Ethical and clinical safety considerations in the design of an effectiveness trial: A comparison of buprenorphine versus naltrexone treatment for opioid dependence

Impact of Medication-Based Treatment on Health Care Utilization Among Individuals With Opioid Use Disorder

OBJECTIVE

This study evaluated the association between medication for opioid use disorder (MOUD) and health care utilization over time among a sample of treatment-seeking individuals with opioid use disorder. In contrast to previous studies, this study used a novel measure of MOUD adherence, more comprehensive utilization data, and analyses that controlled for detailed individual and social determinants of health.

METHODS

This study was a secondary analysis of a comparative effectiveness trial (N=570) of extended-release naltrexone versus buprenorphine-naloxone. The outcome of interest was usage of nonstudy acute care, inpatient and outpatient addiction services, and other outpatient services across 36 weeks of assessment. Adherence (percentage of days taking MOUD) was defined as low (<20%), medium (≥20% but <80%), or high (≥80%). A two-part model evaluated the probability of utilizing a resource and the quantity (utilization days) of the resource consumed. A time-varying approach was used to examine the effect of adherence in a given month on utilization in the same month, with analyses controlling for a wide range of person-level characteristics.

RESULTS

Participants with high adherence (vs. low) were significantly less likely to use inpatient addiction (p<0.001) and acute care (p<0.001) services and significantly more likely to engage in outpatient addiction (p=0.045) and other outpatient (p=0.042) services.

CONCLUSIONS

These findings reinforce the understanding that greater MOUD adherence is associated with reduced usage of high-cost health services and increased usage of outpatient care. The results further suggest the need for enhanced access to MOUD and for interventions that improve adherence.

Secondary Analysis of Agreement Between Negative Timeline Follow Back Report and Negative Urine Toxicology in a Large Trial of Individuals with Opioid Use Disorder

OBJECTIVES

Timeline follow-back (TLFB) is a self-report measure commonly used as a method of assessing historical drug use in both clinical and research settings. Our study considered rates of agreement between TLFB and an objective biological assay of opioid use.

METHODS

We calculated the rates of agreement between negative report of opioid use for the most recent 8 days on TLFB and urine toxicology (UTOX) results in a large multisite opioid use disorder treatment trial.

RESULTS

In total, 3986 assessments were provided by trial participants with both UTOX and TLFB during weeks 1 to 12, 2716 during weeks 13 to 24, and 325 at week 28. Rates of disagreement between negative TLFB and positive opioid UTOX were 2.33% of all assessments (21.68% of those with positive UTOX) over weeks 1 to 12, 2.06% of all assessment (25.00% of those with positive UTOX) over weeks 13 to 24, and 9.85% of all assessments (26.02% of those with positive UTOX) at week 28.

CONCLUSIONS

Negative TLFB seems to be generally associated with negative results on urine toxicology.

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).

Time-lagged association between counseling and/or 12-Step attendance with subsequent opioid use in a secondary analysis from a randomized, clinical trial of medications for opioid use disorder

Introduction

Psychosocial support is recommended in conjunction with medication for opioid use disorder (MOUD), although optimal "dose," modality, and timing of participation is not established. This study comprised a secondary analysis of counseling and 12-Step attendance and subsequent opioid use in a MOUD randomized clinical trial.

Methods

The parent study randomly assigned 570 participants to receive buprenorphine-naloxone (BUP-NX, n=287) or extended-release injectable naltrexone (XR-NTX, n=283). Mixed-effects logistic regression models were fit with opioid use as the response variable, and a counseling/12-Step attendance predictor. Differences by treatment assignment were examined.

Results

Any counseling or 12-Step attendance was associated with reduced odds of opioid use at the subsequent visit, whether considered individually or aggregated across type. A continuous relationship was observed for 12-Step attendance (F(1,5083)=5.01, p=.025); with each additional hour associated with 13% (95% CI: 0.83, 0.90) reduction in odds of opioid use. The strength of this association grew over time. In the BUP-NX arm, group counseling was associated with a greater reduction in odds of opioid use than for XR-NTX, (OR=0.32 (95% CI: .22, 0.48) vs. OR=0.69 (95% CI: 0.43, 1.08)). For XR-NTX, 12-Step was associated with a greater reduction in odds of opioid use (OR=0.35 (95% CI: 0.22, 0.54) vs. OR=0.65 (95% CI: 0.47, 0.89) for BUP-NX)).

Conclusions

Psychosocial engagement has a proximal association with opioid use, the strength of that association may grow with dose and time. Alternatively, more motivated individuals may both attend more counseling/12-Step and have better treatment outcomes, or the relationship may be reciprocal.

Population-level impact of initiating pharmacotherapy and linking to care people with opioid use disorder at inpatient medically managed withdrawal programs: an effectiveness and cost-effectiveness analysis

BACKGROUND AND AIMS

Medications for opioid use disorder (MOUD) are shown to reduce opioid use and the risk of overdose. People with opioid use disorder (OUD) who exit inpatient medically managed withdrawal programs (detox) without initiating MOUD and linking to outpatient care have high rates of overdose. While detox encounters provide a theoretical opportunity for MOUD initiation, this is not ubiquitous in the United States. We used simulation modeling to estimate the population-level health effects and cost-effectiveness of a policy encouraging MOUD initiation during inpatient detox encounters.

DESIGN, SETTING AND PARTICIPANTS

We employed a dynamic population state-transition model to evaluate the effectiveness and cost-effectiveness of using detox programs as venues for initiating MOUD in Massachusetts, United States. We compared standard of care, where no detox patients initiate MOUD or link to outpatient MOUD providers, to strategies of offering MOUD to detox patients and linking those patients to outpatient MOUD.

