Evaluating remyelination compounds for new applications in opioid use disorder management

Opioid use disorder (OUD) is associated with a reduction in brain white matter, affecting critical areas involved in decision-making, impulse control, and reward processing. The FDA has approved several drugs and natural compounds that enhance myelination, targeting oligodendrocyte progenitor cells (OPCs), directly enhancing oligodendrocyte (OL) function, or acting as cofactors for myelin production. This retrospective case study aimed to assess whether current clinical evidence supports the use of myelin-enhancing agents to promote remission in OUD. We evaluated a range of compounds with demonstrated effects on myelination, including muscarinic antagonists, cholesterol and lipid homeostatic agents, anti-aging drugs, immunomodulatory agents, anti-inflammatory medications, and others (25 medications in total), as well as 17 vitamins and supplements. Buprenorphine and methadone were used as positive controls. Sequential analyses were performed to identify individual drugs driving significant changes in remission rates (p ≤ 0.01; N ≥ 3,000) and their effects across age, sex, and Body Mass Index (BMI) categories. Three key findings emerged: (1) melatonin improved remission rates in males but showed no effect in females; (2) ibuprofen significantly increased remission rates, particularly in individuals aged 20-39 and 40-59 years; and (3) thiamin was associated with decreased remission rates in males and individuals with a BMI ranging from normal weight to obese. Additionally, buprenorphine and methadone were confirmed as effective in promoting remission. These findings highlight the importance of personalized medicine in treating OUD and suggest that further research is needed to explore individualized treatment strategies based on sex, age, and BMI.

Ecological momentary assessment and cue-elicited drug craving as primary endpoints: study protocol for a randomized, double-blind, placebo-controlled clinical trial testing the efficacy of a GLP-1 receptor agonist in opioid use disorder

BACKGROUND

Despite continuing advancements in treatments for opioid use disorder (OUD), continued high rates of relapse indicate the need for more effective approaches, including novel pharmacological interventions. Glucagon-like peptide 1 receptor agonists (GLP-1RA) provide a promising avenue as a non-opioid medication for the treatment of OUD. Whereas GLP-1RAs have shown promise as a treatment for alcohol and nicotine use disorders, to date, no controlled clinical trials have been conducted to determine if a GLP-1RA can reduce craving in individuals with OUD. The purpose of the current protocol was to evaluate the potential for a GLP-1RA, liraglutide, to safely and effectively reduce craving in an OUD population in residential treatment.

METHOD

This preliminary study was a randomized, double-blinded, placebo-controlled clinical trial designed to test the safety and efficacy of the GLP-1RA, liraglutide, in 40 participants in residential treatment for OUD. Along with taking a range of safety measures, efficacy for cue-induced craving was evaluated prior to (Day 1) and following (Day 19) treatment using a Visual Analogue Scale (VAS) in response to a cue reactivity task during functional near-infrared spectroscopy (fNIRS) and for craving. Efficacy of treatment for ambient craving was assessed using Ecological Momentary Assessment (EMA) prior to (Study Day 1), across (Study Days 2-19), and following (Study Days 20-21) residential treatment.

DISCUSSION

This manuscript describes a protocol to collect clinical data on the safety and efficacy of a GLP-1RA, liraglutide, during residential treatment of persons with OUD, laying the groundwork for further evaluation in a larger, outpatient OUD population. Improved understanding of innovative, non-opioid based treatments for OUD will have the potential to inform community-based interventions and health policy, assist physicians and health care professionals in the treatment of persons with OUD, and to support individuals with OUD in their effort to live a healthy life.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04199728. Registered 16 December 2019, https://clinicaltrials.gov/study/NCT04199728?term=NCT04199728 .

