Methadone doses of 100 mg or greater are more effective than lower doses at suppressing heroin self-administration in opioid-dependent volunteers

Early experiences and impacts of a fentanyl powder safer supply program in Vancouver, Canada: a qualitative study

Background: North America is experiencing an unrelenting overdose crisis driven by a volatile and toxic unregulated drug supply. Safer supply programs, which provide individuals with pharmaceutical-grade alternatives to the unregulated drug supply, have been implemented in various Canadian jurisdictions. While most programs provide tablet hydromorphone, the Safer Alternatives for Emergency Response (SAFER) program in Vancouver, Canada, offers pharmaceutical-grade fentanyl, including a powder formulation for witnessed consumption.Objectives: To explore early experiences among SAFER program participants receiving powder fentanyl.Methods: Qualitative one-on-one interviews were conducted with 18 (12 men, 6 women) people prescribed fentanyl powder from the SAFER program. Interview coding and analysis involved a team-based approach to identify common themes related to program experiences, focusing on impacts on unregulated drug use.Results: Most (13/18; 72%) participants reported reducing unregulated drug use since program enrollment. This was largely attributed to the SAFER fentanyl powder being effective for managing withdrawal, thereby limiting their need to access street-purchased drugs. Additionally, some participants, particularly those prescribed higher doses, suggested that SAFER fentanyl powder, unlike other safe supply medications, was a suitable alternative to street-purchased fentanyl. Participants also reported reduced overdose risk. Operating hours and dosing challenges were barriers to program engagement contributing to continued unregulated drug use for some.Conclusion: Our findings demonstrate a number of positive outcomes of the SAFER program and suggest that fentanyl safer supply has the potential to play a useful role in addressing the ongoing overdose crisis.

Human laboratory models of reward in substance use disorder

Human laboratory models in substance use disorder provide a key intermediary step between highly controlled and mechanistically informative non-human preclinical methods and clinical trials conducted in human populations. Much like preclinical models, the variety of human laboratory methods provide insights into specific features of substance use disorder rather than modelling the diverse causes and consequences simultaneously in a single model. This narrative review provides a discussion of popular models of reward used in human laboratory research on substance use disorder with a focus on the specific contributions that each model has towards informing clinical outcomes (forward translation) and analogs within preclinical models (backward translation). Four core areas of human laboratory research are discussed: drug self-administration, subjective effects, behavioral economics, and cognitive and executive function. Discussion of common measures and models used, the features of substance use disorder that these methods are purported to evaluate, unique issues for measure validity and application, and translational links to preclinical models and special considerations for studies wishing to evaluate homology across species is provided.

Neural circuits controlling choice behavior in opioid addiction

As the opioid epidemic presents an ever-expanding public health threat, there is a growing need to identify effective new treatments for opioid use disorder (OUD). OUD is characterized by a behavioral misallocation in choice behavior between opioids and other rewards, as opioid use leads to negative consequences, such as job loss, family neglect, and potential overdose. Preclinical models of addiction that incorporate choice behavior, as opposed to self-administration of a single drug reward, are needed to understand the neural circuits governing opioid choice. These choice models recapitulate scenarios that humans suffering from OUD encounter in their daily lives. Indeed, patients with substance use disorders (SUDs) exhibit a propensity to choose drug under certain conditions. While most preclinical addiction models have focused on relapse as the outcome measure, our data suggest that choice is an independent metric of addiction severity, perhaps relating to loss of cognitive control over choice, as opposed to excessive motivational drive to seek drugs during relapse. In this review, we examine both preclinical and clinical literature on choice behavior for drugs, with a focus on opioids, and the neural circuits that mediate drug choice versus relapse. We argue that preclinical models of opioid choice are needed to identify promising new avenues for OUD therapy that are translationally relevant. Both forward and reverse translation will be necessary to identify novel treatment interventions. This article is part of the Special Issue on "Opioid-induced changes in addiction and pain circuits".

Buprenorphine & methadone dosing strategies to reduce risk of relapse in the treatment of opioid use disorder

BACKGROUND

Although there is consensus that having a "high-enough" dose of buprenorphine (BUP-NX) or methadone is important for reducing relapse to opioid use, there is debate about what this dose is and how it should be attained. We estimated the extent to which different dosing strategies would affect risk of relapse over 12 weeks of treatment, separately for BUP-NX and methadone.

METHODS

This was a secondary analysis of three comparative effectiveness trials. We examined four dosing strategies: 1) increasing dose in response to participant-specific opioid use, 2) increasing dose weekly until some minimum dose (16 mg BUP, 100 mg methadone) was reached, 3) increasing dose weekly until some minimum and increasing dose in response to opioid use thereafter (referred to as the "hybrid strategy"), and 4) keeping dose constant after the first 2 weeks of treatment. We used a longitudinal sequentially doubly robust estimator to estimate contrasts between dosing strategies on risk of relapse.

RESULTS

For BUP-NX, increasing dose following the hybrid strategy resulted in the lowest risk of relapse. For methadone, holding dose constant resulted in greatest risk of relapse; the other three strategies performed similarly. For example, the hybrid strategy reduced week 12 relapse risk by 13 % (RR: 0.87, 95 %CI: 0.83-0.95) and by 20 % (RR: 0.80, 95 %CI: 0.71-0.90) for BUP-NX and methadone respectively, as compared to holding dose constant.

CONCLUSIONS

Doses should be targeted toward minimum thresholds and, in the case of BUP-NX, raised when patients continue to use opioids.

Implementation opportunities for scaling up methadone maintenance treatment in Kyrgyzstan: Methadone dosage and retention on treatment over two years

Background

Methadone maintenance treatment (MMT) is the most effective and cost-effective strategy to control HIV in Central Asian countries, where the epidemic is concentrated among people who inject drugs (PWID) who use opioids.

Methods

Using data from a prospective observational database of all people initiated on MMT in Kyrgyzstan since 2008, we analyzed a more contemporary subset of data for all persons receiving MMT from January 2017 through June 2021 after the national treatment guidelines were changed. Retention on MMT was assessed at 1, 6, 12, and 24 months and predictive variables included were dosage levels, HIV status, and type of clinical setting using survival analysis. Predictors of treatment dropout were estimated using Cox multivariate regression models.

Results

Among the 940 MMT patients, the proportion receiving low (<40mg), medium (40-85mg), and high (>85mg) dosage levels was 37.9%, 42.2%, and 19.9%, respectively. Increasing MMT dosage level was significantly (p<0.0001) correlated with retention at 1 (90%, 98%, 100%), 6 (42%, 63%, 95%), 12 (33%, 55%, 89%), and 24 (16%, 45%, 80%) months, respectively, with no differences between community and correctional settings. Significant predictors of dropout at 12 months included low (aHR=8.0; 95%CL=5.8-11.0) and medium (aHR=3.5; 95%CL=2.5-4.9) methadone dosage level relative to high dose, receiving MMT in three administrative regions relative to the capital Bishkek, and lower in the tuberculosis-specialized clinic in Bishkek. Clients with HIV receive higher average MMT doses (79.5mg vs 63.1mg; p<0.0001), but MMT retention did not differ after controlling for dosage in this group.

Conclusions

The proportion of patients receiving optimal dosage was low (19.9%). An implementation strategy that focused on getting a larger proportion of MMT on the optimal dosage to promote retention could potentially improve the quality of existing treatment and promote further scale-up of MMT in Kyrgyzstan.

Twelve-month Treatment Retention and Associated Factors: A Comparison of 2 Medically Assisted Therapy Clinics in Dar es Salaam, Tanzania

OBJECTIVES

Retention in methadone maintenance treatment is instrumental in achieving better treatment outcomes. In this study, we compared 2 medication-assisted treatment (MAT) clinics in Dar es Salaam, Tanzania with respect to patient characteristics, outcomes, and factors that predict 12-month treatment retention.

METHODS

This retrospective registry-based cohort study utilized data collected for routine clinical and program monitoring at 2 sites, Mwananyamala and Muhimbili MAT clinics. Cumulative retention in treatment was calculated using life tables. The analysis of treatment retention predictor variables used both Kaplan-Meier and Cox proportional hazard analyses.

RESULTS

We examined the socio-demographic and program-related characteristics of 362 (181 from each clinic) patients. Twelve-month treatment retention was higher at Mwananyamala (73%) than Muhimbili (64%) MAT clinic, but the difference was not significant. In both clinics, a higher methadone dose (>60 mg) significantly predicted treatment retention (P < 0.05). Being employed and traveling an average short distance (<5 km) from home to clinic significantly increased the likelihood of remaining in treatment in Muhimbili MAT clinic (P  < 0.05) only.