MEASURES

Budgetary impact to the Massachusetts health-care sector, incremental cost-effectiveness ratios (ICER) and total counts and percentage differences of fatal overdoses prevented.

FINDINGS

Initiating MOUD in detox with perfect linkage to outpatient MOUD would reduce fatal overdoses by 4.5% [95% confidence interval (CI) = 2.3-5.9], at an ICER of $56 000 per quality-adjusted life-year (QALY) gained, compared with the standard of care. With moderate linkage, fatal overdoses would be reduced by 2.3% (95% CI= 1.2-3.1) with an ICER of $78 500 per QALY gained, compared with standard of care. Budgetary increase to Massachusetts health-care spending ranged from 0.5-1%.

CONCLUSION

A simulation model indicates that initiation of medications for opioid use disorder and linkage policies among detox patients in Massachusetts, USA could prevent fatal opioid overdoses in the opioid use disorder population and would be cost-effective from a health-care sector perspective.

Association between dynamic dose increases of buprenorphine for treatment of opioid use disorder and risk of relapse

BACKGROUND AND AIMS

Dynamic, adaptive pharmacologic treatment for opioid use disorder (OUD) has been previously recommended over static dosing to prevent relapse, and is aligned with personalized medicine. However, there has been no quantitative evidence demonstrating its advantage. Our objective was to estimate the extent to which a hypothetical intervention that increased buprenorphine dose in response to opioid use would affect risk of relapse over 24 weeks of follow-up.

DESIGN

A secondary analysis of the buprenorphine arm of an open-label randomized controlled 24-week comparative effectiveness trial, 2014-17.

SETTING

Eight community addiction treatment programs in the United States.

PARTICIPANTS

English-speaking adults with DSM-5 OUD, recruited during inpatient admission (n = 270). Participants were mainly white (65%) and male (72%).

INTERVENTION(S)

Participants were treated with daily sublingual buprenorphine-naloxone (BUP-NX), with dose based on clinical indication, determined by the provider. We examined a hypothetical intervention of increasing dose in response to opioid use.

MEASUREMENTS

Outcome was relapse to regular opioid use during the 24 weeks of outpatient treatment, assessed in a survival framework. We estimated the relapse-free survival curves of participants under a hypothetical (i.e. counterfactual) intervention in which their BUP-NX dosage would be increased following their own subject-specific opioid use during the first 12 weeks of treatment versus a hypothetical intervention in which dose would remain constant.

FINDINGS

We estimated that increasing BUP-NX dose in response to recent opioid use would lower risk of relapse by 19.17 percentage points [95% confidence interval (CI) = -32.17, -6.18) (additive risk)] and 32% (0.68, 95% CI = 0.49, 0.86) (relative risk). The number-needed-to-treat with this intervention to prevent a single relapse is 6.

CONCLUSIONS

In people with opioid use disorder, a hypothetical intervention that increases sublingual buprenorphine-naloxone dose in response to opioid use during the first 12 weeks of treatment appears to reduce risk of relapse over 24 weeks, compared with holding the dose constant after week 2.

Longitudinal study of impact of medication for opioid use disorder on Hamilton Depression Rating Scale

OBJECTIVE

This study aimed to evaluate the longitudinal treatment effect on depression measured by Hamilton Depression Rating Scale (HAM-D) score in a randomized clinical trial for the treatment of opioid use disorder (OUD).

METHODS

We conducted a secondary data analysis of data from the National Institute on Drug Abuse's Clinical Trials Network Protocol-0051. Patients with OUD (N = 570) were randomized to receive buprenorphine/naloxone (BUP-NX, n = 287) or extended-release naltrexone injection (XR-NTX, n = 283). The HAM-D score was completed at baseline and follow-up visit up to 36 weeks. A linear mixed model analysis was performed for log transformed HAM-D score and a generalized linear mixed model analysis was conducted for depression status.

RESULTS

Compared with BUP-NX, subjects randomized to XR-NTX had higher HAM-D scores at weeks 1 and 3 (p<0.05). There were significant interactions between treatment and visit on HAM-D score and depression status during the first four weeks of treatments in individuals without lifetime major depressive disorder (MDD). Past year cocaine use was associated with HAM-D score and depression status just in individuals without MDD, whereas past year cannabis use was associated with HAM-D score and depression status just in individuals with MDD. Past year amphetamine use was associated with HAM-D score just in individuals without MDD, however, lifetime anxiety was associated with HAM-D scores regardless of MDD.

CONCLUSION

When prescribing XR-NTX, particularly in the first month of treatment, it is essential to monitor for depressive symptoms. Screening for depression and multiple substance abuse may help clinicians identify appropriate treatment.

Patient Characteristics Associated with Opioid Abstinence after Participation in a Trial of Buprenorphine versus Injectable Naltrexone

Background and Objectives: Better understanding of predictors of opioid abstinence among patients with opioid use disorder (OUD) may help to inform interventions and personalize treatment plans. This analysis examined patient characteristics associated with opioid abstinence in the X:BOT (Extended-Release Naltrexone versus Buprenorphine for Opioid Treatment) trial. Methods: This post-hoc analysis examined factors associated with past-month opioid abstinence at the 36-week follow-up visit among participants in the X:BOT study. 428 participants (75% of original sample) attended the visit at 36 weeks. Logistic regression models were used to estimate the probability of opioid abstinence across various baseline sociodemographics, clinical characteristics, and treatment variables. Results: Of the 428 participants, 143 (33%) reported abstinence from non-prescribed opioids at the 36-week follow-up. Participants were more likely to be opioid abstinent if randomized to XR-NTX (compared to BUP-NX), were on XR-NTX at week 36 (compared to those off OUD pharmacotherapy), successfully inducted onto either study medication, had longer time on study medication, reported a greater number of abstinent weeks, or had longer time to relapse during the 24-week treatment trial. Participants were less likely to be abstinent if Hispanic, had a severe baseline Hamilton Depression Rating (HAM-D) score, or had baseline sedative use. Conclusions: A substantial proportion of participants was available at follow-up (75%), was on OUD pharmacotherapy (53%), and reported past-month opioid abstinence (33%) at 36 weeks. A minority of patients off medication for OUD reported abstinence and additional research is needed exploring patient characteristics that may be associated with successful treatment outcomes.

