Buprenorphine/Naloxone and methadone effects on laboratory indices of liver health: a randomized trial

Buprenorphine Use for Analgesia in Palliative Care

Buprenorphine is a semi-synthetic long-acting partial µ-opioid receptor (MOR) agonist that can be used for chronic pain as a sublingual tablet, transdermal patch (Butrans®), or a buccal film (Belbuca®). Buprenorphine's unique high receptor binding affinity and slow dissociation at the MOR allow for effective analgesia while offering less adverse effects compared to a full agonist opioid, in particular, less concern for respiratory depression and constipation. It is underused in chronic pain and palliative care due to misconceptions and stigma from its use in opioid use disorder (OUD). This case report discusses the unique pharmacology of buprenorphine, including its advantages, disadvantages, available formulations, drug-drug interactions, initiation and conversion strategies, and identifies ideal populations for use, especially within the palliative care patient population.

Empirically contrasting urine drug screening-based opioid use disorder treatment outcome definitions

BACKGROUND AND AIMS

A lack of consensus on the optimal outcome measures to assess opioid use disorder (OUD) treatment efficacy and their precise definition and computation has hampered the pooling of research data for evidence synthesis and meta-analyses. This study aimed to empirically contrast multiple clinical trial definitions of treatment success by applying them to the same dataset.

METHODS

Data analysis used a suite of functions, developed as a software package for the R language, to operationalize 61 treatment outcome definitions based on urine drug screening (UDS) results. Outcome definitions were derived from clinical trials that are among the most influential in the OUD treatment field. Outcome functions were applied to a harmonized dataset from three large-scale National Drug Abuse Treatment Clinical Trials Network (CTN) studies, which tested various medication for OUD (MOUD) options (n = 2492). Hierarchical clustering was employed to empirically contrast outcome definitions.

RESULTS

The optimal number of clusters identified was three. Cluster 1, comprising eight definitions focused on detecting opioid-positive UDS, did not include missing UDS in outcome calculations, potentially resulting in inflated rates of treatment success. Cluster 2, with the highest variability, included 10 definitions characterized by strict criteria for treatment success, relying heavily on UDS results from either a brief period or a single study visit. The 43 definitions in Cluster 3 represented a diverse range of outcomes, conceptualized as measuring abstinence, use reduction and relapse. These definitions potentially offer more balanced measures of treatment success or failure, as they avoid the extreme methodologies characteristic of Clusters 1 and 2.

CONCLUSIONS

Clinical trials using urine drug screening (UDS) for objective substance use assessment in outcome definitions should consider (1) incorporating missing UDS data in outcome computation and (2) avoiding over-reliance on UDS data confined to a short time frame or the occurrence of a single positive urine test following a period of abstinence.

Virtual Hybrid Versus In-Person Administration of Transcending Self Therapy for Veterans with Substance Use Disorders

Objectives

Veterans with substance use disorder (SUD) can show high severity and are at high risk of relapse due to trauma histories and other comorbid conditions. However, evidence-based SUD therapies may not be available to many veterans due to geographic or transportation constraints. Telehealth approaches have shown promise to improve access to different SUD therapy formats but have not been well-studied in open (rolling-admission) group therapy of in-person patients as administered by a single on-screen therapist.

Methods

Social distancing required by the COVID-19 pandemic forced the transition of delivery of Transcending Self Therapy (TST) from an in-person therapist to a single remote (on-screen) therapist. In this virtual model, veterans continued to receive TST but the therapist was off site and provided therapy to veterans who were together in the same room during a 28 day residential Veterans Affairs treatment program. In a program evaluation, we compared their changes in quality of life (QoL), treatment satisfaction ratings and group therapy treatment outcomes with those of Veterans who received TST from an in-person therapist.

Results

In both groups, there was a significant increase in QoL Inventory scores from baseline to post-treatment, with no difference in improvement between treatment modalities (i.e., in-person group vs telehealth-delivered group). Veterans professed knowledge of therapy-driven skills at the end of treatment in both groups and overwhelmingly rated TST as helpful and understandable.

Conclusions

These data extend previous findings of patient acceptability of remotely-delivered SUD treatment, here with a remote therapist administering open group therapy, as evidenced by improvement in QoL and positive patient feedback about the remote intervention.

Individual-Level Risk Prediction of Return to Use During Opioid Use Disorder Treatment

Importance

No existing model allows clinicians to predict whether patients might return to opioid use in the early stages of treatment for opioid use disorder.

Objective

To develop an individual-level prediction tool for risk of return to use in opioid use disorder.

Design, Setting, and Participants

This decision analytical model used predictive modeling with individual-level data harmonized in June 1, 2019, to October 1, 2022, from 3 multicenter, pragmatic, randomized clinical trials of at least 12 weeks' duration within the National Institute on Drug Abuse Clinical Trials Network (CTN) performed between 2006 and 2016. The clinical trials covered a variety of treatment settings, including federally licensed treatment sites, physician practices, and inpatient treatment facilities. All 3 trials enrolled adult participants older than 18 years, with broad pragmatic inclusion and few exclusion criteria except for major medical and unstable psychiatric comorbidities.

Intervention

All participants received 1 of 3 medications for opioid use disorder: methadone, buprenorphine, or extended-release naltrexone.

Main Outcomes and Measures

Predictive models were developed for return to use, which was defined as 4 consecutive weeks of urine drug screen (UDS) results either missing or positive for nonprescribed opioids by week 12 of treatment.

Results

The overall sample included 2199 trial participants (mean [SD] age, 35.3 [10.7] years; 728 women [33.1%] and 1471 men [66.9%]). The final model based on 4 predictors at treatment entry (heroin use days, morphine- and cocaine-positive UDS results, and heroin injection in the past 30 days) yielded an area under the receiver operating characteristic curve (AUROC) of 0.67 (95% CI, 0.62-0.71). Adding UDS in the first 3 treatment weeks improved model performance (AUROC, 0.82; 95% CI, 0.78-0.85). A simplified score (CTN-0094 OUD Return-to-Use Risk Score) provided good clinical risk stratification wherein patients with weekly opioid-negative UDS results in the 3 weeks after treatment initiation had a 13% risk of return to use compared with 85% for those with 3 weeks of opioid-positive or missing UDS results (AUROC, 0.80; 95% CI, 0.76-0.84).

Conclusions and Relevance

The prediction model described in this study may be a universal risk measure for return to opioid use by treatment week 3. Interventions to prevent return to regular use should focus on this critical early treatment period.

Repeated measures analysis of opioid use disorder treatment on clinical opiate withdrawal scale in a randomized clinical trial: sex differences

PURPOSE

Sex differences may exist in opioid use disorder (OUD) treatment. This study examined the treatment effects of buprenorphine/naloxone (BUP/NX) and methadone (MET) on the Clinical Opiate Withdrawal Scale (COWS) score in individuals with OUD and tested whether the associations differ by sex.

METHOD

We performed a secondary analysis of the data from the National Drug Abuse Treatment Clinical Trials Network (CTN) protocol-0027. A total of 1269 participants (861 males and 408 females) being aged 18 or older with OUD were randomly assigned to receive BUP/NX (n = 740) or MET (n = 529). The paired t test was initially used to compare the COWS scores between pre-dose and post-dose for BUP/NX and MET treatments, separately. The linear mixed model was used to examine the changes in COWS score adjusted for baseline demographic, substance use, and mental health disorders. The interaction of sex and treatment was detected and stratified analysis by sex was conducted.

RESULTS

The paired t test showed that both BUP/NX and MET treatments significantly reduced the COWS scores (p values <0.0001). BUP/NX revealed higher COWS scores than MET (p = 0.0008) and females demonstrated significantly higher COWS scores than males (p = 0.0169). Stratified by sex, BUP/NX compared with MET revealed higher COWS scores only in males (p = 0.0043), whereas baseline amphetamines use disorder and major depressive disorder were significantly associated with COWS scores in females (p = 0.0158 and 0.0422, respectively).

CONCLUSIONS

Both BUP/NX and MET are effective in decreasing opioid withdrawal symptoms via COWS scores, however, treatment plans for OUD by clinical providers should consider sex differences.

Population Pharmacokinetic Analysis Supports Initiation Treatment and Bridging from Sublingual Buprenorphine to Subcutaneous Administration of a Buprenorphine Depot (CAM2038) in the Treatment of Opioid Use Disorder

BACKGROUND AND OBJECTIVE

In treating opioid use disorder (OUD), subcutaneous (SC) extended-release buprenorphine (BPN) depots, e.g., CAM2038, have been shown to provide smaller and less frequent fluctuations in BPN plasma concentrations and pharmacodynamic responses, improve outcomes, reduce treatment burden, and lower risks of misuse and diversion compared to daily sublingual (SL) BPN. This analysis characterized the pharmacokinetics (PK) of BPN following intravenous and SL administration, and administration of SC CAM2038 weekly and monthly.