CONCLUSIONS

A methadone dose of 60 mg and above was associated with longer retention in treatment. At 1 clinic in a denser and more central location, employment and a short travel distance from home to clinic were associated with longer tenure in treatment. These findings have potential implications for clinical practice, research, and scaling up MAT services in Tanzania.

Association of the D-amino acid oxidase gene with methadone dose in heroin dependent patients under methadone maintenance treatment

Methadone is a synthetic opioid used for the maintenance treatment (MMT) of heroin dependence. It primarily binds to the μ-opioid receptor (MOR; with its gene, namely OPRM1). Methadone is also an N-methyl-D-aspartate (NMDA) receptor antagonist. The role of NMDA receptor in the regulatory mechanisms of methadone dosage in heroin dependent patients is so far not clear. D-amino acid oxidase (DAO) is an important enzyme that indirectly activates the NMDA receptor through its effect on the D-serine level. To test the hypothesis that genetic polymorphisms in the DAO gene are associated with methadone treatment dose and responses, we selected four single nucleotide polymorphisms (SNPs) in DAO from the literature reports of the Taiwanese population. SNPs were genotyped in 344 MMT patients. In this study, we identified a functional SNP rs55944529 in the DAO gene that reveals a modest but significant association with the methadone dosage in the recessive model of analysis (P = 0.003) and plasma concentrations (P = 0.003) in MMT patients. However, it did not show association with plasma methadone concentration in multiple linear regression analysis. It is also associated with the methadone adverse reactions of dry mouth (P = 0.002), difficulty with urination (P = 0.0003) in the dominant model, and the withdrawal symptoms of yawning (P = 0.005) and gooseflesh skin (P = 0.004) in the recessive model. Our results suggest a role of the indirect regulatory mechanisms of the NMDA reporter, possibly via the DAO genetic variants, in the methadone dose and some adverse reactions in MMT patients.

Current Best Practices for Acute and Chronic Management of Patients with Opioid Use Disorder

This comprehensive review on opioids summarizes the scope of the current opioid epidemic, the diagnosis and treatment of opioid use disorder, and the medical and psychiatric complications of opioid use.

Subjective symptoms and serum methadone concentrations: what should guide dose adjustments in methadone maintenance treatment? A naturalistic cohort study from Norway

BACKGROUND

There is little evidence-based guidance on how to optimize methadone dosages among patients with opioid addiction undergoing methadone maintenance treatment (MMT). This study aims to investigate whether self-perceived opioid withdrawal symptoms, adverse effects, and self-reported substance use in patients on MMT are related to serum methadone concentrations and the role that these variables could play in clinical decisions on dose adjustments.

METHODS

This naturalistic prospective cohort study included clinical and laboratory measurements from 83 patients undergoing MMT in outpatient clinics in Bergen, Norway, from May 2017 to January 2020. Information on age, gender, methadone daily doses and serum concentrations, subjective opioid withdrawal symptoms using 16 items Subjective Opioid Withdrawal Scale (SOWS) questionnaire, self-reported adverse effects, and substance use was obtained. Linear mixed modelling was used for analyzing the data.

RESULTS

The mean age of the participants was 45 years, and 33% were women. Almost half reported mild to moderate subjective opioid withdrawal symptoms, and all had experienced at least one subjective adverse effect. The use of at least one substance was reported by 88% of the participants. Serum concentration-to-dose ratios were lower among those who had reported subjective opioid withdrawal symptoms (p) = 0.039). The total SOWS score (p < 0.001); the specific subjective withdrawal symptoms of anxiety (p = 0.004), bone and muscle aches (p = 0.003), restlessness (p = 0.017), and (slightly) shaking (p = 0.046), also use of heroin (p = 0.015) and alcohol (p = 0.011) were associated with lower methadone concentrations. Cannabis use was slightly related to higher methadone concentrations (p = 0.049).

CONCLUSIONS

The findings suggest that the patient's self-perceived symptoms and current clinical condition are related to the serum concentrations of methadone. This interpretation supports dose adjustments based on patient-reported symptoms. In some aberrant cases, measurement of serum concentrations together with other individual assessments may be considered to support the clinical decision.

Understanding concurrent stimulant use among people on methadone: A qualitative study

INTRODUCTION AND AIMS

Opioid-related overdoses are an epidemic in North America, prompting a greater use of medications for opioid use disorder, such as methadone. Although many people work toward overall drug abstinence while on methadone, a sub-population of people with and without histories of polysubstance use engage in stimulant use while on methadone treatment. This study explores motivations for concurrent stimulant and methadone use in a street-involved drug-using population.

DESIGN AND METHODS

Semi-structured qualitative interviews were conducted with 39 people on methadone in Vancouver, Canada. Participants were recruited from among the participants in two community-based prospective cohort studies consisting of HIV-positive and HIV-negative people who use drugs. Interview transcripts were analysed using an inductive and iterative approach.

RESULTS

Our analysis identified three primary themes. First, participants articulated how stimulants were used to counter the sedating effects of methadone and enable them to engage in daily and survival activities (e.g. income generation). Second, participants described increased stimulant use to compensate for reduced stimulant intoxication while taking methadone. Finally, participants described the desire to achieve intoxication on stimulants once stable on methadone, as their substance use treatment goals did not involve drug abstinence.

DISCUSSION AND CONCLUSION

Among a street-involved drug-using population in which people do not have abstinence-based treatment goals, there are several functional reasons to use stimulants concurrently while on methadone. A deeper and more nuanced understanding of substance use motivators may contribute to further research and inform policy and guideline changes that support low threshold and harm reduction-focused methadone treatment programs and other interventions to reduce drug-related harms.

Effectiveness of the methadone programme in the treatment of patients on a mephedrone binge and dependent on heroin: a retrospective study, 2010-19

Objectives: The purpose of this research was to investigate the effectiveness of the methadone programme in a group of patients taking mephedrone with heroin.Methods: The research involved 230 people who took part in the methadone programme between 2010 and 2019: 101 people on a mephedrone binge and taking heroin and 129 people addicted to heroin.Results: Number of re-hospitalisations was higher in a group of patients on a mephedrone binge taking heroin in comparison to heroin dependent patients (91.9 vs 79.8%, p < 0.01). The interaction of the hepatitis C virus (HCV) infection with the dose of methadone taken explains 67.6% of the variance in the frequency of hospitalisation of the patients on a mephedrone binge (p < 0.001), and in the case of the dose of methadone alone - only 12% (p < 0.001). Regression analysis indicated that statistically significant majority of the subjects (p < 0.001) who received the optimal dose of methadone, namely 100-110 ml, were hospitalised once.Conclusions: The interaction of the methadone dose with HCV infection plays a very important role in the frequency of hospitalisation of patients taking mephedrone with heroin on a regular basis.KEY POINTSThe number of hospitalisations was higher in a group of patients on a mephedrone binge taking heroin in comparison to heroin dependent patientsThe interaction of the sex of the subjects and HCV infection with the dose of methadone taken explains 80.3 and 67.6% of variance in the frequency of hospitalisations, respectivelyThe most optimal dose of methadone in the group of people taking mephedrone with heroin ranges between 100 and 110 ml.

Adverse Events During Treatment Induction With Injectable Diacetylmorphine and Hydromorphone for Opioid Use Disorder

OBJECTIVES

The present study aims to describe a 3-day induction protocol for injectable hydromorphone (HDM) and diacetylmorphine (DAM) used in 3 Canadian studies and examine rates of opioid-related overdose and somnolence during this induction phase.

METHODS

The induction protocol and associated data on opioid-related overdose and somnolence are derived from 2 clinical trials and one cohort study conducted in Vancouver and Montreal (2005-2008; 2011-2014; 2014-2018). In this analysis, using the Medical Dictionary for Regulatory Activities coding system we report somnolence (ie, drowsiness, sleepiness, grogginess) and opioid overdose as adverse events. Overdoses requiring intervention with naloxone are coded as severe adverse events.

RESULTS

Data from the 3 studies provides a total of 1175 induction injections days, with 700 induction injection days for DAM, and 475 induction injection days for HDM. There were 34 related somnolence and adverse event (AE) overdoses (4.899 per 100 injection days) in DAM and 6 (1.467 per 100 days) in HDM. Four opioid overdoses requiring naloxone (0.571 per 100 injection days) were registered in DAM and 1 in HDM (0.211 per 100 injection days), all safely mitigated onsite. The first week maximum daily dose patients received were on average 433.62 mg [standard deviation (SD) = 137.92] and 223.26 mg (SD = 68.06) for DAM and HDM, respectively.