Is extended release naltrexone superior to buprenorphine-naloxone to reduce drinking among outpatients receiving treatment for opioid use disorder? A secondary analysis of the CTN X:BOT trial

BACKGROUND

The comparative effectiveness of extended-release naltrexone versus buprenorphine-naloxone for opioid relapse prevention (X:BOT) trial showed that following induction, treatment with the sublingual agonist (buprenorphine-naloxone, BUP-NX) or injected antagonist (extended release naltrexone, XR-NTX) produced similar reductions in opioid relapse in injection users with opioid use disorder (OUD). Because XR-NTX reduces drinking in alcohol use disorder (AUD), we conducted a secondary analysis of the X:BOT sample of patients successfully inducted onto treatment to determine whether XR-NTX (n = 204) was superior to BUP-NX (n = 270) in reducing drinking or heavy drinking in patients with OUD.

METHODS

Standard drink units consumed were measured using the Timeline Follow-back method. Mixed-models regression was used to examine the monthly frequency of any drinking and heavy drinking over 6 months of treatment. We used a proportional hazard survival analysis to examine the time to first drink.

RESULTS

Both treatment groups reduced drinking from baseline to posttreatment (small to medium effect), but no differences between groups were detected. However, only 29% (n = 136) of the sample had AUD and 19% (n = 26/136) of those were abstinent before treatment. Analysis of a subsample enriched for possible drinking included 136 individuals with an AUD diagnosis plus 43 who did not have AUD, but reported at least one day of heavy drinking prior to the study. However, this subsample reported only 32% of days of any drinking with a median of only 13% of days designated as "heavy." Within this subsample, at baseline, the BUP-NX group reported more mean drinks per drinking day than the XR-NTX group (p = 0.03); however, there were no other significant group differences on drinking observed before, during, or at the end of treatment.

CONCLUSIONS

There was an overall reduction in drinking during treatment of OUD using both agonist and antagonist medications, so that the hypothesis that XR-NTX would be superior to BUP-NX was not supported. The study is limited by low levels of comorbid AUD or heavy drinking observed in X:BOT trial participants seeking treatment for OUD.

Naturalistic follow-up after a trial of medications for opioid use disorder: Medication status, opioid use, and relapse

AIM

This report examined naturalistic opioid use outcomes and utilization of medications for opioid use disorder (MOUD) 36 weeks post-randomization in the National Drug Abuse Treatment Clinical Trials Network (CTN) Extended-Release Naltrexone (XR-NTX) versus Buprenorphine-Naloxone (BUP-NX) for Opioid Treatment trial (CTN-0051, X:BOT).

DESIGN

X:BOT was a multisite, randomized, 24-week comparative effectiveness trial of BUP-NX (N = 287) and XR-NTX (N = 283). Study medications were discontinued following treatment completion, relapse, or dropout. Participants were encouraged to continue MOUD. This report examined opioid use outcomes in 428 (75%) of the 570 participants who attended the 36-week follow-up visit.

SETTING AND PARTICIPANTS

Adults with opioid use disorder recruited from 8 community treatment programs across the United States.

MEASUREMENTS

Outcomes included medication status (on/off MOUD), type of MOUD (BUP-NX, XR-NTX, or methadone), abstinence from non-prescribed opioids, opioid use days, relapse, and other substance use 30 days prior to the 36-week visit. Relapse was defined as opioid use for 4 consecutive weeks or 7 consecutive days in the past month. Baseline and clinical variables included opioid use severity, intravenous drug use, study medication assignment, and induction status.

FINDINGS

Of the 428 participants who completed the 36-week visit, 225 (53%) of participants were receiving MOUD and 203 (47%) were not. Compared to those off medication, participants on medication had fewer opioid use days (4.4 days (SD 9.0) versus 9.8 days (SD 12.1)), fewer met relapse criteria (37 (16.4%) versus 79 (38.9%)), and reported less stimulant use (34 (15.2%) versus 56 (27.7%)) and sedative use (14 (6.3%) versus 31 (15.3%)). There was no difference in abstinence rates between those on or off MOUD. A greater proportion of participants on XR-NTX (47 (53.4%) of 88 participants) were abstinent from non-prescribed opioids compared to those on buprenorphine (28 (23.3%) of 120 participants).

CONCLUSIONS

Naturalistic outcomes data showed that despite potential barriers to continuing treatment in the community, about half of individuals were on opioid use disorder pharmacotherapy at follow-up and those on medication generally had better outcomes. Future research should explore barriers and facilitators to treatment retention in community settings; and developing interventions tailored to improve treatment engagement and adherence.

Optimizing opioid use disorder treatment with naltrexone or buprenorphine

BACKGROUND

Relapse rates during opioid use disorder (OUD) treatment remain unacceptably high. It is possible that optimally matching patients with medication type would reduce risk of relapse. Our objective was to learn a rule by which to assign type of medication for OUD to reduce risk of relapse, and to estimate the extent to which risk of relapse would be reduced if such a rule were used.

