Maintenance medication for opiate addiction: the foundation of recovery

Predicting buprenorphine adherence among patients with opioid use disorder in primary care settings

BACKGROUND

Medications for opioid use disorder (MOUD), including buprenorphine, are effective treatments for opioid use disorder (OUD) and reduce risk for overdose and death. Buprenorphine can be prescribed in outpatient primary care settings to treat OUD; however, prior research suggests adherence to buprenorphine in these settings can be low. The purpose of this study was to identify the rates of and factors associated with buprenorphine adherence among patients with OUD in the first six months after a new start of buprenorphine.

METHODS

Data were extracted from the electronic health record (EHR) from a large integrated health system in the upper Midwest. Patients with OUD (N = 345; Mean age = 37.6 years, SD 13.2; 61.7% male; 78% White) with a new start of buprenorphine between March 2019 and July 2021 were included in the analysis. Buprenorphine adherence in the first six months was defined using medication orders; the proportion of days covered (PDC) with a standard cut-point of 80% was used to classify patients as adherent or non-adherent. Demographic (e.g., age, sex, race and ethnicity, geographic location), service (e.g., encounters, buprenorphine formulations and dosage) and clinical (e.g., diagnoses, urine toxicology screens) characteristics were examined as factors that could be related to adherence. Analyses included logistic regression with adherence group as a binary outcome.

RESULTS

Less than half of patients were classified as adherent to buprenorphine (44%). Adjusting for other factors, male sex (OR = 0.34, 95% CI = 0.20, 0.57, p < .001) and having an unexpected positive for opioids on urine toxicology (OR = 0.42, 95% CI = 0.21, 0.83, p < .014) were associated with lower likelihood of adherence to buprenorphine, whereas being a former smoker (compared to a current smoker; OR = 1.82, 95% CI = 1.02, 3.27, p = .014) was associated with greater likelihood of being adherent to buprenorphine.

CONCLUSIONS

These results suggest that buprenorphine adherence in primary care settings may be low, yet male sex and smoking status are associated with adherence rates. Future research is needed to identify the mechanisms through which these factors are associated with adherence.

Association of Opioid and Concurrent Benzodiazepine, Skeletal Muscle Relaxant, and Gabapentinoid Usage on Healthcare Expenditure and Resource Utilization: A Serial Cross-Sectional Study, 2009 to 2019

BACKGROUND

Healthcare providers may be utilizing central nervous system (CNS) depressants to reduce opioid use due to recent changes in public policy. Combination use of these agents with opioids increases the risk of respiratory depression and death. Healthcare expenditures by individuals using these drug combinations have not been previously quantified. We sought to characterize healthcare costs and expenditures associated with a population reporting concurrent CNS depressants and opioid use compared with nonopioid analgesics in the United States from 2009 to 2019.

METHODS

A serial cross-sectional design was used to compare the healthcare expenditures of adult Medical Expenditure Panel Survey respondents who were prescribed nonopioid analgesics, opioids only, opioids/benzodiazepines (BZD), opioids/BZD/skeletal muscle relaxants (SMR), or opioids/gabapentin (gaba) using pooled data from 2009 to 2019. Expenditure (cost and resource utilization) categories included inpatient, outpatient, office-based, and prescription medicine. Average marginal effects were used to compare survey-weighted annual costs and resource utilizations across the groups as compared to nonopioid analgesic respondents, adjusted for covariates.

RESULTS

A weighted total of 34 241 838 individuals were identified. Most were opioid-only respondents (46.5%), followed by nonopioid analgesic (43.4%), opioid/BZD (5.3%), opioid-gaba (3.5%), and opioid/BZD/SMR respondents (1.3%). In comparison to the study groups with nonopioid analgesics, opioid-gaba users had the highest significant incremental cost difference among the different pairings (+$11 684, P < .001). Opioid-gaba, opioid/BZD, and opioid/BZD/SMR respondents had significantly higher inpatient, emergency department, and prescription drug costs and use compared to nonopioid analgesic respondents. Opioid-only respondents had higher outpatient and office-based costs and visits compared to nonopioid analgesic respondents.