CONCLUSIONS

A 3-day induction protocol allowed patients to safely reach high doses of injectable hydromorphone and diacetylmorphine in a timely manner. These findings suggest that safety is not an evidence-based barrier to the implementation of treatment with injectable hydromorphone and diacetylmorphine.

Adherence among HIV-positive injection drug users undergoing methadone treatment in Taiwan

AIMS

The study aims were to investigate adherence to methadone maintenance treatment (MMT) and to identify associated clinical factors in patients who inject drugs diagnosed with human immunodeficiency virus (HIV) infection in Taiwan.

METHODS

Data were from the National Health Surveillance System on HIV and the National Drug Treatment System on MMT. HIV-positive people who inject drugs (HIVPWID) were defined as the study population. Information obtained included age, sex, education, marital status, employment, methadone dose, and date of diagnosis of HIV infection. Adherence was defined as taking methadone for the past 90, 180 and 365 days, then categorized as high (> 90%), moderate (51 to 90%), or low (<=50%) adherent respectively.

RESULTS

Of 1641 HIVPWID registered in the datasets from 2007 to 2012, 961 (58.56%) had received MMT. For HIVPWID evaluated at 90 days (n = 951), 271 (28.5%), 382 (40.2%), and 298 (31.3%) were classified as high, moderate, and low adherent respectively. For HIVPWID evaluated at 180 days (n = 936), 190 (20.3%), 349 (37.3%), and 397 (42.4%) were classified as high, moderate, and low adherent respectively. For HIVPWID evaluated at 365 days (n = 919), 133 (14.5%), 271 (29.5%), and 515 (56.0%) were classified as high, moderate, and low adherent respectively. After controlling for sociodemographics, results showed that methadone dose, location of MMT clinic, and date of HIV diagnosis were significantly associated with MMT adherence.

CONCLUSIONS

Study findings underscore the importance to MMT adherence of methadone dosage, early diagnosis of patient's HIV infection, and area of patient residence.

Pharmacological validation of a translational model of cocaine use disorder: Effects of d-amphetamine maintenance on choice between intravenous cocaine and a nondrug alternative in humans and rhesus monkeys

Drug self-administration procedures are the gold standard for laboratory research to study mechanisms of drug use disorders and evaluate candidate medications. However, preclinical-to-clinical translation has been hampered by a lack of coordination. To address this limitation, we previously developed homologous intravenous (IV) cocaine choice self-administration procedures in rhesus monkeys and humans, and then demonstrated their functional equivalence. The present studies sought to determine the sensitivity of these procedures to d-amphetamine maintenance. Three (N = 3) rhesus monkeys with histories of cocaine self-administration and 16 (N = 16) humans with cocaine use disorder completed the studies. Monkeys were maintained on IV d-amphetamine (0, 0.019, 0.037 and 0.074 mg/kg/h), and then completed 7 sessions during each condition in which they completed 9 choice trials to receive 0.14 mg/kg/injection IV cocaine (corresponding to 10 mg/70 kg in humans) or 10 food pellets under independent, concurrent progressive-ratio schedules. Humans were maintained on oral extended release d-amphetamine (0, 30 and 60 mg/day, corresponding to the lowest 3 doses in monkeys) and participated in 12 sessions in which they chose money ($6.00) or IV cocaine (0, 3, 10 and 30 mg/70 kg). Blood samples were taken to compare d-amphetamine plasma levels across species. In monkeys and humans, d-amphetamine reduced the number of cocaine choices and produced comparable blood levels at equivalent daily doses. d-Amphetamine had similar efficacy, though lower potency, at reducing choice for an equivalent cocaine dose in monkeys relative to humans. These coordinated studies support the utility of these procedures as a translational model for cocaine use disorder. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Opioid use disorder

Opioid use disorder (OUD) is a chronic relapsing disorder that, whilst initially driven by activation of brain reward neurocircuits, increasingly engages anti-reward neurocircuits that drive adverse emotional states and relapse. However, successful recovery is possible with appropriate treatment, although with a persisting propensity to relapse. The individual and public health burdens of OUD are immense; 26.8 million people were estimated to be living with OUD globally in 2016, with >100,000 opioid overdose deaths annually, including >47,000 in the USA in 2017. Well-conducted trials have demonstrated that long-term opioid agonist therapy with methadone and buprenorphine have great efficacy for OUD treatment and can save lives. New forms of the opioid receptor antagonist naltrexone are also being studied. Some frequently used approaches have less scientifically robust evidence but are nevertheless considered important, including community preventive strategies, harm reduction interventions to reduce adverse sequelae from ongoing use and mutual aid groups. Other commonly used approaches, such as detoxification alone, lack scientific evidence. Delivery of effective prevention and treatment responses is often complicated by coexisting comorbidities and inadequate support, as well as by conflicting public and political opinions. Science has a crucial role to play in informing public attitudes and developing fuller evidence to understand OUD and its associated harms, as well as in obtaining the evidence today that will improve the prevention and treatment interventions of tomorrow.

Genetic polymorphisms in the opioid receptor delta 1 (OPRD1) gene are associated with methadone dose in methadone maintenance treatment for heroin dependence

Delta opioid receptor (DOR) is well known to be involved in heroin dependence. This study tested the hypothesis that single nucleotide polymorphisms (SNPs) in the opioid receptor delta 1 (OPRD1) gene coding region are associated with treatment responses in a methadone maintenance therapy (MMT) cohort in Taiwan. Three hundred forty-four MMT patients were recruited. Diastolic/systolic blood pressure, heart rate, methadone dosage, and plasma concentrations of methadone were recorded. Twenty-five SNPs located within the OPRD1 genetic region were selected and genotyped from the genomic DNA of all 344 participants. After pairwise tagger analyses, tagger SNP rs204047 showed a significant association with methadone dosage (P = 0.0019), and tagger SNPs rs204047 and rs797397 were significantly associated with plasma R, S-methadone concentrations (P < 0.0006) in patients tested negative in the urine morphine test, which indicated patients with a better response to MMT. The major genotype carriers showed a higher methadone dosage and higher plasma concentrations of R, S-methadone than the minor genotype carriers. The results indicated that OPRD1 genetic variants were associated with methadone dosage and methadone plasma concentration in MMT patients with a negative morphine test result.

Haplotype-Based Association and In Silico Studies of OPRM1 Gene Variants with Susceptibility to Opioid Dependence Among Addicted Iranians Undergoing Methadone Treatment

The associations of OPRM1 gene variants with opioid dependence have been demonstrated. This study investigated the association of rs495491, rs1799971 (A118G), rs589046, and rs10457090 variants of OPRM1 gene with opium dependence and their haplotypes among addicted individuals undergoing methadone treatment. Moreover, we investigated whether any of these variants were associated with libido dysfunction or insomnia among addicted people. A total of 404 individuals were genotyped by amplification refractory mutation system (ARMS) PCR. In silico studies were designed through homology modeling of A118G structures (N40 and D40) and docked with 41 FDA-approved drugs of OPRM1 protein by SWISS-MODEL, COACH, MolProbity, ProSA, Errat, Glide XP, and Autodock 4. Results revealed that rs495491, A118G, rs589046, and rs10457090 were significantly associated with opium dependence under recessive (P = 6.66E-10), dominant (P = 0.017), co-dominant (P = 0.001), and recessive (P = 9.28E-6) models of inheritance, respectively. Further analyses indicated three significant haplotypes including A-A-A-C (P-permutation < 1E-9), G-G-A-C (P-permutation = 0.04), and G-A-G-C (P-permutation = 8.69E-4). Genotype-phenotype associations of OPRM1 variants with insomnia and libido dysfunction showed no significant association. Docking showed the higher binding affinity of N40 rather than D40 model; however, methadone and morphine were bonded with D40 structure more powerful. Consequently, rs495491, A118G, rs589046, and rs10457090 were associated with opioid dependence among Iranians; also, A118G might be the most remarkable marker of OPRM1 owing to its vital structural roles.

Opioid maintenance, weaning and detoxification techniques; where we have been, where we are now and what the future holds: an update

In 2017, the US Department of Health and Human Services declared a public health emergency on the opioid crisis. On average, 115 Americans die each day from an opioid overdose. The scope and breadth of this problem is continually evolving. In 2010, there was a shift in causes primarily due to the use of heroin, and currently the latest shift in opioid-related deaths involves a variety of synthetic opioids, particularly illicitly manufactured fentanyl. As the medical, sociological and political environments have drastically changed, especially in the USA, over the last 6 years with regard to opioid use and misuse, an updated review of the literature was necessary.