METHODS

Pharmacokinetic data from two Phase 1 and two Phase 2 trials in healthy participants and participants with OUD, respectively, were used to develop a population PK model using non-linear mixed effects modelling. The analysis included data from 252 participants and 10,658 BPN observations.

RESULTS

The disposition of BPN was best described by a three-compartment model with first-order elimination, and absorption of SL BPN and SC CAM2038 weekly and monthly by dual parallel absorption pathways. Model diagnostics indicated good predictive performance of BPN concentrations. Buprenorphine plasma concentration-time profiles were simulated for treatment initiation, switching from SL BPN to CAM2038 weekly and monthly, and tapering after interrupting treatment with CAM2038. Simulations predicted CAM2038 weekly and monthly doses that provided BPN plasma maximum concentration (Cmax) and trough concentration (Ctrough) values at steady state within those observed following SL BPN administration.

CONCLUSIONS

This population PK model supports the use of CAM2038 doses as individualized treatment for OUD across different treatment stages, including initiation, switching from SL BPN according to established dose conversion schedules, and tapering.

TRIAL REGISTRATIONS

ISRCTN41550730 (05/19/2014), ISRCTN24987553 (07/29/2014), NCT02611752 (11/23/2015), NCT02710526 (03/16/2016).

Risks of returning to opioid use at treatment entry and early in opioid use disorder treatment: Role of non-opioid substances

OBJECTIVE

Patients in treatment with medications for opioid use disorder (MOUD) often report use of other substances in addition to opioids. Few studies exist that examine the relationship between use at treatment entry and early non-opioid use in opioid treatment outcome.

METHODOLOGY

We combined and harmonized three randomized, controlled MOUD clinical trials from the National Institutes of Drug Abuse (NIDA) Clinical Trials Network (CTN) (N=2197) and investigated the association of non-opioid substance use at treatment entry and during early treatment with a return to opioid use. The trials compared MOUD treatment (buprenorphine, methadone, extended-release naltrexone) in populations with opioid use disorder (OUD). Non-opioid substances were identified through harmonizing self-reported use. The primary outcomes were markers of return to opioid use by 12 weeks.

RESULTS

When treatment cohorts were adjusted, no association between self-reported treatment entry use of non-opioid substances and week-12 opioid use was detected. During the first month of treatment, higher use of cocaine (OR 1.41 [1.18-1.69]) and amphetamine (OR 1.70 [1.27-2.26]) was found to be associated with higher likelihood of illicit opioid use by week 12. Exploratory analyses of potential treatment cohort-by-predictor interactions showed that those with heavier cocaine use had a lower rate of returning to opioid use in the extended-release naltrexone group than in the methadone group.

CONCLUSION

Substance use other than opioids at treatment entry is not associated with relapse. Use of cocaine or amphetamines during the first few weeks of MOUD treatment may signal a worse outcome, suggesting a need for additional interventions.

Optimally Choosing Medication Type for Patients With Opioid Use Disorder

Patients with opioid use disorder (OUD) tend to get assigned to one of 3 medications based on the treatment program to which the patient presents (e.g., opioid treatment programs tend to treat patients with methadone, while office-based practices tend to prescribe buprenorphine). It is possible that optimally matching patients with treatment type would reduce the risk of return to regular opioid use (RROU). We analyzed data from 3 comparative effectiveness trials from the US National Institute on Drug Abuse Clinical Trials Network (CTN0027, 2006-2010; CTN0030, 2006-2009; and CTN0051 2014-2017), in which patients with OUD (n = 1,459) were assigned to treatment with either injection extended-release naltrexone (XR-NTX), sublingual buprenorphine-naloxone (BUP-NX), or oral methadone. We learned an individualized rule by which to assign medication type such that risk of RROU during 12 weeks of treatment would be minimized, and then estimated the amount by which RROU risk could be reduced if the rule were applied. Applying our estimated treatment rule would reduce risk of RROU compared with treating everyone with methadone (relative risk (RR) = 0.79, 95% confidence interval (CI): 0.60, 0.97) or treating everyone with XR-NTX (RR = 0.71, 95% CI: 0.47, 0.96). Applying the estimated treatment rule would have resulted in a similar risk of RROU to that of with treating everyone with BUP-NX (RR = 0.92, 95% CI: 0.73, 1.11).

Risk of Experiencing an Overdose Event for Patients Undergoing Treatment With Medication for Opioid Use Disorder

OBJECTIVE

Overdose risk during a course of treatment with medication for opioid use disorder (MOUD) has not been clearly delineated. The authors sought to address this gap by leveraging a new data set from three large pragmatic clinical trials of MOUD.

METHODS

Adverse event logs, including overdose events, from the three trials (N=2,199) were harmonized, and the overall risk of having an overdose event in the 24 weeks after randomization was compared for each study arm (one methadone, one naltrexone, and three buprenorphine groups), using survival analysis with time-dependent Cox proportional hazard models.

RESULTS

By week 24, 39 participants had ≥1 overdose event. The observed frequency of having an overdose event was 15 (5.30%) among 283 patients assigned to naltrexone, eight (1.51%) among 529 patients assigned to methadone, and 16 (1.15%) among 1,387 patients assigned to buprenorphine. Notably, 27.9% of patients assigned to extended-release naltrexone never initiated the medication, and their overdose rate was 8.9% (7/79), compared with 3.9% (8/204) among those who initiated naltrexone. Controlling for sociodemographic and time-varying medication adherence variables and baseline substance use, a proportional hazard model did not show a significant effect of naltrexone assignment. Significantly higher probabilities of experiencing an overdose event were observed among patients with baseline benzodiazepine use (hazard ratio=3.36, 95% CI=1.76, 6.42) and those who either were never inducted on their assigned study medication (hazard ratio=6.64, 95% CI=2.12, 19.54) or stopped their medication after initial induction (hazard ratio=4.04, 95% CI=1.54, 10.65).

CONCLUSIONS

Among patients with opioid use disorder seeking medication treatment, the risk of overdose events over the next 24 weeks is elevated among those who fail to initiate or discontinue medication and those who report benzodiazepine use at baseline.

Buprenorphine administration during gestation induces hepatotoxicity in the rat fetus

This study investigated the effect of buprenorphine (BUP) on the livers of pups exposed to this drug during the fetal stage. BUP decreased the activities of serum liver enzymes in exposed animals versus the controls. BUP (0.5 mg/kg) decreased malondialdehyde levels and increased the glutathione levels in the liver of animals versus other groups. The superoxide dismutase activity was elevated in the BUP 0.5 mg/kg group versus the control group. BUP (1 mg/kg) induced histopathological changes in the livers of pups. In conclusion, BUP may induce hepatotoxicity in pups exposed to this drug during the fetal stage.

Specific polysubstance use patterns predict relapse among patients entering opioid use disorder treatment

Introduction

While polysubstance use has consistently been associated with higher rates of relapse, few studies have examined subgroups with specific combinations and time course of polysubstance use (i.e., polysubstance use patterns). This study aimed to classify and compare polysubstance use patterns, and their associations with relapse to regular opioid use in 2637 participants in three large opioid use disorder (OUD) treatment trials.

Methods

We explored the daily patterns of self-reported substance use in the 28 days prior to treatment entry. Market basket analysis (MBA) and repeated measure latent class analysis (RMLCA) were used to examine the subgroups of polysubstance use patterns, and multiple logistic regression was used to examine associations between identified classes and relapse.

Results

MBA and RMLCA identified 34 "associations rules " and 6 classes, respectively. Specific combinations of polysubstance use and time course (high baseline use and rapid decrease of use prior to initiation) predicts a worse relapse outcome. MBA showed individuals who co-used cocaine, heroin, prescription opioids, and cannabis had a higher risk for relapse (OR = 2.82, 95%CI = 1.13, 7.03). In RMLCA, higher risk of relapse was observed in individuals who presented with high baseline prescription opioid (OR = 1.9, 95% CI = 1.3, 2.76) or heroin use (OR = 3.54, 95%CI = 1.86, 6.72), although use decreased in both cases prior to treatment initiation.

Conclusions

Our analyses identified subgroups with distinct patterns of polysubstance use. Different patterns of polysubstance use differentially predict relapse outcomes. Interventions tailored to these individuals with specific polysubstance use patterns prior to treatment initiation may increase the effectiveness of relapse prevention.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Modeling the cost-effectiveness and impact on fatal overdose and initiation of buprenorphine-naloxone treatment at syringe service programs

AIM

To estimate the number of treatment initiations, averted fatal opioid overdoses and the cost-effectiveness associated with offering buprenorphine-naloxone (buprenorphine) treatment on-site within existing syringe service programs (SSPs) in Massachusetts, USA.

DESIGN, SETTING AND PARTICIPANTS

This was a cohort-based mathematical model and cost-effectiveness analysis. We derived model inputs from state and national surveillance data, clinical trials and observational cohort studies. We compared an intervention scenario where 30% of SSP clients initiated buprenorphine treatment on-site at least once annually to a status quo scenario where no buprenorphine was available on-site among community treatment providers in Massachusetts, 2020-30. In individuals with opioid use disorder (OUD) we assumed that 80% of SSP clients had recently injected drugs and that treatment within SSPs would have similar or improved retention compared with standard-of-care buprenorphine programs, but higher rates of active opioid use while in treatment.

