Employment-based reinforcement of adherence to an FDA approved extended release formulation of naltrexone in opioid-dependent adults: a randomized controlled trial

Contingency Management for Drug Use Disorders: Meta-Analysis and Application of Tolin's Criteria

Several professional organizations and federal agencies recommend contingency management (CM) as an empirically supported treatment for drug use disorder. However, the release of the "Tolin criteria" warrants an updated recommendation. Using this methodology, five meta-analyses (84 studies, 11,000 participants) were reviewed. Two meta-analyses were rated moderate quality, and three were rated low or critically low quality. Comparator conditions included active treatment, placebo, treatment as usual, and no treatment. The primary outcome was abstinence. Considering only the moderate quality meta-analyses, the effect of CM versus control on posttreatment abstinence was d = 0.54 [0.43, 0.64] and follow-up abstinence was d=0.08 [0.00, 0.16]. A "strong" recommendation was provided for CM as an empirically supported treatment for drug use disorder.

A call to action: Contingency management to improve post-release treatment engagement among people with opioid use disorder who are incarcerated

People with opioid use disorder (OUD) are overrepresented in US correctional facilities and experience disproportionately high risk for illicit opioid use and overdose after release. A growing number of correctional facilities offer medication for OUD (MOUD), which is effective in reducing these risks. However, a recent evaluation found that <50% of those prescribed MOUD during incarceration continued MOUD within 30 days after release, demonstrating a need to improve post-release continuity of care. We describe available evidence on contingency management (CM), an intervention wherein patients receive incentives contingent on behavior change, to achieve this goal. A prior systematic review reported strong evidence in support of CM for increasing treatment adherence in MOUD programs, but the trials reviewed did not include incarcerated participants. Research on CM to increase treatment adherence among participants in the criminal justice system is limited with mixed findings. However, in comparison to the trials that supported CM's efficacy in the community, CM trials in the criminal justice system provided smaller rewards with greater delays in the delivery of rewards to patients, which likely contributed to null findings. Indeed, a prior meta-analysis demonstrates a dose-response relationship between the magnitude and immediacy of reward and CM effectiveness. Thus, CM involving larger and more immediately delivered rewards are likely necessary to improve MOUD adherence during the critical period following release from incarceration. Future research on the effectiveness and implementation of CM to improve MOUD retention after release from incarceration is warranted.

History and current status of contingency management programs in the Department of Veterans Affairs

OBJECTIVE

This article describes the Department of Veterans Affairs (VA) national implementation of contingency management within VA substance use disorder (SUD) treatment programs.

METHODS

The rationale for implementing CM, role of VA leadership, and training and supervision procedures are detailed. The role of the Veterans Canteen Service (VCS) in sustaining the CM implementation through the donation of incentives is outlined. Updated outcomes from the primary program, CM to incentivize stimulant abstinence, are provided. Data presented were gathered from June 2011 to January 2023, from VA facilities across the country.

RESULTS

More than 6000 Veterans from 119 VA facilities have received CM in a 12-week program in which two urine samples are obtained per week, with 92% of the samples negative for the targeted substance. Two other CM pilot projects are described. The first incentivizes adherence to injectable medications for opioid and alcohol use disorders, with over 580 veterans from 27 VA sites participating to date. The second incentivized smoking cessation in 312 patients from four sites. A new initiative in which CM is implemented in smaller community-based VA facilities through use of onsite prize cabinets is presented and the possibility of providing CM remotely in VA is discussed.

CONCLUSIONS

It has proved feasible to implement abstinence CM and several other CM pilot programs at many VA facilities. Factors that contributed to the success of the VA CM rollout, challenges that were encountered along the way, and lessons learned that may facilitate wider use of CM outside VA are discussed.

Discounting of employment opportunities with urine drug testing requirements in opioid users enrolled in the Therapeutic Workplace

BACKGROUND

The evidence-based Therapeutic Workplace (TWP) is a promising employment-based treatment where access to work is contingent on objective evidence of abstinence from drugs. TWP is sometimes criticized for requiring individuals who use drugs to voluntarily enroll in a program requiring urine drug testing.

OBJECTIVE

This experiment was conducted to assess whether urine drug testing as a condition of employment decreases the value of employment opportunities and to what degree.

METHODS

Participants were unemployed, DSM-IV opioid-dependent, and enrolled in TWP. Participants completed discounting tasks assessing preference for a hypothetical job paying a constant wage that did not require urine drug testing and a job that paid a variable wage but required drug testing. The primary outcome was 'job value' operationalized as percentage wage difference to accept a job requiring urine drug testing.

RESULTS

Percent wage difference to accept a job that required urine testing was analyzed using GEE. Results revealed a significant main effect of recent drug use (χ2(1) = 10.07, p < .01).

CONCLUSION

Most participants were willing to accept a urine drug-testing job across wages similar non-drug testing jobs. Participants reporting recent cocaine or heroin use were less likely to choose urine drug-testing employment.

Feasibility, Acceptability, and Preliminary Efficacy of a Smartphone-Based Contingency Management Intervention for Buprenorphine Adherence

Buprenorphine is an important medication for treating opioid use disorder, but medication adherence and treatment retention are key issues that can limit its impact, especially when patients have concurrent stimulant use. Contingency management is efficacious in promoting medication adherence and drug abstinence. Delivering contingency management via smartphones addresses practical barriers to its adoption and improves patient access. A single-group (n = 20) nonexperimental study was conducted to evaluate the feasibility of smartphone-based contingency management to promote adherence to buprenorphine treatment in people with opioid use disorder. Participants were recruited from outpatient treatment clinics. Over 12 weeks participants had access to a smartphone app that provided contingency management supported with peer recovery coaching. Adherence was confirmed daily either by GPS monitoring of clinic medication visits or self-recorded video, and salivary toxicology was conducted weekly. The overall rate of confirmed buprenorphine adherence was 76%, and visual inspection of individual participant outcomes shows consistent medication use for a large majority of participants. All participants were able to successfully use all app features and spend earnings. Participants rated the app and intervention highly on measures of likability, ease of use, and helpfulness. All participants (100%) were retained in buprenorphine treatment throughout the study period. Direct methods for confirming adherence appear superior to confirmation via salivary toxicology. This study shows that smartphone-based contingency management is a feasible means of promoting buprenorphine adherence. The potential efficacy of smartphone-based contingency management as a means of promoting buprenorphine adherence warrants evaluation in a randomized controlled trial.

A qualitative exploration of patients' experience of mobile telephone-delivered contingency management to promote adherence to supervised methadone

INTRODUCTION

Despite an increasing evidence base for mobile telephone-delivered contingency management (mCM), there had been no previous qualitative exploration of patients' experience of receiving mCM and the factors that might influence that experience and outcome in a UK setting. The aim of this study was to understand patients' views and experience of receiving mCM by exploring their beliefs, expectations and perceived benefits within the context of the UK's first mCM intervention.

METHODS

Qualitative interviews (N = 15) were conducted with patients undergoing opioid agonist treatment in a UK drug treatment service and receiving mCM to encourage adherence with supervised methadone as part of an existing study. Interviews were conducted at two time points and analysed using Framework to explore patients' expectations and beliefs during the early stage of the intervention (2 weeks) and their perceived benefits and experience at the end of the intervention (12 weeks).

RESULTS

The mCM was perceived as a motivator, providing validation of achievement, and involving discreet and positive interactions. Perceived benefits included enhanced methadone adherence, reduced drug use and the development of a supportive and non-judgemental connection that resembled a therapeutic alliance.

DISCUSSION AND CONCLUSIONS

The mechanisms underpinning contingency management appeared to operate in the absence of human interaction, and the mCM intervention was deemed to be meaningful, acceptable and well received by patients. These findings not only provide support for the application of mCM in this context but also offer insight into the factors that influence outcomes and should be considered in the development of future mCM interventions.

Patients' experiences of continued treatment with extended-release naltrexone: a Norwegian qualitative study

Background

The opioid antagonist extended-release naltrexone (XR-NTX) in the treatment of opioid use disorder (OUD) is effective in terms of safety, abstinence from opioid use and retention in treatment. However, it is unclear how patients experience and adjust to losing the possibility of achieving an opioid effect. This qualitative study is the first to explore how people with opioid dependence experience XR-NTX treatment, focusing on the process of treatment over time.

Methods

Using a purposive sampling strategy, semi-structured interviews were undertaken with 19 persons with opioid use disorder (15 men, four women, 22–55 years of age) participating in a clinical trial of XR-NTX in Norway. The interviewees had received at least three XR-NTX injections. Qualitative content analysis with an inductive approach was used.

Findings

Participants described that XR-NTX treatment had many advantages. However they still faced multiple challenges, some of which they were not prepared for. Having to find a new foothold and adapt to no longer gaining an effect from opioids due to the antagonist medication was challenging. This was especially true for those struggling emotionally and transitioning into the harmful use of non-opioid substances. Additional support was considered crucial. Even so, the treatment led to an opportunity to participate in society and reclaim identity. Participants had strong goals for the future and described that XR-NTX enabled a more meaningful life. Expectations of a better life could however turn into broken hopes. Although participants were largely optimistic about the future, thinking about the end of treatment could cause apprehension.

Conclusions

XR-NTX treatment offers freedom from opioids and can facilitate the recovery process for people with OUD. However, our findings also highlight several challenges associated with XR-NTX treatment, emphasizing the importance of monitoring emotional difficulties and increase of non-opioid substances during treatment. As opioid abstinence in itself does not necessarily equal recovery, our findings underscore the importance of seeing XR-NTX as part of a comprehensive, individualized treatment approach.