PROTOCOL VERSION

10 May 2023.

Geographic variation in availability of opioid treatment programs across U.S. communities

Methadone for Opioid Use Disorder (OUD) treatment is only dispensed at Opioid Treatment Programs (OTPs). Little is known about the geographic variation in OTP availability and community characteristics associated with the availability across smaller geographic communities in the U.S. To (1) describe geographic distribution of OTPs and (2) examine OTP availability by community characteristics in the contiguous U.S. at Zip Code Area Tabulation (ZCTA) level. Logistic regression was used to examine community characteristics associated with OTP availability (N = 30,367). Chi-square and t-tests were conducted to examine statistically significant differences in OTP availability. Maps and descriptive statistics were used to examine geographic variation in OTP availability. Only 5% (1,417) of ZCTAs had at least one OTP for a total of 1,682 OTPs. Rural ZCTAs had 50% lower odds of having an OTP compared to urban ZCTAs [AOR 0.5; (95% CI: 0.41-0.60)]. ZCTAs in the lowest income quartile had higher odds of having an OTP compared to ZCTAs in the highest income quartile [AOR 3.4; (95% CI: 2.71-4.18)]. Further, ZCTAs with OTPs had a higher proportion of minority residents [Black: 17.5% vs. 7.2%; Hispanic: 19.2% vs. 9%] and a lower proportion of White residents [55.1% vs. 78.2%]. Nationally, OTPs are extremely scarce with notable regional and urban-rural disparities. Potential solutions to address these disparities are discussed.

Re-Purposing FDA-Approved Drugs for Opioid Use Disorder

OBJECTIVE

To investigate FDA-approved drugs prescribed for unrelated diseases or conditions that promote remission in subjects diagnosed with opioid use disorder (OUD).

METHODS

This was a retrospective observational study utilizing the TriNetX electronic medical record data. Subjects between 18 and 65 years old were included in this study. First, a drug screen was employed to identify medications used for chronic illness that are associated with OUD remission. Based on Fisher's exact test for significance, 28 of 101 medications were selected for further analysis. Positive (buprenorphine/methadone) and negative controls (benazepril) were included in the analysis. Medications were analyzed in the absence and presence of buprenorphine or methadone, two medications used to treat OUD, to identify the likelihood of OUD remission up to one year following the index event.

RESULTS

We identify 8 medications (prazosin, propranolol, lithium carbonate, olanzapine, quetiapine, bupropion, citalopram, and escitalopram) that may be useful for increasing remission in OUD in the absence of buprenorphine or methadone. Additionally, our results identify psychiatric medications that when taken alongside buprenorphine and methadone improve remission rates.

CONCLUSION

These results provide medication options that may be useful in treating OUD as well as integrated therapies to treat comorbid mental illness.

The inhibition of enkephalin catabolism by dual enkephalinase inhibitor: A novel possible therapeutic approach for opioid use disorders

Despite the increasing impact of opioid use disorders on society, there is a disturbing lack of effective medications for their clinical management. An interesting innovative strategy to treat these disorders consists in the protection of endogenous opioid peptides to activate opioid receptors, avoiding the classical opioid-like side effects. Dual enkephalinase inhibitors (DENKIs) physiologically activate the endogenous opioid system by inhibiting the enzymes responsible for the breakdown of enkephalins, protecting endogenous enkephalins and increasing their half-lives and physiological actions. The activation of opioid receptors by the increased enkephalin levels, and their well-demonstrated safety, suggests that DENKIs could represent a novel analgesic therapy and a possible effective treatment for acute opioid withdrawal, as well as a promising alternative to opioid substitution therapy minimizing side effects. This new pharmacological class of compounds could bring effective and safe medications avoiding the major limitations of exogenous opioids, representing a novel approach to overcome the problem of opioid use disorders. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.