MEASUREMENTS

Number of treatment initiations (i.e. individuals began treatment on a medication for opioid use disorder or entered medically managed withdrawal), averted fatal opioid overdoses, quality-adjusted life-years (QALYs) and life-time discounted costs from a health sector and a limited societal perspective.

FINDINGS

The status quo scenario resulted in 23 051 fatal overdoses and 1 511 613 treatment initiations over a 10-year simulation period. An intervention scenario with on-site SSP buprenorphine treatment averted 4797 (-20.8%) fatal opioid overdoses and resulted in 129 359 (+8.6%) additional treatment initiations compared with the status quo. The intervention scenario was the dominating scenario: providing OUD treatment through Massachusetts SSPs cost less (-$3612 per person) with patients accumulating more QALYs (0.2 per person) compared with the status quo scenario.

CONCLUSIONS

Offering buprenorphine treatment on-site within syringe service programs has the potential to decrease fatal overdoses substantially, improve treatment engagement and save on costs.

Opioid agonist treatment for people who are dependent on pharmaceutical opioids

BACKGROUND

There are ongoing concerns regarding pharmaceutical opioid-related harms, including overdose and dependence, with an associated increase in treatment demand. People dependent on pharmaceutical opioids appear to differ in important ways from people who use heroin, yet most opioid agonist treatment research has been conducted in people who use heroin.  OBJECTIVES: To assess the effects of maintenance opioid agonist pharmacotherapy for the treatment of pharmaceutical opioid dependence.

SEARCH METHODS

We updated our searches of the following databases to January 2022: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, MEDLINE, four other databases, and two trial registers. We checked the reference lists of included studies for further references to relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

We included RCTs with adults and adolescents examining maintenance opioid agonist treatments that made the following two comparisons. 1. Full opioid agonists (methadone, morphine, oxycodone, levo-alpha-acetylmethadol (LAAM), or codeine) versus different full opioid agonists or partial opioid agonists (buprenorphine) for maintenance treatment. 2. Full or partial opioid agonist maintenance versus non-opioid agonist treatments (detoxification, opioid antagonist, or psychological treatment without opioid agonist treatment).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods.

MAIN RESULTS

We identified eight RCTs that met inclusion criteria (709 participants). We found four studies that compared methadone and buprenorphine maintenance treatment, and four studies that compared buprenorphine maintenance to either buprenorphine taper (in addition to psychological treatment) or a non-opioid maintenance treatment comparison. We found low-certainty evidence from three studies of a difference between methadone and buprenorphine in favour of methadone on self-reported opioid use at end of treatment (risk ratio (RR) 0.49, 95% confidence interval (CI) 0.28 to 0.86; 165 participants), and low-certainty evidence from four studies finding a difference in favour of methadone for retention in treatment (RR 1.21, 95% CI 1.02 to 1.43; 379 participants). We found low-certainty evidence from three studies showing no difference between methadone and buprenorphine on substance use measured with urine drug screens at end of treatment (RR 0.81, 95% CI 0.57 to 1.17; 206 participants), and moderate-certainty evidence from one study of no difference in days of self-reported opioid use (mean difference 1.41 days, 95% CI 3.37 lower to 0.55 days higher; 129 participants). There was low-certainty evidence from three studies of no difference between methadone and buprenorphine on adverse events (RR 1.13, 95% CI 0.66 to 1.93; 206 participants). We found low-certainty evidence from four studies favouring maintenance buprenorphine treatment over non-opioid treatments in terms of fewer opioid positive urine drug tests at end of treatment (RR 0.66, 95% CI 0.52 to 0.84; 270 participants), and very low-certainty evidence from four studies finding no difference on self-reported opioid use in the past 30 days at end of treatment (RR 0.63, 95% CI 0.39 to 1.01; 276 participants). There was low-certainty evidence from three studies of no difference in the number of days of unsanctioned opioid use (standardised mean difference (SMD) -0.19, 95% CI -0.47 to 0.09; 205 participants). There was moderate-certainty evidence from four studies favouring buprenorphine maintenance over non-opioid treatments on retention in treatment (RR 3.02, 95% CI 1.73 to 5.27; 333 participants). There was moderate-certainty evidence from three studies of no difference in adverse effects between buprenorphine maintenance and non-opioid treatments (RR 0.50, 95% CI 0.07 to 3.48; 252 participants). The main weaknesses in the quality of the data was the use of open-label study designs, and difference in follow-up rates between treatment arms.

AUTHORS' CONCLUSIONS

There is  very low- to moderate-certainty evidence supporting the use of maintenance agonist pharmacotherapy for pharmaceutical opioid dependence. Methadone or buprenorphine did not differ on some outcomes, although on the outcomes of retention and self-reported substance use some results favoured methadone. Maintenance treatment with buprenorphine appears more effective than non-opioid treatments. Due to the overall very low- to moderate-certainty evidence and small sample sizes, there is the possibility that the further research may change these findings.

Buprenorphine/naloxone versus methadone opioid rotation in patients with prescription opioid use disorder and chronic pain: study protocol for a randomized controlled trial

Background

Opioids are effective in pain-management, but long-term opioid users can develop prescription opioid use disorder (OUD). One treatment strategy in patients with OUD is rotating from a short-acting opioid to a long-acting opioid (buprenorphine/naloxone (BuNa) or methadone). Both BuNa and methadone have been shown to be effective strategies in patients with OUD reducing opioid misuse, however data on head-to-head comparison in patients with chronic non-malignant pain and prescription OUD are limited.

Methods

This two-armed open-label, randomized controlled trial aims to compare effectiveness between BuNa and methadone in patients with chronic non-malignant with prescription OUD (n = 100). Participants receive inpatient rotation to either BuNa or methadone with a flexible dosing regimen. The primary outcome is opioid misuse 2 months after rotation. Secondary outcomes include treatment compliance, side effects, analgesia, opioid craving, quality of life, mood symptoms, cognitive and physical functioning over 2- and 6 months follow-up. Linear mixed model analysis will be used to evaluate change in outcome parameters over time between the treatment arms.

Discussion

This is one of the first studies comparing buprenorphine/naloxone and methadone for treating prescription OUD in a broad patient group with chronic non-malignant pain. Results may guide future treatment for patients with chronic pain and prescription OUD.

Trial registrationhttps://www.trialregister.nl/, NL9781

Under-representation of key demographic groups in opioid use disorder trials

Background

The extent to which clinical trials of medications for opioid use disorder (MOUD) are representative or not is unknown. Some patient characteristics modify MOUD effectiveness; if these same characteristics differ in distribution between the trial population and usual-care population, this could contribute to lack of generalizability-a discrepancy between trial and usual-care effectiveness. Our objective was to identify interpretable, multidimensional subgroups who were prescribed MOUD in substance use treatment programs in the US but who were not represented or under-represented by clinical trial participants.

Methods

This was a secondary descriptive analysis of trial and real-world data. The trial data included twenty-seven US opioid treatment programs in the National Drug Abuse Treatment Clinical Trials Network, N = 2,199 patients. The real-world data included US substance use treatment programs that receive public funding, N = 740,015 patients. We characterized real-world patient populations who were non-represented and under-represented in the trial data in terms of sociodemographic and clinical characteristics that could modify MOUD effectiveness.

Results

We found that 10.7% of MOUD patients in TEDS-A were not represented in the three clinical trials. As expected, pregnant MOUD patients (n = 19,490) were not represented. Excluding pregnancy, education and marital status from the characteristics, 2.6% of MOUD patients were not represented. Patients aged 65 years and older (n = 11,204), and those 50-64 years who identified as other (non-White, non-Black, and non-Hispanic) race/ethnicity or multi-racial (n = 7,281) were under-represented.

Conclusions

Quantifying and characterizing non- or under-represented subgroups in trials can provide the data necessary to improve representation in future trials and address research-to-practice gaps.

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).

Effects of Buprenorphine Dose and Therapeutic Engagement on Illicit Opiate Use in Opioid Use Disorder Treatment Trials

The impact of agonist dose and of physician, staff and patient engagement on treatment have not been evaluated together in an analysis of treatment for opioid use disorder. Our hypotheses were that greater agonist dose and therapeutic engagement would be associated with reduced illicit opiate use in a time-dependent manner. Publicly-available treatment data from six buprenorphine efficacy and safety trials from the Federally-supported Clinical Trials Network were used to derive treatment variables. Three novel predictors were constructed to capture the time weighted effects of buprenorphine dosage (mg buprenorphine per day), dosing protocol (whether physician could adjust dose), and clinic visits (whether patient attended clinic). We used time-in-trial as a predictor to account for the therapeutic benefits of treatment persistence. The outcome was illicit opiate use defined by self-report or urinalysis. Trial participants (N = 3022 patients with opioid dependence, mean age 36 years, 33% female, 14% Black, 16% Hispanic) were analyzed using a generalized linear mixed model. Treatment variables dose, Odds Ratio (OR) = 0.63 (95% Confidence Interval (95%CI) 0.59−0.67), dosing protocol, OR = 0.70 (95%CI 0.65−0.76), time-in-trial, OR = 0.75 (95%CI 0.71−0.80) and clinic visits, OR = 0.81 (95%CI 0.76−0.87) were significant (p-values < 0.001) protective factors. Treatment implications support higher doses of buprenorphine and greater engagement of patients with providers and clinic staff.