METHODS

This was a secondary analysis of an open-label randomized controlled, 24-week comparative effectiveness trial of injection extended-release naltrexone (XR-NTX), delivered approximately every 28 days, or daily sublingual buprenorphine-naloxone (BUP-NX) for treating OUD, 2014-2017 (N = 570). Outcome was a binary indicator of relapse to regular opioid use during the 24 weeks of outpatient treatment.

RESULTS

We found that applying an estimated individualized treatment rule-i.e., a rule that assigns patients with OUD to either XR-NTX or BUP-NX based on their individual characteristics in such a way that risk of relapse is minimized-would reduce risk of relapse by 24 weeks by 12% compared to randomly assigned treatment.

CONCLUSIONS

The number-needed-to-treat with the estimated treatment rule to prevent a single relapse is 14. A simpler, alternative estimated rule in which homeless participants would be treated with XR-NTX and stably housed participants would be treated with BUP-NX performed similarly. These results provide an estimate of the amount by which a relatively simple change in clinical practice could be expected to improve prevention of OUD relapse.

Explaining differential effects of medication for opioid use disorder using a novel approach incorporating mediating variables

BACKGROUND AND AIMS

A recent study found that homeless individuals with opioid use disorder (OUD) had a lower risk of relapse on extended-release naltrexone (XR-NTX) versus buprenorphine-naloxone (BUP-NX), whereas non-homeless individuals had a lower risk of relapse on BUP-NX. This secondary study examined differences in mediation pathways to medication effect between homeless and non-homeless participants.

DESIGN

Secondary analysis of an open-label randomized controlled, 24-week comparative effectiveness trial, 2014-17.

SETTING

Eight community addiction treatment programs in the United States.

PARTICIPANTS

English-speaking adults with DSM-5 OUD, recruited during inpatient admission (n = 570).

INTERVENTION(S)

Randomization to monthly injection of XR-NTX or daily sublingual BUP-NX.

MEASUREMENTS(S)

Mediation analysis estimated the direct effect of XR-NTX versus BUP-NX on relapse and indirect effect through mediators of medication adherence, use of illicit opioids, depressive symptoms and pain, separately by homeless status.

FINDINGS

For the homeless subgroup, the protective indirect path contributed a 3.4 percentage point reduced risk of relapse [95% confidence interval (CI) = -12.0, 5.3] comparing XR-NTX to BUP-NX (explaining 21% of the total effect). For the non-homeless subgroup, the indirect path contributed a 9.4 percentage point increased risk of relapse (95% CI = 3.1, 15.7) comparing XR-NTX to BUP-NX (explaining 57% of the total effect).

CONCLUSIONS

A novel approach to mediation analysis shows that much of the difference in medication effectiveness (extended-release naltrexone versus buprenorphine-naloxone) on opioid relapse among non-homeless adults with opioid use disorder appears to be explained by mediators of adherence, illicit opioid use, depressive symptoms and pain.

Sublingual Buprenorphine-Naloxone Compared With Injection Naltrexone for Opioid Use Disorder: Potential Utility of Patient Characteristics in Guiding Choice of Treatment

OBJECTIVE

Sublingual buprenorphine-naloxone and extended-release injection naltrexone are effective treatments, with distinct mechanisms, for opioid use disorder. The authors examined whether patients' demographic and clinical characteristics were associated with better response to one medication or the other.

METHODS

In a multisite 24-week randomized comparative-effectiveness trial of assignment to buprenorphine-naloxone (N=287) compared with extended-release naltrexone (N=283) comprising inpatients planning to initiate medication treatment for opioid use disorder, 50 demographic and clinical characteristics were examined as moderators of the effect of medication assignment on relapse to regular opioid use and failure to initiate medication. Moderator-by-medication interactions were estimated using logistic regression with correction for multiple testing.

RESULTS

In the intent-to-treat sample, patients who reported being homeless had a lower relapse rate if they were assigned to receive extended-release naltrexone (51.6%) compared with buprenorphine-naloxone (70.4%) (odds ratio=0.45, 95% CI=0.22, 0.90); patients who were not homeless had a higher relapse rate if they were assigned to extended-release naltrexone (70.9%) compared with buprenorphine-naloxone (53.1%) (odds ratio=2.15, 95% CI=1.44, 3.21). In the subsample of patients who initiated medication, the interaction was not significant, with a similar pattern of lower relapse with extended-release naltrexone (41.4%) compared with buprenorphine (68.6%) among homeless patients (odds ratio=0.32, 95% CI=0.15, 0.68) but less difference among those not homeless (extended-release naltrexone, 57.2%; buprenorphine, 52.0%; odds ratio=1.24, 95% CI=0.80, 1.90). For failure to initiate medication, moderators were stated preference for medication (failure was less likely if the patient was assigned to the medication preferred), parole and probation status (fewer failures with extended-release naltrexone for those on parole or probation), and presence of pain and timing of randomization (more failure with extended-release naltrexone for patients endorsing moderate to severe pain and randomized early while still undergoing medically managed withdrawal).

CONCLUSIONS

Among patients with opioid use disorder admitted to inpatient treatment, homelessness, parole and probation status, medication preference, and factors likely to influence tolerability of medication initiation may be important in matching patients to buprenorphine or extended-release naltrexone.

Treatment Trajectories During and After a Medication Trial for Opioid Use Disorder: Moving from Research as Usual to Treatment as Usual

OBJECTIVES

The effectiveness of treatment incorporating relapse prevention medications for opioid use disorder (OUD) is typically examined in research using rigidly predefined endpoints of success versus failure, usually over a single episode of care. But this perspective may not adequately portray the nonlinear trajectories typical of real-world treatment courses in this chronic, remitting, and relapsing disorder.

