, and distributors.

Polyglycerol-opioid conjugate produces analgesia devoid of side effects

Novel painkillers are urgently needed. The activation of opioid receptors in peripheral inflamed tissue can reduce pain without central adverse effects such as sedation, apnoea, or addiction. Here, we use an unprecedented strategy and report the synthesis and analgesic efficacy of the standard opioid morphine covalently attached to hyperbranched polyglycerol (PG-M) by a cleavable linker. With its high-molecular weight and hydrophilicity, this conjugate is designed to selectively release morphine in injured tissue and to prevent blood-brain barrier permeation. In contrast to conventional morphine, intravenous PG-M exclusively activated peripheral opioid receptors to produce analgesia in inflamed rat paws without major side effects such as sedation or constipation. Concentrations of morphine in the brain, blood, paw tissue, and in vitro confirmed the selective release of morphine in the inflamed milieu. Thus, PG-M may serve as prototype of a peripherally restricted opioid formulation designed to forego central and intestinal side effects.

Polyglycerol-opioid conjugate produces analgesia devoid of side effects

Novel painkillers are urgently needed. The activation of opioid receptors in peripheral inflamed tissue can reduce pain without central adverse effects such as sedation, apnoea, or addiction. Here, we use an unprecedented strategy and report the synthesis and analgesic efficacy of the standard opioid morphine covalently attached to hyperbranched polyglycerol (PG-M) by a cleavable linker. With its high-molecular weight and hydrophilicity, this conjugate is designed to selectively release morphine in injured tissue and to prevent blood-brain barrier permeation. In contrast to conventional morphine, intravenous PG-M exclusively activated peripheral opioid receptors to produce analgesia in inflamed rat paws without major side effects such as sedation or constipation. Concentrations of morphine in the brain, blood, paw tissue, and in vitro confirmed the selective release of morphine in the inflamed milieu. Thus, PG-M may serve as prototype of a peripherally restricted opioid formulation designed to forego central and intestinal side effects.

Emerging Drug Use Trends in Kelantan, Malaysia

The primarily rural and agrarian Kelantan province of Malaysia has high rates of drug use and is characterized by unique sociocultural factors. Combining qualitative and ethnographic methods, we investigated drug use and treatment needs of people who use drugs (PWUD) in rural areas of Kelantan. In February 2014, field visits, participant observation, and focus group discussions (FGDs) with 27 active PWUD were conducted in rural areas surrounding the capital city of Kelantan. The findings indicate a high prevalence of opiate and amphetamine type stimulants (ATS) use in these areas. FGD participants reported initiating drug use at early ages due to peer influences, to relieve boredom, to cope with problems, and a high saturation of villages with other PWUD was reported as a major contributor to their own continued drug use. They reported a trend of drug use initiation at younger ages and increased drug use among females. Participants were interested in treatment; however, their limited knowledge about treatment options and perceived limited availability of services were barriers to treatment seeking. Easy access to drugs, primarily from Thailand and facilitated by the use of mobile phones, resulted in an expanding prevalence of drug use that underscores the need to bolster education and prevention efforts and accessibility of treatment services in Kelantan.

Pseudoginsenoside-F11 inhibits methamphetamine-induced behaviors by regulating dopaminergic and GABAergic neurons in the nucleus accumbens

RATIONALE

Although dependence to methamphetamine (METH) is associated with serious psychiatric symptoms and is a global health and social problem, no effective therapeutic approaches have been identified. Pseudoginsenoside-F11 (PF11) is an ocotillol-type saponin that is isolated from Panax quinquefolius (American ginseng) and was shown to have neuroprotective effects to promote learning and memory and to antagonize the pharmacological effects of morphine. Furthermore, PF11 also shows protective effects against METH-induced neurotoxicity in mice. However, the effects of PF11 on METH-induced preference and dopamine (DA) release have not been defined.

OBJECTIVES

We investigated the effects of PF11 administration on METH-induced hyperlocomotion and conditioned place preference (CPP) in mice. Subsequently, extracellular DA and gamma-aminobutyric acid (GABA) levels were determined in the nucleus accumbens (NAc) of mice after co-administration of PF11 and METH using in vivo microdialysis analyses. Moreover, the effects of PF11 administration on the μ-opioid neuronal responses, DAMGO (μ-opioid receptor agonist; [D-Ala(2), N-MePhe(4), Gly-ol]-enkephalin)-induced hyperlocomotion and accumbal extracellular DA increase were investigated to elucidate how PF11 inhibits METH-induced dependence by dopaminergic neuronal hyperfunction.