CONCLUSIONS

As healthcare providers seek to utilize fewer opioids for pain management, attention must be paid to ensuring safe and effective use of concurrent CNS depressants to mitigate high healthcare costs and burden.

Survey of barriers and opportunities for prescribing buprenorphine for opioid use disorder in Alabama

Opioid-related overdose deaths have significantly increased in the USA and in Alabama. Despite this, medications for opioid use disorder (MOUD) remains significantly underutilized. Thus, this study aims to gain a better understanding of clinicians' viewpoints on potential barriers and opportunities that are likely to impact and improve the access to MOUD, especially buprenorphine prescribing. A cross-sectional survey study was conducted with Alabama's clinicians (n = 492). The survey containing a QR code was mailed to clinicians throughout the state and was asked about their viewpoints and thoughts on prescribing buprenorphine. Multivariable linear regression was used to examine associations between OUD self-efficacy, beliefs about the effectiveness of MOUD, attitudes regarding whether or not MOUD is addictive, and positive affect surrounding the treatment of OUD patients. A minority of respondents (39.8%) reported that they have an active X-waiver for MOUD. Results showed that beliefs that MOUD is addictive were significantly inversely correlated with beliefs about MOUD being effective. Furthermore, both self-efficacy and positive affect were significantly and positively associated with beliefs that MOUD is effective. Furthermore, nurse practitioners were more likely than physicians to have higher scores on the "MAT is Addictive" construct. Self-efficacy with OUD patients was positively associated with the "MOUD is Effective" construct. Finally, results showed that X-waivered providers expressed greater positive affect toward OUD patients than providers who were not X-waivered (b = 2.9, p < 0.001). Belief that MOUD is effective was also positively associated with higher scores on the positive affect construct (b = 0.5, p < 0.001). Several barriers and opportunities were identified in our survey data which could be used to explore MOUD expansion, especially buprenorphine prescribing. Strategic plans in expanding MOUD access may include educational trainings on MOUD, motivating clinicians to utilize their capacity by implementing incentive plans, increasing provider self-efficacy, reducing stigma around MOUD, and providing more financial support to uninsured patients.

Nerve growth factor gene polymorphisms may be associated with heroin dependence in women but do not mediate specific personality traits

Heroin dependence (HD) is a complex disease with a substantial genetic contribution and is associated with traits of impulsivity and specific personality traits. The neurotrophic factor nerve growth factor (NGF) may mediate the reward processes in HD. This study aims to investigate whether NGF gene polymorphisms are associated with the co-occurrence of HD and impulsivity/specific personality traits in HD patients. To minimize the potential confounding effects of population stratification, we selected a homogeneous Han Chinese population and recruited 1364 participants (831 HD patients and 533 healthy controls). In addition, 163 female HD patients completed the Chinese version of the Barratt Impulsiveness Scale Version 11 (BIS-11), and 440 HD patients completed the Chinese version of the Tridimensional Personality Questionnaire (TPQ) for subsequent analysis. We identified three polymorphisms with altered allele and genotype frequency in HD patients versus controls (p = 0.035 for rs2254527; p = 0.005 for rs6678788; p = 0.006 for rs7523654), especially in the female subgroup. Four associations identified via haplotype analysis were significant in the female subgroup (p = 0.003 for T-T-A haplotype and p = 0.002 for C-C-A haplotype in block 1; p = 0.011 for T-T haplotype and p = 0.009 for C-T haplotypes in block 2), but not in the male subgroup. Male HD patients had higher novelty-seeking (NS) scores, and female HD patients had higher harm avoidance (HA) scores. However, there was no significant association between the selected NGF polymorphisms and BIS or TPQ scores in HD patients. NGF variants may contribute to the risk of HD development in females but do not mediate the relationship between impulsivity and specific personality traits in the female population.

Methadone Initiation in the Emergency Department for Opioid Use Disorder

Introduction

Overdose deaths from high-potency synthetic opioids, including fentanyl and its analogs, continue to rise along with emergency department (ED) visits for complications of opioid use disorder (OUD). Fentanyl accumulates in adipose tissue; although rare, this increases the risk of precipitated withdrawal in patients upon buprenorphine initiation. Many EDs have implemented medication for opioid use disorder (MOUD) programs using buprenorphine. However, few offer methadone, a proven therapy without the risk of precipitated withdrawal associated with buprenorphine initiation. We describe the addition of an ED-initiated methadone treatment pathway and compared its 72-hour follow-up outpatient treatment engagement rates to our existing ED-initiated buprenorphine MOUD program.

