Long-Acting Injectable Naltrexone Induction: A Randomized Trial of Outpatient Opioid Detoxification With Naltrexone Versus Buprenorphine

Opioid Maintenance Therapy: A Review of Methadone, Buprenorphine, and Naltrexone Treatments for Opioid Use Disorder

The rates of opioid use and opioid related deaths are escalating in the United States. Despite this, evidence-based treatments for Opioid Use Disorder are underutilized. There are three medications FDA approved for treatment of Opioid Use Disorder: Methadone, Buprenorphine, and Naltrexone. This article reviews the history, criteria, and mechanisms associated with Opioid Use Disorder. Pertinent pharmacology considerations, treatment strategies, efficacy, safety, and challenges of Methadone, Buprenorphine, and Naltrexone are outlined. Lastly, a practical decision making algorithm is discussed to address pertinent psychiatric and medical comorbidities when prescribing pharmacology for Opioid Use Disorder.

Rapid Initiation of Injection Naltrexone for Opioid Use Disorder: A Stepped-Wedge Cluster Randomized Clinical Trial

Importance

Injectable extended-release (XR)-naltrexone is an effective treatment option for opioid use disorder (OUD), but the need to withdraw patients from opioid treatment prior to initiation is a barrier to implementation.

Objective

To compare the effectiveness of the standard procedure (SP) with the rapid procedure (RP) for XR-naltrexone initiation.

Design, Setting, and Participants

The Surmounting Withdrawal to Initiate Fast Treatment with Naltrexone study was an optimized stepped-wedge cluster randomized trial conducted at 6 community-based inpatient addiction treatment units. Units using the SP were randomly assigned at 14-week intervals to implement the RP. Participants admitted with OUD received the procedure the unit was delivering at the time of their admission. Participant recruitment took place between March 16, 2021, and July 18, 2022. The last visit was September 21, 2022.

Interventions

Standard procedure, based on the XR-naltrexone package insert (approximately 5-day buprenorphine taper followed by a 7- to 10-day opioid-free period and RP, defined as 1 day of buprenorphine at minimum necessary dose, 1 opioid-free day, and ascending low doses of oral naltrexone and adjunctive medications (eg, clonidine, clonazepam, antiemetics) for opioid withdrawal.

Main Outcomes and Measures

Receipt of XR-naltrexone injection prior to inpatient discharge (primary outcome). Secondary outcomes included opioid withdrawal scores and targeted safety events and serious adverse events. All analyses were intention-to-treat.

Results

A total of 415 participants with OUD were enrolled (mean [SD] age, 33.6 [8.48] years; 205 [49.4%] identified sex as male); 54 [13.0%] individuals identified as Black, 91 [21.9%] as Hispanic, 290 [69.9%] as White, and 22 [5.3%] as multiracial. Rates of successful initiation of XR-naltrexone among the RP group (141 of 225 [62.7%]) were noninferior to those of the SP group (68 of 190 [35.8%]) (odds ratio [OR], 3.60; 95% CI, 2.12-6.10). Withdrawal did not differ significantly between conditions (proportion of days with a moderate or greater maximum Clinical Opiate Withdrawal Scale score (>12) for RP vs SP: OR, 1.25; 95% CI, 0.62-2.50). Targeted safety events (RP: 12 [5.3%]; SP: 4 [2.1%]) and serious adverse events (RP: 15 [6.7%]; SP: 3 [1.6%]) were infrequent but occurred more often with RP than SP.

Conclusions and Relevance

In this trial, the RP of XR-naltrexone initiation was noninferior to the standard approach and saved time, although it required more intensive medical management and safety monitoring. The results of this trial suggest that rapid initiation could make XR-naltrexone a more viable treatment for patients with OUD.

Trial Registration

ClinicalTrials.gov Identifier: NCT04762537.

Managing Opioid Withdrawal Symptoms During the Fentanyl Crisis: A Review

Illicitly manufactured fentanyl (IMF) is a significant contributor to the increasing rates of overdose-related deaths. Its high potency and lipophilicity can complicate opioid withdrawal syndromes (OWS) and the subsequent management of opioid use disorder (OUD). This scoping review aimed to collate the current OWS management of study populations seeking treatment for OWS and/or OUD directly from an unregulated opioid supply, such as IMF. Therefore, the focus was on therapeutic interventions published between January 2010 and November 2023, overlapping with the period of increasing IMF exposure. A health science librarian conducted a systematic search on November 13, 2023. A total of 426 studies were screened, and 173 studies were reviewed at the full-text level. Forty-nine studies met the inclusion criteria. Buprenorphine and naltrexone were included in most studies with the goal of transitioning to a long-acting injectable version. Various augmenting agents were tested (buspirone, memantine, suvorexant, gabapentin, and pregabalin); however, the liberal use of adjunctive medication and shortened timelines to initiation had the most consistently positive results. Outside of FDA-approved medications for OUD, lofexidine, gabapentin, and suvorexant have limited evidence for augmenting opioid agonist initiation. Trials often have low retention rates, particularly when opioid agonist washout is required. Neurostimulation strategies were promising; however, they were developed and studied early. Precipitated withdrawal is a concern; however, the rates were low and adequately mitigated or managed with low- or high-dose buprenorphine induction. Maintenance treatment continues to be superior to detoxification without continued management. Shorter induction protocols allow patients to initiate evidence-based treatment more quickly, reducing the use of illicit or non-prescribed substances.

Attitudes toward extended-release naltrexone treatment for opioid use disorder among African Americans

BACKGROUND

Extended-release naltrexone (XR-NTX; Vivitrol®) is a long-acting injectable form of naltrexone, which is a medication used to treat opioid use disorder (OUD). In 2010, XR-NTX received Food and Drug Administration approval to treat OUD, becoming the first non-addictive and non-psychoactive medication for this condition. Because uptake of XR-NTX has been relatively low, less is known regarding how persons with OUD view this form of treatment. And because previous studies tend to rely on samples that lack racial diversity or are conducted outside the United States, we know very little about how African Americans view XR-NTX. The objective of this study, therefore, was to identify/explain the most salient attitudes toward XR-NTX as a form of OUD treatment among African Americans.

METHODS

In-depth interviews (n = 30) were conducted with a sample of African American adults who used opioids in Southwest Florida between August 2021 and February 2022. Audiotapes of interviews were transcribed, coded, and thematically analyzed.

RESULTS

Analyses revealed that participants' attitudes toward XR-NTX were generally positive. Specifically, participants found XR-NTX's monthly injection administration, non-addictive and non-intoxicating properties, and perceived effectiveness (compared to other medications for OUD) most appealing.

CONCLUSIONS

Study findings suggest that African Americans who use opioids may have more favorable attitudes toward XR-NTX than other medications for OUD (e.g., methadone), which tend to be highly stigmatized. These data uniquely contribute to the literature by capturing the voices of African Americans who use opioids, a group with high rates of opioid-related deaths.

Effects of Bundling Medication for Opioid Use Disorder With an mHealth Intervention Targeting Addiction: A Randomized Clinical Trial

OBJECTIVE

Medication for opioid use disorder (MOUD) improves treatment retention and reduces illicit opioid use. A-CHESS is an evidence-based smartphone intervention shown to improve addiction-related behaviors. The authors tested the efficacy of MOUD alone versus MOUD plus A-CHESS to determine whether the combination further improved outcomes.

METHODS

In an unblinded parallel-group randomized controlled trial, 414 participants recruited from outpatient programs were assigned in a 1:1 ratio to receive either MOUD alone or MOUD+A-CHESS for 16 months and were followed for an additional 8 months. All participants were on methadone, buprenorphine, or injectable naltrexone. The primary outcome was abstinence from illicit opioid use; secondary outcomes were treatment retention, health services use, other substance use, and quality of life; moderators were MOUD type, gender, withdrawal symptom severity, pain severity, and loneliness. Data sources were surveys comprising multiple validated scales, as well as urine screens, every 4 months.

