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

Incentivized collaborative care to disseminate and enhance contingency-management services

Contingency management is especially effective in supporting medication adherence and drug abstinence among people with opioid use disorder. However, the incorporation of contingency management into clinical practice has been slow. The present study was designed to evaluate the feasibility, acceptability, and usability of incentives for providers as a means of accelerating collaborative care with contingency management. Thirteen buprenorphine prescribers served as participants in a nonexperimental study. The prescribers who referred patients to a contingency-management service received monetary incentives for reviewing patient performance data and describing their use of these data in treatment decisions. The results show that this approach is feasible, acceptable, and easy to use for everyone involved. Self-reports indicate improved prescriber-patient relationships and more informed care. However, prescriber-focused incentives did not appear to greatly enhance access to contingency-management services for patients. Thus, provider incentives may be beneficial but further research is needed to advance adoption of contingency management.

Thinking Inside the Bounds: Improved Error Distributions for Indifference Point Data Analysis and Simulation Via Beta Regression using Common Discounting Functions

Standard nonlinear regression is commonly used when modeling indifference points due to its ability to closely follow observed data, resulting in a good model fit. However, standard nonlinear regression currently lacks a reasonable distribution-based framework for indifference points, which limits its ability to adequately describe the inherent variability in the data. Software commonly assumes data follow a normal distribution with constant variance. However, typical indifference points do not follow a normal distribution or exhibit constant variance. To address these limitations, this paper introduces a class of nonlinear beta regression models that offers excellent fit to discounting data and enhances simulation-based approaches. This beta regression model can accommodate popular discounting functions. This work proposes three specific advances. First, our model automatically captures non-constant variance as a function of delay. Second, our model improves simulation-based approaches since it obeys the natural boundaries of observable data, unlike the ordinary assumption of normal residuals and constant variance. Finally, we introduce a scale-location-truncation trick that allows beta regression to accommodate observed values of 0 and 1. A comparison between beta regression and standard nonlinear regression reveals close agreement in the estimated discounting rate k obtained from both methods.

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.

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.

Dissemination of Contingency Management for the Treatment of Opioid Use Disorder

Contingency management is an intervention for substance use disorders based on operant principles. The evidence base in support of contingency management is massive. It is effective in treating substance use disorder in general and opioid use disorder in particular. Dissemination has remained slow despite the urgency created by the opioid epidemic. Key barriers include a lack of expertise, time, and money. Implementing contingency management with smartphones eliminates the need for special training. It also solves logistical issues and requires little time on the part of clinicians. Thus, remaining barriers relate to cost. Federal anti-kickback regulations complicate solutions to the cost barrier. Other important regulatory challenges related to cost include the lack of billing codes and the difficulty of obtaining FDA approval for digital therapeutics. Even after the cost barrier is overcome, provider adoption is not guaranteed. Incentivizing providers for collaborative care may increase adoption and generate referrals. Recently proposed legislation and governmental policy statements provide optimism regarding the near-term large-scale adoption of contingency management in the treatment of opioid use disorder.

Relative effectiveness of medications for opioid-related disorders: A systematic review and network meta-analysis of randomized controlled trials

INTRODUCTION

Several pharmacotherapeutic interventions are available for maintenance treatment for opioid-related disorders. However, previous meta-analyses have been limited to pairwise comparisons of these interventions, and their efficacy relative to all others remains unclear. Our objective was to unify findings from different healthcare practices and generate evidence to strengthen clinical treatment protocols for the most widely prescribed medications for opioid-use disorders.

METHODS

We searched Medline, EMBASE, PsycINFO, CENTRAL, and ClinicalTrials.gov for all relevant randomized controlled trials (RCT) from database inception to February 12, 2022. Primary outcome was treatment retention, and secondary outcome was opioid use measured by urinalysis. We calculated risk ratios (RR) and 95% credible interval (CrI) using Bayesian network meta-analysis (NMA) for available evidence. We assessed the credibility of the NMA using the Confidence in Network Meta-Analysis tool.