Trial registration: Clinicaltrials.gov # NCT03647774, first Registered: Aug 28, 2018.

Examining differences in retention on medication for opioid use disorder: An analysis of Ohio Medicaid data

BACKGROUND

Medications for opioid use disorder (MOUDs), including methadone, buprenorphine and naltrexone, are associated with lower death rates and improved quality of life for people in recovery from opioid use disorder (OUD). Less is known about each MOUD modality's association with treatment retention and the contribution of behavioral health therapy (BHT). The objectives of the current study were to estimate the association between MOUD type and treatment retention and determine whether BHT was associated with length of time retained.

METHODS

We investigated the time from initiation to discontinuation from MOUD by medication type and exposure to BHT using statewide Medicaid Claims data (N = 81,752). We estimated covariate adjusted hazard ratios (AHR) using a Cox proportional hazards model.

RESULTS

Compared to methadone, buprenorphine was associated with a higher risk of discontinuation at the time of initiation (AHR = 2.41, 95% CI = 2.28-2.55), however that difference decreased over one year of maintained retention (AHR = 1.44, 95% CI = 1.37-1.50). Compared to methadone and buprenorphine, naltrexone was associated with a higher risk of discontinuation at the time of initiation (naltrexone vs. methadone AHR = 2.49, 95% CI = 2.30-2.65; naltrexone vs. buprenorphine AHR 1.03, 95% CI = 1.00-1.07), and that relative risk increased over the course of one year of retention (naltrexone vs. methadone AHR = 3.85, 95% CI = 3.63-4.09; naltrexone vs. buprenorphine AHR = 2.67, 95% CI = 2.54-2.81). In general, independent of MOUD type, exposure to BHT during MOUD treatment was associated with a lower risk of discontinuation (AHR = 0.94, 95% CI = 0.92-0.96). However, BHT during the treatment episode was not associated with retention in the adolescent/young adult and pregnant women subpopulations.

DISCUSSION

From the standpoint of early success, methadone was associated with the lowest risk of treatment discontinuation. While buprenorphine and naltrexone were associated with similar risks at the beginning of treatment, the relative discontinuation risk for buprenorphine was less than half that of naltrexone at one year of retention. In general, BHT with MOUD was associated with a lower risk of treatment discontinuation.

Contingency Management for Patients Receiving Medication for Opioid Use Disorder: A Systematic Review and Meta-analysis

Importance

Medication treatment for opioid use disorder (MOUD) is efficacious, but comorbid stimulant use and other behavioral health problems often undermine efficacy.

Objective

To examine the association of contingency management, a behavioral intervention wherein patients receive material incentives contingent on objectively verified behavior change, with end-of-treatment outcomes for these comorbid behavioral problems.

Data Sources

A systematic search of PubMed, Cochrane CENTRAL, Web of Science, and reference sections of articles from inception through May 5, 2020. The following search terms were used: vouchers OR contingency management OR financial incentives.

Study Selection

Prospective experimental studies of monetary-based contingency management among participants receiving MOUD.

Data Extraction and Synthesis

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline, 3 independent investigators extracted data from included studies for a random-effects meta-analysis.

Main Outcomes and Measures

Primary outcome was the association of contingency management at end-of-treatment assessments with 6 clinical problems: stimulant use, polysubstance use, illicit opioid use, cigarette smoking, therapy attendance, and medication adherence. Random-effects meta-analysis models were used to compute weighted mean effect size estimates (Cohen d) and corresponding 95% CIs separately for each clinical problem and collapsing across the 3 categories assessing abstinence and the 2 assessing treatment adherence outcomes.

Results

The search identified 1443 reports of which 74 reports involving 10 444 unique adult participants met inclusion criteria for narrative review and 60 for inclusion in meta-analyses. Contingency management was associated with end-of-treatment outcomes for all 6 problems examined separately, with mean effect sizes for 4 of 6 in the medium-large range (stimulants, Cohen d = 0.70 [95% CI, 0.49-0.92]; cigarette use, Cohen d = 0.78 [95% CI, 0.43-1.14]; illicit opioid use, Cohen d = 0.58 [95% CI, 0.30-0.86]; medication adherence, Cohen d = 0.75 [95% CI, 0.30-1.21]), and 2 in the small-medium range (polysubstance use, Cohen d = 0.46 [95% CI, 0.30-0.62]; therapy attendance, d = 0.43 [95% CI, 0.22-0.65]). Collapsing across abstinence and adherence categories, contingency management was associated with medium effect sizes for abstinence (Cohen d = 0.58; 95% CI, 0.47-0.69) and treatment adherence (Cohen d = 0.62; 95% CI, 0.40-0.84) compared with controls.

Conclusions and Relevance

These results provide evidence supporting the use of contingency management in addressing key clinical problems among patients receiving MOUD, including the ongoing epidemic of comorbid psychomotor stimulant misuse. Policies facilitating integration of contingency management into community MOUD services are sorely needed.

Cost-effectiveness of Treatments for Opioid Use Disorder

IMPORTANCE

Opioid use disorder (OUD) is a significant cause of morbidity and mortality in the US, yet many individuals with OUD do not receive treatment.

OBJECTIVE

To assess the cost-effectiveness of OUD treatments and association of these treatments with outcomes in the US.

DESIGN AND SETTING

This model-based cost-effectiveness analysis included a US population with OUD.

INTERVENTIONS

Medication-assisted treatment (MAT) with buprenorphine, methadone, or injectable extended-release naltrexone; psychotherapy (beyond standard counseling); overdose education and naloxone distribution (OEND); and contingency management (CM).

MAIN OUTCOMES AND MEASURES

Fatal and nonfatal overdoses and deaths throughout 5 years, discounted lifetime quality-adjusted life-years (QALYs), and costs.

RESULTS

In the base case, in the absence of treatment, 42 717 overdoses (4132 fatal, 38 585 nonfatal) and 12 660 deaths were estimated to occur in a cohort of 100 000 patients over 5 years, and 11.58 discounted lifetime QALYs were estimated to be experienced per person. An estimated reduction in overdoses was associated with MAT with methadone (10.7%), MAT with buprenorphine or naltrexone (22.0%), and when combined with CM and psychotherapy (range, 21.0%-31.4%). Estimated deceased deaths were associated with MAT with methadone (6%), MAT with buprenorphine or naltrexone (13.9%), and when combined with CM, OEND, and psychotherapy (16.9%). MAT yielded discounted gains of 1.02 to 1.07 QALYs per person. Including only health care sector costs, methadone cost $16 000/QALY gained compared with no treatment, followed by methadone with OEND ($22 000/QALY gained), then by buprenorphine with OEND and CM ($42 000/QALY gained), and then by buprenorphine with OEND, CM, and psychotherapy ($250 000/QALY gained). MAT with naltrexone was dominated by other treatment alternatives. When criminal justice costs were included, all forms of MAT (with buprenorphine, methadone, and naltrexone) were associated with cost savings compared with no treatment, yielding savings of $25 000 to $105 000 in lifetime costs per person. The largest cost savings were associated with methadone plus CM. Results were qualitatively unchanged over a wide range of sensitivity analyses. An analysis using demographic and cost data for Veterans Health Administration patients yielded similar findings.

CONCLUSIONS AND RELEVANCE

In this cost-effectiveness analysis, expanded access to MAT, combined with OEND and CM, was associated with cost-saving reductions in morbidity and mortality from OUD. Lack of widespread MAT availability limits access to a cost-saving medical intervention that reduces morbidity and mortality from OUD. Opioid overdoses in the US likely reached a record high in 2020 because of COVID-19 increasing substance use, exacerbating stress and social isolation, and interfering with opioid treatment. It is essential to understand the cost-effectiveness of alternative forms of MAT to treat OUD.

Patients' beliefs towards contingency management: Target behaviours, incentives and the remote application of these interventions

INTRODUCTION

Contingency management interventions are among the most efficacious psychosocial interventions in promoting abstinence from smoking, alcohol and substance use. The aim of this study was to assess the beliefs and objections towards contingency management among patients in UK-based drug and alcohol services to help understand barriers to uptake and support the development and implementation of these interventions.

METHODS

The Service User Survey of Incentives was developed and implemented among patients (N = 181) at three UK-based drug and alcohol treatment services. Descriptive analyses were conducted to ascertain positive and negative beliefs about contingency management, acceptability of different target behaviours, incentives and delivery mechanisms including delivering incentives remotely using technology devices such as mobile telephones.

RESULTS

Overall, 81% of participants were in favour of incentive programs, with more than 70% of respondents agreeing with the majority of positive belief statements. With the exception of two survey items, less than a third of participants agreed with negative belief statements. The proportion of participants indicating a neutral response was higher for negative statements (27%) indicating greater levels of ambiguity towards objections and concerns regarding contingency management.

DISCUSSION AND CONCLUSIONS

Positive beliefs towards contingency management interventions were found, including high levels of acceptability towards a range of target behaviours, incentives and the use of technology devices to remotely monitor behaviour and deliver incentives. These findings have implications for the development and implementation of remote contingency management interventions within the UK drug treatment services.