Methods

We expanded our ED MOUD program with a methadone treatment pathway. From February 20-September 19, 2023, we screened 20,504 ED arrivals; 5.1% had signs of OUD. We enrolled 61 patients: 28 in the methadone; and 33 in the buprenorphine pathways. For patients who screened positive for opioid use, shared decision-making was employed to determine whether buprenorphine or methadone therapy was more appropriate. Patients in the methadone pathway received their first dose of up to 30 milligrams (mg) of methadone in the ED. Two additional methadone doses of up to 40 mg were dispensed at the time of the ED visit and held in the department, allowing patients to return each day for observed dosing until intake at an opioid treatment program (OTP). We compared 72-hour rates of outpatient follow-up treatment engagement at the OTP (for those on methadone) or at the addiction treatment center (ATC) (for those on buprenorphine) for the two treatment pathways.

Results

Of the 28 patients enrolled in the methadone pathway, 12 (43%) successfully engaged in follow-up treatment at the OTP. Of the 33 patients enrolled in the buprenorphine pathway, 15 (45%) successfully engaged in follow-up treatment at the ATC (relative risk 1.06; 95% confidence interval 0.60-1.87).

Conclusion

Methadone initiation in the ED to treat patients with OUD resulted in similar 72-hour follow-up outpatient treatment engagement rates compared to ED-buprenorphine initiation, providing another viable option for MOUD.

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.

Attitudinal barriers to buprenorphine prescription and former waiver training

OBJECTIVE

Opioid use disorder (OUD) can be effectively treated with buprenorphine maintenance. Recent changes in federal policy have removed the requirement for physicians to complete additional training to apply for a Drug Enforcement Administration (DEA) waiver to prescribe buprenorphine. At that time, few primary care providers (PCPs) had completed the training for a DEA waiver to prescribe buprenorphine. Our goal was to identify addressable barriers that may persist despite updates to federal legislation.

DESIGN

A 42-item survey was distributed to 662 physicians and nurse practitioners at two academic medical centers with 100 respondents.

SETTING

The survey was sent via email and administered anonymously through SurveyMonkey.

PATIENTS AND PARTICIPANTS

All participants were PCPs, and all PCPs at the two academic medical centers were eligible to participate.

INTERVENTIONS

PCPs responded to the survey by answering questions online.

MAIN OUTCOME MEASURES

PCPs answered questions regarding previous buprenorphine waiver training status, local OUD prevalence, the effectiveness of OUD treatment modalities, and previous barriers to training.

RESULTS

Respondents were compared using descriptive statistics and logistic regression. Of the 100 respondents (response rate: 15 percent), 69 percent had not completed the training. Ninety-nine percent of PCPs agreed that OUD was an issue in their area, 94 percent saw patients with OUD, and 91 percent rated buprenorphine maintenance as a very effective treatment for OUD. Previously waivered and nonwaivered providers did not differ in their responses to these questions. Those who had been waivered were less likely to say they did not see enough patients with OUD to justify training (odds ratio [OR] 0.267, p = 0.005) and were less likely to express concern about allowing patients with OUD into their practice (OR 0.348, p = 0.020) than PCPs who had applied for the DEA waiver.

CONCLUSIONS

Despite nonwaivered PCPs recognizing OUD's prevalence, they were concerned about allowing patients with OUD into their practice and said there were not enough patients to justify training. This suggests that attitudinal barriers are the most appropriate target for current intervention.

Pharmacologic profile of ITI-333: a novel molecule for treatment of substance use disorders

RATIONALE

Medications are urgently needed to treat symptoms of drug withdrawal and mitigate dysphoria and psychiatric comorbidities that drive opioid abuse and relapse. ITI-333 is a novel molecule in development for treatment of substance use disorders, psychiatric comorbidities, and pain.

OBJECTIVE

Characterize the preclinical profile of ITI-333 using pharmacological, behavioral, and physiological assays.