METHODS

This descriptive study examined 12-month treatment trajectories of n = 60 patients enrolled at a single site of a larger multisite randomized controlled trial examining the comparative effectiveness of buprenorphine versus extended-release naltrexone. While the parent study provided medication treatment through the research protocol for 6 months, this study documents treatment up to 12 months, including medications, provided through standard community resources (treatment as usual) outside of the protocol.

RESULTS

Some patients continued medications past the end of the study intervention, whereas others did not. Some patients initiated medications other than the one assigned by the study. Some patients switched from 1 medication to the other. Many patients returned to treatment after 1 or more periods of dropout and/or relapse. Patients utilized multiple episodes of bed-based care, including short-term acute residential and long-term residential treatment, and also recovery housing supports. Described trajectories are also depicted graphically. At 12 months, while rates of continuous treatment retention were low (8%), rates of cross-sectional treatment engagement including return to treatment after drop out were higher (35%).

CONCLUSIONS

This description of nonlinear treatment trajectories highlights the potential benefits of flexibility and optimism in the promotion of re-engagement, despite interim outcomes that might traditionally be considered "failure" endpoints.

Examination of Correlates of OUD Outcomes in Young Adults: Secondary Analysis From the XBOT Trial

BACKGROUND AND OBJECTIVES

Opioid use disorder (OUD) treatment outcomes are poorer for young adults than older adults. Developmental differences are broadly implicated, but particular vulnerability factor interactions are poorly understood. This study sought to identify moderators of OUD relapse between age groups.

METHODS

This secondary analysis compared young adults (18-25) to older adults (26+) from a comparative effectiveness trial ("XBOT") that randomized (N = 570) participants to extended-release naltrexone or sublingual buprenorphine-naloxone. We explored the relationship between 25 prespecified patient baseline characteristics and relapse to regular opioid use by age group and treatment condition, using logistic regression.

RESULTS

Young adults (n = 111) had higher rates of 24-week relapse than older adults (n = 459) (70.3% vs 58.8%) and differed on a number of specific characteristics, including more smokers, more intravenous opioid use, and more cannabis use. No significant moderators predicted relapse, in either three-way or two-way interactions.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

No baseline factors were identified as moderating the relationship between age group and opioid relapse, nor any interactions between baseline characteristics, age group, and treatment condition to predict opioid relapse. Poorer treatment outcomes for young adults are likely associated with multiple developmental vulnerabilities rather than any single predominant factor. Although not reaching significance, several characteristics (using heroin, smoking tobacco, high levels of depression/anxiety, or treatment because of family/friends) showed higher odds ratio point estimates for relapse in young adults than older adults. This is the first study to explore moderators of worse OUD treatment outcomes in young adults, highlighting the need to identify predictor variables that could inform treatment enhancements. (Am J Addict 2021;00:1-12).

Reductions in tobacco use in naltrexone, relative to buprenorphine-maintained individuals with opioid use disorder: Secondary analysis from the National Drug Abuse Treatment Clinical Trials Network

BACKGROUND

Smoking prevalence in individuals with opioid use disorder (OUD) is over 80%. Research suggests that opioid use significantly increases smoking, which could account for the strikingly low smoking-cessation rates observed in both methadone- and buprenorphine-maintained patients, even with the use of first-line smoking-cessation interventions. If opioids present a barrier to smoking-cessation, then better smoking outcomes should be observed in OUD patients treated with extended-release naltrexone (XR-NTX, an opioid antagonist) compared to those receiving buprenorphine (BUP-NX, a partial opioid agonist).

METHODS

The current study is a secondary analysis of a 24-week, multi-site, open-label, randomized clinical trial conducted within the National Drug Abuse Treatment Clinical Trials Network comparing the effectiveness of XR-NTX vs. BUP-NX for adults with OUD. Longitudinal mixed effects models were used to determine if there was a significant reduction in cigarette use among daily smokers successfully inducted to treatment (n = 373) and a subset of those who completed treatment (n = 169).

RESULTS

Among daily smokers inducted onto OUD medication, those in the XR-NTX group smoked fewer cigarettes per day (M = 11.36, SE = 0.62) relative to smokers in the BUP-NX group (M = 13.33, SE = 0.58) across all study visits, (b (SE) = -1.97 (0.55), p < .01). Results were similar for the treatment completers.

CONCLUSIONS

OUD patients treated with XR-NTX reduced cigarette use more than those treated with BUP-NX, suggesting that XR-NTX in combination with other smoking cessation interventions might be a better choice for OUD smokers interested in reducing their tobacco use.

Association between methadone or buprenorphine use during medically supervised opioid withdrawal and extended-release injectable naltrexone induction failure

BACKGROUND

Extended-release naltrexone (XR-NTX) is an effective maintenance treatment for opioid use disorder, but induction from active opioid use is a challenge as individuals must complete detoxification before induction. We aimed to determine whether use of methadone or buprenorphine, long acting agonist opioids commonly used for detoxification, were associated with decreased likelihood of induction onto XR-NTX.

METHODS

We performed a secondary analysis of a large open-label randomized trial of buprenorphine versus XR-NTX for treatment of individuals with opioid use disorder recruited from eight short term residential (detoxification) units. This analysis only included individuals randomized to the XR-NTX arm of the trial (N = 283). The method of detoxification varied according to usual practices at each inpatient program. Logistic regression models estimating the log-odds of induction onto XR-NTX were fit, with detoxification regimen received as the predictor.