Social Influences in Animal Models of Opiate Addiction

Opiate addiction has reached an epidemic prevalence in recent years, yet social influences on the use and abuse of opiates has been widely understudied. In particular, the neurobiological substrates of opiate addiction and their modulation by social influences are largely unknown, perhaps due to the lack of widespread incorporation of social variables into animal models of opiate addiction. As reviewed here, animal models such as oral and intravenous drug self-administration, conditioned place preference, behavioral sensitization, and the effects of various stressors, have been useful in identifying some of the neurochemical circuitry that mediate social influences on opiate addiction. However, it is clear from our review that newer paradigms that incorporate various social elements are greatly needed to provide more translational insights into the neurobiological basis of opiate addiction. These elements include social and environmental enrichment, presence of conspecifics, and procedures that require subjects to exert effort to engage in prosocial behavior. A wider implementation of social variables into animal models of opiate addiction will help inform neurobehavioral strategies to increase the efficacy of treatment.

The effect of high-dose dronabinol (oral THC) maintenance on cannabis self-administration

BACKGROUND

There is a clear need for advancing the treatment of cannabis use disorders. Prior research has demonstrated that dronabinol (oral THC) can dose-dependently suppress cannabis withdrawal and reduce the acute effects of smoked cannabis. The present study was conducted to evaluate whether high-dose dronabinol could reduce cannabis self-administration among daily users.

METHODS

Non-treatment seeking daily cannabis users (N = 13) completed a residential within-subjects crossover study and were administered placebo, low-dose dronabinol (120 mg/day; 40 mg tid), or high-dose dronabinol (180-240 mg/day; 60-80 mg tid) for 12 consecutive days (order counterbalanced). During each 12-day dronabinol maintenance phase, participants were allowed to self-administer smoked cannabis containing <1% THC (placebo) or 5.7% THC (active) under forced-choice (drug vs. money) or progressive ratio conditions.

RESULTS

Participants self-administered significantly more active cannabis compared with placebo in all conditions. When active cannabis was available, self-administration was significantly reduced during periods of dronabinol maintenance compared with placebo maintenance. There was no difference in self-administration between the low- and high-dose dronabinol conditions.

CONCLUSIONS

Chronic dronabinol dosing can reduce cannabis self-administration in daily cannabis users and suppress withdrawal symptoms. Cannabinoid agonist medications should continue to be explored for therapeutic utility in the treatment of cannabis use disorders.

Influence of tiagabine maintenance on cannabis effects and related behaviors in daily cannabis users

No medications are approved for cannabis use disorder (CUD). Gamma-aminobutyric acid (GABA) reuptake is modulated by cannabinoid (CB) receptor agonists, and there are shared effects between CB agonists and the GABA reuptake inhibitor tiagabine. This overlapping neuropharmacology suggested that tiagabine might be useful for CUD. The study determined the ability of tiagabine maintenance to reduce cannabis self-administration using a placebo-controlled, double-blind, counterbalanced, within-subjects design. Nontreatment-seeking daily cannabis users (N = 12; 3 female, 9 male) completed two 12-day outpatient maintenance phases (0 or 12 mg of tiagabine/day). Each phase consisted of a safety session, 7 maintenance days, and 4 experimental sessions. During experimental sessions, maintenance continued and participants completed two 2-day blocks of sampling and self-administration sessions to determine the reinforcing effects of smoked cannabis (0% and 5.9% Δ9-tetrahydrocannabinol). Naturalistic cannabis use, the subjective, performance and physiological response to cannabis, as well as side effects, sleep quality, craving, other self-reported substance use, and observer ratings were also measured. Cannabis functioned as a reinforcer and produced prototypical effects (e.g., increased heart rate and ratings of "high"), but tiagabine generally did not impact the effects of cannabis, or alter naturalistic use. Furthermore, tiagabine produced small, but significant, increases on 2 subscales of a Marijuana Craving Questionnaire, and reductions in both the amount of time slept in the past 24 hr and ratings of positive mood upon awakening. These human laboratory results from a sample of nontreatment-seeking cannabis users do not support the potential efficacy of 12 mg of tiagabine as a stand-alone pharmacotherapy for CUD. (PsycINFO Database Record

Concurrent drug use among methadone maintenance patients in mountainous areas in northern Vietnam

OBJECTIVES

With the rise in methadone maintenance therapy (MMT) for drug users in Vietnam, there has been growing interest in understanding if and how often MMT patients engage in concurrent illicit drug use while on methadone therapy in various settings. This study examined factors associated with concurrent opioid use among patients on MMT in a mountainous area in Vietnam.

SETTING

One urban and one rural MMT clinics in Tuyen Quang province.

PARTICIPANTS

Survey participants consisted of patients who were taking MMT at the selected study sites. A convenience sampling approach was used to recruit the participants.

PRIMARY AND SECONDARY OUTCOME MEASURES

Participants were asked a series of questions about their socioeconomic status, current alcohol and tobacco use, health problems (measured by the EuroQol-Five Dimension-Five Level instrument), psychological distress (measured by Kessler score), and factors associated with current and/or previous drug use. Regression models were used to determine factors associated with concurrent drug use among MMT patients.

RESULTS

Among the 241 male MMT patients included in the study, 13.4% reported concurrent opioid use. On average, the longer patients had been enrolled in MMT, the less likely they were to concurrently use drugs. Conversely, patients with higher levels of psychological distress were more likely to engage in concurrent drug use while on MMT.

CONCLUSION

Longer duration of MMT was significantly correlated with reduced illicit drug use among participants. Higher levels of psychological distress were associated with increased use of illicit drugs among MMT patients. Regardless of distance, long-term MMT is still effective and should be expanded in mountainous areas.

Methadone Dose Adjustments, Plasma R-Methadone Levels and Therapeutic Outcome of Heroin Users: A Randomized Clinical Trial

AIMS

We aimed to improve the retention in treatment and therapeutic outcome of methadone maintenance treatment (MMT) patients by adjusting the oral methadone dose in order to reach a "target" plasma R-methadone level (80-250 ng/mL).

METHODS

A multicenter randomized controlled trial was organized.

RESULTS

The intention-to-treat statistical analysis showed that repeated dose adjustments performed in order to obtain therapeutic plasma R-methadone levels did not improve retention in treatment of heroin-dependent patients. However, patients having plasma methadone levels in the "target range" at the beginning of the study had a better retention in treatment than controls. Furthermore, patients succeeding in keeping plasma R-methadone target levels (per protocol analysis) remained in treatment and improved their social scores better than controls. -Conclusion: Although the primary endpoint of this study was not demonstrated, a post hoc and a per protocol analysis suggested that patients in MMT with plasma R-methadone concentrations in the target range have a better therapeutic outcome than controls.

The Role of Program Directors in Treatment Practices: The Case of Methadone Dose Patterns in U.S. Outpatient Opioid Agonist Treatment Programs

OBJECTIVE

To describe changes in characteristics of directors of outpatient opioid agonist treatment (OAT) programs, and to examine the association between directors' characteristics and low methadone dosage.

DATA SOURCE

Repeated cross-sectional surveys of OAT programs in the United States from 1995 to 2011.

STUDY DESIGN

We used generalized linear regression models to examine associations between directors' characteristics and methadone dose, adjusting for program and patient factors.

DATA COLLECTION

Data were collected through telephone surveys of program directors.

PRINCIPAL FINDINGS

The proportion of OAT programs with an African American director declined over time, from 29 percent in 1995 to 16 percent in 2011. The median percentage of patients in each program receiving <60 mg/day declined significantly, from 48.5 percent in 1995 to 29 percent in 2005 and 23 percent in 2011. Programs with an African American director were significantly more likely to provide low methadone doses than other programs. This association was even stronger in programs with an African American director who served populations with higher percentages of African American patients.

CONCLUSIONS

Demographic characteristics of OAT program directors (e.g., their race) may play a key role in explaining variations in methadone dosage across programs and patients. Further research should investigate the causal pathways through which directors' characteristics affect treatment practices. This may lead to new, multifaceted managerial interventions to improve patient outcomes.