RESULTS

There was no difference in abstinence between participants in the MOUD+A-CHESS and MOUD-alone arms across time (odds ratio=1.10, 95% CI=0.90-1.33). However, abstinence was moderated by withdrawal symptom severity (odds ratio=0.95, 95% CI=0.91-1.00) and MOUD type (odds ratio=0.57, 95% CI=0.34-0.97). Among participants without withdrawal symptoms, abstinence rates were higher over time for those in the MOUD+A-CHESS arm than for those in the MOUD-alone arm (odds ratio=1.30, 95% CI=1.01-1.67). Among participants taking methadone, those in the MOUD+A-CHESS arm were more likely to be abstinent over time (b=0.28, SE=0.09) than those in the MOUD-alone arm (b=0.06, SE=0.08), although the two groups did not differ significantly from each other (∆b=0.22, SE=0.11). MOUD+A-CHESS was also associated with greater meeting attendance (odds ratio=1.25, 95% CI=1.05-1.49) and decreased emergency department and urgent care use (odds ratio=0.88, 95% CI=0.78-0.99).

CONCLUSIONS

Overall, MOUD+A-CHESS did not improve abstinence relative to MOUD alone. However, MOUD+A-CHESS may provide benefits for subsets of patients and may impact treatment utilization.

Clinical and psychosocial outcomes by sex among individuals prescribed buprenorphine-naloxone (BUP-NX) or extended-release naltrexone (XR-NTX) for opioid use disorder

BACKGROUND AND OBJECTIVES

Limited research has explored sex differences in opioid use disorder medication (MOUD) treatment outcomes. The purpose of this study was to examine MOUD initiation onto buprenorphine-naloxone (BUP-NX) versus extended-release naltrexone (XR-NTX) by sex, and sex differences in clinical and psychosocial outcomes.

METHODS

Using data from a 24-week open-label comparative effectiveness trial of BUP-NX or XR-NTX, this study examined MOUD initiation (i.e., receiving a minimum one XR-NTX injection or first BUP-NX dose) and 24-week self-report outcomes. We used regression models to estimate the probability of MOUD initiation failure among the intent-to-treat sample (N = 570), and the main and interaction effects of sex on outcomes of interest among the subsample of participants who successfully initiated MOUD (n = 474).

RESULTS

In the intent-to-treat sample, the odds of treatment initiation failure were not significantly different by sex. In the subsample of successful MOUD initiates, the effect of treatment on employment at week 24 was significantly moderated by sex (p = .003); odds of employment were not significantly different among males by MOUD type; females randomized to XR-NTX versus BUP-NX had 4.63 times greater odds of employment (p < .001). Males had significantly lower odds of past 30-day exchanging sex for drugs versus females (adjusted odds ratios [aOR] = 0.10, p = .004), controlling for treatment and baseline outcomes.

DISCUSSION AND CONCLUSIONS

Further research should explore how to integrate employment support into OUD treatment to improve patient outcomes, particularly among women.

SCIENTIFIC SIGNIFICANCE

The current study addressed gaps in the literature by examining sex differences in MOUD initiation and diverse treatment outcomes in a large, national sample.

Open label trial of lofexidine-assisted non-opioid induction onto naltrexone extended-release injection for opioid use disorder

Background: Opioid use disorder (OUD) continues to be major public health problem in the US and innovative medication strategies are needed. The extended-release injectable formulation of naltrexone (ER-NTX), an opioid receptor antagonist, is an effective treatment for OUD, but the need for an opioid-free period during the induction phase of treatment is a barrier to treatment success, particularly in the outpatient setting. Lofexidine, an alpha-2-adrenergic agonist, is an effective treatment for opioid withdrawal.Objectives: To evaluate the feasibility, safety, and tolerability of lofexidine for facilitating induction onto ER-NTX in the management of OUD.Methods: In an open-label, uncontrolled, 10-week outpatient clinical trial, 20 adults (four women) with OUD were treated with a fixed-flexible dosing strategy (maximum 0.54 mg 4×/daily) of lofexidine for up to 10 days to manage opioid withdrawal prior to receiving ER-NTX. The COVID-19 pandemic resulted in a modification of the study methods after enrolling 10 participants who attended all visits in person. The second group of 10 participants attended most induction period visits remotely.Results: Overall, 10 of the 20 participants (50%) achieved the primary outcome by receiving the first ER-NTX injection. Rates of induction success did not differ by the presence of fentanyl or remote visit attendance, although the small sample size provided limited statistical power. Six out of 20 participants (30%) initiated on lofexidine required dose adjustments. There were no study-related serious adverse events.Conclusions: This study provides preliminary evidence supporting the feasibility of inducting individuals with OUD onto ER-NTX using lofexidine.

Noninvasive Vagal Nerve Stimulation for Opioid Use Disorder

Background

Opioid Use Disorder (OUD) is an escalating public health problem with over 100,000 drug overdose-related deaths last year most of them related to opioid overdose, yet treatment options remain limited. Non-invasive Vagal Nerve Stimulation (nVNS) can be delivered via the ear or the neck and is a non-medication alternative to treatment of opioid withdrawal and OUD with potentially widespread applications.

Methods

This paper reviews the neurobiology of opioid withdrawal and OUD and the emerging literature of nVNS for the application of OUD. Literature databases for Pubmed, Psychinfo, and Medline were queried for these topics for 1982-present.

Results

Opioid withdrawal in the context of OUD is associated with activation of peripheral sympathetic and inflammatory systems as well as alterations in central brain regions including anterior cingulate, basal ganglia, and amygdala. NVNS has the potential to reduce sympathetic and inflammatory activation and counter the effects of opioid withdrawal in initial pilot studies. Preliminary studies show that it is potentially effective at acting through sympathetic pathways to reduce the effects of opioid withdrawal, in addition to reducing pain and distress.

Conclusions

NVNS shows promise as a non-medication approach to OUD, both in terms of its known effect on neurobiology as well as pilot data showing a reduction in withdrawal symptoms as well as physiological manifestations of opioid withdrawal.

Surmounting Withdrawal to Initiate Fast Treatment with Naltrexone (SWIFT): A stepped wedge hybrid type 1 effectiveness-implementation study

BACKGROUND

Extended-release injectable naltrexone (XR-NTX) is an effective treatment for opioid use disorder (OUD), but initiation remains a barrier to implementation. Standard practice requires a 10- to 15-day inpatient admission prior to XR-NTX initiation and involves a methadone or buprenorphine taper followed by a 7- to 10-day washout, as recommended in the Prescribing Information for XR-NTX. A 5- to 7-day rapid induction approach was developed that utilizes low-dose oral naltrexone and non-opioid medications.

METHODS

The CTN-0097 Surmounting Withdrawal to Initiate Fast Treatment with Naltrexone (SWIFT) study was a hybrid type I effectiveness-implementation trial that compared the effectiveness of the standard procedure (SP) to the rapid procedure (RP) for XR-NTX initiation across six community inpatient addiction treatment units, and evaluated the implementation process. Sites were randomized to RP every 14 weeks in an optimized stepped wedge design. Participants (target recruitment = 450) received the procedure (SP or RP) that the site was implementing at time of admission. The hypothesis was RP will be non-inferior to SP on proportion of inpatients who receive XR-NTX, with a shorter admission time for RP. Superiority testing of RP was planned if the null hypothesis of inferiority of RP to SP was rejected.

DISCUSSION

If RP for XR-NTX initiation is shown to be effective, the shorter inpatient stay could make XR-NTX more feasible and have an important public health impact expanding access to OUD pharmacotherapy. Further, a better understanding of facilitators and barriers to RP implementation can help with future translatability and uptake to other community programs.

TRIAL REGISTRATION

NCT04762537 Registered February 21, 2021.