RESULTS

In the unadjusted logistic regression model, detoxification drug received (either methadone or buprenorphine) was significantly associated with decreased likelihood of induction onto XR-NTX compared to receiving non-opioid detoxification (Overall: P < 0.001); buprenorphine vs non-opioid detoxification: OR (95% CI) = 0.32 (0.15-0.67); methadone vs non-opioid detoxification: OR (95% CI) = 0.23 (0.11-0.46). After controlling for site as a random effect, the association of detoxification drug with induction success lost statistical significance.

CONCLUSIONS

Use of agonist medication during detoxification was associated with XR-NTX induction failure. Medication choice was determined by each site's clinical practice and therefore this association could not be separated from other site level variables.

CLINICAL TRIAL REGISTRATION

NCT02032433.

An alternative analysis of illicit opioid use during treatment in a randomized trial of extended-release naltrexone versus buprenorphine-naloxone: A per-protocol and completers analysis

BACKGROUND

The distinct pharmacological properties and clinical uses of extended-release naltrexone (XR-NTX) and sublingual buprenorphine-naloxone (BUP-NX) present challenges in analyzing patient outcomes.

METHODS

We conducted a secondary analysis of a multi-site randomized trial comparing XR-NTX with sublingual BUP-NX treatment for opioid use disorder initiated during inpatient detoxification and continued in outpatient treatment. Urine testing data for non-study opioids from the last 22 weeks of the 24-week trial were analyzed in both a per-protocol sample (n = 474 participants who received at least one dose of medication) and a completers sample (n = 211 participants who received all XR-NTX doses or all BUP-NX prescriptions). The present analyses sought to identify differences in the weekly percentages of opioid-positive urine tests between participants treated with the two medications.

RESULTS

The proportion of opioid-positive tests in both conditions was less than 20 % for 21 of the 22 weeks in the per-protocol sample and all 22 weeks in the completers sample. Generalized linear mixed model analyses revealed a significant treatment (XR-NTX vs. BUP-NX) X week (weeks 3-24) interaction in the per-protocol sample but not the completers sample. In the per-protocol analysis, the BUP-NX, compared to XR-NTX, had significantly greater proportions of opioid-positive tests in 14 out of the 22 weeks.

CONCLUSIONS

Longitudinal modeling approaches that utilize flexible procedures for handling missing data can offer a different perspective on study findings. Results from the present analyses suggest that XR-NTX appeared to be somewhat more effective than BUP-NX in reducing illicit opioid use in the per-protocol sample.

Kentucky Women's Justice Community Opioid Innovation Network (JCOIN): A type 1 effectiveness-implementation hybrid trial to increase utilization of medications for opioid use disorder among justice-involved women

The opioid crisis has disproportionately affected women, but research on approaches to increase initiation of medications for opioid use disorder (MOUD) among women is limited. The Kentucky Justice Community Opioid Innovation Network (JCOIN) will implement a type 1 hybrid effectiveness and implementation trial to examine an innovative MOUD pretreatment model using telehealth (alone and in combination with peer navigators) for justice-involved women in transition from jail to the community. The overall goal of the project is to increase initiation and maintenance of MOUD among high-risk justice-involved women during community reentry to reduce opioid relapse and overdose. This project and other studies through the JCOIN network have the potential to significantly impact the OUD treatment field by contributing empirical evidence about the effectiveness and implementation of innovative technologies to increase initiation and maintenance of MOUD during a critical, high-risk time of community reentry among vulnerable, justice-involved individuals in both urban and nonurban communities.

Young Adults Have Worse Outcomes Than Older Adults: Secondary Analysis of a Medication Trial for Opioid Use Disorder

PURPOSE

Young adults are disproportionately affected by the current opioid crisis. Although medications for opioid use disorder are broadly effective, with reductions in morbidity and mortality, the particular effectiveness of medications for opioid use disorder among young adults is less well understood.

METHODS

This secondary analysis compared young adults (aged 18-25 years) with older adults (aged ≥26 years) in a large comparative effectiveness trial ("XBOT") that randomized subjects to extended-release naltrexone or sublingual buprenorphine-naloxone for 6 months. Opioid relapse was defined by opioid use over four consecutive weeks or seven consecutive days, using urine testing and self-report.

RESULTS

Among subjects in the intention-to-treat sample (n = 570, all randomized participants), a main effect of age group was found, with higher relapse rates among young adults (70.3%) compared with older adults (58.2%), with an odds ratio of 1.72 (95% confidence interval = 1.08-2.70), p = .02. In the per-protocol sample (n = 474, only participants who started medication), relapse rates were higher among young adults (66.3%) compared with older adults (50.8%), with an odds ratio of 1.91 (95% confidence interval = 1.19-3.06). Among the intention-to-treat sample, survival analysis revealed a significant time-by-age group interaction (p = .01) with more relapse over time in young adults. No significant interactions between age and medication group were detected.

CONCLUSIONS

Young adults have increased rates of relapse compared with older adults, perhaps because of vulnerabilities that increase their risk for treatment dropout and medication nonadherence, regardless of medication assignment. These results suggest that specialized, developmentally informed interventions may be needed to improve retention and successful treatment of opioid use disorder among young adults.