The Abuse Potential of Prescription Opioids in Humans-Closing in on the First Century of Research

While opioids are very effective analgesics for treating acute pain, humans have struggled with opiate addiction for millenia. An opium abuse epidemic in the early 1900's led the US government to develop a systematic research infrastructure and scientific plan to produce new compounds with analgesic properties but without abuse liability. This review describes the techniques that were developed for testing in the human laboratory, including empirically derived outcome measures and required elements for human abuse potential assessment. The evaluation and characterization of semi-synthetic and synthetic opioids, including full mu opioid agonists, partial agonists and mixed agonist-antagonists, are described across several decades of research. Finally, the prescription opioid epidemic beginning in the 1990's in the US led to a resurgence in abuse potential evaluations, and the application of these methods to the study of novel abuse-deterrent formulations is discussed.

Clinical Laboratory Evaluation of Electronic Cigarettes/Electronic Nicotine Delivery Systems: Methodological Challenges

OBJECTIVE

Evaluating electronic cigarettes (ECIGs) in the clinical laboratory is critical to understanding their effects. However, laboratory evaluation of ECIGs can be challenging, as they are a novel, varied, and evolving class of products. The objective of this paper is to describe some methodological challenges to the clinical laboratory evaluation of ECIGs.

METHODS

The authors gathered information about challenges involved in the laboratory evaluation of ECIGs. Challenges were categorized and solutions provided when possible.

RESULTS

Methods used to study combustible cigarettes may need to be adapted to account for ECIG novelty and differences within the class. Challenges to ECIG evaluation can include issues related to 1) identification of ECIG devices and liquids, 2) determination of short -term ECIG abstinence, 3) measurement of use behavior, and 4) assessment of dependence. These challenges are discussed, and some suggestions to inform ECIG evaluation using clinical laboratory methods are provided.

CONCLUSIONS

Awareness of challenges and developing, validating, and reporting methods used to address them aids interpretation of results and replication efforts, thus enhancing the rigor of science used to protect public health through appropriate, empirically-based, ECIG regulation.

Buprenorphine dosing choices in specific populations: review of expert opinion

INTRODUCTION

Treatment of opioid dependence with buprenorphine improves outcomes. Typical dosing ranges for all patients from clinical evidence and as defined in the product information are wide. For specific groups with complex clinical scenarios, there is no clear consensus on dosing choices to achieve best possible outcomes.

AREAS COVERED

The doses of buprenorphine used in 6 European countries was reviewed. A review of published evidence supported rapid induction with buprenorphine and the benefits of higher doses but did not identify clearly useful guidance on dosing choices for groups with complex clinical scenarios. An expert group of physicians with experience in addiction care participated in a discussion meeting to share clinical practice experience and develop a consensus on dosing choices.

EXPERT OPINION

There was general agreement that treatment outcomes can be improved by optimising buprenorphine doses in specific subgroups. Specific groups in whom buprenorphine doses may be too low and who could have better outcomes with optimised dosing were identified on the basis of clinical practice experience. These groups include people with severe addiction, high tolerance to opioids, and psychiatric comorbidities. In these groups it is recommended to review dosing choices to ensure buprenorphine dosing is sufficient.

Sensitive determination of methadone in human serum and urine by dispersive liquid-liquid microextraction based on the solidification of a floating organic droplet followed by HPLC-UV

Dispersive liquid-liquid microextraction based on solidification of floating organic droplet was developed for the extraction of methadone and determination by high-performance liquid chromatography with UV detection. In this method, no microsyringe or fiber is required to support the organic microdrop due to the usage of an organic solvent with a low density and appropriate melting point. Furthermore, the extractant droplet can be collected easily by solidifying it at low temperature. 1-Undecanol and methanol were chosen as extraction and disperser solvents, respectively. Parameters that influence extraction efficiency, i.e. volumes of extracting and dispersing solvents, pH, and salt effect, were optimized by using response surface methodology. Under optimal conditions, enrichment factor for methadone was 134 and 160 in serum and urine samples, respectively. The limit of detection was 3.34 ng/mmL in serum and 1.67 ng/mL in urine samples. Compared with the traditional dispersive liquid-liquid microextraction, the proposed method obtained lower limit of detection. Moreover, the solidification of floating organic solvent facilitated the phase transfer. And most importantly, it avoided using high-density and toxic solvents of traditional dispersive liquid-liquid microextraction method. The proposed method was successfully applied to the determination of methadone in serum and urine samples of an addicted individual under methadone therapy.

Correlates of cocaine use during methadone treatment: implications for screening and clinical management (ANRS Methaville study)

Background

Cocaine use is frequent in patients receiving methadone maintenance treatment (MMT) and can jeopardize their treatment response. Identifying clinical predictors of cocaine use during methadone treatment can potentially improve clinical management. We used longitudinal data from the ANRS Methaville trial both to describe self-reported occasional and regular cocaine use during MMT and to identify clinical predictors.

Methods

We selected 183 patients who had data on cocaine (or crack) use at months 0 (M0), M6, and/or M12, accounting for 483 visits. The outcome was “cocaine use” in three categories: “no,” “occasional,” and “regular” use. To identify factors associated with the outcome over time, we performed a mixed multinomial logistic regression.

Results

Time on methadone was significantly associated with a decrease in occasional but not in regular cocaine use from 14.7 % at M0 to 7.1 % at M12, and from 10.7 % at baseline to 6.5 % at M12, respectively. After multiple adjustments, opiate injection, individuals screening positive for attention deficit hyperactivity disorder (ADHD) symptoms, and those presenting depressive symptoms were more likely to regularly use cocaine.

Conclusions

Although time on MMT had a positive impact on occasional cocaine use, it had no impact on regular cocaine use. Moreover, regular cocaine users were more likely to report opiate injection and to present ADHD and depressive symptoms. Early screening of these disorders and prompt tailored pharmacological and behavioral interventions can potentially reduce cocaine use and improve response to MMT.

Trial registration

The trial is registered with the French Agency of Pharmaceutical Products (AFSSAPS) under the number 2008-A0277-48, the European Union Drug Regulating Authorities Clinical Trials, number Eudract 2008-001338-28, the ClinicalTrials.gov Identifier: NCT00657397, and the International Standard Randomised Controlled Trial Number Register ISRCTN31125511.

Public health and international drug policy

In September 2015, the member states of the United Nations endorsed sustainable development goals (SDG) for 2030 that aspire to human rights-centered approaches to ensuring the health and well-being of all people. The SDGs embody both the UN Charter values of rights and justice for all and the responsibility of states to rely on the best scientific evidence as they seek to better humankind. In April 2016, these same states will consider control of illicit drugs, an area of social policy that has been fraught with controversy, seen as inconsistent with human rights norms, and for which scientific evidence and public health approaches have arguably played too limited a role.

The previous UN General Assembly Special Session (UNGASS) on drugs in 1998 – convened under the theme “a drug-free world, we can do it!” – endorsed drug control policies based on the goal of prohibiting all use, possession, production, and trafficking of illicit drugs. This goal is enshrined in national law in many countries. In pronouncing drugs a “grave threat to the health and well-being of all mankind,” the 1998 UNGASS echoed the foundational 1961 convention of the international drug control regime, which justified eliminating the “evil” of drugs in the name of “the health and welfare of mankind.” But neither of these international agreements refers to the ways in which pursuing drug prohibition itself might affect public health. The “war on drugs” and “zero-tolerance” policies that grew out of the prohibitionist consensus are now being challenged on multiple fronts, including their health, human rights, and development impact.

The Johns Hopkins – Lancet Commission on Drug Policy and Health has sought to examine the emerging scientific evidence on public health issues arising from drug control policy and to inform and encourage a central focus on public health evidence and outcomes in drug policy debates, such as the important deliberations of the 2016 UNGASS on drugs.

The Johns Hopkins-Lancet Commission is concerned that drug policies are often colored by ideas about drug use and drug dependence that are not scientifically grounded. The 1998 UNGASS declaration, for example, like the UN drug conventions and many national drug laws, does not distinguish between drug use and drug abuse. A 2015 report by the UN High Commissioner for Human Rights, by contrast, found it important to emphasize that “[d]rug use is neither a medical condition nor does it necessarily lead to drug dependence.” The idea that all drug use is dangerous and evil has led to enforcement-heavy policies and has made it difficult to see potentially dangerous drugs in the same light as potentially dangerous foods, tobacco, alcohol for which the goal of social policy is to reduce potential harms.