Sufficient Dimension Reduction: An Information-Theoretic Viewpoint

There has been a lot of interest in sufficient dimension reduction (SDR) methodologies, as well as nonlinear extensions in the statistics literature. The SDR methodology has previously been motivated by several considerations: (a) finding data-driven subspaces that capture the essential facets of regression relationships; (b) analyzing data in a ‘model-free’ manner. In this article, we develop an approach to interpreting SDR techniques using information theory. Such a framework leads to a more assumption-lean understanding of what SDR methods do and also allows for some connections to results in the information theory literature.

Long-term follow-up assessment of opioid use outcomes among individuals with comorbid mental disorders and opioid use disorder treated with buprenorphine or methadone in a randomized clinical trial

AIMS

To investigate whether reduction in opioid use differs when treated by either buprenorphine-naloxone (BUP) or methadone (MET) among adults with comorbid opioid use disorder (OUD) and mental disorders.

DESIGN, SETTING AND PARTICIPANTS

In a randomized controlled trial, adults with OUD were randomized to 24 weeks of either BUP or MET treatment and were followed up in 3-yearly assessments. The present secondary analyses were based on 597 participants who completed all assessments.

MEASUREMENTS

The outcome measure was the number of days of using opioids per month during the follow-up period. The Mini-International Neuropsychiatric Interview (MINI) was used to classify participants into three groups: life-time mood disorder (n = 302), life-time mental disorder other than mood disorder (n = 114) and no mental disorder (n = 181). Medication treatment (BUP, MET, no treatment) during the follow-up period was a time-varying predictor.

FINDINGS

Based on zero-inflated Poisson (ZIP) mixed regression analysis, it was found that relative to no treatment, opioid use during the follow-up was significantly reduced by BUP [odds ratio (OR) = 0.12, 95% confidence interval (CI) = 0.07-0.21 for any use; risk ratio (RR) = 0.77, 95% CI =0.66-0.89 for days of use] and by MET [OR = 0.33, 95% CI = 0.25-0.45 for any use; RR = 0.78, 95% CI = 0.72-0.84 for days of use]. Relative to MET, BUP was associated with a lower likelihood of any opioid use among participants with mood disorders (OR = 0.52, 95% CI = 0.36-0.74) and for participants without mental disorder (OR = 0.37, 95% CI = 0.21-0.66) and fewer number of days using opioids (RR = 0.37, 95% CI = 0.25-0.56) among participants with other mental disorders.

CONCLUSIONS

Among adults with comorbid opioid use disorder and mental disorders, treatment with buprenorphine-naloxone produced greater reductions in opioid use than treatment with methadone.

Psychiatric comorbidity and treatment outcomes in patients with opioid use disorder: Results from a multisite trial of buprenorphine-naloxone and methadone

BACKGROUND

Individuals treated for opioid use disorder (OUD) have high rates of psychiatric disorders potentially diminishing treatment outcomes. We examined long-term treatment experiences and outcomes by type of psychiatric disorder among participants who participated in the Starting Treatment with Agonist Replacement Therapies (START) study and its follow-up study.

METHODS

We categorized the 593 participants who completed the Mini-International Neuropsychiatric Interview (MINI) during the START follow-up study into four mutually exclusive groups to indicate current psychiatric diagnosis: 1) bipolar disorder (BPD; n = 51), 2) major depressive disorder (MDD; n = 85), 3) anxiety disorder (AXD; n = 121), and 4) no comorbid mental disorder (NMD; n = 336). We compared participants' baseline characteristics and treatment outcomes.

RESULTS

Groups with mental disorders had worse substance use outcomes and poorer psychosocial functioning than the NMD group. Participants with BPD had significantly more self-reported days using opioids (Mean: 8.6 for BPD vs. 3.4 days for NMD, p < 0.01) and heroin (Mean: 6.4 for BPD vs. 2.0 for MDD, 3.1 days for NMD, p < 0.05) in the 30 days prior to the final interview. Compared to patients without mental disorders, patients with MDD spent more time engaged with OUD pharmacotherapy during the ∼16-month period between MINI and final interview (mean: 71.6 % vs. 50.6 %; p < 0.001).

CONCLUSIONS

Our results show that treatment outcomes in individuals with OUD vary by psychiatric comorbidity groups, which supports the need for mental health assessment and treatment for psychiatric conditions in the context of pharmacotherapy for patients with OUD.

Long-acting buprenorphine vs. naltrexone opioid treatments in CJS-involved adults (EXIT-CJS)

The EXIT-CJS (N = 1005) multisite open-label randomized controlled trial will compare retention and effectiveness of extended-release buprenorphine (XR-B) vs. extended-release naltrexone (XR-NTX) to treat opioid use disorder (OUD) among criminal justice system (CJS)-involved adults in six U.S. locales (New Jersey, New York City, Delaware, Oregon, Connecticut, and New Hampshire). With a pragmatic, noninferiority design, this study hypothesizes that XR-B (n = 335) will be noninferior to XR-NTX (n = 335) in retention-in-study-medication treatment (the primary outcome), self-reported opioid use, opioid-positive urine samples, opioid overdose events, and CJS recidivism. In addition, persons with OUD not eligible or interested in the RCT will be recruited into an enhanced treatment as usual arm (n = 335) to examine usual care outcomes in a quasi-experimental observational cohort.

Gender differences in the associations of multiple psychiatric and chronic conditions with major depressive disorder among patients with opioid use disorder

PURPOSE

The study examined the associations of multiple psychiatric and chronic conditions with the self-reported history of major depressive disorder (MDD) among patients with opioid use disorder (OUD) and tested whether the associations differed by gender.

METHODS

We conducted a secondary data analysis of baseline data from a clinical trial including 1,646 participants with OUD, of which 465 had MDD. A variable cluster analysis was used to classify chronic medical and psychiatric conditions. Multivariable logistic regression analyses were used to estimate their associations with MDD in subjects with OUD.

RESULTS

Nine variables were divided into three clusters: cluster 1 included heart condition, hypertension, and liver problems; cluster 2 included gastrointestinal (GI) problems and head injury, and cluster 3 included anxiety disorder, bipolar disorder, and schizophrenia. The overall prevalence of MDD in participants with OUD was 28.3% (22.8% for males and 39.5% for females). Gender, anxiety disorder, schizophrenia, liver problems, heart condition, GI problems, and head injury were significantly associated with MDD. Gender-stratified analyses showed that bipolar disorder, liver problems and individuals with one chronic condition were associated with MDD only in males, whereas heart condition, hypertension, and GI problems were associated with MDD only in females. In addition, anxiety disorder, head injury, individuals with one or more than two psychiatric conditions, and individuals with more than two chronic conditions were associated with MDD regardless of gender.

CONCLUSIONS

Treatment plans in patients with OUD should not only address MDD but also co-morbid psychiatric and chronic medical conditions that occur with MDD.

Secondary Analysis of Pain Outcomes in a Large Pragmatic Randomized Trial of Buprenorphine/Naloxone Versus Methadone for Opioid Use Disorder

OBJECTIVE

Opioid use disorder (OUD) is associated with chronic pain. We investigated the association between medication treatments for OUD and pain in a post-hoc secondary analysis of a randomized trial of methadone versus buprenorphine/naloxone.

METHODS

1241 individuals with OUD participated in an open label, pragmatic randomized trial of methadone versus buprenorphine/naloxone in nine treatment programs licensed to dispense agonist medication for OUD between 2006 to 2009. In this post-hoc analysis, pain was dichotomized (present or not present) using responses from the Short Form-36. Logistic regression models were fit to test the effect of (1) having baseline pain on week 24 retention, (2) treatment assignment on improvement in pain among those reporting pain at baseline, and (3) pain improvement at week 4 on week 24 retention among those reporting pain at baseline.

RESULTS

Almost half (48.2%) of the sample reported pain at baseline. Participants with baseline pain did not significantly differ in week 24 retention compared to those without baseline pain. Among those reporting pain at baseline, there was no significant difference between treatment arms in improvement of pain at week 4, but improvement in pain at week 4 was associated with significantly greater odds of being retained at week 24 (OR [95% CI] = 1.76 [1.10, 2.82], P = 0.020).

CONCLUSION AND RELEVANCE

In this large multisite randomized trial of medication treatments for OUD, nearly half of the participants reported pain at baseline, and improvement in pain early in treatment was associated with increased likelihood of retention in treatment.