Substances detected in used syringes of injecting drug users across 7 cities in Europe in 2017 and 2018: The European Syringe Collection and Analysis Project Enterprise (ESCAPE)

BACKGROUND AND AIMS

Injecting drug use is a matter of public health concern, associated with risks of overdoses, addiction and increased risk of bloodborne viral transmissions. Self-reported data on substances injected can be inaccurate or subject to bias or drug users might be oblivious to their injected substances or adulterations. Gathering of robust analytical information on the actual composition of substances injected might provide better information about the drugs that are being used. Therefore, this study aimed to analyse the residual content of discarded syringes collected across 7 European cities, collectively called the European Syringe Collection and Analysis Project Enterprise (ESCAPE).

METHODS

Used syringes were collected at street automatic injection kit dispensers or at harm-reduction services in Amsterdam, Budapest, Cologne, Glasgow, Helsinki, Lausanne and Paris. Two sampling periods were executed thus far, in 2017 and 2018. Qualitative chemical analysis of the content of used syringes was performed combining gas chromatographic (GC) and ultra(high)performance liquid chromatographic ((U)HPLC) analytical techniques with detection by mass spectrometry (MS).

RESULTS

Substances detected most frequently across both campaigns were cocaine, heroin, buprenorphine, amphetamines and synthetic cathinones. In Amsterdam, Cologne, Lausanne and Glasgow heroin and cocaine were the psychoactive substances most often detected, often in conjunction with each other. Helsinki showed a high presence of buprenorphine and amphetamines. In Budapest and Paris, synthetic cathinones were frequently detected. Less synthetic cathinones and cocaine was detected in 2018, whereas buprenorphine was detected almost twice as much. Inner-city variations were found, probably reflecting the types of people who inject drugs (PWID) in different areas of the city.

CONCLUSION

Overall, laboratory-confirmed local data on injected substances showed resemblance to national surveys done among PWID. However, the ESCAPE data also showed some interesting differences, showing it can be used for local interventions and complementing existing monitoring data.

Effect of the morphine/heroin vaccine on opioid and non-opioid drug-induced antinociception in mice

Pain is a common symptom in patients with opioid use disorder (OUD), which increases synthetic and illicit synthetic opioid abuse and even fatalities due to opioid overdose. Many FDA-approved drugs are available for the treatment of OUD, however, the use of these medications is limited, mainly due to the development of various side effects. Active vaccination is a new therapeutic approach but the resulting antibodies may compromise the use and efficiency of opioid and non-opioid drugs. In this study, we evaluated whether the antibodies produced by the morphine/heroin vaccine (M-TT) would alter the antinociceptive effects of opioid and non-opioid drugs. Female Balb-c mice were immunized with the M-TT vaccine. A solid-phase antibody-capture ELISA was used for monitoring antibody titer responses after each booster dose in vaccinated animals, followed by tail-flick testing. This study found that the M-TT vaccine did not affect the antinociception induced by different doses of morphine or the ability of non-opioid and synthetic opioid drugs to decrease thermal pain. Moreover, the combination of vaccination and naloxone increased the time-course of morphine antagonism relative to either vaccination or naloxone alone. These results suggest that the antibody titers generated by the M-TT vaccine 1) are capable of reducing morphine-induced antinociception and 2) are selective enough not to alter antinociception induced by non-opioid or synthetic drugs. These characteristics support its potential as a treatment agent for patients with symptoms of pain comorbid to OUD.

Monitoring and Improving Naltrexone Adherence in Patients with Substance Use Disorder

OBJECTIVE

Naltrexone is an opioid antagonist used for the treatment of patients with opioid use disorder and alcohol use disorder. This population often presents problems of follow-up and therapeutic efficacy related to adherence to treatment. The purpose of our study is to provide an exhaustive summary of the current evidence regarding naltrexone adherence in people with substance use disorders and to identify possible variables that may influence adherence to naltrexone.

METHODS

Two searches were performed in bibliographic databases (PubMed, Embase), and studies included in the systematic review were those published from January 1, 2011 to September 2020, with participants over 18 years of age, evaluating treatment with naltrexone in alcohol use disorder and opioid use disorder. From the total of 133 articles initially selected, 36 were included and analyzed in the systematic review.

RESULTS

Naltrexone has not demonstrated superiority over other available treatments in terms of adherence and abstinence, although reinforcement systems have obtained favorable results as an additional strategy to improve adherence.

CONCLUSION

It is necessary to study other psychosocial variables involved in improving adherence, in addition to taking patient preferences into account in order to improve the external validity of the results.

Retention Strategies for Medications for Opioid Use Disorder in Adults: A Rapid Evidence Review

OBJECTIVES

Although medications for opioid use disorder (MOUD) save lives, treatment retention remains challenging. Identification of interventions to improve MOUD retention is of interest to policymakers and researchers. On behalf of the Agency for Healthcare Research and Quality, we conducted a rapid evidence review on interventions to improve MOUD retention.

METHODS

We searched MEDLINE and the Cochrane Library from February 2009 through August 2019 for systematic reviews and randomized trials of care settings, services, logistical support, contingency management, health information technology (IT), extended-release (XR) formulations, and psychosocial interventions that assessed retention at least 3 months.

RESULTS

Two systematic reviews and 39 primary studies were included; most did not focus on retention as the primary outcome. Initiating MOUD in soon-to-be-released incarcerated people improved retention following release. Contingency management may improve retention using antagonist but not agonist MOUD. Retention with interventions integrating medical, psychiatric, social services, or IT did not differ from in-person treatment-as-usual approaches. Retention was comparable with XR- compared to daily buprenorphine formulations and conflicting with XR-naltrexone monthly injection compared to daily buprenorphine. Most psychosocial interventions did not improve retention.

DISCUSSION

Consistent but sparse evidence supports criminal justice prerelease MOUD initiation, and contingency management interventions for antagonist MOUD. Integrating MOUD with medical, psychiatric, social services, delivering through IT, or administering via XR-MOUD formulations did not worsen retention. Fewer than half of the studies we identified focused on retention as a primary outcome. Studies used different measures of retention, making it difficult to compare effectiveness. Additional inquiry into the causes of low retention would inform future interventions.Registration: PROSPERO: CRD42019134739.

Adapting treatment length to opioid-dependent individuals' needs and preferences: A 2-year follow-up to a 1-year study of extended-release naltrexone

BACKGROUND AND AIM

Extended-release naltrexone (XR-NTX) is an underused treatment option for opioid dependence, today only available in a few countries in the world. Although effective, safe and feasible in short-term treatment, long-term data are scarce and there is no recommendation for required treatment length. The aims of the study were to determine the perceived need of long-term XR-NTX treatment and to examine long-term treatment outcomes.

DESIGN

In this prospective cohort study, following a parent 1-year study of XR-NTX, participants received treatment with XR-NTX at their own discretion for a maximum of 104 weeks.

SETTING

Five urban, outpatient addiction clinics in Norway.

PARTICIPANTS

Opioid-dependent adults 18-60 years old (n=50) already participating in the parent study.

INTERVENTION

XR-NTX administrated as intra-muscular injections (380 mg) every 4 weeks.

MEASUREMENTS

Time in the study, use of opioids and other illicit substances, opioid craving, and treatment satisfaction reported every 4 weeks.

FINDINGS

Among 58 participants who completed the 1-year parent study, 50 chose to continue the treatment with XR-NTX. Median prolonged treatment time was 44.0 weeks (95% CI: 25.5-62.5), ranging from 8 to 104 weeks. Most participants (35, 70%) reported no relapse to opioid use during treatment while a subgroup (15, 30%) reported relapses to opioids during the study. Scores for mean treatment satisfaction and recommending treatment to others were very high (>9) and mean opioid craving score was very low (<1) on a scale ranging from 0 to 10.

CONCLUSIONS

Extended-release naltrexone (XR-NTX) was well tolerated in long-term treatment of opioid dependent individuals in Norway already in XR-NTX treatment. On average, the participants chose to continue treatment for almost 1 year beyond the initial 9 to 12 months of treatment. Participants reported high treatment satisfaction and 70% showed no relapse to opioids during the treatment period.

Behavior-Analytic Approaches to the Management of Diabetes Mellitus: Current Status and Future Directions

Diabetes mellitus is the seventh leading cause of death in the United States, requiring a series of complex behavior changes that must be sustained for a lifetime (e.g., counting carbohydrates, self-monitoring blood glucose, adjusting insulin). Although complex, all of these tasks involve behavior, making them amenable targets for behavior analysts. In this article, the authors describe interventions that have focused on antecedent, consequent, multicomponent, and alternate procedures for the management of diabetes, highlighting ways in which technology has been used to overcome common barriers to the use of these intensive, evidence-based interventions. Additional variables relevant to poorly managed diabetes (e.g., delay discounting) are also discussed. Future research and practice should focus on harnessing continued advances in information technology while also considering underexplored behavioral technologies for the effective treatment of diabetes, with a focus on identifying sustainable, long-term solutions for maintaining proper diabetes management. Practical implementation of these interventions will depend on having qualified behavior analysts working in integrated primary care settings where the interventions are most likely to be used, which will require interdisciplinary training and collaboration.

Misalignment of Stakeholder Incentives in the Opioid Crisis

The current opioid epidemic has killed more than 446,000 Americans over the past two decades. Despite the magnitude of the crisis, little is known to what degree the misalignment of incentives among stakeholders due to competing interests has contributed to the current situation. In this study, we explore evidence in the literature for the working hypothesis that misalignment rooted in the cost, quality, or access to care can be a significant contributor to the opioid epidemic. The review identified several problems that can contribute to incentive misalignment by compromising the triple aims (cost, quality, and access) in this epidemic. Some of these issues include the inefficacy of conventional payment mechanisms in providing incentives for providers, practice guidelines in pain management that are not easily implementable across different medical specialties, barriers in adopting multi-modal pain management strategies, low capacity of providers/treatments to address opioid/substance use disorders, the complexity of addressing the co-occurrence of chronic pain and opioid use disorders, and patients' non-adherence to opioid substitution treatments. In discussing these issues, we also shed light on factors that can facilitate the alignment of incentives among stakeholders to effectively address the current crisis.