RESULTS

Seventy-nine RCTs met the inclusion criteria. Due to heterogeneity in measuring opioid use and reporting format between studies, we conducted NMA only for treatment retention. Methadone was the highest ranked intervention (Surface Under the Cumulative Ranking [SUCRA] = 0.901) in the network with control being the lowest (SUCRA = 0.000). Methadone was superior to buprenorphine for treatment retention (RR = 1.22; 95% CrI = 1.06-1.40) and buprenorphine superior to naltrexone (RR = 1.39; 95% CrI = 1.10-1.80). However, due to a limited number of high-quality trials, confidence in the network estimates of other treatment pairs involving naltrexone and slow-release oral morphine (SROM) remains low.

CONCLUSION

All treatments had higher retention than the non-pharmacotherapeutic control group. However, additional high-quality RCTs are needed to estimate more accurately the extent of efficacy of naltrexone and SROM relative to other medications. For pharmacotherapies with established efficacy profiles, assessment of their long-term comparative effectiveness may be warranted.

TRIAL REGISTRATION

This systematic review has been registered with PROSPERO (https://www.crd.york.ac.uk/prospero) (identifier CRD42021256212).

Innovating for real-world care: A systematic review of interventions to improve post-detoxification outcomes for opioid use disorder

BACKGROUND

Inpatient detoxification is a common health care entry point for people with Opioid Use Disorder (OUD). However, many patients return to opioid use after discharge and also do not access OUD treatment. This systematic review reports on the features and findings of research on interventions developed specifically to improve substance use outcomes and treatment linkage after inpatient detoxification for OUD.

METHODS

Of 6419 articles, 64 met inclusion criteria for the current review. Articles were coded on key domains including sample characteristics, study methods and outcome measures, bias indicators, intervention type, and findings.

RESULTS

Many studies did not report sample characteristics, including demographics and co-occurring psychiatric and substance use disorders, which may impact postdetoxification OUD treatment outcomes and the generalizability of interventions. Slightly more than half of studies examined interventions that were primarily medical in nature, though only a third focused on initiating medication treatment beyond detoxification. Medical and combination interventions that focused on initiating medications for OUD generally performed well, as did psychological interventions with one or more reinforcement-based components.

CONCLUSIONS

Research efforts to improve post-detoxification outcomes would benefit from clearer reporting of sample characteristics that are associated with treatment and recovery outcomes, including diagnostic comorbidities. Findings also support the need to identify ways to introduce medication for opioid use disorder (MOUD) and other effective treatments including reinforcement-based interventions during detoxification or soon after.

Contextual extinction of drug-associated discriminative stimuli fails to attenuate drug-vs-food choice in rhesus monkeys

Relapse within the context of a substance use disorder can be triggered by cues that function as discriminative stimuli to signal contingencies of drug availability and promote drug-taking behavior. Extinction procedures can weaken this association between drug-associated cues and drug-taking behavior and may reduce the probability of relapse. This study evaluated a regimen of extinction training on cocaine and heroin self-administration in rhesus monkeys under a drug-vs-food choice procedure. Behavior was initially maintained under a concurrent schedule of food (1-g food pellets; fixed-ratio 100 schedule) and cocaine injections (0-0.1 mg/kg/injection; fixed-ratio 10) (n = 4 males) or heroin injections (0-0.01 mg/kg/injection; fixed-ratio 10) (n = 3 females and 1 male) during daily 2-hr choice sessions. Subsequently, choice sessions were supplemented by daily 20-hr saline self-administration sessions for 14 consecutive days. During saline self-administration sessions, only drug-associated discriminative stimuli were presented and responding produced saline injections. Drug continued to be available during choice sessions. Prior to extinction training, both cocaine and heroin maintained dose-dependent increases in drug-vs-food choice. Exposure to 14 saline self-administration sessions failed to significantly decrease drug choice and increase food choice. These preclinical results do not support the effectiveness of extinguishing drug-associated discriminative stimuli as a nonpharmacological treatment strategy for reducing drug choice.