Prior National Drug Abuse Treatment Clinical Trials Network (CTN) opioid use disorder trials as background and rationale for NIDA CTN-0100 "optimizing retention, duration and discontinuation strategies for opioid use disorder pharmacotherapy (RDD)"

Opioid use disorder continues to be a significant problem in the United States and worldwide. Three medications—methadone, buprenorphine, and extended-release injectable naltrexone,— are efficacious for treating opioid use disorder (OUD). However, the utility of these medications is limited, in part due to poor rates of retention in treatment. In addition, minimum recovery milestones and other factors that influence when and whether individuals can safely discontinue medications are unknown. The National Drug Abuse Treatment Clinical Trials Network (CTN) study “Optimizing Retention, Duration, and Discontinuation Strategies for Opioid Use Disorder Pharmacotherapy” (RDD; CTN-0100) will be among the largest clinical trials on treatment of OUD yet conducted, consisting of two phases, the Retention phase, and the Duration-Discontinuation phase. The Retention phase, open to patients initiating treatment, will test different doses and formulations of buprenorphine (standard dose sublingual, high dose sublingual, or extended-release injection), and a digital therapeutic app delivering contingency management and cognitive behavioral counseling on the primary outcome of retention in treatment. The Discontinuation phase, open to patients in stable remission from OUD and choosing to discontinue medication (including participants from the Retention phase or from the population of patients treated at the clinical site, referred by an outside prescriber or self-referred) will study different tapering strategies for buprenorphine (sublingual taper vs taper with injection buprenorphine), and a digital therapeutic app which provides resources to promote recovery, on the primary outcome of relapse-free discontinuation of medication. This paper describes how the RDD trial derives from two decades of research in the CTN. Initial trials (CTN-0001; CTN-0002; CTN-0003) focused on opioid detoxification, showing buprenorphine-naloxone was effective for detoxification, but that acute detoxification did not appear to be an effective treatment strategy. Trials on comparative effectiveness of medications for opioid use disorder (MOUD) (CTN-0027; CTN-0030; and CTN-0051) highlighted the problem of dropout from treatment and few trials defined retention on MOUD as the primary outcome. Long-term follow-up studies on those patient samples demonstrated the importance of long-term continuation of medication for many patients to sustain remission. Overall, these trials highlight the potential of a stable research infrastructure such as CTN to advance treatment effectiveness through a programmatic succession of large clinical trials.

Projected Estimates of Opioid Mortality After Community-Level Interventions

Importance

The United States is experiencing a crisis of opioid overdose. In response, the US Department of Health and Human Services has defined a goal to reduce overdose mortality by 40% by 2022.

Objective

To identify specific combinations of 3 interventions (initiating more people to medications for opioid use disorder [MOUD], increasing 6-month retention with MOUD, and increasing naloxone distribution) associated with at least a 40% reduction in opioid overdose in simulated populations.

Design, Setting, and Participants

This decision analytical model used a dynamic population-level state-transition model to project outcomes over a 2-year horizon. Each intervention scenario was compared with the counterfactual of no intervention in simulated urban and rural communities in Massachusetts. Simulation modeling was used to determine the associations of community-level interventions with opioid overdose rates. The 3 examined interventions were initiation of more people to MOUD, increasing individuals' retention with MOUD, and increasing distribution of naloxone. Data were analyzed from July to November 2020.

Main Outcomes and Measures

Reduction in overdose mortality, medication treatment capacity needs, and naloxone needs.

Results

No single intervention was associated with a 40% reduction in overdose mortality in the simulated communities. Reaching this goal required use of MOUD and naloxone. Achieving a 40% reduction required that 10% to 15% of the estimated OUD population not already receiving MOUD initiate MOUD every month, with 45% to 60%% retention for at least 6 months, and increased naloxone distribution. In all feasible settings and scenarios, attaining a 40% reduction in overdose mortality required that in every month, at least 10% of the population with OUD who were not currently receiving treatment initiate an MOUD.

Conclusions and Relevance

In this modeling study, only communities with increased capacity for treating with MOUD and increased MOUD retention experienced a 40% decrease in overdose mortality. These findings could provide a framework for developing community-level interventions to reduce opioid overdose death.

A review of the pharmacogenomics of buprenorphine for the treatment of opioid use disorder

As the opioid epidemic continues to grow across the United States, the number of patients requiring treatment for opioid use disorder continues to climb. Although medication-assisted treatment presents a highly effective tool that can help address this epidemic, its use has been limited. Nonetheless, with easier dosing protocols (compared to the more complex dosing required of methadone due to its long and variable half-life) and fewer prescribing limitations (may be prescribed outside the setting of federally approved clinics), the increase in buprenorphine use in the United States has been dramatic in recent years. Despite buprenorphine's demonstrated efficacy, patient-specific factors can alter the response to the medications, which may lead to treatment failure in some patients. Clinical characteristics (sex, concurrent medications, and mental health comorbidities) as well as social determinants of health (housing status, involvement with the criminal justice system, and socioeconomic status) may impact treatment outcomes. Furthermore, a growing body of data suggests that genetic variations can alter pharmacological effects and influence therapeutic response. This review will cover the available pharmacogenomic data for the use of buprenorphine in the management of opioid use disorders. Pharmacogenomic determinants that affect opioid receptors, the dopaminergic system, metabolism of buprenorphine, and adverse events are discussed. Although much of the existing data comes from observational studies, clinical research is ongoing. Nevertheless, the development of pharmacogenomic-guided strategies has the potential to reduce opioid misuse, improve clinical outcomes, and save healthcare resources.

Impact of Pharmacological Treatments for Opioid Use Disorder on Mortality

The use of pharmacological treatments for opioid use disorders, including methadone, buprenorphine and naltrexone has been associated with a reduction in mortality compared with illicit opioid use. However, these treatments can also contribute significantly to the risk of death. The opioid agonists methadone and buprenorphine achieve clinical efficacy in patients with an opioid use disorder through suppressing craving and diminishing the effectiveness of illicit opioid doses, while the antagonist naltrexone blocks the action of opioids. Pharmacological differences between opioid pharmacotherapies then create different temporal patterns of protection and mortality risk, different risks of relapse to illicit opioid use, and variations in direct and indirect toxicity, which are revealed in clinical and epidemiological studies. Induction onto methadone and the cessation of oral naltrexone treatment are associated with an elevated risk of opioid poisoning, which is not apparent in patients treated with buprenorphine or sustained-release naltrexone. Beyond drug-related mortality, these pharmacotherapies can impact a participant's risk of death. Buprenorphine may also have some advantages over methadone in patients with depressive disorders or cardiovascular abnormalities. Naltrexone, which is also commonly prescribed to manage problem alcohol use, may reduce deaths in chronic co-alcohol users. Understanding these pharmacologically driven patterns then guides the judicious choice of drug and dosing schedule and the proactive risk management that is crucial to minimising the risk of death in treatment.

Buprenorphine Pharmacology Review: Update on Transmucosal and Long-acting Formulations

: Buprenorphine is an effective treatment for opioid use disorder. As a high-affinity, partial agonist for the mu-opioid receptor, buprenorphine suppresses opioid withdrawal and craving, reduces illicit opioid use, and blocks exogenous opioid effects including respiratory depression. Other pharmacologic benefits of buprenorphine are its superior safety profile compared with full opioid agonists and its long half-life that allows daily or less-than-daily dosing. New and innovative buprenorphine formulations, with pharmacokinetic profiles that differ from the original tablet formulation, continue to be developed. These include higher bioavailability transmucosal tablets and films and also 6-month implantable and monthly injectable products. This growing array of available formulations allows more choices for patients and increased opportunity for clinicians to individualize treatment; thus, it is important for buprenorphine prescribers to understand these differences.

A call for consensus in defining efficacy in clinical trials for opioid addiction: combined results from a systematic review and qualitative study in patients receiving pharmacological assisted therapy for opioid use disorder

Background

Given the complex nature of opioid addiction treatment and the rising number of available opioid substitution and antagonist therapies (OSAT), there is no ‘gold standard’ measure of treatment effectiveness, and each successive trial measures a different set of outcomes which reflect success in arbitrary or opportune terms. We sought to describe the variation in current outcomes employed across clinical trials for opioid addiction, as well as determine whether a discrepancy exists between the treatment targets that patients consider important and how treatment effectiveness is measured in the literature.

Methods

We searched nine commonly used databases (e.g., EMBASE, MEDLINE) from inception to August 1, 2015. Outcomes used across trials were extracted and categorized according to previously established domains. To evaluate patient-reported goals of treatment, semi-structured interviews were conducted with 18 adults undergoing methadone treatment.

Results

We identified 60 trials eligible for inclusion. Once outcomes were categorized into eight broad domains (e.g., abstinence/substance abuse), we identified 21 specific outcomes with furthermore 53 subdomains and 118 measurements. Continued opioid use and treatment retention were the most commonly reported measures (46%, n = 28). The majority of patients agreed that abstinence from opioids was a primary goal in their treatment, although they also stressed goals under-reported in clinical trials.