METHODS

Cell-based assays were used to measure receptor binding and intrinsic efficacy of ITI-333; animal models were employed to assess effects on opioid reinstatement, precipitated oxycodone withdrawal, and drug abuse liability.

RESULTS

In vitro, ITI-333 is a potent 5-HT2A receptor antagonist (Ki = 8 nM) and a biased, partial agonist at μ-opioid (MOP) receptors (Ki = 11 nM; lacking β-arrestin agonism) with lesser antagonist activity at adrenergic α1A (Ki = 28 nM) and dopamine D1 (Ki = 50 nM) receptors. In vivo, ITI-333 blocks 5-HT2A receptor-mediated head twitch and MOP receptor-mediated effects on motor hyperactivity in mice. ITI-333 alone is a naloxone-sensitive analgesic (mice) which suppresses somatic signs of naloxone-precipitated oxycodone withdrawal (mice) and heroin cue-induced reinstatement responding without apparent tolerance or physical dependence after chronic dosing (rats). ITI-333 did not acutely impair gastrointestinal or pulmonary function (rats) and was not intravenously self-administered by heroin-maintained rats or rhesus monkeys.

CONCLUSIONS

ITI-333 acts as a potent 5-HT2A receptor antagonist, as well a biased MOP receptor partial agonist with low intrinsic efficacy. ITI-333 mitigates opioid withdrawal/reinstatement, supporting its potential utility as a treatment for OUD.

Development and validation of machine-learning algorithms predicting retention, overdoses, and all-cause mortality among US military veterans treated with buprenorphine for opioid use disorder

BACKGROUND

Buprenorphine for opioid use disorder (B-MOUD) is essential to improving patient outcomes; however, retention is essential.

OBJECTIVE

To develop and validate machine-learning algorithms predicting retention, overdoses, and all-cause mortality among US military veterans initiating B-MOUD.

METHODS

Veterans initiating B-MOUD from fiscal years 2006-2020 were identified. Veterans' B-MOUD episodes were randomly divided into training (80%;n = 45,238) and testing samples (20%;n = 11,309). Candidate algorithms [multiple logistic regression, least absolute shrinkage and selection operator regression, random forest (RF), gradient boosting machine (GBM), and deep neural network (DNN)] were used to build and validate classification models to predict six binary outcomes: 1) B-MOUD retention, 2) any overdose, 3) opioid-related overdose, 4) overdose death, 5) opioid overdose death, and 6) all-cause mortality. Model performance was assessed using standard classification statistics [e.g., area under the receiver operating characteristic curve (AUC-ROC)].

RESULTS

Episodes in the training sample were 93.0% male, 78.0% White, 72.3% unemployed, and 48.3% had a concurrent drug use disorder. The GBM model slightly outperformed others in predicting B-MOUD retention (AUC-ROC = 0.72). RF models outperformed others in predicting any overdose (AUC-ROC = 0.77) and opioid overdose (AUC-ROC = 0.77). RF and GBM outperformed other models for overdose death (AUC-ROC = 0.74 for both), and RF and DNN outperformed other models for opioid overdose death (RF AUC-ROC = 0.79; DNN AUC-ROC = 0.78). RF and GBM also outperformed other models for all-cause mortality (AUC-ROC = 0.76 for both). No single predictor accounted for >3% of the model's variance.

CONCLUSIONS

Machine-learning algorithms can accurately predict OUD-related outcomes with moderate predictive performance; however, prediction of these outcomes is driven by many characteristics.

Change in substance use among patients in opioid maintenance treatment: baseline to 1-year follow-up

BACKGROUND

Individuals with opioid use disorder (OUD) often have concurrent use of non-opioid substances. When patients enter opioid maintenance treatment (OMT), less is known about outcomes regarding the use of other types of drugs. Here we aimed to investigate changes in substance use among patients entering outpatient OMT, from treatment initiation to 1-year follow-up.

METHODS

We used data from the prospective Norwegian Cohort of Patient in OMT and Other Drug Treatment Study (NorComt). Among 283 patients who entered OMT at participating facilities across Norway, 179 were assessed at follow-up. Of these patients, 131 were in a non-controlled environment, and were included in the present analysis. The main outcome was change in substance use. Logistic regression analysis was applied to identify factors associated with abstinence from all substances (other than agonist medication) at follow-up.