Combining a Candidate Vaccine for Opioid Use Disorders with Extended-Release Naltrexone Increases Protection against Oxycodone-Induced Behavioral Effects and Toxicity

Opioid use disorders (OUDs) and opioid-related fatal overdoses are a significant public health concern in the United States and worldwide. To offer more effective medical interventions to treat or prevent OUD, antiopioid vaccines are in development that reduce the distribution of the targeted opioids to brain and subsequently reduce the associated behavioral and toxic effects. It is of critical importance that antiopioid vaccines do not interfere with medications that treat OUD. Hence, this study tested the preclinical proof of concept of combining a candidate oxycodone vaccine [oxycodone-keyhole limpet hemocyanin (OXY-KLH)] with an FDA-approved extended-release naltrexone (XR-NTX) depot formulation in rats. The effects of XR-NTX on oxycodone-induced motor activity and antinociception were first assessed in nonvaccinated naïve rats to establish a baseline for subsequent studies. Next, OXY-KLH and XR-NTX were coadministered to determine whether the combination would affect the efficacy of each individual treatment, and it was found that the combination of OXY-KLH and XR-NTX offered greater efficacy in reducing oxycodone-induced motor activity, thigmotaxis, antinociception, and respiratory depression over a range of repeated or escalating oxycodone doses in rats. These data support the feasibility of combining antibody-based therapies with opioid receptor antagonists to provide greater or prolonged protection against opioid-related toxicity or overdose. Combining antiopioid vaccines with XR-NTX may provide prophylactic measures to subjects at risk of relapse and accidental or deliberate exposure. Combination therapy may extend to other biologics (e.g., monoclonal antibodies) and medications against substance use disorders. SIGNIFICANCE STATEMENT: Opioid use disorders (OUDs) remain a major problem worldwide, and new therapies are needed. This study reports on the combination of an oxycodone vaccine [oxycodone-keyhole limpet hemocyanin (OXY-KLH)] with a currently approved OUD therapy, extended-release naltrexone (XR-NTX). Results demonstrated that XR-NTX did not interfere with OXY-KLH efficacy, and combination of low doses of XR-NTX with vaccine was more effective than each individual treatment alone to reduce behavioral and toxic effects of oxycodone, suggesting that combining OXY-KLH with XR-NTX may improve OUD outcomes.

Effects of lorcaserin on oxycodone self-administration and subjective responses in participants with opioid use disorder

BACKGROUND

Lorcaserin, a high-affinity 5-HT_2C receptor agonist approved for treating obesity, decreased self-administration of oxycodone and cue-induced reinstatement of drug-seeking behavior in preclinical studies. The current investigation is the first clinical trial to evaluate the ability of lorcaserin to alter the reinforcing and subjective effects of oxycodone.

METHODS

In this 7-week inpatient trial, 12 non-treatment-seeking volunteers (11 males) with moderate-to-severe opioid use disorder were detoxified from opioids. In a randomized cross-over fashion, participants were first stabilized on lorcaserin (10 mg BID) or placebo (0 mg BID). Participants underwent a two-week testing period during which the reinforcing and subjective effects of intranasal oxycodone were examined in verbal choice, cue-exposure, and progressive-ratio choice sessions. The two testing weeks were identical with the exception that during the first week, active oxycodone (10 mg) was available during verbal choice (self-administration) sessions, and during the second week placebo oxycodone was available. Subsequently, participants were stabilized on the other medication condition (placebo or lorcaserin) and underwent the same testing procedures again.

RESULTS

Lorcaserin did not alter oxycodone self-administration. However, lorcaserin had a trend to increase "wanting heroin" when oxycodone was available, and to accentuate oxycodone-induced miosis.

CONCLUSION

Under the current experimental conditions, lorcaserin at a dose of 10 mg BID did not reliably decrease the abuse liability of oxycodone, even though the study was sufficiently powered (≥80 %) to detect clinically meaningful differences in the main outcome variables between the placebo and active lorcaserin condition. Future research could explore a wider dose range of lorcaserin and oxycodone.

The Utility of Operant Conditioning to Address Poverty and Drug Addiction

Poverty is associated with poor health. This article reviews research on proximal and distal operant interventions to address drug addiction and poverty. Proximal interventions promote health behaviors directly. Abstinence reinforcement, a common proximal intervention for the treatment of drug addiction, can be effective. Manipulating familiar parameters of operant conditioning can improve the effectiveness of abstinence reinforcement. Increasing reinforcement magnitude can increase the proportion of individuals that respond to abstinence reinforcement, arranging long-term exposure to abstinence reinforcement can prevent relapse, and arranging abstinence reinforcement sequentially across drugs can promote abstinence from multiple drugs. Distal interventions reduce risk factors that underlie poor health and may have an indirect beneficial effect on health. In the case of poverty, distal interventions seek to move people out of poverty. The therapeutic workplace includes both proximal and distal interventions to treat drug addiction and poverty. In the therapeutic workplace, participants earn stipends or wages to work. The therapeutic workplace uses employment-based reinforcement in which participants are required to provide drug-free urine samples or take scheduled doses of addiction medications to work and/or maintain maximum pay. The therapeutic workplace has two phases, a training and an employment phase. Special contingencies appear required to promote skill development during the training phase, employment-based reinforcement can promote abstinence from heroin and cocaine and adherence to naltrexone, and the therapeutic workplace can increase employment. Behavior analysts are well-suited to address both poverty and drug addiction using operant interventions like the therapeutic workplace.

The effects of extended-release injectable naltrexone and incentives for opiate abstinence in heroin-dependent adults in a model therapeutic workplace: A randomized trial

AIM

To determine whether extended-release injectable naltrexone (XR-NTX), incentives for opiate abstinence, and their combination reduce opiate use compared to a usual care control and whether the combination reduces opiate use compared to either treatment alone.

DESIGN

Randomized 2 × 2 single-site controlled trial conducted from November 2012 through May 2016. After a detoxification and oral naltrexone induction, participants were assigned to a Usual Care, Abstinence Incentives, XR-NTX, or XR-NTX plus Abstinence Incentives group for a six-month intervention period.

SETTING

A model therapeutic workplace where participants could work on automated computer programs that targeted job-skills training for 4 h every weekday for 24 weeks and earn about $10 per hour.

PARTICIPANTS

84 heroin-dependent adults who were unemployed and medically approved for naltrexone. Most participants were male (71.4%), African American (80.1%), and cocaine dependent (71.4%).

MEASUREMENTS

The primary outcome measure was the percentage of urine samples negative for opiates that were collected at once weekly assessments (24 per participant) that were not part of the intervention and for which participants were paid $10 for completing.

INTERVENTION

Participants who attended the workplace provided thrice-weekly urine samples. Abstinence Incentives participants had to provide opiate-free urine samples to maintain maximum pay. XR-NTX participants received one injection every 4 weeks and were required to take injections in order to work and to maintain maximum pay. Usual Care participants were not offered XR-NTX and opiate urinalysis results did not affect pay.

FINDINGS

A large percentage (65 of 149; 43.6%) of individuals failed the induction protocol required for randomization and to be eligible to receive XR-NTX. When missing urine samples were considered positive, there was no significant interaction between XR-NTX and Abstinence Incentives. XR-NTX plus Abstinence Incentives participants provided significantly more opiate-negative samples (81.3%, SD 39.0%) than XR-NTX participants (64.5%, SD 47.9%; aOR 10.4, 95% CI 1.3-85.5; P = .030). When urine samples were not replaced, there was a significant interaction between XR-NTX and Abstinence Incentives (aOR 77.0, 95% CI 1.3-4432;P = 0.036); XR-NTX plus Abstinence Incentives participants provided significantly more opiate-negative samples (99.6%, SD 0.1%) than XR-NTX participants (85.0%, SD 35.7%; aOR 147.6, 95% CI 6.3-3472; P = 0.002), Abstinence Incentives participants (91.9%, SD 27.3%; aOR 121.7, 95% CI 4.8-3067; P =0.004), and Usual Care participants (78.7%, SD 41.0%; aOR 233.4, 95% CI 9.4-5814; P <.001). No other group differences were significant.

CONCLUSION

XR-NTX plus incentives for opiate abstinence increased opiate abstinence, but XR-NTX alone did not. XR-NTX can promote opiate abstinence when it is combined with incentives for opiate abstinence in a model therapeutic workplace.

Pharmacological and Behavioral Treatment of Opioid Use Disorder

Objective:

Opioid use disorder (OUD) in the United States has surged, with an estimated 2.5 million needing treatment. The aim of this article is to provide a clinical overview of the key pharmacological and behavioral treatments for OUD.

Methods:

A nonsystematic review of the literature was conducted to investigate OUD treatments, including their mechanism of action, efficacy, clinical guidelines in the United States, and consideration of frequently occurring comorbid conditions.