Satisfaction With Methadone Among Heroin-Dependent Patients With Current Substance Use Disorders During Methadone Maintenance Treatment

Methadone maintenance treatment (MMT) has long been used to treat heroin-dependent patients. However, satisfaction with methadone in this patient population is unknown. The aim of this cross-sectional case-control study was to evaluate satisfaction with methadone in heroin-dependent patients with current substance use disorders (SUDs). Cases included 152 methadone-maintained patients with current SUD, requiring inpatient detoxification treatment, and controls included 33 methadone-maintained patients in sustained full remission for SUD. Satisfaction with methadone as a medication to treat heroin addiction was measured by using the Scale to Assess Satisfaction with Medications for Addiction Treatment-methadone for heroin addiction (SASMAT-METHER). The SASMAT-METHER subscales assess the following domains: personal functioning and well-being, antiaddictive effect on heroin, and antiaddictive effect on other substances. Compared with patients with remitted SUD, patients with current SUD scored lower on all SASMAT-METHER assessments. In such patients, overall SASMAT-METHER scores were independently and negatively associated with downward desired adjustment of methadone dose and days of heroin use during last month; although various sets of factors were independently associated with each of the SASMAT-METHER subscales, the only determinant of dissatisfaction on all subscales was the desire for downward adjustment of methadone dose. In summary, MMT patients with current SUD are less satisfied with methadone than MMT patients with remitted SUD. In patients with current SUD, downward desired adjustment of methadone dose and days of heroin use during last month are independently associated with overall dissatisfaction with methadone.

Factors associated with initiation of antiretroviral therapy among HIV-positive people who use injection drugs in a Canadian setting

OBJECTIVE

To identify behavioral, social, and structural factors associated with time from HIV seroconversion to antiretroviral therapy (ART) initiation among people who use injection drugs (PWID).

DESIGN

Two complementary prospective cohorts of PWID linked to comprehensive ART dispensation records in a setting of universal no-cost HIV/AIDS treatment and care.

METHODS

Multivariable extended Cox models of time to ART initiation among baseline HIV-seronegative PWID who seroconverted after recruitment adjusted with a time-updated measure of clinical eligibility for ART.

RESULTS

We included 133 individuals of whom 98 (74%) initiated ART during follow-up at a rate of 12.4 per 100 person-years. In a multivariable model adjusted for ART eligibility, methadone maintenance therapy [adjusted hazard ratio (AHR) = 2.37, 95% confidence interval (95% CI): 1.56-3.60] and a more recent calendar year of observation (AHR = 1.06, 95% CI: 1.00-1.12) were associated with more rapid ART initiation, whereas informal income generation (AHR = 0.51, 95% CI: 0.32-0.79) and incarceration (AHR = 0.52, 95% CI: 0.28-0.97) were negatively associated with ART initiation.

CONCLUSION

In this sample of community-recruited HIV-positive PWID with well defined dates of HIV seroconversion, we found that two measures related to the criminalization of illicit drug use each independently delayed ART initiation regardless of clinical eligibility. Engagement in methadone promoted ART initiation. Programs to scale-up HIV treatment among PWID should consider decreased criminalization of PWID and increased access to opioid substitution therapy to optimize the impact of ART on HIV/AIDS-associated morbidity, mortality, and HIV transmission.

Improvements in health-related quality of life among methadone maintenance clients in Dar es Salaam, Tanzania

BACKGROUND

Injection of heroin has become widespread in Dar es Salaam, Tanzania and is spreading throughout the country. To prevent potential bridging of HIV epidemics, the Tanzanian government established a methadone maintenance treatment (MMT) clinic in February 2011. We assess the effect of MMT on health-related quality of life (HRQOL) and examine factors, particularly HIV infection and methadone dose, associated with changes in HRQOL.

METHODS

This study utilized routine data on clients enrolling in methadone from February 2011 to April 2012 at Muhimbili National Hospital. Change in physical (PCS) and mental health (MCS) composite scores, as measured by the SF-12 tool, were the primary outcomes. Backward stepwise linear regression, with a criterion of p<0.2 was used to identify baseline exposure variables for inclusion in multivariable models, while adjusting for baseline scores.

RESULTS

A total of 288 MMT clients received baseline and follow-up assessments. Mean methadone dose administered was 45mg (SD±25) and 76 (27%) were confirmed HIV-positive. Significant improvements were observed in PCS and MCS, with mean increases of 15.7 and 3.3, respectively. In multivariable models, clients who had previous poly-substance use with cocaine [p=0.040] had a significantly higher mean change in PCS. Clients who were living with HIV [p=0.002]; satisfied with current marital situation [p=0.045]; had a history of suicidal thoughts [p=0.021]; and previously experienced cognitive difficulties [p=0.012] had significantly lower mean change in PCS. Clients with shorter history of heroin use [p=0.012] and who received higher methadone doses [p=0.028] had significantly higher mean change in MCS, compared to their counterparts.

CONCLUSION

Aspects of mental and physical health, risk behaviors and quality of life among drug users are intertwined and complex. Our research revealed positive short-term effects of MMT on HRQOL and highlights the importance of sustained retention for optimal benefits. Comprehensive supportive services in addition to provision of methadone are needed to address the complex health needs of people who inject drugs.

Dose-response relationship between methadone dose and adherence to antiretroviral therapy among HIV-positive people who use illicit opioids

BACKGROUND AND AIMS

For HIV-positive individuals who use illicit opioids, engagement in methadone maintenance therapy (MMT) can contribute to improved HIV treatment outcomes. However, to our knowledge, the role of methadone dosing in adherence to antiretroviral therapy (ART) has not yet been investigated. We sought to examine the relationship between methadone dose and ART adherence among a cohort of people who use illicit opioids.

DESIGN AND SETTING

We used data from the AIDS Care Cohort to Evaluate Access to Survival Services (ACCESS) study, an ongoing prospective observational cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, linked confidentially to comprehensive HIV treatment data in a setting of universal no-cost medical care, including medications. We evaluated the longitudinal relationship between methadone dose and the likelihood of ≥ 95% adherence to ART among ART-exposed participants during periods of engagement in MMT.

PARTICIPANTS

Two hundred and ninety-seven ART-exposed individuals on MMT were recruited between December 2005 and May 2013 and followed for a median of 42.1 months.

MEASUREMENTS

We measured methadone dose at ≥ 100 versus < 100 mg/day and the likelihood of ≥ 95% adherence to ART.

FINDINGS

In adjusted generalized estimating equation (GEE) analyses, MMT dose ≥ 100 mg/day was associated independently with optimal adherence to ART [adjusted odds ratio (AOR) = 1.38; 95% confidence interval (CI) = 1.08-1.77). In a subanalysis, we observed a dose-response relationship between increasing MMT dose and ART adherence (AOR = 1.06 per 20 mg/day increase, 95% CI = 1.00-1.12).

CONCLUSION

Among HIV-positive individuals in methadone maintenance therapy, those receiving higher doses of methadone (≥ 100 mg/day) are more likely to achieve ≥ 95% adherence to antiretroviral therapy than those receiving lower doses.

Opioid Exacerbation of Gram-positive sepsis, induced by Gut Microbial Modulation, is Rescued by IL-17A Neutralization

Sepsis is the predominant cause of mortality in ICUs, and opioids are the preferred analgesic in this setting. However, the role of opioids in sepsis progression has not been well characterized. The present study demonstrated that morphine alone altered the gut microbiome and selectively induced the translocation of Gram-positive gut bacteria in mice. Using a murine model of poly-microbial sepsis, we further demonstrated that morphine treatment led to predominantly Gram-positive bacterial dissemination. Activation of TLR2 by disseminated Gram-positive bacteria induced sustained up-regulation of IL-17A and IL-6. We subsequently showed that overexpression of IL-17A compromised intestinal epithelial barrier function, sustained bacterial dissemination and elevated systemic inflammation. IL-17A neutralization protected barrier integrity and improved survival in morphine-treated animals. We further demonstrated that TLR2 expressed on both dendritic cells and T cells play essential roles in IL-17A production. Additionally, intestinal sections from sepsis patients on opioids exhibit similar disruption in gut epithelial integrity, thus establishing the clinical relevance of this study. This is the first study to provide a mechanistic insight into the opioid exacerbation of sepsis and show that neutralization of IL-17A might be an effective therapeutic strategy to manage Gram-positive sepsis in patients on an opioid regimen.

Predictors of non-use of illicit heroin in opioid injection maintenance treatment of long-term heroin dependence

AIMS

To investigate baseline and concurrent predictors of non-use of illicit heroin among participants randomized to injectable opioids in the North American Opiate Medication Initiative (NAOMI) clinical trial.