RESULTS

Along with opioid use, most patients reported polysubstance use prior to entering treatment. No significant differences were found in baseline characteristics between the included and non-included groups when examining attrition. At the 1-year follow-up, reduced substance use was reported. While in treatment, around two-thirds of patients continued using other drugs to varying degrees. At follow-up, about one-third of patients reported abstinence from all drugs, apart from the agonist medication. Factors related to abstinence included a goal of abstinence at baseline (OR = 5.26; 95% CI 1.14-19.55; p = 0.013) and increasing age (OR = 1.05; 95% CI 1.00-1.09; p = 0.034).

CONCLUSIONS

The majority of patients entering OMT used other substances in addition to opioids. About one-third of patients reported abstinence at the 1-year follow up. Although the majority of patients continued co-use of other drugs while in treatment, for most substances, less than 10% reported daily use at follow-up, with the exception of cannabis which was used daily/almost daily by about 2 in 10. Higher age and treatment goal at the start of OMT were important factors related to reducing concomitant substance use during treatment. These findings suggest that many patients entering OMT are in need of treatment and support related to the use of other substances, to further improve prognosis.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov no. NCT05182918. Registered 10/01/2022 (the study was retrospectively registered).

Retention of people who inject drugs enrolled in a 'medications for opioid use disorder' (MOUD) programme in Uganda

BACKGROUND

Injection Drug use is associated with increased HIV risk behaviour that may result in the transmission of HIV and poor access to HIV prevention and treatment. In 2020, Uganda introduced the 'medication for opioid use disorder (MOUD) treatment' for People who inject drugs (PWID). We analysed the 12-month retention and associated factors among PWID enrolled on MOUD treatment in Kampala, Uganda.

METHODS

We conducted a retrospective analysis of 343 PWID with OUD who completed 14 days of methadone induction from September 2020 to July 2022. Retention was defined as the number of individuals still in the programme divided by the total number enrolled, computed at 3-, 6-, 9-, and 12 months using lifetable and Kaplan-Meier survival analyses. Cox proportional regression analyses were conducted to assess factors associated with retention in the programme in the first 12 months.

RESULTS

Overall, 243 (71%) of 343 participants stabilized at a methadone dose of 60 mg or more. The majority of participants were males (n = 284, 82.8%), and the median (interquartile range, IQR) age was 31 (26-38) years. Most participants (n = 276, 80.5%) lived 5 km or more away from the MOUD clinic. Thirty (8.8%) were HIV-positive, 52 (15.7%) had a major mental illness and 96 (27.9%) had a history of taking alcohol three months before enrollment. The cumulative retention significantly declined from 83.4% (95%CI = 79.0-87.0) at 3months to 71.9% (95%CI = 67.2-76.6) at 6months, 64% 95%CI = 58.7-68.9) at 9months, and 55.2%; 95% CI (49.8-60.3% at 12months. The 12-month retention was significantly higher for participants on methadone doses of 60 mg or more (adj.HR = 2.1, 95%CI = 1.41-3.22), while participants resident within 5 km of the MOUD clinic were 4.9 times more likely to be retained at 12 months, compared to those residing 5 km or more, (adj. HR = 4.81, 95%CI = 1.54-15). Other factors, including predisposing, need, and enabling factors, were not associated with retention.

CONCLUSION

Our study demonstrates acceptable 12-month retention rates for people who inject drugs, comparable to previous studies done in both developing and developed countries. Sustaining and improving retention may require enhanced scaling up of MOUD dose to an optimal level in the first 14 days and reducing the distance between participant locale and MOUD clinics.

Opioid Prescribing by Emergency Physicians: Trends Study of Medicare Part D Prescriber Data 2013-2019

BACKGROUND

Emergency physicians play a critical role in mitigating the opioid epidemic in public health.

OBJECTIVES

To analyze the prescribing of emergency physicians for opioids among Medicare beneficiaries enrolled in the Part D program from 2013 to 2019.