Conclusions

There is inconsistency in the measures used to evaluate the effectiveness of OSATs. Individual and population level decision making is being guided by a standard of effect considered useful to researchers yet in direct conflict with what patients deem important.

Trial registration

PROSPERO, CRD42013006507.

Clinical Trials for Opioid Use Disorder

This chapter describes recent clinical trials for opioid use disorder (OUD), an area that has rapidly accelerated in response to the opioid overdose crisis in the USA and newly appropriated funding. Trials involve a wide range of compounds including cannabinoids and psychedelics, new and existing compounds targeting domains emerging from addiction neuroscience, agents repurposed from other indications, and novel strategies including vaccines, enzymes, and other biologicals. In parallel, new formulations of existing compounds offer immediate promise, as do a variety of web-based interventions and smartphone-delivered apps. Trials focused on implementing existing effective interventions in mainstream healthcare settings, and others focused on special populations, e.g., adolescents, criminal justice, pregnant women, native Americans, etc., have the potential to vastly expand treatment in the near term. Given the range of ongoing and recent trials, this chapter is not intended to be an exhaustive review but rather to present an overview of approaches within the framework of the opioid treatment cascade and the context of current OUD pharmacotherapies.

Treating Opioid Use Disorder With a Monthly Subcutaneous Buprenorphine Depot Injection: 12-Month Safety, Tolerability, and Efficacy Analysis

BACKGROUND

BUP-XR (RBP-6000 or SUBLOCADE) is the first Food and Drug Administration-approved subcutaneously administered monthly extended-release buprenorphine medication for the treatment of moderate or severe opioid use disorder. The primary objective of this phase III study was to assess the long-term safety, tolerability, and efficacy of BUP-XR.

METHODS

This open-label multicenter study in adults with moderate or severe opioid use disorder enrolled 257 participants from a previously conducted placebo-controlled, double-blind phase III study (rollover group) and 412 de novo participants not previously treated with BUP-XR. Participants received an initial injection of BUP-XR 300 mg and subsequent monthly 300 mg or 100 mg flexible doses. By study end, participants received up to 12 injections.

RESULTS

Overall, 66.8% of participants reported more than 1 treatment-emergent adverse event (TEAE). Injection-site TEAEs (13.2% of participants) were mostly mild or moderate in severity. There were no clinically meaningful changes in safety assessments. An integrated analysis of the double-blind and open-label study participants showed that the incidence of TEAEs, including injection-site TEAEs, was lower in the second 6 months of treatment versus the first 6 months. After 12 months of treatment, 61.5% of the rollover participants and 75.8% of the de novo participants were abstinent. Retention rates after 12 months were 50.6% for the participants who initiated BUP-XR in the double-blind study and 50.5% for de novo participants.

CONCLUSIONS

This study demonstrates that the clinical benefits and acceptable safety profile of BUP-XR demonstrated in the 6-month double-blind study are sustained over a 12-month open-label study, with lower incidence of TEAEs in the second 6 months of treatment.

Inpatient Addiction Medicine Consultation and Post-Hospital Substance Use Disorder Treatment Engagement: a Propensity-Matched Analysis

BACKGROUND

Hospitalizations due to medical and surgical complications of substance use disorder (SUD) are rising. Most hospitals lack systems to treat SUD, and most people with SUD do not engage in treatment after discharge.

OBJECTIVE

Determine the effect of a hospital-based addiction medicine consult service, the Improving Addiction Care Team (IMPACT), on post-hospital SUD treatment engagement.

DESIGN

Cohort study using multivariable analysis of Oregon Medicaid claims comparing IMPACT patients with propensity-matched controls.

PARTICIPANTS

18-64-year-old Oregon Medicaid beneficiaries with SUD, hospitalized at an Oregon hospital between July 1, 2015, and September 30, 2016. IMPACT patients (n = 208) were matched to controls (n = 416) using a propensity score that accounted for SUD, gender, age, race, residence region, and diagnoses.

INTERVENTIONS

IMPACT included hospital-based consultation care from an interdisciplinary team of addiction medicine physicians, social workers, and peers with lived experience in recovery. IMPACT met patients during hospitalization; offered pharmacotherapy, behavioral treatments, and harm reduction services; and supported linkages to SUD treatment after discharge.

OUTCOMES

Healthcare Effectiveness Data and Information Set (HEDIS) measure of SUD treatment engagement, defined as two or more claims on two separate days for SUD care within 34 days of discharge.

RESULTS

Only 17.2% of all patients were engaged in SUD treatment before hospitalization. IMPACT patients engaged in SUD treatment following discharge more frequently than controls (38.9% vs. 23.3%, p < 0.01; aOR 2.15, 95% confidence interval [CI] 1.29-3.58). IMPACT participation remained associated with SUD treatment engagement when limiting the sample to people who were not engaged in treatment prior to hospitalization (aOR 2.63; 95% CI 1.46-4.72).

CONCLUSIONS

Hospital-based addiction medicine consultation can improve SUD treatment engagement, which is associated with reduced substance use, mortality, and other important clinical outcomes. National expansion of such models represents an opportunity to address an enduring gap in the SUD treatment continuum.

Effects of access barriers and medication acceptability on buprenorphine-naloxone treatment utilization over 2 years: Results from a multisite randomized trial of adults with opioid use disorder

BACKGROUND

Nationwide efforts seek to address the opioid epidemic by increasing access to medications for opioid use disorder (OUD), particularly with buprenorphine. A poorly understood challenge is that among individuals with OUD who do receive buprenorphine, many do not adhere to the pharmacotherapy long enough to achieve sustained benefits. We aimed to identify factors associated with buprenorphine treatment utilization over time.

METHODS

We used random-intercept modeling to identify factors associated with buprenorphine treatment utilization over 2 years after first follow-up by 789 individuals with OUD who had participated in a multi-site randomized clinical trial of buprenorphine compared to methadone. Key predictors were participants' reports of buprenorphine treatment accessibility and acceptability (assessed at first follow-up) and their interaction effects, controlling for baseline randomization status, sociodemographics, and other covariates.

RESULTS

Approximately 9.3-11.2% of participants utilized buprenorphine treatment over the 2 years of follow-up. Interaction effects indicated that individuals who perceived buprenorphine to be both accessible and acceptable were most likely to use buprenorphine during follow-up, controlling for other factors. In contrast, individuals who perceived buprenorphine to be unacceptable were least likely to use buprenorphine, regardless the level of perceived access to the medication. Buprenorphine treatment utilization was also negatively associated with Hispanic ethnicity, West coast context, and cumulative months receiving methadone treatment and incarceration during follow-up.

CONCLUSIONS

To engage more individuals with OUD in long-term treatment with buprenorphine, interventions should target buprenorphine treatment acceptability, in addition to increasing buprenorphine access, and tailor efforts to meet the needs of vulnerable populations.

TRIAL REGISTRATION

The START Follow-up Study on ClinicalTrials.gov (NCT01592461).

Criminal justice outcomes over 5 years after randomization to buprenorphine-naloxone or methadone treatment for opioid use disorder

AIMS

To compare long-term criminal justice outcomes among opioid-dependent individuals randomized to receive buprenorphine or methadone.

DESIGN, SETTING AND PARTICIPANTS

A 5-year follow-up was conducted in 2011-14 of 303 opioid-dependent participants entering three opioid treatment programs in California, USA in 2006-09 and randomized to receive either buprenorphine/naloxone or methadone.

INTERVENTION AND COMPARATOR

Participants received buprenorphine/naloxone (BUP; n = 179) or methadone (MET; n = 124) for 24 weeks and then were tapered off their treatment over ≤ 8 weeks or referred for ongoing clinical treatment. Midway through the study, the randomization scheme was switched from 1 : 1 BUP : MET to 2 : 1 because of higher dropout in the BUP arm.

MEASUREMENTS

Study outcomes included arrests and self-reported incarceration. Predictors included randomization condition (buprenorphine versus methadone), age, gender, race/ethnicity, use of cocaine, drug injection in the 30 days prior to baseline and study site. Treatment status (buprenorphine, methadone, none) during follow-up was included as a time-varying covariate.

FINDINGS

There was no significant difference by randomization condition in the proportion arrested (buprenorphine: 55.3%, methadone: 54.0%) or incarcerated (40.9%, 47.3%) during follow-up. Among methadone-randomized individuals, arrest was less likely with methadone treatment (0.50, 0.35-0.72) during follow-up (relative to no treatment) and switching to buprenorphine had a lower likelihood of arrest than those receiving no treatment (0.39, 0.18-0.87). Among buprenorphine-randomized individuals, arrest was less likely with receipt of buprenorphine (0.49, 0.33-0.75) during follow-up and switching to methadone had a similar likelihood of arrest as methadone-randomized individuals receiving no treatment. Likelihood of arrest was also negatively associated with older age (0.98, 0.96-1.00); it was positively associated with Hispanic ethnicity (1.63, 1.04-2.56), cocaine use (2.00, 1.33-3.03), injection drug use (2.19, 1.26-3.83), and study site.