Suboxone: History, controversy, and open questions

There are more than 200 opioid overdose deaths each day in the US. In combating this epidemic we look to available treatment tools. Here, we find only three medications approved by the Food and Drug Administration (FDA) for the treatment of opioid use disorder. Of the three, buprenorphine is of particular importance due to its reduced overdose potential as a partial opioid agonist. Evidence supports its clinical equivalence to its full agonist cousin methadone, and suggests that it is better slated for long-term treatment of opioid use disorder compared to the non-selective opioid antagonist naltrexone. Buprenorphine is most popularized within Suboxone, a medication which also contains the non-selective opioid antagonist naloxone. The naloxone has no additional effect when the drug is taken as instructed, as it is intended to prevent diversion in those that would attempt to inject the medication. While Suboxone is regarded by some as the future of medical treatment, others have expressed concerns. This review aims to explore the history, controversy, and open questions that surround buprenorphine and its most prescribed variation, Suboxone. These include its pharmacological, legislative, and social history, alternative indications, efficacy as a treatment of opioid use disorder, and more. Armed with this information, the reader will have a more in-depth and holistic understanding of the medication's place in their community.

A MULTIVARIATE SPATIOTEMPORAL CHANGE-POINT MODEL OF OPIOID OVERDOSE DEATHS IN OHIO

Ohio is one of the states most impacted by the opioid epidemic and experienced the second highest age-adjusted fatal drug overdose rate in 2017. Initially it was believed prescription opioids were driving the opioid crisis in Ohio. However, as the epidemic evolved, opioid overdose deaths due to fentanyl have drastically increased. In this work we develop a Bayesian multivariate spatiotemporal model for Ohio county overdose death rates from 2007 to 2018 due to different types of opioids. The log-odds are assumed to follow a spatially varying change point regression model. By assuming the regression coefficients are a multivariate conditional autoregressive process, we capture spatial dependence within each drug type and also dependence across drug types. The proposed model allows us to not only study spatiotemporal trends in overdose death rates but also to detect county-level shifts in these trends over time for various types of opioids.

Impact of Pharmacological Treatments for Opioid Use Disorder on Mortality

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

Medication Treatment of Opioid Use Disorder

Opioid use disorder (OUD) is a chronic, relapsing condition, often associated with legal, interpersonal, and employment problems. Medications demonstrated to be effective for OUD are methadone (a full opioid agonist), buprenorphine (a partial agonist), and naltrexone (an opioid antagonist). Methadone and buprenorphine act by suppressing opioid withdrawal symptoms and attenuating the effects of other opioids. Naltrexone blocks the effects of opioid agonists. Oral methadone has the strongest evidence for effectiveness. Longer duration of treatment allows restoration of social connections and is associated with better outcomes. Treatments for OUD may be limited by poor adherence to treatment recommendations and by high rates of relapse and increased risk of overdose after leaving treatment. Treatment with methadone and buprenorphine has the additional risk of diversion and misuse of medication. New depot and implant formulations of buprenorphine and naltrexone have been developed to address issues of safety and problems of poor treatment adherence. For people with OUD who do not respond to these treatments, there is accumulating evidence for supervised injectable opioid treatment (prescribing pharmaceutical heroin). Another medication mode of minimizing risk of overdose is take-home naloxone. Naloxone is an opioid antagonist used to reverse opioid overdose, and take-home naloxone programs aim to prevent fatal overdose. All medication-assisted treatment is limited by lack of access and by stigma. In seeking to stem the rising toll from OUD, expanding access to approved treatment such as methadone, for which there remains the best evidence of efficacy, may be the most useful approach.

Effects of medication-assisted treatment on mortality among opioids users: a systematic review and meta-analysis