Negative allosteric modulation of CB1 cannabinoid receptor signaling suppresses opioid-mediated reward

Blockade of cannabinoid type 1 (CB₁)-receptor signaling decreases the rewarding properties of many drugs of abuse and has been proposed as an anti-addiction strategy. However, psychiatric side-effects limit the clinical potential of orthosteric CB₁ antagonists. Negative allosteric modulators (NAMs) represent a novel and indirect approach to attenuate CB₁ signaling by decreasing affinity and/or efficacy of CB₁ ligands. We hypothesized that a CB₁-NAM would block opioid reward while avoiding the unwanted effects of orthosteric CB₁ antagonists. GAT358, a CB₁-NAM, failed to elicit cardinal signs of direct CB₁ activation or inactivation when administered by itself. GAT358 decreased catalepsy and hypothermia but not antinociception produced by the orthosteric CB₁ agonist CP55,940, suggesting that a CB₁-NAM blocked cardinal signs of CB₁ activation. Next, GAT358 was evaluated using in vivo assays of opioid-induced dopamine release and reward in male rodents. In the nucleus accumbens shell, a key component of the mesocorticolimbic reward pathway, morphine increased electrically-evoked dopamine efflux and this effect was blocked by a dose of GAT358 that lacked intrinsic effects on evoked dopamine efflux. Moreover, GAT358 blocked morphine-induced reward in a conditioned place preference (CPP) assay without producing reward or aversion alone. GAT358-induced blockade of morphine CPP was also occluded by GAT229, a CB₁ positive allosteric modulator (CB₁-PAM), and absent in CB₁-knockout mice. Finally, GAT358 also reduced oral oxycodone (but not water) consumption in a two-bottle choice paradigm. Our results support the therapeutic potential of CB₁-NAMs as novel drug candidates aimed at preventing opioid reward and treating opioid abuse while avoiding unwanted side-effects.

Adjunctive Management of Opioid Withdrawal with the Nonopioid Medication Cannabidiol

Introduction: Opioid use disorder (OUD) is a major public health crisis worldwide. Patients with OUD inevitably experience withdrawal symptoms when they attempt to taper down on their current opioid use, abstain completely from opioids, or attempt to transition to certain medications for opioid use disorder. Acute opioid withdrawal can be debilitating and include a range of symptoms such as anxiety, pain, insomnia, and gastrointestinal symptoms. Whereas acute opioid withdrawal only lasts for 1-2 weeks, protracted withdrawal symptoms can persist for months after the cessation of opioids. Insufficient management of opioid withdrawal often leads to devastating results including treatment failure, relapse, and overdose. Thus, there is a critical need for cost-effective, nonopioid medications, with minimal side effects to help in the medical management of opioid withdrawal syndrome. We discuss the potential consideration of cannabidiol (CBD), a nonintoxicating component of the cannabis plant, as an adjunctive treatment in managing the opioid withdrawal syndrome. Materials and Methods: A review of the literature was performed using keywords related to CBD and opioid withdrawal syndrome in PubMed and Google Scholar. A total of 144 abstracts were identified, and 41 articles were selected where CBD had been evaluated in clinical studies relevant to opioid withdrawal. Results: CBD has been reported to have several therapeutic properties including anxiolytic, antidepressant, anti-inflammatory, anti-emetic, analgesic, as well as reduction of cue-induced craving for opioids, all of which are highly relevant to opioid withdrawal syndrome. In addition, CBD has been shown in several clinical trials to be a well-tolerated with no significant adverse effects, even when co-administered with a potent opioid agonist. Conclusions: Growing evidence suggests that CBD could potentially be added to the standard opioid detoxification regimen to mitigate acute or protracted opioid withdrawal-related symptoms. However, most existing findings are either based on preclinical studies and/or small clinical trials. Well-designed, prospective, randomized-controlled studies evaluating the effect of CBD on managing opioid withdrawal symptoms are warranted.

Pharmacotherapy of Opioid Use Disorder-Update and Current Challenges

The incidence of opioid use disorder (OUD) and overdose deaths is rising yearly within the United States. Many cases are associated with illicitly manufactured fentanyl use. In addition to offering patients medications for OUD (methadone, buprenorphine, and naltrexone), the approach to this epidemic should involve increasing provider awareness and education about substance use disorders, expanding urine toxicology screens to test for fentanyl, and using low-threshold treatment approaches.

Transcutaneous cervical vagus nerve stimulation reduces behavioral and physiological manifestations of withdrawal in patients with opioid use disorder: A double-blind, randomized, sham-controlled pilot study

BACKGROUND

Opioid Use Disorder (OUD) is a serious public health problem, and the behavioral and physiological effects of opioid withdrawal can be a major impediment to recovery. Medication for OUD is currently the mainstay of treatment; however, it has limitations and alternative approaches are needed.

OBJECTIVE

The purpose of this study was to assess the effects of transcutaneous cervical vagus nerve stimulation (tcVNS) on behavioral and physiological manifestations of acute opioid withdrawal.

METHODS

Patients with OUD undergoing acute opioid withdrawal were randomly assigned to receive double blind active tcVNS (N = 10) or sham stimulation (N = 11) while watching neutral and opioid cue videos. Subjective opioid withdrawal, opioid craving, and anxiety were measured using a Visual Analogue Scale (VAS). Distress was measured using the Subjective Units of Distress Scale (SUDS), and pain was measured using the Numerical Rating Scale (NRS) for pain. Electrocardiogram signals were measured to compute heart rate. The primary outcomes of this initial phase of the clinical trial (ClinicalTrials.gov NCT04556552) were heart rate and craving.

RESULTS

tcVNS compared to sham resulted in statistically significant reductions in subjective opioid withdrawal (p = .047), pain (p = .045), and distress (p = .004). In addition, tcVNS was associated with lower heart rate compared to sham (p = .026). Craving did not significantly differ between groups (p = .11).

CONCLUSIONS

tcVNS reduces behavioral and physiological manifestations of opioid withdrawal, and should be evaluated in future studies as a possible non-pharmacologic, easily implemented approach for adjunctive OUD treatment.

Patient characteristics associated with initiation of XR-naltrexone for opioid use disorder in clinical trials

BACKGROUND

Extended-release injectable naltrexone (XR-naltrexone) is effective for treatment of patients with opioid use disorder (OUD), but initiation remains a barrier due to the challenge of tolerating opioid withdrawal prior to administration. Understanding factors associated with successful initiation of XR-naltrexone could facilitate its implementation through patient-treatment matching.

METHODS

We combined data from five consecutive studies that sought to initiate patients with active opioid use onto XR-naltrexone using a rapid procedure consisting of minimal buprenorphine, non-opioid medications for treating opioid withdrawal, and ascending low doses of oral naltrexone. Associations between patient characteristics and initiating naltrexone were estimated with logistic regression models. To evaluate whether associations differed between inpatient and outpatient settings, patient characteristic-by-setting interactions were also estimated.

RESULTS

409 patients were included in the analyses and 228 (56%) received the first injection. A significantly greater percent of inpatients (62%) vs outpatients (48%) initiated XR-naltrexone. Initiation success was significantly more likely on an inpatient basis for heroin (60.9% inpatient vs 36.2% outpatient), intravenous (56.3% inpatient vs 22.5% outpatient), and speedball users (68.1% inpatient vs 32.3% outpatient). Prescription opioid users showed similar, higher initiation rates across settings (68.9% inpatient; 73.7% outpatient).

CONCLUSIONS

An inpatient setting may be the preferred strategy for rapid initiation of XR-naltrexone for opioid users with greater severity, including heroin or speedball injection users or those who use opioids intravenously. Initiation on an outpatient basis may be more likely to succeed for prescription opioid users.

Initiating Long-acting Injectable Naltrexone: Procedure for a Second Attempt After a First Attempt Fails

BACKGROUND AND OBJECTIVE

Many patients are unable to initiate long-acting injectable naltrexone (XR-NTX) on a first attempt, due to the prerequisite abstinence and withdrawal from opioids.