CONCLUSIONS

In a US sample of people treated for opioid use disorder, continued treatment with either buprenorphine or methadone was associated with a reduction in arrests relative to no treatment. Cocaine use, injection drug use, Hispanic ethnicity and younger age were associated with higher likelihood of arrest.

Buprenorphine Treatment for Opioid Use Disorder: An Overview

Opioid use disorder affects over 26 million individuals worldwide. There are currently three World Health Organization-recommended and US Food and Drug Administration-approved medication treatments for opioid use disorder: the full opioid agonist methadone, the opioid partial agonist buprenorphine, and the opioid receptor antagonist naltrexone. We provide a review of the use of buprenorphine for the treatment of opioid use disorder and discuss the barriers, challenges, risks, and efficacy of buprenorphine treatment vs. other treatments. Although evidence from numerous studies has shown buprenorphine to be effective for the treatment of opioid use disorder, a majority of patients with opioid use disorder do not receive buprenorphine, or any other medical treatment. We review the different formulations of buprenorphine, including newer long-acting injectable formulations that may decrease the risk of diversion and improve adherence.

Physicians' Decision-making When Implementing Buprenorphine With New Patients: Conjoint Analyses of Data From a Cohort of Current Prescribers

OBJECTIVES

Few studies have considered how providers make decisions to prescribe buprenorphine to new patients with opioid use disorder. This study examined the relative importance of patients' clinical, financial, and social characteristics on physicians' decision-making related to willingness to prescribe buprenorphine to new patients and the number of weeks of medication that they are willing to initially prescribe after induction.

METHODS

A national sample of 1174 current prescribers was surveyed. Respondents rated willingness to prescribe on a 0 to 10 scale and indicated the number of weeks of medication (ranging from none to >4 weeks) for 20 hypothetical patients. Conjoint analysis estimated relative importance scores and part-worth utilities for these 2 outcome ratings.

RESULTS

The mean rating for willingness to prescribe was 5.52 (SD 2.47), indicating a moderate willingness to implement buprenorphine treatment. The mean prescription length was 2.06 (SD 1.34), which corresponds to 1 week of medication. For both ratings, the largest importance scores were for other risky substance use, method of payment, and spousal involvement in treatment. Illicit benzodiazepine use, having Medicaid insurance to pay for the office visit, and having an opioid-using spouse were negatively associated with these outcome ratings, whereas a history of no risky alcohol or benzodiazepine use, cash payment, and having an abstinent spouse were positively associated with both ratings.

CONCLUSIONS

Reticence to prescribe to individuals using an illicit benzodiazepine and individuals with a drug-using spouse aligns with practice guidelines. However, reluctance to prescribe to patients with Medicaid may hamper efforts to expand access to treatment.

A systematic review of sex differences in treatment outcomes among people with opioid use disorder receiving buprenorphine maintenance versus other treatment conditions

BACKGROUND

Opioid use disorder is a major health concern in North America. Currently, buprenorphine is one of the most common pharmacological interventions used to treat opioid use disorder. Despite increasing prevalence of opioid use disorder among females, little is known about sex considerations in relation to treatment with buprenorphine.

METHODS

CINAHL, PsycINFO, EMBASE, PubMed/MEDLINE and Cochrane Central were searched for randomized controlled trials examining buprenorphine maintenance versus other medication-assisted treatment, placebo, or withdrawal management to determine if there were any sex differences in treatment outcomes reported.

RESULTS

This review included 25 studies and found that only 52% included information related to sex differences in treatment outcomes or discussed any sex considerations in their studies. Of the 6,466 patients represented by these studies, only 26% were female. Of the studies conducting sex-specific analyses, seven studies examined treatment retention, five examined opioid use, two examined other substance use and one examined sexual risk behaviours. However, due to mixed findings, small sample sizes, and inability to conduct meta-analyses, no conclusive statements can be made about sex differences in these outcomes. None of the studies described sex differences in quality of life, legal involvement or mental and physical health.

CONCLUSIONS

Low numbers of females have been included in randomized controlled trials examining buprenorphine compared to males. While sex differences in treatment outcomes were identified in this review, further research is needed in order to add to these findings. Future studies should include greater numbers of female participants and conduct sex-specific analyses.

Replication of the pharmacogenetic effect of rs678849 on buprenorphine efficacy in African-Americans with opioid use disorder

Many patients with opioid use disorder do not have successful outcomes during treatment but the underlying reasons are not well understood. An OPRD1 variant (rs678849) was previously associated with methadone and buprenorphine efficacy in African-Americans with opioid use disorder. The objective of this study was to determine if the effect of rs678849 on opioid use disorder treatment outcome could be replicated in an independent population. Participants were recruited from African-American patients who had participated in previous studies of methadone or buprenorphine treatment at the outpatient treatment research clinic of the NIDA Intramural Research Program in Baltimore, MD, USA between 2000 and 2017. Rs678849 was genotyped retrospectively, and genotypes were compared with urine drug screen results from the previous studies for opioids other than the one prescribed for treatment. Genotypes were available for 24 methadone patients and 55 buprenorphine patients. After controlling for demographics, the effect of rs678849 genotype was significant in the buprenorphine treatment group (RR = 1.69, 95% confidence interval (CI) 1.59-1.79, p = 0.021). Buprenorphine patients with the C/C genotype were more likely to have opioid-positive drug screens than individuals with the C/T or T/T genotypes, replicating the original pharmacogenetic finding. The effect of genotype was not significant in the methadone group (p = 0.087). Thus, the genotype at rs678849 is associated with buprenorphine efficacy in African-Americans being treated for opioid use disorder. This replication suggests that rs678849 genotype may be a valuable pharmacogenetic marker for deciding which opioid use disorder medication to prescribe in this population.

Treatment of opioid dependence with buprenorphine: current update

Opioid maintenance treatment is the first-line approach in opioid dependence. Both the full opioid agonist methadone (MET) and the partial agonist buprenorphine (BUP) are licensed for the treatment of opioid dependence. BUP differs significantly from MET in its pharmacology, side effects, and safety issues. For example, the risk of respiratory depression is lower than with MET. The risk of diversion and injection of BUP have been reduced by also making it available as a tablet containing the opioid antagonist naloxone. This review summarizes the clinical effects of BUP and examines possible factors that can support decisions regarding the use of BUP or MET in opioid-dependent people.

A brief review of the genetics and pharmacogenetics of opioid use disorders

Increased physician prescribing of opioids to treat chronic nonprogressive pain has been accompanied by an increase in opioid addiction. Twin studies of opioid addiction are consistent with an inherited component of risk, approximately 50%. Several genome-wide association study (GWAS) reports indicate that genetic risk for opioid addiction is conveyed by many alleles of small effect (odds ratios <1.5). These reports have detected alleles in potassium-ion-channel genes (KCNC1 and KCNG2) and in a glutamate receptor auxiliary protein (CNIH3). Additionally, a variant at the µ-opioid receptor gene (OPRM1), which regulates OPRM1 expression appears promising. In pharmacogenetics of opioid addictions, methadone dose may be regulated by variants in cytochrome P450 2B6 (CYP2B6), a methadone-metabolizing enzyme, and by a locus 300 kb 5' to OPRM1. A δ-opioid-receptor gene single-nucleotide polymorphism may predict treatment response to methadone versus buprenorphine. To achieve better progress, larger sample sizes are needed for GWAS research, including controls with chronic opioid exposure, but no addiction. Large clinical trials comparing effective pharmacotherapies for opioid addiction (naltrexone, methadone, and buprenorphine) are needed for pharmacogenetic progress.

A review of contingency management for the treatment of substance-use disorders: adaptation for underserved populations, use of experimental technologies, and personalized optimization strategies

This review of contingency management (CM; the behavior-modification method of providing reinforcement in exchange for objective evidence of a desired behavior) for the treatment of substance-use disorders (SUDs) begins by describing the origins of CM and how it has come to be most commonly used during the treatment of SUDs. Our core objective is to review, describe, and discuss three ongoing critical advancements in CM. We review key emerging areas wherein CM will likely have an impact. In total, we qualitatively reviewed 31 studies in a systematic fashion after searching PubMed and Google Scholar. We then describe and highlight CM investigations across three broad themes: adapting CM for underserved populations, CM with experimental technologies, and optimizing CM for personalized interventions. Technological innovations that allow for mobile delivery of reinforcers in exchange for objective evidence of a desired behavior will likely expand the possible applications of CM throughout the SUD-treatment domain and into therapeutically related areas (eg, serious mental illness). When this mobile technology is coupled with new, easy-to-utilize biomarkers, the adaptation for individual goal setting and delivery of CM-based SUD treatment in hard-to-reach places (eg, rural locations) can have a sustained impact on communities most affected by these disorders. In conclusion, there is still much to be done, not only technologically but also in convincing policy makers to adopt this well-established, cost-effective, and evidence-based method of behavior modification.