Results:

Food and Drug Administration (FDA)–approved pharmacotherapies for OUD include methadone, buprenorphine, and naltrexone, each of which has different actions on opioid receptors. Although these medications all show efficacy in some dosages and formulations, barriers to accessibility may be most pronounced for methadone, whereas treatment retention poses greater challenges for naltrexone and, to a lesser extent, buprenorphine. Lofexidine, an α₂‐adrenergic agonist, has recently been approved by the FDA for treatment of opioid withdrawal symptoms. OUD is commonly treated with medication‐assisted treatment (MAT), which offers pharmacotherapy in the context of counseling and/or behavioral treatments. Behavioral therapies, rarely offered as stand‐alone treatments for OUD, are generally used in the context of MAT, in structured settings or to prevent relapse after detoxification and stabilization. The aim of behavioral interventions is to improve medication compliance and target problems not addressed with medication alone. Individuals with OUD commonly have other comorbid psychiatric and substance use conditions, which are not exclusionary for initiating MAT but should be carefully evaluated and monitored because they may reduce treatment effectiveness.

Conclusions:

MAT is the first‐line treatment for patients with OUD and should be provided in combination with behavioral interventions. Treatment retention remains challenging in this population. Future studies should focus on approaches that will serve the complex needs of patients with OUD, including those with comorbid psychiatric and substance use conditions.

Behavior analysts in the war on poverty: Developing an operant antipoverty program

Poverty is associated with poor health and affects many United States residents. The therapeutic workplace, an operant intervention designed to treat unemployed adults with histories of drug addiction, could form the basis for an effective antipoverty program. Under the therapeutic workplace, participants receive pay for work. To promote drug abstinence or medication adherence, participants must provide drug-free urine samples or take scheduled doses of medication, respectively, to maintain maximum pay. Therapeutic workplace participants receive job-skills training in Phase 1 and perform income-producing jobs in Phase 2. Many unemployed, drug-addicted adults lack skills they would need to obtain high-skilled and high-paying jobs. Many of these individuals attend therapeutic workplace training reliably, but only when offered stipends for attendance. They also work on training programs reliably, but only when they earn stipends for performance on training programs. A therapeutic workplace social business can promote employment, although special contingencies may be needed to ensure that participants are punctual and work entire work shifts, and social businesses do not reliably promote community employment. Therapeutic workplace participants work with an employment specialist to seek community employment, but primarily when they earn financial incentives. Reducing poverty is more challenging than promoting employment, because it requires promoting employment in higher paying, full-time and steady jobs. Although a daunting challenge, promoting the type of employment needed to reduce poverty is an important goal, both because of the obvious benefit in reducing poverty itself and in the potential secondary benefit of reducing poverty-related health disparities. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Accounting for the uncounted: Physical and affective distress in individuals dropping out of oral naltrexone treatment for opioid use disorder

BACKGROUND

The theoretical benefits of naltrexone as a treatment for opioid use disorder (e.g., safety, non-addictive, low risk of diversion) stand in sharp contrast to its disappointing record on retention in most samples. The relationship of uncomfortable physical and dysphoric symptoms to retention on naltrexone is a controversial and under-studied issue.

METHODS

Using data from a randomized controlled trial of voucher-based contingency management and support from a significant other to enhance retention on oral naltrexone, we compared self-reported somatic and dysphoric symptoms, measured weekly, for individuals who were retained on naltrexone through the 12-week trial (n = 50) versus those who dropped out (n = 70).

RESULTS

There were no differences between participants who completed treatment and those who dropped out on multiple baseline characteristics, including somatic or affective symptoms prior to treatment. However, whether analyzed cross-sectionally or over time, participants who dropped out consistently reported higher rates of somatic symptoms, particularly difficulty sleeping, as well as affective symptoms, including multiple indicators of depression, anxiety, and anhedonia.

CONCLUSIONS

Although the smaller group of participants who were retained on oral naltrexone for 12 weeks reported decreasing physical and affective discomfort over time, there was substantial evidence that those who dropped out experienced continued and significant levels of distress. Individuals who report physical or affective distress while taking naltrexone may be at higher risk of dropout.

Effectiveness, safety and feasibility of extended-release naltrexone for opioid dependence: a 9-month follow-up to a 3-month randomized trial

BACKGROUND AND AIM

This is a follow-up study of a previously published randomized clinical trial conducted in Norway that compared extended-release naltrexone (XR-NTX) to buprenorphine-naloxone (BP-NLX) over 3 months. At the conclusion of the trial, participants were offered their choice of study medication for an additional 9 months. While BP-NLX was available at no cost through opioid maintenance treatment programmes, XR-NTX was available only through study participation, accounting for why almost all participants chose XR-NTX in the follow-up. The aim of this follow-up study was to compare differences in outcome between adults with opioid dependence continuing XR-NTX and those inducted on XR-NTX for a 9-month period, on measures of effectiveness, safety and feasibility.

DESIGN

In this prospective cohort study, participants were either continuing XR-NTX, changed from BP-NLX to XR-NTX or re-included into the study and inducted on XR-NTX treatment.

SETTING

Five urban, out-patient addiction clinics in Norway.

PARTICIPANTS

Opioid-dependent adults continuing (n = 54) or inducted on (n = 63) XR-NTX.

INTERVENTION

XR-NTX administrated as intramuscular injections (380 mg) every fourth week.

MEASUREMENTS

Data on retention, use of heroin and other illicit substances, opioid craving, treatment satisfaction, addiction-related problems and adverse events were reported every fourth week.

FINDINGS

Nine-month follow-up completion rates were 51.9% among participants continuing XR-NTX in the follow-up and 47.6% among those inducted on XR-NTX. Opioid abstinence rates were, respectively, 53.7 and 44.4%. No significant group differences were found in use of heroin and other opioids.

CONCLUSIONS

Opioid-dependent individuals who elect to switch from buprenorphine-naltrexone treatment after 3 months to extended-release naltrexone treatment for 9 months appear to experience similar treatment completion and abstinence rates and similar adverse event profiles to individuals who had been on extended-release naltrexone from the start of treatment.

Extended-release injectable naltrexone for opioid use disorder: a systematic review

AIMS

To review systematically the published literature on extended-release naltrexone (XR-NTX, Vivitrol^® ), marketed as a once-per-month injection product to treat opioid use disorder. We addressed the following questions: (1) how successful is induction on XR-NTX; (2) what are adherence rates to XR-NTX; and (3) does XR-NTX decrease opioid use? Factors associated with these outcomes as well as overdose rates were examined.

METHODS

We searched PubMed and used Google Scholar for forward citation searches of peer-reviewed papers from January 2006 to June 2017. Studies that included individuals seeking treatment for opioid use disorder who were offered XR-NTX were included.

RESULTS

We identified and included 34 studies. Pooled estimates showed that XR-NTX induction success was lower in studies that included individuals that required opioid detoxification [62.6%, 95% confidence interval (CI) = 54.5-70.0%] compared with studies that included individuals already detoxified from opioids (85.0%, 95% CI = 78.0-90.1%); 44.2% (95% CI = 33.1-55.9%) of individuals took all scheduled injections of XR-NTX, which were usually six or fewer. Adherence was higher in prospective investigational studies (i.e. studies conducted in a research context according to a study protocol) compared to retrospective studies of medical records taken from routine care (6-month rates: 46.7%, 95% CI = 34.5-59.2% versus 10.5%, 95% CI = 4.6-22.4%, respectively). Compared with referral to treatment, XR-NTX reduced opioid use in adults under criminal justice supervision and when administered to inmates before release. XR-NTX reduced opioid use compared with placebo in Russian adults, but this effect was confounded by differential retention between study groups. XR-NTX showed similar efficacy to buprenorphine when randomization occurred after detoxification, but was inferior to buprenorphine when randomization occurred prior to detoxification.

CONCLUSIONS

Many individuals intending to start extended-release naltrexone (XR-NTX) do not and most who do start XR-NTX discontinue treatment prematurely, two factors that limit its clinical utility significantly. XR-NTX appears to decrease opioid use but there are few experimental demonstrations of this effect.

Antagonists in the medical management of opioid use disorders: Historical and existing treatment strategies

BACKGROUND AND OBJECTIVES

Opioid use disorder (OUD) is a chronic condition with potentially severe health and social consequences. Many who develop moderate to severe OUD will repeatedly seek treatment or interact with medical care via emergency department visits or hospitalizations. Thus, there is an urgent need to develop feasible and effective approaches to help persons with OUD achieve and maintain abstinence from opioids. Treatment that includes one of the three FDA-approved medications is an evidence-based strategy to manage OUD. The purpose of this review is to address practices for managing persons with moderate to severe OUD with a focus on opioid withdrawal and naltrexone-based relapse-prevention treatment.

METHODS

Literature available on PubMed was used to review the evolution of treatment strategies from the 1960s onward to manage opioid withdrawal and initiate treatment with naltrexone.

RESULTS

Emerging practices for extended-release naltrexone induction include the use of agonist tapers and adjuvant medications. Clinical challenges frequently encountered when initiating this therapy include managing withdrawal and ongoing opioid use during treatment. Clinical factors may inform decisions regarding patient selection and length of naltrexone treatment, such as recent opioid use and patient preferences.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Treatment strategies to manage opioid withdrawal have evolved, but many patients with OUD do not receive medication for the prevention of relapse. Clinical strategies for induction onto extended-release naltrexone are now available and can be safely and effectively implemented in specialty and select primary care settings. (© 2018 The Authors. The American Journal on Addictions Published by Wiley Periodicals, Inc. on behalf of The American Academy of Addiction Psychiatry (AAAP);27:177-187).