Opioid use disorder (OUD) is associated with a high risk of premature death. Medication-assisted treatment (MAT) is the primary treatment for opioid dependence. We comprehensively assessed the effects of different MAT-related characteristics on mortality among those with OUD by a systematic review and meta-analysis. The all-cause and overdose crude mortality rates (CMRs) and relative risks (RRs) by treatment status, different type, period, and dose of medication, and retention time were pooled using random effects, subgroup analysis, and meta-regression. Thirty cohort studies involving 370,611 participants (1,378,815 person-years) were eligible in the meta-analysis. From 21 studies, the pooled all-cause CMRs were 0.92 per 100 person-years (95% CI: 0.79-1.04) while receiving MAT, 1.69 (1.47-1.91) after cessation, and 4.89 (3.54-6.23) for untreated period. Based on 16 studies, the pooled overdose CMRs were 0.24 (0.20-0.28) while receiving MAT, 0.68 (0.55-0.80) after cessation of MAT, and 2.43 (1.72-3.15) for untreated period. Compared with patients receiving MAT, untreated participants had higher risk of all-cause mortality (RR 2.56 [95% CI: 1.72-3.80]) and overdose mortality (8.10 [4.48-14.66]), and discharged participants had higher risk of all-cause death (2.33 [2.02-2.67]) and overdose death (3.09 [2.37-4.01]). The all-cause CMRs during and after opioid substitution treatment with methadone or buprenorphine were 0.93 (0.76-1.10) and 1.79 (1.47-2.10), and corresponding estimate for antagonist naltrexone treatment were 0.26 (0-0.59) and 1.97 (0-5.18), respectively. Retention in MAT of over 1-year was associated with a lower mortality rate than that with retention ≤1 year (1.62, 1.31-1.93 vs. 5.31, -0.09-10.71). Improved coverage and adherence to MAT and post-treatment follow-up are crucial to reduce the mortality. Long-acting naltrexone showed positive advantage on prevention of premature death among persons with OUD.

Circumstances of death of opioid users being treated with naltrexone

BACKGROUND AND AIMS

Naltrexone is an opioid antagonist used as a maintenance drug for the treatment of opioid dependence and in opioid withdrawal regimens. The current study aimed to: (1) determine the clinical characteristics and circumstances of death of people undergoing naltrexone treatment for opioid dependence; and (2) determine the blood toxicology of cases including naltrexone concentrations, the presence of other drugs and a comparison of morphine concentrations in the presence and absence of naltrexone.

DESIGN

Retrospective study of all deaths among people undergoing naltrexone treatment for opioid dependence retrieved from the National Coronial Information System, 2000-17.

SETTING

Australia-wide.

CASES

Seventy-four cases, with a mean age of 32.5 years; 81.1% male.

MEASUREMENTS

Information was collected on demographics, manner of death, naltrexone treatment history, toxicology and major organ pathology.

FINDINGS

Death was attributed to opioid toxicity in 86.5% of cases: accidental (79.7%), deliberate (6.8%). In 55.4% of all cases the decedent was maintained on oral naltrexone and 32.4% had a recent naltrexone implant. In five cases the decedent was undergoing opioid detoxification. Among those screened for naltrexone, naltrexone was present in the blood or urine of 52.5% (15.8% of oral maintenance cases, 85.7% of implant cases). Fourteen cases were known to have died from opioid toxicity with naltrexone present in their blood or urine. The median blood naltrexone concentrations were within the reported therapeutic range.

CONCLUSIONS

The primary cause of death among people undergoing naltrexone treatment for opioid dependence in Australia from 2000 to 2017 was opioid toxicity, the majority of cases having been maintained on oral naltrexone. Cases in which naltrexone was not detected indicate the importance of treatment compliance. Deaths due to opioid toxicity where naltrexone was present indicates the possibility of overdose while naltrexone medication is maintained.

Potential uses of naltrexone in emergency department patients with opioid use disorder

Introduction: Despite widespread recognition of the opioid crisis, opioid overdose remains a common reason for Emergency Department (ED) utilization. Treatment for these patients after stabilization often involves the provision of information for outpatient treatment options. Ideally, an ED visit for overdose would present an opportunity to start treatment for opioid use disorder (OUD) immediately. Although widely recognized as effective, opioid agonist therapy with methadone and buprenorphine commonly referred to as "medication-assisted therapy" but more correctly as "medication for addiction treatment" (MAT), can be difficult to access even for motivated individuals due to shortages of prescribers and treatment programs. Moreover, opioid agonist therapy may not be appropriate for all patients, as many patients who present after overdose are not opioid dependent. More treatment options are required to successfully match patients with diverse needs to an optimal treatment plan in order to avoid relapse. Naltrexone, a long-acting opioid antagonist, available orally and as a monthly extended-release intramuscular injection, may represent another treatment option. Methods: We conducted a literature search of MEDLINE and PubMed. We aimed to capture references related to naltrexone and is use as MAT for OUD, as well as manuscripts that discussed naltrexone in comparison toother agents used for MAT, opioid detoxification, and naltrexone metabolism. Our initial search logic returned a total of 618 articles. Following individual evaluation for relevance, we selected 65 for in-depthreview. Manuscripts meeting criteria were examined for citations meriting further review, leading to the addition of 30 manuscripts Conclusions: Here, we review the pharmacology of naltrexone as it relates to OUD, its history of use, and highlight recent studies and new approaches for use of the drug as MAT including its potential initiation after ED visit for opioid overdose.