METHODS

Thirty patients who were unable to initiate XR-NTX were recruited to receive buprenorphine for 1 week, followed by a 3-week buprenorphine taper, and an ascending titration of oral naltrexone before XR-NTX injection.

RESULTS

Eight (27%) initiated XR-NTX, 7 (23%) transitioned to buprenorphine maintenance treatment and 15 (50%) were lost to follow up.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

A second attempt at XR- NTX initiation using buprenorphine stabilization and cross taper may be a reasonable approach for some patients.

Cost-effectiveness implications of increasing the efficiency of the extended-release naltrexone induction process for the treatment of opioid use disorder: a secondary analysis

BACKGROUND AND AIMS

In a US randomized-effectiveness trial comparing extended-release naltrexone (XR-NTX) with buprenorphine-naloxone (BUP-NX) for the prevention of opioid relapse among participants recruited during inpatient detoxification (CTN-0051), the requirement to complete opioid detoxification prior to initiating XR-NTX resulted in lower rates of initiation of XR-NTX (72% XR-NTX versus 94% BUP-NX).

DESIGN

This was a retrospective secondary analysis of CTN-0051 trial data, including follow-up data over 24-36 weeks.

SETTING

Eight community-based, inpatient-detoxification and follow-up outpatient treatment facilities in the United States.

PARTICIPANTS

A total of 283 participants randomized to receive XR-NTX.

MEASUREMENTS

Efficiency was estimated using a multivariable generalized structural equation model to explore simultaneous determinants of XR-NTX induction and induction duration (detoxification + residential days). Cost-effectiveness was estimated from the health-care sector perspective and included expected costs and quality-adjusted life-years (QALYs).

FINDINGS

Treatment site was the only modifiable factor that simultaneously increased the likelihood of XR-NTX induction and decreased induction duration. Incorporating the higher predicted probability of XR-NTX induction, and fewer predicted days of detoxification and subsequent residential treatment into the cost-effectiveness framework, reduced the incremental average 24-week total cost of XR-NTX treatment from $5317 more than that of BUP-NX (P = 0.01) to a non-statistically-significant difference of $1016 (P = 0.63). QALYs gained remained similar across arms.

CONCLUSION

Adopting an efficient model of extended-release naltrexone initiation could result in extended-release naltrexone and buprenorphine-naloxone being of comparable economic value from the health-care sector perspective over 24-36 weeks for patients seeking treatment for opioid use disorder at an inpatient detoxification facility.

'Not at all what I had expected': Discontinuing treatment with extended-release naltrexone (XR-NTX): A qualitative study

BACKGROUND

Extended-release naltrexone (XR-NTX), an opioid antagonist, has demonstrated equal treatment outcomes, in terms of safety, opioid use, and retention, to the recommended OMT medication buprenorphine. However, premature discontinuation of XR-NTX treatment is still common and poorly understood. Research on patient experiences of XR-NTX treatment is limited. We sought to explore participants' experiences with discontinuation of treatment with XR-NTX, particularly motivation for XR-NTX, experiences of initiation and treatment, and rationale for leaving treatment.

METHODS

We conducted qualitative, semi-structured interviews with participants from a clinical trial of XR-NTX. The study participants (N = 13) included seven women and six men with opioid dependence, who had received a minimum of one and maximum of four injections of XR-NTX. The study team analyzed transcribed interviews, employing thematic analysis with a critical realist approach.

FINDINGS

The research team identified three themes, and we present them as a chronological narrative: theme 1: Entering treatment - I thought I knew what I was going into; theme 2: Life with XR-NTX - I had something in me that I didn't want; and theme 3: Leaving treatment - I want to go somewhere in life. Patients' unfulfilled expectations of how XR-NTX would lead to a better life were central to decisions about discontinuation, including unexpected physical, emotional, or mental reactions as well as a lack of expected effects, notably some described an opioid effect from buprenorphine. A few participants ended treatment because they had reached their treatment goal, but most expressed disappointment about not achieving this goal. Some also expressed renewed acceptance of OMT. The participants' motivation for abstinence from illegal substances generally remained.

CONCLUSION

Our findings emphasize that a dynamic understanding of discontinuation of treatment is necessary to achieve a long-term approach to recovery: the field should understand discontinuation as a feature of typical treatment trajectories, and discontinuation can be followed by re-initiation of treatment.

Associations between fentanyl use and initiation, persistence, and retention on medications for opioid use disorder among people living with uncontrolled HIV disease

BACKGROUND

Associations between fentanyl use and initiation and retention on medications for opioid use disorder (MOUD) are poorly understood.

METHODS

Data were from a multisite clinical trial comparing extended-release naltrexone (XR-NTX) with treatment as usual (TAU; buprenorphine or methadone) to achieve HIV viral suppression among people with OUD and uncontrolled HIV disease. The exposure of interest was fentanyl use, as measured by urine drug screening. Outcomes were time to MOUD initiation, defined as date of first injection of XR-NTX, buprenorphine prescription, or methadone administration; MOUD persistence, the total number of injections, prescriptions, or administrations received over 24 weeks; and MOUD retention, having an injection, prescription, or administration during weeks 20-24.

RESULTS

Participants (N = 111) averaged 47 years old and 62% were male. Just over half (57%) were Black and 13% were Hispanic. Sixty-four percent of participants tested positive for fentanyl at baseline. Participants with baseline fentanyl positivity were 11 times less likely to initiate XR-NTX than those negative for fentanyl (aHR = 0.09, 95% CI 0.03-0.24, p < .001), but there was no evidence that fentanyl use impacted the likelihood of TAU initiation (aHR = 1.50, 0.67-3.36, p = .323). Baseline fentanyl use was not associated with persistence or retention on any MOUD.

CONCLUSIONS

Fentanyl use was a substantial barrier to XR-NTX initiation for the treatment of OUD in persons with uncontrolled HIV infection. There was no evidence that fentanyl use impacted partial/full agonist initiation and, once initiated, retention on any MOUD.

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.

Dose Escalation of Naltrexone to Reduce Stress Responses Associated With Opioid Antagonist Induction: A Double-blind Randomized Trial

CONTEXT

To describe the role of opioid antagonist induction in reducing stress response and withdrawal symptoms.

OBJECTIVE

Complexity of naltrexone induction is limiting broader applicability of opioid antagonist-assisted abstinence. The aim of this clinical trial was to assess the stress response to 2 low-dose naltrexone induction protocols under minimal oral sedation.

DESIGN

Double-blind randomized controlled trial.

SETTING

Open setting in-patient unit.

PARTICIPANTS

Adults with opioid use disorder, and at least a year-long history of opioid use.

INTERVENTION PROTOCOL

Patients received either a single 12.5 mg naltrexone oral dose (SI group) or escalating dosage regimen starting from 50 μg up to a cumulative dose of 12.5 mg (ED group).

MAIN OUTCOME MEASURE

Differences in cortisol and adrenocorticotropic hormone (ACTH) concentrations 1 hour after the start of naltrexone induction.

RESULTS

In all, 124 patients were enrolled and 68 remained in the trial at the point of randomization-33 in SI and 35 in ED group. Eight patients were excluded from final analysis. Plasma cortisol and ACTH concentrations were significantly higher in SI group; mean difference between groups 313 nmol/L (95% confidence interval [CI] 182-444, P < 0.001) and 36.9 pg/mL (95% CI 12.3-61.4, P = 0.004), respectively.

SECONDARY OUTCOMES

SI patients experienced significant increases in plasma cortisol and ACTH concentrations, and withdrawal scores. In ED group these measures remained at or below baseline throughout the 24-hour period from start of naltrexone induction.

CONCLUSIONS

Contrary to a single 12.5-mg dose, the escalating naltrexone dosing regimen produced no significant increase in stress response and withdrawal scores during antagonist induction.