METHODS

NAOMI was an open-label randomized controlled trial comparing the effectiveness of injectable diacetylmorphine and hydromorphone for long-term opioid-dependency. Outcomes were assessed at baseline and during treatment (3, 6, 9, 12months). Days of non-use of illicit heroin in the prior month at each follow-up visit were divided into three categories: Non-use; Low use (1 to 7days) and High use (8days or more). Tested covariates were: Sociodemographics, Health, Treatment, Drug use and illegal activities. Mixed-effect proportional odds models with random intercept for longitudinal ordinal outcomes were used to assess the predictors of the non-use of illicit heroin.

RESULTS

139 participants were included in the present analysis. At each follow-up visit, those with non-use of illicit heroin represented 47.5% to 54.0% of the sample. Fewer days of cocaine use (p=0.074), fewer days engaged in illegal activities at baseline (p<0.01) and at each visit (p<0.01), less money spent on drugs (p<0.001), days with injection opioid or oral methadone treatment (p<0.001) and total mg of injectable opioids taken (p<0.001), independently predicted lower use of illicit heroin.

CONCLUSIONS

The independent effect of several concurrent factors besides the injection of opioid dose suggests benefits from the clinic that go beyond the provision of the medication alone. Thus, this supervised model of care presents an opportunity to maximize the beneficial impact of medical and psychosocial components of the treatment on improving outcomes associated with non-use of illicit heroin.

Who uses methadone services in China? Monitoring the world's largest methadone programme

AIMS

To describe the data collected by the Chinese methadone maintenance treatment (MMT) system and the characteristics of clients entering the programme.

DESIGN

Descriptive study using routinely collected data from the MMT data management system for the period March 2004 and March 2010.

SETTING

All MMT clinics in China.

PARTICIPANTS

Clients who enrolled for services between March 2004 and March 2010.

MEASUREMENTS

Routinely collected data included: demographic information; drug use, sexual and criminal behaviours; status of infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV) and syphilis; random urine-opiate test results; and the daily methadone dose received. Differences among clients by year were examined.

FINDINGS

During the period examined, there were 251,974 clients attending 684 clinics in 27 provinces. Overall, the mean age was 34.4 years, 83.8% were male, 70.2% were unemployed, 75% had ever injected drugs, 17% had shared needles and 7.4% were HIV-positive. The profile of clients changed over time, with fewer HIV-positive individuals, fewer injecting drug users, fewer needle-sharers, fewer females and fewer unemployed. Half the clients dropped out within 6 months. The average final dose received was 49.4 mg. The estimated probability of interrupting treatment before 6 months was 52.5%.

CONCLUSIONS

The profile of clients enrolling in methadone maintenance treatment in China is continually changing and appears to be associated with reduced risk of HIV. High dropout in the programme may limit its effectiveness. The availability of a centralized, real-time data system was extremely useful for monitoring the progress of the Chinese methadone maintenance treatment programme.

Association between methadone dose and concomitant cocaine use in methadone maintenance treatment: a register-based study

Background

Concomitant cocaine use is a major problem in clinical practice in methadone maintenance treatment (MMT) and may interfere with successful treatment. Data from European methadone populations is sparse. This register-based study sought to explore the association between prescribed methadone dose and concomitant cocaine and heroin use in the methadone population of Basel City.

Methods

The study included 613 methadone patients between April 1, 2003 and March 31, 2004. Anonymized data was taken from the methadone register of Basel City. For analysis of the prescribed methadone dose distribution, the patient sample was split into three methadone dosage groups: a low dose group (LDG) (n = 200; < 60 mg/day), a medium dose group (MDG) (n = 273; 60 to 100 mg/day), and a high dose group (HDG) (n = 140; > 100 mg/day). Concomitant drug use was based on self-report.

Results

Analysis showed a significant difference in self-reported cocaine use between groups (p < 0.001). Patients in the LDG reported significantly fewer cocaine consumption days compared to the MDG (p < 0.001) and the HDG (p < 0.05). Patients in the HDG reported significantly fewer heroin consumption days than those in the LDG (p < 0.01) and the MDG (p < 0.001). In logistic regression analysis, cocaine use was significantly associated with heroin use (OR 4.9).

Conclusions

Cocaine use in methadone patients may be associated with heroin use, which indicates the importance of prescribing appropriate methadone dosages in order to indirectly reduce cocaine use.

Relationship between intranasal cocaine self-administration and subject-rated effects: predictors of cocaine taking on progressive-ratio schedules

OBJECTIVE

Subject-rated measures and drug self-administration represent two of the most commonly used methods of assessing abuse potential of drugs, as well as screening intervention efficacy in the human laboratory. Although the results from these methods are often consistent, dissociations between subject-rated and self-administration data have been observed. The purpose of the present retrospective analysis was to examine the relationship between subject-rated effects and intranasal cocaine self-administration to help guide future research design and intervention assessment.

METHODS

Data were combined from two previous studies in which drug and an alternative reinforcer (i.e., money) were available on concurrent progressive-ratio schedules of reinforcement. Pearson correlation coefficients and regression model selection utilizing corrected Akaike information criterion were used to determine which subject-rated measures were associated with and best predicted cocaine self-administration.

RESULTS

Eleven subject-rated effects were positively associated with cocaine-maintained breakpoints. A combination of three of these subject ratings (i.e., Like Drug, Performance Improved, and Rush) best predicted cocaine taking.

CONCLUSIONS

The present findings suggest that, at least under certain conditions with intranasal cocaine, some, but not all, positive subject-rated effects may predict drug self-administration. These findings will be useful in guiding future examinations of putative interventions for cocaine-use disorders.

Clinical Efficacy of Acupuncture as an Adjunct to Methadone Treatment Services for Heroin Addicts: A Randomized Controlled Trial

Scant scientific evidence supports the efficacy of acupuncture in the treatment of opiate dependence. The purpose of this study was to examine the effectiveness of acupuncture for heroin addicts on methadone maintenance by measuring the daily consumption of methadone, variations in the 36-item Short Form Health Survey-36 (SF-36) and Pittsburgh Sleep Quality Index (PSQI) scores, and heroin craving. Sixty heroin addicts were randomly assigned to true acupuncture (electroacupuncture at the Hegu [LI4] and Zusanli [ST36] acupoints, as well as acupuncture at the Ear Shenmen) or sham acupuncture (minimal acupuncture at the Hegu and Zusanli acupoints without electrical stimulation and superficial acupuncture at the Ear Shenmen), twice weekly for 4 weeks. From week 2 onwards, the daily dose of methadone was reduced by a significantly greater amount with true acupuncture compared with sham acupuncture. True acupuncture was also associated with a greater improvement in sleep latency at follow-up. All adverse events were mild in severity. Acupuncture appears to be a useful adjunct to methadone maintenance therapy (MMT) in heroin addiction.

Methadone treatment for HIV prevention-feasibility, retention, and predictors of attrition in Dar es Salaam, Tanzania: a retrospective cohort study

BACKGROUND

People who inject drugs (PWID) in Dar es Salaam, Tanzania, have an estimated human immunodeficiency virus (HIV) prevalence of 42%-50% compared with 6.9% among the general population. Extensive evidence supports methadone maintenance to lower morbidity, mortality, and transmission of HIV and other infectious diseases among PWID. In 2011, the Tanzanian government launched the first publicly funded methadone clinic on the mainland of sub-Saharan Africa at Muhimbili National Hospital.

METHODS

We conducted a retrospective cohort study of methadone-naive patients enrolling into methadone maintenance treatment. Kaplan-Meier survival curves were constructed to assess retention probability. Proportional hazards regression models were used to evaluate the association of characteristics with attrition from the methadone program.

RESULTS

Overall, 629 PWID enrolled into methadone treatment during the study. At 12 months, the proportion of clients retained in care was 57% (95% confidence interval [CI], 53%-62%). Compared with those receiving a low dose (<40 mg), clients receiving a medium (40-85 mg) (adjusted hazard ratio [aHR], 0.50 [95% CI, .37-.68]) and high (>85 mg) (aHR, 0.41 [95% CI, .29-.59]) dose of methadone had a lower likelihood of attrition, adjusting for other characteristics. Older clients (aHR, 0.53 per 10 years [95% CI, .42-.69]) and female clients (aHR, 0.50 [95% CI, .28-.90]) had a significantly lower likelihood of attrition, whereas clients who reported a history of sexual abuse (aHR, 2.84 [95% CI, 1.24-6.51]) had a significantly higher likelihood of attrition.

CONCLUSIONS

Patient retention in methadone maintenance is comparable to estimates from programs in North America, Europe, and Asia. Future implementation strategies should focus on higher doses and flexible dosing strategies to optimize program retention and strengthened efforts for clients at higher risk of attrition.