RESULTS

Co-administration of PF11 and METH for 6 days attenuated METH-induced locomotor sensitization compared with treatment with METH alone. In the CPP test, PF11 administration also inhibited METH-induced place preference. In vivo microdialysis analyses indicated that co-administration of PF11 and METH for 7 days prevented METH-induced extracellular DA increase in the NAc and repeated PF11 administration with or without METH for 7 days increased extracellular GABA levels in the NAc, whereas single administration of PF11 did not. Furthermore, DAMGO-induced hyperlocomotion and accumbal extracellular DA increase were significantly inhibited by acute PF11 administration.

CONCLUSIONS

The present data suggest that PF11 inhibits METH-induced hyperlocomotion, preference, and accumbal extracellular DA increase by regulating GABAergic neurons and μ-opioid receptors.

Illicit Heroin and Methamphetamine Use among Methadone Maintenance Treatment Patients in Dehong Prefecture of Yunnan Province, China

Objective

Methadone maintenance treatment (MMT) was introduced to China in 2004 to reduce the harm of injecting drug users (IDUs). However, little is known about continued drug use, especially methamphetamine (MAMP), among MMT patients.

Methods

A survey was conducted among patients attending five major MMT clinics in Dehong Prefecture in 2014 to investigate the heroin and MAMP use and their associated risk factors. Participants were administered with face-to-face interviews, and urine tests for morphine and MAMP.

Results

A total of 2,121 were eligible and participated in the study. Among them, 220 (10.4%) were only positive for morphine, 12.9% were only positive for MAMP, and 196 (9.2%) were positive for both morphine and MAMP. Compared with neither use of heroin nor MAMP during MMT, heroin use (not using MAMP) was associated with ethnicity, shorter duration of MMT, lower dose of methadone, and having had no more than two sex partners in the past year; MAMP use (not using heroin) was associated with ethnicity, longer duration of MMT, higher dose of methadone and being aged <30 years (vs. ≥50 years); use of both heroin and MAMP was associated with being Dai minority (vs. Han), a marital status of divorced or widowed, having used drugs for ≥10 years and shorter duration of MMT.

Conclusion

These findings indicate the complexity in the treatment of heroin users and underscore the importance in prescribing appropriate methadone dosages in order to reduce both heroin and MAMP use.

AMN082, a metabotropic glutamate receptor 7 allosteric agonist, attenuates locomotor sensitization and cross-sensitization induced by cocaine and morphine in mice

Previous studies have indicated that metabotropic glutamate receptors 7 (mGluR7s) are involved in drug addiction. However, the role of these receptors in drug-induced behavioral sensitization is unknown. The aim of the present study was to determine whether systemic injection of AMN082, a selective mGluR7 allosteric agonist, reduces the cocaine- and morphine-induced hyperactivity and the development and expression of locomotor sensitization, and also affects the reciprocal cross-sensitization to the stimulant effect of cocaine and morphine in mice. AMN082 (1.25-10.0 mg/kg, i.p.) did not have an impact on locomotion of naive mice and did not affect the acute cocaine- or morphine-induced hyperactivity, except the dose of 10 mg/kg that suppressed the locomotor effect of both drugs. Repeated exposure to cocaine or morphine (10 mg/kg, 5× every 3 days) gradually increased locomotion during induction of sensitization and after 4 (cocaine) or 7 day (morphine) withdrawal phase when challenged with cocaine (10 mg/kg, i.p.) or morphine (10 mg/kg, i.p.) on day 17 or 20, respectively. Pretreatment of animals with the lower doses of AMN082 (1.25-5.0 mg/kg, i.p.), 30 min before every cocaine or morphine injection during repeated drug administration or before cocaine or morphine challenge, dose-dependently attenuated the development, as well as the expression of cocaine or morphine locomotor sensitization. AMN082 also inhibited the reciprocal cross-sensitization between these drugs. Prior to administration of MMPIP (10 mg/kg, i.p.), a selective mGluR7 antagonist reversed the inhibitory effect of AMN082 on the development or expression of cocaine or morphine sensitization. These data indicate that AMN082 attenuated the development and expression of cocaine and morphine sensitization, and the reciprocal cross-sensitization via a mechanism that involves mGluR7s. Thus, AMN082 might have therapeutic implications not only in the treatment of cocaine or opioid addiction but also in the treatment of cocaine/opioid polydrug-abusers.