Treatment of opioid use disorder in primary care

Opioid use disorder (OUD) is a common, treatable chronic disease that can be effectively managed in primary care settings. Untreated OUD is associated with considerable morbidity and mortality-notably, overdose, infectious complications of injecting drug use, and profoundly diminished quality of life. Withdrawal management and medication tapers are ineffective and are associated with increased rates of relapse and death. Pharmacotherapy is the evidence based mainstay of OUD treatment, and many studies support its integration into primary care settings. Evidence is strongest for the opioid agonists buprenorphine and methadone, which randomized controlled trials have shown to decrease illicit opioid use and mortality. Discontinuation of opioid agonist therapy is associated with increased rates of relapse and mortality. Less evidence is available for the opioid antagonist extended release naltrexone, with a meta-analysis of randomized controlled trials showing decreased illicit opioid use but no effect on mortality. Treating OUD in primary care settings is cost effective, improves outcomes for both OUD and other medical comorbidities, and is highly acceptable to patients. Evidence on whether behavioral interventions improve outcomes for patients receiving pharmacotherapy is mixed, with guidelines promoting voluntary engagement in psychosocial supports, including counseling. Further work is needed to promote the integration of OUD treatment into primary care and to overcome regulatory barriers to integrating methadone into primary care treatment in the US.

Extended-release naltrexone for youth with opioid use disorder

BACKGROUND

Few published research studies have examined the effectiveness of extended-release naltrexone (XR-NTX) for the treatment of opioid use disorder (OUD) among adolescents and young adults.

METHODS

This two-group randomized controlled trial recruited 288 youth, ages 15-21, with moderate/severe OUD from a residential addiction treatment program in Baltimore, Maryland. The study randomized the youth within the first week of treatment entry to receive either XR-NTX or treatment-as-usual (TAU; either buprenorphine maintenance treatment or treatment without OUD medication following medically managed withdrawal) prior to discharge, with continued treatment in the community for 6 months. However, due to various reasons spanning patients' and caregivers' preferences and constraints, considerable participant nonadherence to randomized condition occurred (i.e., only 30% of the participants randomized to XR-NTX received an initial injection, while 27% of participants randomized to TAU received an XR-NTX injection at treatment discharge, instead of their assigned treatment). The study used generalized linear mixed modeling (GLiMM) to examine self-reported 90-day opioid, cocaine, marijuana, and alcohol use as well as DSM-5 OUD criteria on "intention-to-treat" (as randomized), "as-received" (XR-NTX vs. not XR-NTX), and "as-medicated" (XR-NTX vs. buprenorphine vs. no medication) bases.

RESULTS

The condition x time interactions in the intention-to-treat analyses failed to reach significance for past-90-day self-reported use of illicit opioids, cocaine, marijuana, or alcohol, or in meeting DSM-5 OUD criteria at 3 or 6 months [all ps > 0.05]. However, these findings are of limited interpretive value due to participant nonadherence to their randomized condition. When the study analyzed results by the treatment received at discharge, the "as-received" group x time interaction for illicit opioid use was significant [p = .003], with the XR-NTX group reporting less opioid use in the past 90 days at 3 and 6 months. Participants who received their first XR-NTX dose at inpatient discharge (n = 82) received, on average, 1.3 subsequent injections in the community over the 6-month study follow-up period. Only 2 of the 82 study participants received XR-NTX continuously through the 6-month postdischarge follow-up period. Twelve serious adverse events (SAEs) occurred during the study, but the study determined that only 1 was possibly study related (hepatitis C/elevated liver function test results).

CONCLUSION

None of the condition x time interactions in the intention-to-treat analyses reached significance. Participants' nonadherence may have contributed to the failure to reject the null hypothesis. Irrespective of randomized condition, participants who received XR-NTX for OUD demonstrated low retention in treatment, receiving an average of only 1.3 subsequent injections, yet reported less opioid use at follow-up than participants who did not received XR-NTX. Treatment programs should consider XR-NTX as a treatment option for youth motivated to receive it. Future research should focus on building developmentally informed strategies to improve uptake of and adherence to relapse prevention medication in this population.

Recent Advances in the Treatment of Opioid Use Disorder

PURPOSE OF REVIEW

Opioid use disorder (OUD) remains a national epidemic with an immense consequence to the United States' healthcare system. Current therapeutic options are limited by adverse effects and limited efficacy.

RECENT FINDINGS

Recent advances in therapeutic options for OUD have shown promise in the fight against this ongoing health crisis. Modifications to approved medication-assisted treatment (MAT) include office-based methadone maintenance, implantable and monthly injectable buprenorphine, and an extended-release injectable naltrexone. Therapies under investigation include various strategies such as heroin vaccines, gene-targeted therapy, and biased agonism at the G protein-coupled receptor (GPCR), but several pharmacologic, clinical, and practical barriers limit these treatments' market viability. This manuscript provides a comprehensive review of the current literature regarding recent innovations in OUD treatment.

Lorcaserin treatment for extended-release naltrexone induction and retention for opioid use disorder individuals: A pilot, placebo-controlled randomized trial

BACKGROUND

Opioid Use Disorder (OUD) is a significant public health problem associated with severe morbidity and mortality. While effective pharmacotherapies are available, limitations exist with each. Induction onto extended-release naltrexone (XR-NTX) is more difficult than initiation of buprenorphine or methadone, even in inpatient settings, as it is recommended that patients remain abstinent for at least 7 days prior to initiating XR-NTX. The purpose of this trial was to determine if lorcaserin, a 5HT2c agonist, improves outpatient XR-NTX induction rates.

METHODS

An 8-week trial beginning with a brief detoxification period and induction onto XR-NTX. Sixty participants with OUD were enrolled in the trial, with 49 participants at the initiation of detoxification randomized to lorcaserin or placebo for 39 days. Additionally, ancillary medications were provided. The primary outcome was the proportion of participants inducted onto the first XR-NTX injection. Secondary outcomes were withdrawal severity (measured by COWS and SOWS) prior to the first injection and the proportion of participants receiving the second XR-NTX injection.

RESULTS

The proportion of participants inducted onto the first (lorcaserin: 36 %; placebo: 44 %; p = .67) and the second XR-NTX injection (lorcaserin: 27 %; placebo: 31 %; p = .77) was not significantly different between treatment arms. Prior to the first injection, withdrawal scores did not significantly differ between treatment arms over time (treatment*time interaction COWS: p = .11; SOWS: p = .39).

CONCLUSIONS

Lorcaserin failed to improve outpatient XR-NTX induction rates. Although this study is small, the findings do not support the use of lorcaserin in promoting induction onto XR-NTX or in mitigating withdrawal symptoms.

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.

The changing opioid crisis: development, challenges and opportunities

The current opioid epidemic is one of the most severe public health crisis in US history. Responding to it has been difficult due to its rapidly changing nature and the severity of its associated outcomes. This review examines the origin and evolution of the crisis, the pharmacological properties of opioids, the neurobiology of opioid use and opioid use disorder (OUD), medications for opioid use disorder (MOUD), and existing and promising approaches to prevention. The results of the review indicate that the opioid epidemic is a complex, evolving phenomenon that involves neurobiological vulnerabilities and social determinants of health. Successfully addressing the epidemic will require advances in basic science, development of more acceptable and effective treatments, and implementation of public health approaches, including prevention. The advances achieved in addressing the current crisis should also serve to advance the science and treatment of other substance use disorders.

Monitoring and Improving Naltrexone Adherence in Patients with Substance Use Disorder

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Patients' perspectives on initiating treatment with extended-release naltrexone (XR-NTX)

BACKGROUND

The National Drug Abuse Treatment Clinical Trials Network (CTN) multisite comparative-effectiveness study ("X:BOT") by Lee et al. (2018) found that, once initiated, extended-release naltrexone (XR-NTX) is as similarly safe and effective as sublingual buprenorphine-naloxone (BUP-NX) for the treatment of opioid use disorder (OUD). However, the detoxification hurdle makes XR-NTX much more difficult to initiate than BUP-NX. This hurdle highlights the need to better understand how patients transition from active opioid use to XR-NTX treatment.