Effects of incentives for naltrexone adherence on opiate abstinence in heroin-dependent adults

AIM

To test whether an incentive-based intervention that increased adherence to naltrexone also increased opiate abstinence.

DESIGN

Post-hoc combined analysis of three earlier randomized controlled trials that showed individually that incentives for adherence to oral and to extended-release injection naltrexone dosing schedules increased naltrexone adherence, but not opiate abstinence.

SETTING

Out-patient therapeutic work-place in Baltimore, MD, USA.

PARTICIPANTS

One hundred and forty unemployed heroin-dependent adults participating from 2006 to 2010.

INTERVENTIONS

Participants were hired in a model work-place for 26 weeks and randomized to a contingency (n = 72) or prescription (n = 68) group. Both groups were offered naltrexone. Contingency participants were required to take scheduled doses of naltrexone in order to work and earn wages. Prescription participants could earn wages independent of naltrexone adherence.

MEASURES

Thrice-weekly and monthly urine samples tested for opiates and cocaine and measures of naltrexone adherence (percentage of monthly urine samples positive for naltrexone or percentage of scheduled injections received). All analyses included pre-randomization attendance, opiate use and cocaine use as covariates. Additional analyses controlled for cocaine use and naltrexone adherence during the intervention.

FINDINGS

Contingency participants had more opiate abstinence than prescription participants (68.1 versus 52.9% opiate-negative thrice-weekly urine samples, respectively; and 71.9 versus 61.7% opiate-negative monthly urine samples, respectively) based on initial analyses [thrice-weekly samples, odds ratio (OR) = 3.3, 95% confidence interval (CI) = 1.7-6.5, P < 0.01; monthly samples, OR = 2.6, 95% CI = 1.0-7.1, P = 0.06] and on analyses that controlled for cocaine use (thrice-weekly samples, OR = 3.9, 95% CI = 3.3-4.5, P < 0.01; monthly samples, OR = 3.4, 95% CI = 1.1-11.1, P = 0.04), which was high and associated with opiate use. The difference in opiate abstinence rates between contingency and prescription participants was reduced when controlling for naltrexone adherence (monthly samples, OR = 1.1, 95% CI = 0.7-1.7, P = 0.84).

CONCLUSIONS

Incentives for naltrexone adherence increase opiate abstinence in heroin-dependent adults, an effect that appears to be due to increased naltrexone adherence produced by the incentives.

Predictors of induction onto extended-release naltrexone among unemployed heroin-dependent adults

BACKGROUND AND AIM

Extended-release naltrexone (XR-NTX) blocks the effects of opioids for 4weeks; however, starting treatment can be challenging because it requires 7 to 10days of abstinence from all opioids. In the present study we identified patient and treatment characteristics that were associated with successful induction onto XR-NTX.

METHODS

144 unemployed heroin-dependent adults who had recently undergone opioid detoxification completed self-report measures and behavioral tasks before starting an outpatient XR-NTX induction procedure. Employment-based reinforcement was used to promote opioid abstinence and adherence to oral naltrexone during the induction. Participants were invited to attend a therapeutic workplace where they earned wages for completing jobs skills training. Participants who had used opioids recently were initially invited to attend the workplace for a 7-day washout period. Then those participants were required to provide opioid-negative urine samples and then take scheduled doses of oral naltrexone to work and earn wages. Participants who had not recently used opioids could begin oral naltrexone immediately. After stabilization on oral naltrexone, participants were eligible to receive XR-NTX and were randomized into one of four treatment groups, two of which were offered XR-NTX. Binary and multiple logistic regressions were used to identify characteristics at intake that were associated with successfully completing the XR-NTX induction.

RESULTS

58.3% of participants completed the XR-NTX induction. Those who could begin oral naltrexone immediately were more likely to complete the induction than those who could not (79.5% vs. 25.0%). Of 15 characteristics, 2 were independently associated with XR-NTX induction success: legal status and recent opioid detoxification type. Participants who were not on parole or probation (vs. on parole or probation) were more likely to complete the induction (OR [95% CI]=2.5 [1.1-5.7], p=0.034), as were those who had come from a longer-term detoxification program (≥21days) (vs. a shorter-term [<21days]) (OR [95% CI]=7.0 [3.0-16.6], p<0.001).

CONCLUSIONS

Our analyses suggest that individuals recently leaving longer-term opioid detoxification programs are more likely to complete XR-NTX induction. Individuals on parole or probation are less likely to complete XR-NTX induction and may need additional supports or modifications to induction procedures to be successful.

Prescription opioid poisoning across urban and rural areas: identifying vulnerable groups and geographic areas

AIMS

To determine (1) whether prescription opioid poisoning (PO) hospital discharges spread across space over time, (2) the locations of 'hot-spots' of PO-related hospital discharges, (3) how features of the local environment contribute to the growth in PO-related hospital discharges and (4) where each environmental feature makes the strongest contribution.

DESIGN

Hierarchical Bayesian Poisson space-time analysis to relate annual discharges from community hospitals to postal code characteristics over 10 years.

SETTING

California, USA.

PARTICIPANTS

Residents of 18 517 postal codes in California, 2001-11.

MEASUREMENTS

Annual postal code-level counts of hospital discharges due to PO poisoning were related to postal code pharmacy density, measures of medical need for POs (i.e. rates of cancer and arthritis-related hospital discharges), economic stressors (i.e. median household income, percentage of families in poverty and the unemployment rate) and concentration of manual labor industries.

FINDINGS

PO-related hospital discharges spread from rural and suburban/exurban 'hot-spots' to urban areas. They increased more in postal codes with greater pharmacy density [rate ratio (RR) = 1.03; 95% credible interval (CI) = 1.01, 1.05], more arthritis-related hospital discharges (RR = 1.08; 95% CI = 1.06, 1.11), lower income (RR = 0.85; 95% CI = 0.83, 0.87) and more manual labor industries (RR = 1.15; 95% CI = 1.10, 1.19 for construction; RR = 1.12; 95% CI = 1.04, 1.20 for manufacturing industries). Changes in pharmacy density primarily affected PO-related discharges in urban areas, while changes in income and manual labor industries especially affected PO-related discharges in suburban/exurban and rural areas.

CONCLUSIONS

Hospital discharge rates for prescription opioid (PO) poisoning spread from rural and suburban/exurban hot-spots to urban areas, suggesting spatial contagion. The distribution of age-related and work-place-related sources of medical need for POs in rural areas and, to a lesser extent, the availability of POs through pharmacies in urban areas, partly explain the growth of PO poisoning across California, USA.

Factors associated with using opiates while under extended-release naltrexone blockade: A descriptive pilot study

BACKGROUND AND AIM

Extended-release naltrexone (XR-NTX) blocks the effects of opioids for 4weeks, yet many patients continue to use them. To learn more about why this occurs, we collected self-reports on subjective effects and drug use factors from participants' most recent heroin/opiate use while under XR-NTX blockade.

METHODS

Participants (n=38) were unemployed, heroin-dependent adults enrolled in a randomized controlled trial evaluating employment-based incentives to promote adherence to XR-NTX. A subset of participants (n=18) were asked to complete a survey about their most recent use of heroin/opiates when they provided an opiate-positive urine sample while under XR-NTX blockade. Surveys were administered weekly, and participants could complete multiple surveys throughout the trial. Participants reported how high they were (11-point scale; 0=not at all, 10=extremely), how much heroin/opiates they took (less, more, or about the same as usual before starting naltrexone), whether they used cocaine at the same time, and the routes of administration for heroin/opiates and cocaine (if used). All analyses were descriptive.

RESULTS

Of the 107 surveys, 75.7% indicated being "not at all" high the last time heroin/opiates were used. 75.5% of surveys reported opiate amounts that were less than usual, and only 7.5% reported amounts larger than usual. Cocaine was used at the same time as heroin for 57.9% of surveys but typically through a different route (74.2%).

DISCUSSION

Using heroin/opiates while under XR-NTX blockade is not strongly associated with self-reports of high, taking larger than normal amounts of opiates, or taking opiates and cocaine simultaneously via the same route. Future research should incorporate measures of naltrexone concentration and more comprehensive and frequent assessments using ecological momentary assessment.

A review of the literature on contingency management in the treatment of substance use disorders, 2009-2014

This report describes a systematic literature review of voucher and related monetary-based contingency management (CM) interventions for substance use disorders (SUDs) over 5.2years (November 2009 through December 2014). Reports were identified using the search engine PubMed, expert consultations, and published bibliographies. For inclusion, reports had to (a) involve monetary-based CM; (b) appear in a peer-reviewed journal; (c) include an experimental comparison condition; (d) describe an original study; (e) assess efficacy using inferential statistics; (f) use a research design allowing treatment effects to be attributed to CM. Sixty-nine reports met inclusion criteria and were categorized into 7 research trends: (1) extending CM to special populations, (2) parametric studies, (3) extending CM to community clinics, (4) combining CM with pharmacotherapies, (5) incorporating technology into CM, (6) investigating longer-term outcomes, (7) using CM as a research tool. The vast majority (59/69, 86%) of studies reported significant (p<0.05) during-treatment effects. Twenty-eight (28/59, 47%) of those studies included at least one follow-up visit after CM was discontinued, with eight (8/28, 29%) reporting significant (p<0.05) effects. Average effect size (Cohen's d) during treatment was 0.62 (95% CI: 0.54, 0.70) and post-treatment it was 0.26 (95% CI: 0.11, 0.41). Overall, the literature on voucher-based CM over the past 5years documents sustained growth, high treatment efficacy, moderate to large effect sizes during treatment that weaken but remain evident following treatment termination, and breadth across a diverse set of SUDs, populations, and settings consistent with and extending results from prior reviews.