A joint spatial model of opioid-associated deaths and treatment admissions in Ohio

PURPOSE

Opioid misuse is a national epidemic, and Ohio is one of the states most impacted by this crisis. Ohio collects county-level counts of opioid-associated deaths and treatment admissions. We jointly model these two outcomes and assess the association of each rate with social and structural factors.

METHODS

We use a joint spatial rates model of death and treatment counts using a generalized common spatial factor model. In addition to covariate effects, we estimate a spatial factor for each county that characterizes structural factors not accounted for by other covariates in the model that are associated with both outcomes.

RESULTS

We observed an association of health professional shortage area with death rates and the rate of people 18-64 on disability with treatment rates. The proportion of single female households was associated with both outcomes. We estimated the presence of unmeasured risk factors in the southwestern part of the state and unmeasured protective factors in the eastern region.

CONCLUSIONS

We described associations of social and structural covariates with the death and treatment rates. We also characterized counties with latent risk that can provide a launching point for future investigations to determine potential sources of that risk.

Improvement in Residents' Attitudes Toward Individuals with Substance Use Disorders Following an Online Training Module on Stigma

BACKGROUND

Resident physicians have been shown to possess negative attitudes toward individuals with substance use disorders (SUDs), even if the residents believe they have adequate knowledge and skills to care for these patients. Residents' negative attitudes may have an adverse impact on patient engagement, treatment, and outcomes.

QUESTIONS/PURPOSES

The goal of this study was to examine the impact of an online training module on residents' attitudes toward people with SUDs. We hypothesized that residents who received the educational intervention would show improved attitudes toward people with alcohol and opioid use disorders.

METHODS

A web-based questionnaire, including demographic information and the Medical Condition Regard Scale (MCRS) about individuals with alcohol and opioid use disorders, was sent to internal medicine and psychiatry residents before and 6 months after they took an online training module on stigma toward individuals with SUDs.

RESULTS

A total of 46 residents completed the initial questionnaire and 29 completed the follow-up questionnaire 6 months later. Attitudes toward individuals with SUDs, as reflected by an increase in MCRS scores, were improved 6 months after the online training module.

CONCLUSION

Residents' attitudes toward individuals with SUDs improved after taking an online training module. This is encouraging, as studies have shown that attitudes toward individuals with SUDs tend to decline during residency training and negatively affect patient care. Larger studies are needed to determine if such online modules can improve attitudes of other groups of clinicians, result in sustained change over time, and improve patient outcomes.

Evidence of validity and reliability of the Opiate Dosage Adequacy Scale (ODAS) in a sample of heroin addicted patients in buprenorphine/naloxone maintenance treatment

OBJECTIVE

The Opiate Dosage Adequacy Scale (ODAS) is a clinical tool to individually measure the "adequacy" of opioid doses in patients on maintenance treatment. The aim of this paper is to provide evidence for the validity and reliability of the ODAS in a sample of patients in buprenorphine/naloxone (B/N) maintenance treatment.

METHOD

Cross-sectional study of a convenience sample of B/N-treated patients (n = 316) from four Autonomous Communities in Spain. Participants completed a battery of instruments to assess the following: buprenorphine dose adequacy; heroin dependence severity; psychological adjustment; and patient-desired adjustment of buprenorphine dose.