OBJECTIVE

To explore patient-identified barriers and facilitators to initiating antagonist treatment (XR-NTX) within the context of an inpatient hospital setting and to reflect postdischarge experiences of those who did and did not initiate XR-NTX treatment.

METHOD

We used a convenience sampling strategy to identify study candidates, with the intention of recruiting approximately an equal number of medication-initiated and noninitiated patients. Study participants (N = 14) included 13 males and 1 female with OUD randomized to the XR-NTX arm of the X:BOT study at 1 of the 8 study sites. Seven participants in this sample initiated XR-NTX treatment, and seven did not. Each participant completed one semistructured qualitative interview. We analyzed transcripts using deductive and inductive approaches to conventional content analysis.

RESULTS

Although the majority of participants viewed opioid blockade, once-monthly dosing, and no dependence or withdrawal as favorable attributes of XR-NTX, participant ambivalence and lack of familiarity with antagonist treatment were barriers to treatment initiation. The long duration of action and the perceived "commitment" to the medication (e.g., "At the time, a month sounded like a year") compounded the patients' concerns and ambivalence. The majority of those who initiated XR-NTX described it as an effective treatment for OUD, with treatment satisfaction and sustained abstinence emerging as central themes among this population. Some participants who did not successfully initiate XR-NTX expressed regret and a willingness to try XR-NTX in the future.

CONCLUSION

Achieving full opioid detoxification is one, but not the only, barrier to initiating treatment with XR-NTX. Additional participant-identified barriers to XR-NTX initiation include fears and ambivalence regarding antagonist treatment. Once initiated, participants perceive XR-NTX to be an effective treatment for maintaining abstinence from opioids. XR-NTX appealed to participants due to the autonomy it affords with once-monthly dosing and no physical dependence.

Safety and Efficacy of Lofexidine for Medically Managed Opioid Withdrawal: A Randomized Controlled Clinical Trial

Supplemental Digital Content is available in the text

Objectives:

To investigate the safety and efficacy of lofexidine for treating opioid withdrawal syndrome (OWS) and facilitating completion of opioid withdrawal.

Methods:

A multicenter, double-blind, placebo-controlled study was conducted at 18 US centers from June 2013 to December 2014. Participants (n = 603) aged ≥18 years, dependent on short-acting opioids, and seeking withdrawal treatment, randomized 3:3:2 to receive lofexidine 2.88 mg/d (n = 222), lofexidine 2.16 mg/d (n = 230), or placebo (n = 151) for 7 days. Primary outcome was the Short Opiate Withdrawal Scale of Gossop (SOWS-Gossop) scores rating withdrawal symptoms over days 1 to 7.

Results:

Participants were of mean age, 35 years; 71% male. Pairwise differences in overall SOWS-Gossop log-transformed least squares means were statistically significant for lofexidine 2.16 mg (difference, −0.21; 95% CI, −0.37 to −0.04; P = 0.02) and 2.88 mg (−0.26; 95% CI, −0.44 to −0.09; P = 0.003) compared with placebo. Fewer than half of participants in both groups completed the study. Completion rates for lofexidine 2.16 mg (41.5%; odds ratio [OR], 1.85; P = 0.007) and 2.88 mg (39.6%; OR, 1.71; P = 0.02) were significantly better compared with placebo (27.8%). Overall adverse event (AE) rates were similar across groups. Common AEs for lofexidine included orthostatic hypotension, hypotension, and bradycardia, but resulted in few study discontinuations.

Conclusions:

Lofexidine 2.16 mg and 2.88 mg significantly reduced symptoms of OWS versus placebo, and increased absolute rates of completing the 7-day study by 14% and 12%, respectively (a relative increase of 85% and 71%). Data suggest that lofexidine is a generally safe and effective nonopioid treatment for opioid withdrawal. Lofexidine could serve as a withdrawal treatment option when a nonopioid agent is preferred or required, when agonist-assisted withdrawal is unavailable, when agonist discontinuation caused OWS, and during induction into maintenance treatment with opioid agonists or antagonists.

Trial Registration:

ClinicalTrials.gov identifier: NCT01863186.

Transition of Patients with Opioid Use Disorder from Buprenorphine to Extended-Release Naltrexone: A Randomized Clinical Trial Assessing Two Transition Regimens

Background and Objective

When patients seek to discontinue buprenorphine (BUP) treatment, monthly injectable extended‐release naltrexone (XR‐NTX) may help them avoid relapse. The efficacy of low ascending doses of oral NTX vs placebo for patients transitioning from BUP to XR‐NTX is evaluated in this study.

Methods

In a phase 3, hybrid residential/outpatient study, clinically stable participants with opioid use disorder (N = 101), receiving BUP for more than or equal to 3 months and seeking antagonist treatment, were randomized (1:1) to 7 residential days of descending doses of BUP and low ascending doses of oral NTX (NTX/BUP, n = 50) or placebo (PBO‐N/BUP, n = 51). Both groups received standing ancillary medications and psychoeducational counseling. Following negative naloxone challenge, participants received XR‐NTX (day 8). The primary endpoint was the proportion of participants who received and tolerated XR‐NTX.

Results

There was no statistical difference between groups for participants receiving a first dose of XR‐NTX: 68.6% (NTX/BUP) vs 76.0% (PBO‐N/BUP; P = .407). The mean number of days with peak Clinical Opiate Withdrawal Scale (COWS) score less than or equal to 12 during the treatment period (days 1‐7) was similar for NTX/BUP and PBO‐N/BUP groups (5.8 vs 6.3; P = .511). Opioid withdrawal symptoms during XR‐NTX induction and post‐XR‐NTX observation period (days 8‐11) were mild and similar between groups (mean peak COWS score: NTX/BUP, 5.1 vs PBO‐N/BUP, 5.4; P = .464). Adverse events were mostly mild/moderate.

Conclusions and Scientific Significance

Low ascending doses of oral NTX did not increase induction rates onto XR‐NTX compared with placebo. The overall rate of successful induction across treatment groups supports a brief BUP taper with standing ancillary medications as a well‐tolerated approach for patients seeking transition from BUP to XR‐NTX. (Am J Addict 2020;00:00–00)

Differences in Availability and Use of Medications for Opioid Use Disorder in Residential Treatment Settings in the United States

Importance

While many individuals with opioid use disorder seek treatment at residential facilities to initiate long-term recovery, the availability and use of medications for opioid use disorder (MOUDs) in these facilities is unclear.

Objective

To examine differences in MOUD availability and use in residential facilities as a function of Medicaid policy, facility-level factors associated with MOUD availability, and admissions-level factors associated with MOUD use.

Design, Setting, and Participants

This cross-sectional study used deidentified facility-level and admissions-level data from 2863 residential treatment facilities and 232 414 admissions in the United States in 2017. Facility-level data were extracted from the 2017 National Survey of Substance Abuse Treatment Services, and admissions-level data were extracted from the 2017 Treatment Episode Data Set-Admissions. Statistical analyses were conducted from June to November 2019.

Exposures

Admissions for opioid use disorder at residential treatment facilities in the United States that identified opioids as the patient's primary drug of choice.

Main Outcomes and Measures

Availability and use of 3 MOUDs (ie, extended-release naltrexone, buprenorphine, and methadone).