Assessment of CYP450 genetic variability effect on methadone dose and tolerance

Aim: Methadone dose is related to treatment success in individuals under methadone maintenance treatment (MMT). We constructed a gene matrix using previously identified genetic polymorphisms in CYP450 and determined their genetic influence on methadone dose or tolerance. Materials & methods: The allelic combinations of CYP450 genetic variants (two from CYP2C19, four from CYP2B6 and five from CYP3A4) were analyzed in 366 MMT heroin dependent patients as possible determinants of methadone dose and tolerance using analysis of covariance. Results: Methadone dose (p = 0.007) and tolerance (p = 0.06) were mainly influenced by CYP2C19 gene dose. Moreover, dominant influence of the CYP2C19 gene dose on methadone dose and tolerance was only found among MMT patients with negative urine morphine test results, but not among those with positive results. Conclusion: The findings suggest that CYP2C19 gene dose may serve as a potential indicator for assessing methadone dose and tolerance in MMT patients.

Original submitted 5 September 2013; Revision submitted 23 January 2014

Opioid maintenance, weaning and detoxification techniques: where we have been, where we are now and what the future holds

SUMMARY Medically supervised opioid withdrawal is a complex and constantly evolving exercise in multimodal therapy that draws from the expertise of a variety of clinical specialties. Acute substitution and weaning has been performed utilizing opioid agonists, partial agonists (e.g., buprenorphine), mixed agonist/antagonists (e.g., Suboxone®), and α2 adrenergic agonists. While thousands of patients are being treated with these 'classic' opioid-withdrawal techniques, traditional treatment approaches are being challenged by the emergence of innovative techniques based on an understanding of the neurochemistry of addiction. Pharmacotherapy with controlled withdrawal is currently the most reliable method of opioid detoxification, but, as translational medicine continues to advance and genomic markers for opioid sensitivity and dependence are identified, the future shows great potential for growth and change.

The association of genetic polymorphisms in the κ-opioid receptor 1 gene with body weight, alcohol use, and withdrawal symptoms in patients with methadone maintenance

Methadone is a synthetic opioid that binds to the κ-opioid receptor with a low affinity. This study tested the hypotheses that the genetic polymorphisms in the κ-opioid receptor 1 (OPRK1) gene region are associated with methadone treatment responses in a Taiwan methadone maintenance treatment (MMT) cohort. Seventeen single nucleotide polymorphisms (SNPs) in OPRK1 were selected and genotyped on DNA of 366 MMT patients. Six SNPs from rs7843965 to rs1051660 (intron 2 to exon 2) were significantly associated with body weight (P < 0.007). A haplotype of 4 SNPs rs7832417-rs16918853-rs702764-rs7817710 (exon 4 to intron 3) was associated with bone or joint aches (P ≤ 0.004) and with the amount of alcohol use (standard drinks per day; global P < 0.0001). The haplotype rs10958350-rs7016778-rs12675595 was associated with gooseflesh skin (global P < 0.0001), yawning (global P = 0.0001), and restlessness (global P < 0.0001) withdrawal symptoms. The findings suggest that genetic polymorphisms in OPRK1 were associated with the body weight, alcohol use, and opioid withdrawal symptoms in MMT patients.

Effect of Methadone Dose on Maintenance Treatment and Health Consequences Among Heroin Addicts in South China

A retrospective cross-sectional study was conducted with a convenience sample of 197 adults receiving methadone maintenance treatment in Kunming city, South China, in 2010. The aim of the study was to determine the association of methadone maintenance dose on a variety of treatment outcomes. Treatment modalities, the adverse reactions to methadone treatment, the physical and mental outcomes of the treatment, and risk behavior changes were assessed. Multilevel negative and logistic binomial regression analyses were carried out, which demonstrated that methadone maintenance dose in this sample was not associated with improved treatment adherence or with quality of life. We concluded that dose had a small, if negligible, influence on the changes in adverse effects of methadone. Further research in dose differences between the genders should be conducted.

Preclinical efficacy of N-substituted benztropine analogs as antagonists of methamphetamine self-administration in rats

Atypical dopamine-uptake inhibitors have low abuse potential and may serve as leads for development of cocaine-abuse treatments. Among them, the benztropine (BZT) derivatives, N-butyl (JHW007), N-allyl (AHN2-005), and N-methyl (AHN1-055) analogs of 3α-[bis(4'-fluorophenyl)methoxy]-tropane dose-dependently decreased cocaine self-administration without effects on food-maintained responding. Our study examined selectivity by assessing their effects on self-administration of other drugs. As with cocaine, each BZT analog (1.0-10.0 mg/kg i.p.) dose-dependently decreased maximal self-administration of d-methamphetamine (0.01-0.32 mg/kg/infusion) but was inactive against heroin (1.0-32.0 µg/kg/infusion) and ketamine (0.032-1.0 mg/kg/infusion) self-administration. Further, standard dopamine indirect-agonists [WIN35,428 ((-)-3β-(4-fluorophenyl)-tropan-2-β-carboxylic acid methyl ester tartrate), d-amphetamine (0.1-1.0 mg/kg i.p., each)] dose-dependently left-shifted self-administration dose-effect curves for d-methamphetamine, heroin, and ketamine. Noncompetitive NMDA-glutamate receptor/channel antagonists [(+)-MK-801 (0.01-0.1 mg/kg i.p.), memantine (1.0-10.0 mg/kg i.p.)] also left-shifted dose-effect curves for d-methamphetamine and ketamine (but not heroin) self-administration. The µ-agonists [dl-methadone and morphine (1.0-10.0 mg/kg i.p., each)] dose-dependently decreased maximal self-administration of µ-agonists (heroin, remifentanil) but not d-methamphetamine or ketamine self-administration. The µ-agonist-induced decreases were similar to the effects of BZT analogs on stimulant self-administration and effects of food prefeeding on responding maintained by food reinforcement. Radioligand-binding and behavioral studies suggested that inhibition of dopamine transporters and σ receptors were critical for blocking stimulant self-administration by BZT-analogs. Thus, the present results suggest that the effects of BZT analogs on stimulant self-administration are similar to effects of µ-agonists on µ-agonist self-administration and food prefeeding on food-reinforced responding, which implicates behavioral mechanisms for these effects and further supports development of atypical dopamine uptake inhibitors as medications for stimulant abuse.

Accessibility versus quality of care plus retention: the formula for service delivery in Australian opioid replacement therapy?

The aim of this paper is to investigate how Australian Opioid Replacement Therapy (ORT) policy influences access to ORT treatment, including the resources required for implementation. In doing so, we also compare the accessibility of ORT treatment in Australia (AU) with ORT in the United Kingdom (UK) and United States (US). A review of government data and policy that influence service delivery was undertaken. When comparing across AU, the UK, and the US, we found several differences. To improve access to treatment in Australia more general practitioners need to provide ORT. Additionally, criteria for quality care, a centralised intake system, a national ORT treatment outcome measure, and a shift towards a recovery focus are recommended.

The effect of methadone maintenance on illicit opioid use, human immunodeficiency virus and hepatitis C virus infection, health status, employment, and criminal activity among heroin abusers during 6 months of treatment in china

PURPOSE

: This study was designed to evaluate the effects of methadone maintenance treatment (MMT) on severity of dependence, depression, human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection, health status, employment, and criminal activity among heroin abusers after 3 and 6 months of treatment, compared with baseline, in China.

METHODS

: A total of 102 methadone maintenance treatment (MMT) patients (87 men and 15 women; mean age, 36.1 years; standard deviation = 6.9) without major medical or psychiatric comorbidity participated in the experimental procedure. They were given oral methadone (maximum daily dose 80 mg, minimum daily dose 30 mg). Opioid use was assessed by twice-weekly urinalysis; HIV and HCV status were assessed by standard blood tests. Questionnaires were administered to assess blood-borne-virus risk behavior, severity of dependence, depression, health status, employment, and criminal activity. Changes over time were evaluated by 1-way analysis of variance (ANOVA) followed by post hoc t tests.

RESULTS

: Opioid use was reduced from 26.7 days per month at baseline to 0.7 and 0.0 days at 3 and 6 months, respectively. No participant seroconverted to HIV and HCV positivity during the 6 months of MMT. Health status significantly improved, as did severity of dependence, depression, and criminal activity, after 3 and 6 months MMT.

CONCLUSIONS

: The results support the broad beneficial effects of MMT in China.