Diversity inclusion in United States opioid pharmacological treatment trials: A systematic review

Pharmacological treatments for opioid use disorders (OUDs) may have mixed efficacy across diverse groups, i.e., sex/gender, race/ethnicity, and socioeconomic status (SES). The present systematic review aims to examine how diverse groups have been included in U.S. randomized clinical trials examining pharmacological treatments (i.e., methadone, buprenorphine, or naltrexone) for OUDs. PubMed was systematically searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The initial search yielded 567 articles. After exclusion of ineligible articles, 50 remained for the present review. Of the included articles, 14.0% (n = 7) reported both full (i.e., accounting for all participants) sex/gender and race/ethnicity information; only two of those articles also included information about any SES indicators. Moreover, only 22.0% (n = 11) reported full sex/gender information, and 42.0% (n = 21) reported full racial/ethnic information. Furthermore, only 10.0% (n = 5) reported that their lack of subgroup analyses or diverse samples was a limitation to their studies. Particularly underrepresented were American Indian/Alaska Native (AI/AN), Asian, Native Hawaiian/Other Pacific Islander (NH/OPI), and multiracial individuals. These results also varied by medication type; Black individuals were underrepresented in buprenorphine randomized controlled trials (RCTs) but were well represented in RCTs for methadone and/or naltrexone. In conclusion, it is critical that all people receive efficacious pharmacological care for OUDs given the ongoing opioid epidemic. Findings from the present review, however, support that participants from diverse or marginalized backgrounds are underrepresented in treatment trials, despite being at increased risk for disparities related to OUDs. Suggestions for future research are advanced. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Medications Development for Treatment of Opioid Use Disorder

This review describes methods for preclinical evaluation of candidate medications to treat opioid use disorder (OUD). The review is founded on the propositions that (1) drug self-administration procedures provide the most direct method for assessment of medication effectiveness, (2) procedures that assess choice between opioid and nondrug reinforcers are especially useful, and (3) states of opioid dependence and withdrawal profoundly influence both opioid reinforcement and effects of candidate medications. Effects of opioid medications and vaccines on opioid choice in nondependent and opioid-dependent subjects are reviewed. Various nonopioid medications have also been examined, but none yet have been identified that safely and reliably reduce opioid choice. Future research will focus on (1) strategies for increasing safety and/or effectiveness of opioid medications (e.g., G-protein-biased μ-opioid agonists), and (2) continued development of nonopioid medications (e.g., clonidine) that might serve as adjunctive agents to current opioid medications.

Effectiveness and selectivity of a heroin conjugate vaccine to attenuate heroin, 6-acetylmorphine, and morphine antinociception in rats: Comparison with naltrexone

BACKGROUND

One emerging strategy to address the opioid crisis includes opioid-targeted immunopharmacotherapies. This study compared effectiveness of a heroin-tetanus toxoid (TT) conjugate vaccine to antagonize heroin, 6-acetylmorphine (6-AM), morphine, and fentanyl antinociception in rats.

METHODS

Adult male and female Sprague Dawley rats received three doses of active or control vaccine at weeks 0, 2, and 4. Vaccine pharmacological selectivity was assessed by comparing opioid dose-effect curves in 50 °C  warm-water tail-withdrawal procedure before and after active or control heroin-TT vaccine. Route of heroin administration [subcutaneous (SC) vs. intravenous [IV)] was also examined as a determinant of vaccine effectiveness. Continuous naltrexone treatment (0.0032-0.032 mg/kg/h) effects on heroin, 6-AM, and morphine antinociceptive potency were also determined as a benchmark for minimal vaccine effectiveness.

RESULTS

The heroin-TT vaccine decreased potency of SC heroin (5-fold), IV heroin (3-fold), and IV 6-AM (3-fold) for several weeks without affecting IV morphine or SC and IV fentanyl potency. The control vaccine did not alter potency of any opioid. Naltrexone dose-dependently decreased antinociceptive potency of SC heroin, and treatment with 0.01 mg/kg/h naltrexone produced similar, approximate 8-fold decreases in potencies of SC and IV heroin, IV 6-AM, and IV morphine. The combination of naltrexone and active vaccine was more effective than naltrexone alone to antagonize SC heroin but not IV heroin.

CONCLUSIONS

The heroin-TT vaccine formulation examined is less effective, but more selective, than chronic naltrexone to attenuate heroin antinociception in rats. Furthermore, these results provide an empirical framework for future preclinical opioid vaccine research to benchmark effectiveness against naltrexone.

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.