Results

Of 232 414 admissions, 205 612 (88.5%) contained complete demographic data (166 213 [80.8%] aged 25-54 years; 136 854 [66.6%] men; 151 867 [73.9%] white). Among all admissions, MOUDs were used in only 34 058 of 192 336 (17.7%) in states that expanded Medicaid and 775 of 40 078 (1.9%) in states that did not expand Medicaid (P < .001). A relatively low percentage of the 2863 residential treatment facilities in this study offered extended-release naltrexone (854 [29.8%]), buprenorphine (953 [33.3%]), or methadone (60 [2.1%]). Compared with residential facilities that offered at least 1 MOUD, those that offered no MOUDs had lower odds of also offering psychiatric medications (odds ratio [OR], 0.06; 95% CI, 0.05-0.08; Wald χ21 = 542.09; P < .001), being licensed by a state or hospital authority (OR, 0.39; 95% CI, 0.27-0.57; Wald χ21 = 24.28; P < .001), or being accredited by a health organization (OR, 0.28; 95% CI, 0.23-0.33; Wald χ21 = 180.91; P < .001). Residential facilities that did not offer any MOUDs had higher odds of accepting cash-only payments than those that offered at least 1 MOUD (OR, 4.80; 95% CI, 3.47-6.64; Wald χ21 = 89.65; P < .001).

Conclusions and Relevance

In this cross-sectional study of residential addiction treatment facilities in the United States, MOUD availability and use were sparse. Public health and policy efforts to improve access to and use of MOUDs in residential treatment facilities could improve treatment outcomes for individuals with opioid use disorder who are initiating recovery.

Endogenous opiates and behavior: 2017

This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Improving naltrexone compliance and outcomes with putative pro- dopamine regulator KB220, compared to treatment as usual

A recent analysis from Stanford University suggested that without any changes in currently available treatment, prevention, and public health approaches, we should expect to have 510,000 deaths from prescription opioids and street heroin from 2016 to 2025 in the US. In a recent review, Mayo Clinic Proceedings (October 2019), Gold and colleagues at Mayo Clinic reviewed the available medications used in opioid use disorders and concluded that in private and community practice adherence is more important as a limiting factor to retention, relapse, and repeat overdose. It is agreed that the primary utilization of known opioid agonists like methadone, buprenorphine and naloxone combinations, while useful as a way of reducing societal harm, is limited by 50% of more discontinuing treatment within 6 months, their diversion, and addiction liability. Opioid agonists may have other unintended consequences, like continuing the down regulation of dopamine systems. While naltrexone would be expected to have opposite effects, adherence is also low even after detoxification and long acting naltrexone injections. Recent studies have shown Naltrexone is beneficial by attenuation of craving via “psychological extinction” and reducing relapse. Buprenorphine is the MAT of choice currently but injectable Naltrexone plus an agent to improve dopaminergic function and tone may renew interest amongst addiction physicians and patients. Understanding this dilemma there is increasing movement to opt for the non-addicting narcotic antagonist Naltrexone. Even with extended injectable option there is still poor compliance. As such, we describe an open label investigation in humans showing improvement of naltrexone compliance and outcomes with dopamine augmentation with the pro- dopamine regulator KB220 (262 days) compared to naltrexone alone (37days). This well studied complex consists of amino-acid neurotransmitter precursors and enkephalinase inhibitor therapy compared to treatment as usual. Consideration of this novel paradigm shift may assist in not only addressing the current opioid epidemic but the broader question of reward deficiency in general.

A week-long outpatient induction onto XR-naltrexone in patients with opioid use disorder

BACKGROUND

Extended-release (XR) naltrexone can prevent relapse to opioid use disorder following detoxification. However, one of the barriers to initiating XR-naltrexone is the recommendation for a 7-10-day period of abstinence from opioids prior to the first dose.

OBJECTIVES

The current study evaluated the feasibility of an XR-naltrexone induction protocol that can be implemented over 1 week in the outpatient clinic.

METHODS

Participants (N = 44) were seen in the clinic daily. On Day 1, after abstaining from opioids for at least 12 h, they received buprenorphine 6-8 mg. Adjunctive medications (clonidine, clonazepam, zolpidem, trazodone, and prochlorperazine) were dispensed on Days 2-5, while ascending oral doses of naltrexone were given on Days 3-5 starting with 1 mg dose. An injection of XR-naltrexone was given on Day 5, 1 h after receiving and tolerating naltrexone 24 mg.

RESULTS

Of the 44 participants (38 males), 35 (80%) were heroin users and 9 (20%) used prescription opioids. A total of 26 participants (59%) completed the induction and received their first injection of XR-naltrexone. XR-naltrexone was initiated in 54% (19/35) of heroin users and 78% (7/9) of prescription opioid users.

CONCLUSION

The results support the feasibility of a week-long outpatient induction onto XR-naltrexone with ascending doses of naltrexone and standing doses of adjunctive medications. By circumventing the need for a protracted period of abstinence and mitigating the severity of withdrawal symptoms experienced during naltrexone titration, this strategy has the potential to increase patient acceptability and access to relapse prevention treatment with XR-naltrexone.

Treating opioid dependence with extended-release naltrexone (XR-NTX) in Ukraine: Feasibility and three-month outcomes

BACKGROUND

Although opioid agonist treatments (OAT) with methadone or buprenorphine are available to treat opioid use disorders (OUD) in Ukraine, OAT acceptability and coverage remains low. Extended-release naltrexone (XR-NTX) that recently became available as another treatment option provides new opportunities for treating OUDs in this region and we aimed to test its feasibility.

METHODS

Patients with OUD (N=135) and interested in treatment with XR-NTX were initiated on monthly XR-NTX injections and monitored for three months. Correlates of 3-month retention on XR-NTX and drug use at each time-point using self-reports and urine drug testing (UDT) were assessed.

RESULTS

Of the 134 participants initiated XR-NTX, 101 (75%) completed three months, defined as 4 consecutive XR-NTX injections. Independent factors negatively associated with retention in XR-NTX treatment included previous maintenance with OAT (aOR=0.3; 95%CI=0.1-0.9) and extrinsic help-seeking treatment motivation (aOR=0.7; 95%CI=0.5-0.9). Of these 101 participants completing three months of treatment, opioid use markedly reduced using self-report (67%% to 22%; p>0.001) and UDT (77% to 24%; p<0.001) outcomes over time. Alcohol, marijuana and stimulant use, however, remained unchanged. Craving for opioids and symptoms of depression also significantly decreased, while health-related quality of life scores improved over time. No adverse side effects were reported during the period of observation.

CONCLUSION

The first introduction of XR-NTX in Ukraine among persons with OUD resulted in high levels of retention, marked reductions in opioid use and improved quality of life. These descriptive results suggest that XR-NTX treatment is feasible and well-tolerated over a 3-month period in Ukraine.

Transitioning Hospitalized Patients with Opioid Use Disorder from Methadone to Buprenorphine without a Period of Opioid Abstinence Using a Microdosing Protocol

STUDY OBJECTIVE

Buprenorphine, a partial μ-opioid agonist, is an effective treatment for opioid use disorder that conventionally requires symptoms of withdrawal before initiation to avoid precipitating withdrawal. Our institution implemented a microdosing approach to transition patients from full μ-opioid agonists to buprenorphine without requiring patients to undergo a period of opioid abstinence. Little has been published about this strategy in the inpatient setting in the United States, and even less has been published dealing with the transition from methadone to buprenorphine. Our objective was to demonstrate that a microdosing protocol to transition patients from methadone to buprenorphine can be feasibly implemented in a U.S. hospital setting.

DESIGN

Case series.

PATIENTS

Three hospitalized adults with opioid use disorder who received a 1-week buprenorphine microdosing protocol.

MEASUREMENTS AND MAIN RESULTS

In January 2019, we implemented a 1-week buprenorphine microdosing protocol for hospitalized adult patients with opioid use disorder who were initially stabilized on methadone and wished to start buprenorphine. We gave low-dose buprenorphine concurrently with each patient's full dose of methadone, and the buprenorphine dose was gradually titrated up over 7 days. On day 8, methadone was abruptly discontinued. The buprenorphine dose was further increased based on clinical judgment. All three patients were successfully transitioned from methadone 40-100 mg/day to buprenorphine 12-16 mg/day with minimal symptoms of opioid withdrawal. One patient relapsed and was lost to follow-up; two remained in treatment.