Correlates of Long-Term Opioid Abstinence After Randomization to Methadone Versus Buprenorphine/Naloxone in a Multi-Site Trial

Opioid use disorder (OUD) is a chronic, relapsing condition with severe negative health consequences. Previous studies have reported that 5-year opioid abstinence is a good predictor of reduced likelihoods of relapse, but factors that shape long-term opioid abstinence are poorly understood. The present study is based on data from a prospective study of 699 adults with OUD who had been randomized to either methadone or buprenorphine/naloxone and who were followed for at least 5 years. During the 5 years prior to the participants' last follow-up interview, 232 (33.2%) had achieved 5-year abstinence from heroin. Of those 232, 145 (20.7% of the total) had remained abstinent from both heroin and other opioids (e.g., hydrocodone, oxycodone, other opioid analgesics, excluding methadone or buprenorphine). Compared to non-abstinent individuals, those in both categories of opioid abstinence had lower problem severity in health and social functioning at the final follow-up. Logistic regression results indicated that cocaine users and injection drug users were less likely to achieve 5-year heroin abstinence, whereas Hispanics (vs. whites) and those treated in clinics on the West Coast (vs. East) were less likely to achieve 5-year abstinence from heroin and other opioids. For both abstinence category groups, abstinence was positively associated with older age at first opioid use, lower impulsivity, longer duration of treatment for OUD, and greater social support. Reducing cocaine use and injection drug use and increasing social support and retention in treatment may help maintain long-term abstinence from opioids among individuals treated with agonist pharmacotherapy.

Alcohol and Opioid Use, Co-Use, and Chronic Pain in the Context of the Opioid Epidemic: A Critical Review

The dramatic increase in opioid misuse, opioid use disorder (OUD), and opioid-related overdose deaths in the United States has led to public outcry, policy statements, and funding initiatives. Meanwhile, alcohol misuse and alcohol use disorder (AUD) are a highly prevalent public health problem associated with considerable individual and societal costs. This study provides a critical review of alcohol and opioid misuse, including issues of prevalence, morbidity, and societal costs. We also review research on interactions between alcohol and opioid use, the influence of opioids and alcohol on AUD and OUD treatment outcomes, respectively, the role of pain in the co-use of alcohol and opioids, and treatment of comorbid OUD and AUD. Heavy drinking, opioid misuse, and chronic pain individually represent significant public health problems. Few studies have examined co-use of alcohol and opioids, but available data suggest that co-use is common and likely contributes to opioid overdose-related morbidity and mortality. Co-use of opioids and alcohol is related to worse outcomes in treatment for either substance. Finally, chronic pain frequently co-occurs with use (and co-use) of alcohol and opioids. Opioid use and alcohol use are also likely to complicate the treatment of chronic pain. Research on the interactions between alcohol and opioids, as well as treatment of the comorbid disorders is lacking. Currently, most alcohol research excludes patients with OUD and there is lack of measurement in both AUD and OUD research in relation to pain-related functioning. Research in those with chronic pain often assesses opioid use, but rarely assesses alcohol use or AUD. New research to examine the nexus of alcohol, opioids, and pain, as well as their treatment, is critically needed.

Pharmacogenetic analysis of opioid dependence treatment dose and dropout rate

BACKGROUND

Currently, no pharmacogenetic tests for selecting an opioid-dependence pharmacotherapy have been approved by the US Food and Drug Administration.

OBJECTIVES

Determine the effects of variants in 11 genes on dropout rate and dose in patients receiving methadone or buprenorphine/naloxone (ClinicalTrials.gov Identifier: NCT00315341).

METHODS

Variants in six pharmacokinetic genes (CYP1A2, CYP2B6, CYP2C19, CYP2C9, CYP2D6, CYP3A4) and five pharmacodynamic genes (HTR2A, OPRM1, ADRA2A, COMT, SLC6A4) were genotyped in samples from a 24-week, randomized, open-label trial of methadone and buprenorphine/naloxone for the treatment of opioid dependence (n = 764; 68.7% male). Genotypes were then used to determine the metabolism phenotype for each pharmacokinetic gene. Phenotypes or genotypes for each gene were analyzed for association with dropout rate and mean dose.

RESULTS

Genotype for 5-HTTLPR in the SLC6A4 gene was nominally associated with dropout rate when the methadone and buprenorphine/naloxone groups were combined. When the most significant variants associated with dropout rate were analyzed using pairwise analyses, SLC6A4 (5-HTTLPR) and COMT (Val158Met; rs4860) had nominally significant associations with dropout rate in methadone patients. None of the genes analyzed in the study was associated with mean dose of methadone or buprenorphine/naloxone.

CONCLUSIONS

This study suggests that functional polymorphisms related to synaptic dopamine or serotonin levels may predict dropout rates during methadone treatment. Patients with the S/S genotype at 5-HTTLPR in SLC6A4 or the Val/Val genotype at Val158Met in COMT may require additional treatment to improve their chances of completing addiction treatment. Replication in other methadone patient populations will be necessary to ensure the validity of these findings.

Distinctive Trajectories of Opioid Use Over an Extended Follow-up of Patients in a Multisite Trial on Buprenorphine + Naloxone and Methadone

OBJECTIVES

Uncovering heterogeneities in longitudinal patterns (trajectories) of opioid use among individuals with opioid use disorder can increase our understanding of disease progression and treatment responses to improve care. The present study aims to identify distinctive opioid use trajectories and factors associated with these patterns among participants randomized to treatment with methadone (MET) or buprenorphine + naloxone (BUP).

METHODS

Growth mixture modeling was applied to identify distinctive opioid use trajectories among 795 opioid users after their enrollment in a multisite trial during 2006 to 2009, with follow-up interviews conducted during 2011 to 2014.

RESULTS

Four distinctive trajectories were identified based on opioid use over the follow-up period: low use (42.0%), high use (22.3%), increasing use (17.1%), and decreasing use (18.6%). Greater odds of being in the high use group (relative to low use) was associated with Hispanics (relative to African American, odds ratio [OR] 3.21), injection drug use (OR 2.12), higher mental health functioning at baseline (OR 1.23), location on the West Coast (vs East Coast, OR 2.15), and randomization to BUP (relative to MET, OR 1.53). High use and increasing use groups had greater severity in problems related to drug, employment, legal, and social/family relationships, and worsened mental health functioning at follow-up. Participation in treatment significantly accounted for both within and between-group differences in opioid use.

CONCLUSIONS

Continued treatment is necessary to reduce risk for opioid use and related adverse consequences, particularly among individuals (eg, injecting drug) at risk for consistently high level of opioid use.

Methadone Treatment of Opiate Addiction: A Systematic Review of Comparative Studies

Opiate misuse is a chronic relapsing disease that has become an epidemic in the United States. Methadone is the mainstay of treatment for opiate addiction and has been researched widely. Recently, new avenues of treatment have been researched and developed. The objective of this review is to study methadone in comparison to other pharmacological options available or being considered for opiate addiction treatment through a methodical search and review of evidence provided by recent clinical trials conducted in this regard. There is a paucity of high quality randomized controlled trials focusing on the comparison between buprenorphine and methadone for treatment of opiate use disorder. Buprenorphine should be researched more for patient retention and satisfaction, as well as for its prospect for better outcomes in neonatal abstinence syndrome to generate more decisive recommendations. Current data suggest monitoring of liver enzymes with the use of buprenorphine/naloxone for better liver outcomes. In light of the analyzed data, the authors conclude that methadone should still be considered the preferred treatment mode in comparison to slow-release oral morphine and heroin.

Causes of death and expected years of life lost among treated opioid-dependent individuals in the United States and Taiwan

AIMS

This study compared the cause-specific standardized mortality ratios (SMRs) and expected years of life lost (EYLL) among opioid-dependent individuals in the United States and Taiwan.

METHODS

Survival data came from two cohorts followed until 2014: The U.S. data were based on a randomized trial of 1267 opioid-dependent participants enrolled between 2006 and 2009; the Taiwan data were from a study of 983 individuals that began in 2006, when opioid agonist treatment (OAT) was implemented in Taiwan. SMRs were calculated for each national cohort and compared. Kaplan-Meier estimation was performed on the survival data, then lifespans were extrapolated to 70 years (840 months) to estimate life expectancy using a semi-parametric method. EYLLs for both cohorts were estimated by subtracting their life expectancies from the age- and gender-matched referents within the general population of their respective country.

RESULTS

Compared with age- and gender-matched referents, the SMRs were 3.2 for the U.S. sample and 7.8 for the Taiwan sample; the EYLLs were 7.7 and 16.4 years, respectively. Half of decedents died of unnatural causes in both cohorts; overdose deaths predominated in the U.S. and suicide in Taiwan.

CONCLUSIONS

Our study identified differences by country in EYLL and causes of deaths. These findings suggest that intervention strategies to reduce mortality risk by overdose (particularly in the U.S.) and suicide (particularly in Taiwan) are urgently needed in these countries.