RESULTS

Exploratory Factor Analysis identified four factors from the ODAS that together account for 85.4% of the total variance: "Heroin craving and use"; "Overmedication"; "Objective opiate withdrawal symptoms (OWS)" and 'Subjective OWS'. Compared to patients with an "inadequate" B/N dose (ODAS), patients with "adequate" doses had less heroin use in the last week (0.01 vs. 0.40; t = -2.73; p < 0.01, 95% CI: -0.67, -0.10), less severe heroin dependence (2.20 vs. 5.26, t = -5.14, p < 0.001; 95% CI: -4.23, -1.88), less psychological distress (3.00 vs. 6.31, t = -4.37, p < 0.001; 95% CI: -4.80, -1.81), and greater satisfaction with their doses (42.1% vs. 13.6%, χ² = 14.44, p < 0.01). Cronbach's alpha coefficient was 0.76 (0.81, 0.92, 0.94, and 0.93, respectively, for the four factor dimensions).

CONCLUSION

These findings support the validity and reliability of the ODAS as a tool to measure and assess buprenorphine dose adequacy in the context of an opioid dependency treatment program.

Effectiveness of Injectable Extended-Release Naltrexone vs Daily Buprenorphine-Naloxone for Opioid Dependence: A Randomized Clinical Noninferiority Trial

Importance

To date, extended-release naltrexone hydrochloride has not previously been compared directly with opioid medication treatment (OMT), currently the most commonly prescribed treatment for opioid dependence.

Objective

To determine whether treatment with extended-release naltrexone will be as effective as daily buprenorphine hydrochloride with naloxone hydrochloride in maintaining abstinence from heroin and other illicit substances in newly detoxified individuals.

Design, Setting and Participants

A 12-week, multicenter, outpatient, open-label randomized clinical trial was conducted at 5 urban addiction clinics in Norway between November 1, 2012, and December 23, 2015; the last follow-up was performed on October 23, 2015. A total of 232 adult opioid-dependent (per DSM-IV criteria) individuals were recruited from outpatient addiction clinics and detoxification units and assessed for eligibility. Intention-to-treat analyses of efficacy end points were performed with all randomized participants.

Interventions

Randomization to either daily oral flexible dose buprenorphine-naloxone, 4 to 24 mg/d, or extended-release naltrexone hydrochloride, 380 mg, administered intramuscularly every fourth week for 12 weeks.

Main Outcomes and Measures

Primary end points (protocol) were the randomized clinical trial completion rate, the proportion of opioid-negative urine drug tests, and number of days of use of heroin and other illicit opioids. Secondary end points included number of days of use of other illicit substances. Safety was assessed by adverse event reporting.

Results

Of 159 participants, mean (SD) age was 36 (8.6) years and 44 (27.7%) were women. Eighty individuals were randomized to extended-release naltrexone and 79 to buprenorphine-naloxone; 105 (66.0%) completed the trial. Retention in the extended-release naltrexone group was noninferior to the buprenorphine-naloxone group (difference, -0.1; with 95% CI, -0.2 to 0.1; P = .04), with mean (SD) time of 69.3 (25.9) and 63.7 (29.9) days, correspondingly (P = .33, log-rank test). Treatment with extended-release naltrexone showed noninferiority to buprenorphine-naloxone on group proportion of total number of opioid-negative urine drug tests (mean [SD], 0.9 [0.3] and 0.8 [0.4], respectively, difference, 0.1 with 95% CI, -0.04 to 0.2; P < .001) and use of heroin (mean difference, -3.2 with 95% CI, -4.9 to -1.5; P < .001) and other illicit opioids (mean difference, -2.7 with 95% CI, -4.6 to -0.9; P < .001). Superiority analysis showed significantly lower use of heroin and other illicit opioids in the extended-release naltrexone group. No significant differences were found between the treatment groups regarding most other illicit substance use.

Conclusions and Relevance

Extended-release naltrexone was as effective as buprenorphine-naloxone in maintaining short-term abstinence from heroin and other illicit substances and should be considered as a treatment option for opioid-dependent individuals.

Trial Registration

clinicaltrials.gov Identifier: NCT01717963.