CONCLUSION

A protocol using microdosing of buprenorphine can successfully transition patients receiving full μ-opioid agonist therapy, including methadone, to buprenorphine without the need for a period of opioid abstinence.

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.

Management of opioid use disorder in the USA: present status and future directions

Opioid use disorder is characterised by the persistent use of opioids despite the adverse consequences of its use. The disorder is associated with a range of mental and general medical comorbid disorders, and with increased mortality. Although genetics are important in opioid use disorder, younger age, male sex, and lower educational attainment level and income, increase the risk of opioid use disorder, as do certain psychiatric disorders (eg, other substance use disorders and mood disorders). The medications for opioid use disorder, which include methadone, buprenorphine, and extended-release naltrexone, significantly improve opioid use disorder outcomes. However, the effectiveness of medications for opioid use disorder is limited by problems at all levels of the care cascade, including diagnosis, entry into treatment, and retention in treatment. There is an urgent need for expanding the use of medications for opioid use disorder, including training of health-care professionals in the treatment and prevention of opioid use disorder, and for development of alternative medications and new models of care to expand capabilities for personalised interventions.

A Randomized Trial Comparing Extended-Release Injectable Suspension and Oral Naltrexone, Both Combined With Behavioral Therapy, for the Treatment of Opioid Use Disorder

OBJECTIVE

The oral formulation of the opioid antagonist naltrexone has shown limited effectiveness for treatment of opioid use disorder due to poor adherence. Long-acting injection naltrexone (XR-naltrexone), administered monthly, circumvents the need for daily pill taking, potentially improving adherence, and has been shown to be superior to placebo in reducing opioid use over 6 months of treatment. This open-label trial compared the outcomes of patients with opioid use disorder treated with XR-naltrexone or oral naltrexone in combination with behavioral therapy.

METHOD

Sixty opioid-dependent adults completed inpatient opioid withdrawal and were transitioned to oral naltrexone. They were stratified by severity of opioid use (six or fewer bags versus more than six bags of heroin per day) and randomly assigned (1:1) to continue treatment with oral naltrexone (N=32) or XR-naltrexone (N=28) for 24 weeks. The first dose of XR-naltrexone (380 mg) was administered prior to discharge, with monthly doses thereafter, and oral naltrexone was given in a 50-mg daily dose. All participants received weekly behavioral therapy to support treatment and adherence to naltrexone.

RESULTS

A Cox proportional hazards model adjusting for race, gender, route of use, and baseline opioid use severity indicated that significantly more patients were retained in treatment for 6 months in the XR-naltrexone group (16 of 28 patients, 57.1%) than in the oral naltrexone group (nine of 32 patients, 28.1%) (hazard ratio=2.18, 95% CI=1.07, 4.43).

CONCLUSIONS

Patients receiving XR-naltrexone had twice the rate of treatment retention at 6 months compared with those taking oral naltrexone. These results support the use of XR-naltrexone combined with behavioral therapy as an effective treatment for patients seeking opioid withdrawal and nonagonist treatment for preventing relapse to opioid use disorder.

Cost-Effectiveness of Buprenorphine-Naloxone Versus Extended-Release Naltrexone to Prevent Opioid Relapse

BACKGROUND

Not enough evidence exists to compare buprenorphine-naloxone with extended-release naltrexone for treating opioid use disorder.

OBJECTIVE

To evaluate the cost-effectiveness of buprenorphine-naloxone versus extended-release naltrexone.

DESIGN

Cost-effectiveness analysis alongside a previously reported randomized clinical trial of 570 adults in 8 U.S. inpatient or residential treatment programs.

DATA SOURCES

Study instruments.

TARGET POPULATION

Adults with opioid use disorder.

TIME HORIZON

24-week intervention with an additional 12 weeks of observation.

PERSPECTIVE

Health care sector and societal.

INTERVENTIONS

Buprenorphine-naloxone and extended-release naltrexone.

OUTCOME MEASURES

Incremental costs combined with incremental quality-adjusted life-years (QALYs) and incremental time abstinent from opioids.

RESULTS OF BASE-CASE ANALYSIS

Use of the health care sector perspective and a willingness-to-pay threshold of $100 000 per QALY showed buprenorphine-naloxone to be preferable to extended-release naltrexone in 97% of bootstrap replications at 24 weeks and in 85% at 36 weeks. Similar results were obtained with incremental time abstinent from opioids as an outcome and with use of the societal perspective.

RESULTS OF SENSITIVITY ANALYSIS

The base-case results were sensitive to the cost of the 2 treatments and the success of randomized treatment initiation.

LIMITATION

Relatively short follow-up for a chronic condition, substantial missing data, no information on patient out-of-pocket and social service costs.

CONCLUSION

Buprenorphine-naloxone is preferred to extended-release naltrexone as first-line treatment when both options are clinically appropriate and patients require detoxification before initiating extended-release naltrexone.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse, National Institutes of Health.

Psychoeducational Strategies During Outpatient Transition to Extended-Release Naltrexone for Patients With Opioid Use Disorder

BACKGROUND: The United States is experiencing an opioid epidemic. Better approaches to encourage outpatient utilization of Food and Drug Administration-approved medications for the treatment of opioid use disorder, including extended-release naltrexone (XR-NTX), are needed. Withdrawal management before initiation of XR-NTX is challenging for clinicians and patients and represents a major barrier to treatment. AIMS: To review psychoeducational strategies that support patients during outpatient withdrawal management and transition to XR-NTX. METHOD: We reviewed the literature on psychoeducational strategies used during opioid withdrawal management and described the role that nurses can play in facilitating transition to XR-NTX in a Phase 3, placebo-controlled, outpatient trial comparing induction regimens. RESULTS: Supportive interventions include general psychoeducation on addiction, overcoming ambivalence, treatment adherence, anticipating XR-NTX induction, managing psychological and physiological aspects of opioid withdrawal, risks of opioid use, and sources of support during recovery. CONCLUSIONS: Psychoeducational strategies led by nurses can promote treatment adherence during withdrawal management and induction onto XR-NTX.

Cost of pharmacotherapy for opioid use disorders following inpatient detoxification

OBJECTIVES

To estimate the costs of providing extended-release injectable naltrexone (XR-NTX) and buprenorphine-naloxone (BUP-NX) following inpatient detoxification using data derived from a multisite randomized controlled trial at 8 US community-based treatment programs.

STUDY DESIGN

Cost data were collected for 3 intervention phases: program start-up, inpatient detoxification, and up to 24 weeks of medication induction and management visits (post detoxification). Cost analyses were from the healthcare sector perspective (2015 US$); patient costs are also reported.

METHODS

We conducted site visits, administered a cost survey to treatment programs, and analyzed study data on medication and services utilization. Nationally representative sources were used to estimate unit costs. Uncertainty was evaluated in sensitivity analyses.

RESULTS

Mean start-up costs were $1071 per program for XR-NTX and $828 per program for BUP-NX. Mean costs per participant were $5416 for XR-NTX (57% detoxification, 37% medication, 3% provider, 3% patient) and $4148 for BUP-NX (64% detoxification, 12% medication, 10% provider, 14% patient). Total cost per participant ranged by site from $2979 to $8963 for XR-NTX and from $2521 to $6486 for BUP-NX.

CONCLUSIONS

For treatment providers, offering XR-NTX and/or BUP-NX as part of existing detoxification treatment modalities generates modest costs in addition to the costs of detoxification, which vary substantially among the 8 sites. From the patient's perspective, the costs associated with medication management visits may be a barrier for some individuals considering these treatments.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND AND AIM

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

DESIGN

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

SETTING

Five urban, out-patient addiction clinics in Norway.

PARTICIPANTS

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

INTERVENTION

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

MEASUREMENTS

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

FINDINGS

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

CONCLUSIONS

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

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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