The Therapeutic Utility of Employment in Treating Drug Addiction: Science to Application

Research on a model Therapeutic Workplace has allowed for evaluation of the use of employment in the treatment of drug addiction. Under the Therapeutic Workplace intervention, adults with histories of drug addiction are hired and paid to work. To promote drug abstinence or adherence to addiction medications, participants are required to provide drug-free urine samples or take prescribed addiction medications, respectively, to gain access to the workplace and/or to maintain their maximum rate of pay. Research has shown that the Therapeutic Workplace intervention is effective in promoting and maintaining abstinence from heroin, cocaine and alcohol and in promoting adherence to naltrexone. Three models could be used to implement and maintain employment-based reinforcement in the treatment of drug addiction: A Social Business model, a Cooperative Employer model, and a Wage Supplement model. Under all models, participants initiate abstinence in a training and abstinence initiation phase (Phase 1). Under the Social Business model, Phase 1 graduates are hired as employees in a social business and required to maintain abstinence to maintain employment and/or maximum pay. Under the Cooperative Employer model, cooperating community employers hire graduates of Phase 1 and require them to maintain abstinence to maintain employment and/or maximum pay. Under the Wage Supplement Model, graduates of Phase 1 are offered abstinence-contingent wage supplements if they maintain competitive employment in a community job. Given the severity and persistence of the problem of drug addiction and the lack of treatments that can produce lasting effects, continued development of the Therapeutic Workplace is warranted.

A Systematic Review on the Use of Psychosocial Interventions in Conjunction With Medications for the Treatment of Opioid Addiction

Opioid use and overdose rates have risen to epidemic levels in the United States during the past decade. Fortunately, there are effective medications (ie, methadone, buprenorphine, and oral and injectable naltrexone) available for the treatment of opioid addiction. Each of these medications is approved for use in conjunction with psychosocial treatment; however, there is a dearth of empirical research on the optimal psychosocial interventions to use with these medications. In this systematic review, we outline and discuss the findings of 3 prominent prior reviews and 27 recent publications of empirical studies on this topic. The most widely studied psychosocial interventions examined in conjunction with medications for opioid addiction were contingency management and cognitive behavioral therapy, with the majority focusing on methadone treatment. The results generally support the efficacy of providing psychosocial interventions in combination with medications to treat opioid addictions, although the incremental utility varied across studies, outcomes, medications, and interventions. The review highlights significant gaps in the literature and provides areas for future research. Given the enormity of the current opioid problem in the United States, it is critical to gain a better understanding of the most effective ways to deliver psychosocial treatments in conjunction with these medications to improve the health and well-being of individuals suffering from opioid addiction.

Predictors of Continued Use of Extended-Released Naltrexone (XR-NTX) for Opioid-Dependence: An Analysis of Heroin and Non-Heroin Opioid Users in Los Angeles County

Extended-release naltrexone (XR-NTX) is associated with an increased number of opioid-free days, improved adherence rates in substance use disorder treatment programs, and reduced cravings and drug-seeking behaviors. There is little evidence on the predictive associations between baseline characteristics of opioid-dependent patients and XR-NTX utilization. Some studies have demonstrated better pharmacotherapy adherence and/or retention rates among non-heroin opioid users compared to heroin users. This study examines predictive associations between characteristics of patients and XR-NTX utilization, as well as participants' urge to use opiates. Our findings suggest that XR-NTX may contribute to decreases in urges to use among both heroin and non-heroin opioid users. Non-heroin opioid users and heroin users were retained in XR-NTX treatment for comparable periods of time. However, those who identified as homeless, injected opioids (regardless of opioid-type), or were diagnosed with a mental illness were less likely to be retained in treatment with XR-NTX.

Treating Opioid Dependence With Injectable Extended-Release Naltrexone (XR-NTX): Who Will Respond?

OBJECTIVES

Once-monthly intramuscular extended-release naltrexone (XR-NTX) has demonstrated efficacy for the prevention of relapse in opioid dependence, providing an alternative to agonist or partial agonist maintenance (ie, methadone and buprenorphine). The question remains, for whom is this unique treatment most efficacious and can patient-treatment matching factors be identified?

METHODS

A moderator analysis was conducted on a previously reported 24-week, placebo-controlled, multisite, randomized controlled trial of XR-NTX (n = 126) versus placebo (n = 124) among recently detoxified opioid-dependent adults in Russia, which showed XR-NTX superior to placebo in proportion of opioid abstinent weeks. The moderator analysis examined a dichotomous indicator of good clinical response-achieving at least 90% of weeks abstinent over the 24-week trial. A series of logistic regression models were fit for this outcome as functions of treatment (XR-NTX vs placebo), each baseline moderator variable, and their interactions. The 25 baseline variables included demographics, clinical severity (Addiction Severity Index, SF-36, and Clinical Global Impression-Severity), functioning (EQ-5D), craving, and HIV serostatus (HIV+).

RESULTS

More XR-NTX patients achieved 90% abstinence (64/126, 51%) versus placebo (39/124, 31%; P = 0.002). There were no significant interactions between baseline variables and treatment. There was a significant main effect of Clinical Global Impression-Severity score (P = 0.02), such that higher severity score was associated with a lower rate of Good Clinical Response.

CONCLUSIONS

The absence of significant baseline by treatment interactions indicates that no patient-treatment matching variables could be identified. This suggests that XR-NTX was effective in promoting abstinence from opioids across a range of demographic and severity characteristics.

Medication-assisted treatment of opioid use disorder: review of the evidence and future directions

Medication-assisted treatment of opioid use disorder with physiological dependence at least doubles rates of opioid-abstinence outcomes in randomized, controlled trials comparing psychosocial treatment of opioid use disorder with medication versus with placebo or no medication. This article reviews the current evidence for medication-assisted treatment of opioid use disorder and also presents clinical practice imperatives for preventing opioid overdose and the transmission of infectious disease. The evidence strongly supports the use of agonist therapies to reduce opioid use and to retain patients in treatment, with methadone maintenance remaining the gold standard of care. Combined buprenorphine/naloxone, however, also demonstrates significant efficacy and favorable safety and tolerability in multiple populations, including youth and prescription opioid-dependent individuals, as does buprenorphine monotherapy in pregnant women. The evidence for antagonist therapies is weak. Oral naltrexone demonstrates poor adherence and increased mortality rates, although the early evidence looks more favorable for extended-release naltrexone, which has the advantages that it is not subject to misuse or diversion and that it does not present a risk of overdose on its own. Two perspectives-individualized treatment and population management-are presented for selecting among the three available Food and Drug Administration-approved maintenance therapies for opioid use disorder. The currently unmet challenges in treating opioid use disorder are discussed, as are the directions for future research.

Academic skills of chronically unemployed drug-addicted adults

BACKGROUND

The strong association between unemployment and drug addiction suggests that employment interventions are an important and needed focus of drug-addiction treatment. The increasing necessity of possessing basic academic skills to function in the workplace may require that some individuals receive educational training along with vocational training.

OBJECTIVE

This study investigated the academic skills of drug-addicted and chronically-unemployed adults (N = 559) who were enrolled in one of six studies conducted at the Center for Learning and Health in Baltimore, MD.

METHODS

Upon study enrollment, academic skills in math, spelling, and reading were examined using the Wide Range Achievement Test (WRAT-3 or WRAT-4) and educational history was examined using the Addiction Severity Index-Lite.

RESULTS

Although participants completed an average of 11 years of education, actual academic skill level was at or below the seventh grade level for 81% of participants in math, 61% in spelling, and 43% in reading, and most participants were classified as Low Average or below based on age group norms. Despite the fact that participants in this analysis were studied across several years and were from diverse populations, rates of high school completion and academic skill levels were remarkably similar.

CONCLUSIONS

Programs designed to improve the long-term employment status of drug-addicted individuals may benefit from the inclusion of basic adult education; future research on the topic is needed. Although establishing basic skills does not directly address chronic unemployment, it may help individuals obtain the jobs they desire and function effectively in those jobs.

The therapeutic workplace to promote treatment engagement and drug abstinence in out-of-treatment injection drug users: a randomized controlled trial

OBJECTIVE

Determine if employment-based reinforcement can increase methadone treatment engagement and drug abstinence in out-of-treatment injection drug users.

METHOD

This study was conducted from 2008 to 2012 in a therapeutic workplace in Baltimore, MD. After a 4-week induction, participants (N=98) could work and earn pay for 26 weeks and were randomly assigned to Work Reinforcement, Methadone & Work Reinforcement, and Abstinence, Methadone & Work Reinforcement conditions. Work Reinforcement participants had to work to earn pay. Methadone & Work Reinforcement and Abstinence, Methadone, & Work Reinforcement participants had to enroll in methadone treatment to work and maximize pay. Abstinence, Methadone, & Work Reinforcement participants had to provide opiate- and cocaine-negative urine samples to maximize pay.

RESULTS

Most participants (92%) enrolled in methadone treatment during induction. Drug abstinence increased as a graded function of the addition of the methadone and abstinence contingencies. Abstinence, Methadone & Work Reinforcement participants provided significantly more urine samples negative for opiates (75% versus 54%) and cocaine (57% versus 32%) than Work Reinforcement participants. Methadone & Work Reinforcement participants provided significantly more cocaine-negative samples than Work Reinforcement participants (55% versus 32%).