Extended-release naltrexone versus buprenorphine-naloxone to treat opioid use disorder among black adults

Few studies examine the effectiveness of treatments for opioid use disorder (OUD) among Black individuals despite recent evidence suggesting opioid overdose death rates are, in some cases, highest and increasing at a faster rate among Black people compared to other racial/ethnic groups. This secondary analysis study investigated treatment preference, retention, and relapse rates amongst a subgroup of 73 Black participants with OUD (81% male, mean age 39.05, SD = 11.80) participating in a 24-week multisite randomized clinical trial ("X:BOT") comparing the effectiveness of extended-release naltrexone (XR-NTX) and sublingual buprenorphine-naloxone (BUP-NX) between 2014 and 2017. Chi-square analyses were used to investigate treatment preference assessed at baseline, and logistic regression analyses were used to investigate differences in the odds of retention and relapse assessed over the 24-week course of treatment between treatment groups. Our findings suggest no differences in preference for XR-NTX versus BUP-NX. However, similar to the parent trial, there was an induction hurdle such that only 59.5% of those randomized to XR-NTX successfully initiated medication compared to 91.6% of those randomized to BUP-NX (OR = 0.13, 95% CI = 0.04, 0.52). No significant differences were found in treatment retention (intention-to-treat: OR = 1.19, 95% CI = 0.43, 3.28; per-protocol [i.e., those who initiated medication]: OR = 0.60, 95% CI = 0.20, 1.82) or relapse rates between treatment groups (intention-to-treat: OR = 1.53, 95% CI = 0.57, 4.13; per-protocol: OR = 0.69, 95% CI = 0.23, 2.06). Although there is a significant initiation hurdle with XR-NTX, once inducted, both medications appear similar in effectiveness, but as in the main study, dropout rates were high. Future research is needed on how to improve adherence.

Psychosocial intervention utilization and substance abuse treatment outcomes in a multisite sample of individuals who use opioids

BACKGROUND

There are several relatively safe and effective FDA-approved medications for Opioid Use Disorder (OUD). Despite the existence of these medications, the rate of returning to opioid use after treatment is relatively high, underscoring the need for continued enhancement of treatments. Adjunctive psychosocial interventions paired with medication have been shown to improve OUD treatment outcomes. However, studies have yet to conclusively examine the distinct effects of the most widely utilized psychosocial treatment modalities. The current study will investigate the relationship between individual counseling, group therapy, and 12-Step participation and illicit opioid abstinence at the end of treatment, 1 and 3 months after treatment.

METHOD

A secondary analysis was conducted with data from a sample of 570 individuals diagnosed with OUD who were recruited from eight substance abuse treatment centers in the United States. Participants were enrolled in a two-group randomized, controlled trial testing buprenorphine-naloxone versus extended-release naltrexone for OUD. A two-level hierarchical linear growth model was used to examine the effects of individual counseling, group therapy, and 12-Step participation on illicit opioid abstinence (urinanalyses) 1- and 3-months post-treatment.

RESULTS

Hours of individual counseling and 12-Step participation significantly predicted abstinence at follow-up (p < .001, b = -0.59, 95% CI [0.42, 0.74]; p < .01, b = -0.05, 95% CI [0.92, 0.98]). There was a significant interaction between individual counseling and 12-Step participation (p < .01, b = -0.06, 95% CI [1.02, 1.10]). Additionally, participant age and employment status were significant predictors of illicit opioid abstinence (p < .01, b = -0.02, 95% CI [0.97, 0.99]; p < .01, b = -0.38, 95% CI [0.52, 0.90]). Hours of group therapy was not found to significantly predict illicit opioid abstinence.

CONCLUSIONS

Findings suggest that greater levels of individual therapy and 12-Step participation may be beneficial for individuals receiving medication treatment for OUD.

Trajectory classes of opioid use among individuals in a randomized controlled trial comparing extended-release naltrexone and buprenorphine-naloxone

OBJECTIVES

To advance our understanding of medication treatments for opioid use disorders (OUDs), identification of distinct subgroups and factors associated with differential treatment response is critical. We examined trajectories of opioid use for patients with OUD who were randomized to (but not in all cases inducted onto) buprenorphine-naloxone (BUP-NX) or extended-release naltrexone (XR-NTX), and identified characteristics associated with each trajectory.

METHODS

Growth mixture models (GMMs) were run to identify distinct trajectories of days of opioid use among a subsample of 535 individuals with OUD who participated in a 24-week randomized controlled trial (RCT; 2014-2016) of BUP-NX (n = 281) or XR-NTX (n = 254).

RESULTS

Four distinct opioid use trajectory classes were identified for BUP-NX (near abstinent/no use (59%); low use (13.2%); low use, increasing over time (15%); and moderate use, increasing over time (12.8%)). Three distinct opioid use trajectory classes were found for XR-NTX (near abstinent/no use (59.1%); low use (14.6%); and moderate use, increasing over time (26.4%)). Across both BUP-NX and XR-NTX, the near abstinent/no use class had the highest number of medical management visits. Within BUP-NX, the low use class had a greater proportion of individuals with a previous successful treatment history compared with other classes. Within XR-NTX, the moderate use, increasing over time class had the highest proportion of Hispanic participants compared with other classes.

CONCLUSIONS

Findings highlight the significant heterogeneity of opioid use during a RCT of BUP-NX and XR-NTX and factors associated with opioid use patterns including medical management visits and history of treatment success.

Factors influencing recruitment to a randomised placebo-controlled trial of oral naltrexone and extended release implant naltrexone: Qualitative study

AIMS

To understand the influences on recruitment to the Naltrexone Enhanced Addiction Treatment (NEAT) study, a randomised placebo-controlled trial of extended-release naltrexone (XR-NTX) implants for opioid use disorder (OUD), to learn lessons for the design and conduct of similar future research.

METHODS

29 face-to-face, semi-structured qualitative interviews were conducted with patients recruited to NEAT (n = 6), patients not recruited (n = 11), researchers who designed the trial (n = 5), and staff who delivered the trial (n = 7). The social marketing mix was used as a framework to guide the data analyses.