CONCLUSION

The therapeutic workplace can promote drug abstinence in out-of-treatment injection drug users. Clinical trial registration number: NCT01416584.

Employment-based abstinence reinforcement promotes opiate and cocaine abstinence in out-of-treatment injection drug users

We examined the use of employment-based abstinence reinforcement in out-of-treatment injection drug users, in this secondary analysis of a previously reported trial. Participants (N = 33) could work in the therapeutic workplace, a model employment-based program for drug addiction, for 30 weeks and could earn approximately $10 per hr. During a 4-week induction, participants only had to work to earn pay. After induction, access to the workplace was contingent on enrollment in methadone treatment. After participants met the methadone contingency for 3 weeks, they had to provide opiate-negative urine samples to maintain maximum pay. After participants met those contingencies for 3 weeks, they had to provide opiate- and cocaine-negative urine samples to maintain maximum pay. The percentage of drug-negative urine samples remained stable until the abstinence reinforcement contingency for each drug was applied. The percentage of opiate- and cocaine-negative urine samples increased abruptly and significantly after the opiate- and cocaine-abstinence contingencies, respectively, were applied. These results demonstrate that the sequential administration of employment-based abstinence reinforcement can increase opiate and cocaine abstinence among out-of-treatment injection drug users.

Injectable and implantable sustained release naltrexone in the treatment of opioid addiction

Sustained release technologies for administering the opioid antagonist naltrexone (SRX) have the potential to assist opioid-addicted patients in their efforts to maintain abstinence from heroin and other opioid agonists. Recently, reliable SRX formulations in intramuscular or implantable polymers that release naltrexone for 1-7 months have become available for clinical use and research. This qualitative review of the literature provides an overview of the technologies currently available for SRX and their effectiveness in reducing opioid use and other relevant outcomes. The majority of studies indicate that SRX is effective in reducing heroin use, and the most frequently studied SRX formulations have acceptable adverse events profiles. Registry data indicate a protective effect of SRX on mortality and morbidity. In some studies, SRX also seems to affect other outcomes, such as concomitant substance use, vocational training attendance, needle use, and risk behaviour for blood-borne diseases such as hepatitis or human immunodeficiency virus. There is a general need for more controlled studies, in particular to compare SRX with agonist maintenance treatment, to study combinations of SRX with behavioural interventions, and to study at-risk groups such as prison inmates or opioid-addicted pregnant patients. The literature suggests that sustained release naltrexone is a feasible, safe and effective option for assisting abstinence efforts in opioid addiction.

Reduction of classroom noise levels using group contingencies

The therapeutic workplace is an employment-based abstinence reinforcement intervention for unemployed drug users where trainees receive on-the-job employment skills training in a classroom setting. The study is an extension of prior therapeutic workplace research, which suggested that trainees frequently violated noise standards. Participants received real-time graphed feedback of noise levels and had the opportunity to earn monetary group reinforcement for maintaining a low number of noise violations. Results suggested that feedback and monetary reinforcement reduced the number of noise violations.

Employment-based reinforcement of adherence to oral naltrexone in unemployed injection drug users: 12-month outcomes

Oral naltrexone could be a promising relapse-prevention pharmacotherapy for recently detoxified opioid-dependent patients; however, interventions are often needed to promote adherence with this treatment approach. We recently conducted a study to evaluate a 26-week employment-based reinforcement intervention of oral naltrexone in unemployed injection drug users (Dunn et al., 2013). Participants were randomly assigned into a contingency (n = 35) group required to ingest naltrexone under staff observation to gain entry into a therapeutic workplace or a prescription (n = 32) group given a take-home supply of oral naltrexone and access to the workplace without observed ingestion. Monthly urine samples were collected and analyzed for evidence for naltrexone adherence, opioid use, and cocaine use. As previously reported, contingency participants provided significantly more naltrexone-positive urine samples than prescription participants during the 26-week intervention period. The goal of this current study is to report the 12-month outcomes, which occurred 6 months after the intervention ended. Results at the 12-month visit showed no between-groups differences in naltrexone-positive, opioid-negative, or cocaine-negative urine samples and no participant self-reported using naltrexone at the follow-up visit. These results show that even after a period of successfully reinforced oral naltrexone adherence, longer-term naltrexone use is unlikely to be maintained after reinforcement contingencies are discontinued. (PsycINFO Database Record

Employment-based abstinence reinforcement following inpatient detoxification in HIV-positive opioid and/or cocaine-dependent patients

Employment-based reinforcement interventions have been used to promote abstinence from drugs among chronically unemployed injection drug users. The current study used an employment-based reinforcement intervention to promote opioid and cocaine abstinence among opioid and/or cocaine-dependent, HIV-positive participants who had recently completed a brief inpatient detoxification. Participants (n = 46) were randomly assigned to an abstinence and work group that was required to provide negative urine samples in order to enter the workplace and to earn incentives for work (n = 16), a work-only group that was permitted to enter the workplace and to earn incentives independent of drug use (n = 15), and a no-voucher control group that did not receive any incentives for working (n = 15) over a 26-week period. The primary outcome was urinalysis-confirmed opioid, cocaine, and combined opioid/cocaine abstinence. Participants were 78% male and 89% African American. Results showed no significant between-groups differences in urinalysis-verified drug abstinence or HIV risk behaviors during the 6-month intervention. The work-only group had significantly greater workplace attendance, and worked more minutes per day when compared to the no-voucher group. Several features of the study design, including the lack of an induction period, setting the threshold for entering the workplace too high by requiring immediate abstinence from several drugs, and increasing the risk of relapse by providing a brief detoxification that was not supported by any continued pharmacological intervention, likely prevented the workplace from becoming established as a reinforcer that could be used to promote drug abstinence. However, increases in workplace attendance have important implications for adult training programs.

Does incentivising pill-taking 'crowd out' risk-information processing? Evidence from a web-based experiment

The use of financial incentives for changing health-related behaviours raises concerns regarding their potential to undermine the processing of risks associated with incentivised behaviours. Uncertainty remains about the validity of such concerns. This web-based experiment assessed the impact of financial incentives on i) willingness to take a pill with side-effects; ii) the time spent viewing risk-information and iii) risk-information processing, assessed by perceived-risk of taking the pill and knowledge of its side-effects. It further assesses whether effects are moderated by limiting cognitive capacity. Two-hundred and seventy-five UK-based university staff and students were recruited online under the pretext of being screened for a fictitious drug-trial. Participants were randomised to the offer of different compensation levels for taking a fictitious pill (£0; £25; £1000) and the presence or absence of a cognitive load task (presentation of five digits for later recall). Willingness to take the pill increased with the offer of £1000 (84% vs. 67%; OR 3.66, CI 95% 1.27-10.6), but not with the offer of £25 (79% vs. 67%; OR 1.68, CI 95% 0.71-4.01). Risk-information processing was unaffected by the offer of incentives. The time spent viewing the risk-information was affected by the offer of incentives, an effect moderated by cognitive load: Without load, time increased with the value of incentives (£1000: M = 304.4sec vs. £0: M = 37.8sec, p < 0.001; £25: M = 66.6sec vs. £0: M = 37.8sec, p < 0.001). Under load, time decreased with the offer of incentives (£1000: M = 48.9sec vs. £0: M = 132.7sec, p < 0.001; £25: M = 60.9sec vs. £0: M = 132.7sec, p < 0.001), but did not differ between the two incentivised groups (p = 1.00). This study finds no evidence to suggest incentives "crowd out" risk-information processing. On the contrary, incentives appear to signal risk, an effect, however, which disappears under cognitive load. Although these findings require replication, they highlight the need to maximise cognitive capacity when presenting information about incentivised health-related behaviours.

Endogenous opiates and behavior: 2012

This paper is the thirty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2012 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).

Effects of acute oral naltrexone on the subjective and physiological effects of oral D-amphetamine and smoked cocaine in cocaine abusers

Despite the prevalent worldwide abuse of stimulants, such as amphetamines and cocaine, no medications are currently approved for treating this serious public health problem. Both preclinical and clinical studies suggest that the opioid antagonist naltrexone (NTX) is effective in reducing the abuse liability of amphetamine, raising the question of whether similar positive findings would be obtained for cocaine. The purpose of this study was to evaluate the ability of oral NTX to alter the cardiovascular and subjective effects of D-amphetamine (D-AMPH) and cocaine (COC). Non-treatment-seeking COC users (N=12) completed this 3-week inpatient, randomized, crossover study. Participants received 0, 12.5, or 50 mg oral NTX 60 min before active or placebo stimulant administration during 10 separate laboratory sessions. Oral AMPH (0, 10, and 20 mg; or all placebo) was administered in ascending order within a laboratory session using a 60-min interdose interval. Smoked COC (0, 12.5, 25, and 50 mg; or all placebo) was administered in ascending order within a laboratory session using a 14-min interdose interval. Active COC and AMPH produced dose-related increases in cardiovascular function that were of comparable magnitude. In contrast, COC, but not AMPH, produced dose-related increases in several subjective measures of positive drug effect (eg, high, liking, and willingness to pay for the drug). NTX did not alter the cardiovascular effects of AMPH or COC. NTX also did not alter positive subjective ratings after COC administration, but it did significantly reduce ratings of craving for COC and tobacco during COC sessions. These results show that (1) oral AMPH produces minimal abuse-related subjective responses in COC smokers, and (2) NTX reduces craving for COC and tobacco during COC sessions. Future studies should continue to evaluate NTX as a potential anti-craving medication for COC dependence.