RESULTS

Dimensions of the 7Ps of the social marketing mix - product, price, place, promotion, physical environment, people, and processes all influenced recruitment to the NEAT trial. Among other things, the potential to receive a naltrexone implant (product); the provision of transport passes and shopping vouchers (price); clear verbal explanations (promotion); familiarity of the trial setting (physical environment); and approachable, friendly and informative trial delivery staff (people) positively influenced recruitment. Whereas, wanting a less medical approach to recovery (product); the perceived time, physical, and psychological costs of taking part (price); service ideological opposition to naltrexone in recovery (place); inaccessible written information (promotion); the location and nature of the trial setting (physical environment); a lack of knowledge about implants (people); and the blind allocation and potential of placebo (processes) deterred people from joining the trial.

CONCLUSIONS

Qualitative research informed by the social marketing mix as an analytical framework yielded detailed insights into understanding the factors and circumstances that influenced recruitment to the NEAT trial. Our findings have implications for the planning and implementation of future addiction trials, especially trials of extended-release formulations.

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

BACKGROUND AND AIM

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

DESIGN

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

SETTING

Five urban, out-patient addiction clinics in Norway.

PARTICIPANTS

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

INTERVENTION

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

MEASUREMENTS

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

FINDINGS

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

CONCLUSIONS

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

Comparative effectiveness of extended-release naltrexone versus buprenorphine-naloxone for opioid relapse prevention (X:BOT): a multicentre, open-label, randomised controlled trial

BACKGROUND

Extended-release naltrexone (XR-NTX), an opioid antagonist, and sublingual buprenorphine-naloxone (BUP-NX), a partial opioid agonist, are pharmacologically and conceptually distinct interventions to prevent opioid relapse. We aimed to estimate the difference in opioid relapse-free survival between XR-NTX and BUP-NX.

METHODS

We initiated this 24 week, open-label, randomised controlled, comparative effectiveness trial at eight US community-based inpatient services and followed up participants as outpatients. Participants were 18 years or older, had Diagnostic and Statistical Manual of Mental Disorders-5 opioid use disorder, and had used non-prescribed opioids in the past 30 days. We stratified participants by treatment site and opioid use severity and used a web-based permuted block design with random equally weighted block sizes of four and six for randomisation (1:1) to receive XR-NTX or BUP-NX. XR-NTX was monthly intramuscular injections (Vivitrol; Alkermes) and BUP-NX was daily self-administered buprenorphine-naloxone sublingual film (Suboxone; Indivior). The primary outcome was opioid relapse-free survival during 24 weeks of outpatient treatment. Relapse was 4 consecutive weeks of any non-study opioid use by urine toxicology or self-report, or 7 consecutive days of self-reported use. This trial is registered with ClinicalTrials.gov, NCT02032433.

FINDINGS

Between Jan 30, 2014, and May 25, 2016, we randomly assigned 570 participants to receive XR-NTX (n=283) or BUP-NX (n=287). The last follow-up visit was Jan 31, 2017. As expected, XR-NTX had a substantial induction hurdle: fewer participants successfully initiated XR-NTX (204 [72%] of 283) than BUP-NX (270 [94%] of 287; p<0·0001). Among all participants who were randomly assigned (intention-to-treat population, n=570) 24 week relapse events were greater for XR-NTX (185 [65%] of 283) than for BUP-NX (163 [57%] of 287; hazard ratio [HR] 1·36, 95% CI 1·10-1·68), most or all of this difference accounted for by early relapse in nearly all (70 [89%] of 79) XR-NTX induction failures. Among participants successfully inducted (per-protocol population, n=474), 24 week relapse events were similar across study groups (p=0·44). Opioid-negative urine samples (p<0·0001) and opioid-abstinent days (p<0·0001) favoured BUP-NX compared with XR-NTX among the intention-to-treat population, but were similar across study groups among the per-protocol population. Self-reported opioid craving was initially less with XR-NTX than with BUP-NX (p=0·0012), then converged by week 24 (p=0·20). With the exception of mild-to-moderate XR-NTX injection site reactions, treatment-emergent adverse events including overdose did not differ between treatment groups. Five fatal overdoses occurred (two in the XR-NTX group and three in the BUP-NX group).

INTERPRETATION

In this population it is more difficult to initiate patients to XR-NTX than BUP-NX, and this negatively affected overall relapse. However, once initiated, both medications were equally safe and effective. Future work should focus on facilitating induction to XR-NTX and on improving treatment retention for both medications.

FUNDING

NIDA Clinical Trials Network.

How Drug Control Policy and Practice Undermine Access to Controlled Medicines

Drug conventions serve as the cornerstone for domestic drug laws and impose a dual obligation upon states to prevent the misuse of controlled substances while ensuring their adequate availability for medical and scientific purposes. Despite the mandate that these obligations be enforced equally, the dominant paradigm enshrined in the drug conventions is an enforcement-heavy criminal justice response to controlled substances that prohibits and penalizes their misuse. Prioritizing restrictive control is to the detriment of ensuring adequate availability of and access to controlled medicines, thereby violating the rights of people who need them. This paper argues that the drug conventions' prioritization of criminal justice measures-including efforts to prevent non-medical use of controlled substances-undermines access to medicines and infringes upon the right to health and the right to enjoy the benefits of scientific progress. While the effects of criminalization under drug policy limit the right to health in multiple ways, we draw on research and documented examples to highlight the impact of drug control and criminalization on access to medicines. The prioritization and protection of human rights-specifically the right to health and the right to enjoy the benefits of scientific progress-are critical to rebalancing drug policy.