METHODS

We conducted a retrospective, cross-sectional, descriptive analysis of Medicare Part D prescriber data, focusing on opioid claims between 2013 and 2019. The primary outcome variables evaluated included proportion of opioid claims, trends of the most prescribed opioids, cost of opioid claims, and days' supply per claim.

RESULTS

A total of 63,586 emergency physicians were identified over the study period. Opioid prescription by emergency physicians decreased from 14.45% to 11.55%, and the cost spent on opioid drugs declined by 50%. The use of drugs such as hydrocodone-acetaminophen and oxycodone-acetaminophen declined substantially, whereas tramadol and acetaminophen-codeine prescription increased. The opioid prescribing rate and days' supply also decreased.

CONCLUSIONS

The decline in traditional opioid agents such as hydrocodone-acetaminophen was partly offset by an increase in opioids like tramadol, which carry additional potential adverse events. Opioid prescribing rate, average days' supply, and cost of opioid drugs significantly decreased from 2015 to 2019, after a spike in 2015. All regions observed a decrease in emergency physicians, but opioid prescribing rates varied across regions. These trends highlight successful opioid stewardship practices in some areas and the need for further development in others. This information can aid in designing tailored guidelines and policies for emergency physicians to promote effective opioid stewardship practices.

Low-dose buprenorphine initiation and treatment continuation among hospitalized patients with opioid dependence: A retrospective cohort study

BACKGROUND

Buprenorphine is an effective treatment for both opioid use disorder (OUD) and chronic pain, but buprenorphine's pharmacology complicates treatment initiation for some patients. Low-dose buprenorphine initiation is a novel strategy that may reduce precipitated withdrawal. Few studies describe what patient populations benefit most from low-dose initiations and the clinical parameters that impact treatment continuation. This study aimed to 1) describe experiences with low-dose buprenorphine initiation, including both successes and failures among hospitalized patients in an urban underserved community; 2) identify patient- and treatment-related characteristics associated with unsuccessful initiation and treatment discontinuation; and 3) assess buprenorphine treatment continuation after discharge.

METHODS

This is a retrospective cohort study with opioid-dependent (meaning OUD or receiving long-term opioid therapy for chronic pain) patients who underwent low-dose buprenorphine initiation during hospital admission from October 2021 through April 2022. The primary outcome was successful completion of low-dose initiation. Bivariate analysis identified patient- and treatment-related factors associated with unsuccessful initiation. Secondary outcomes were buprenorphine treatment discontinuation at post-discharge follow-up, 30- and 90-days.

RESULTS

Of 28 patients who underwent low-dose buprenorphine initiation, 68 % successfully completed initiation. Unsuccessful initiation was associated with receipt of methadone during admission and higher morphine milligram equivalents (MME) of supplemental opioids. Of 22 patients with OUD, the percent receiving a buprenorphine prescription at a follow-up visit, 30 days, and 90 days, respectively, was 46 %, 36 %, and 36 %. Of 6 patients with chronic pain, the percent receiving a buprenorphine prescription at a follow-up visit, 30 days, and 90 days, respectively, was 100 %, 100 %, and 83 %.

CONCLUSION

Low-dose buprenorphine initiation can be successful in opioid-dependent hospitalized patients. Patients taking methadone or requiring higher MME of supplemental opioids may have more difficulty with the low-dose buprenorphine initiation approach, but these findings should be replicated in larger studies. This study suggests patient- and treatment-related factors that clinicians could consider when determining the optimal treatment strategy for patients wishing to transition to buprenorphine.

Canadian Addiction Treatment Centre (CATC) opioid agonist treatment cohort in Ontario, Canada

PURPOSE

The Canadian Addiction Treatment Centre (CATC) cohort was established during a period of increased provision of opioid agonist treatment (OAT), to study patient outcomes and trends related to the treatment of opioid use disorder (OUD) in Canada. The CATC cohort's strengths lie in its unique physician network, shared care model and event-level data, making it valuable for validation and integration studies. The CATC cohort is a valuable resource for examining OAT outcomes, providing insights into substance use trends and the impact of service-level factors.

PARTICIPANTS

The CATC cohort comprises 32 246 people who received OAT prescriptions between April 2014 and February 2021, with ongoing tri-annual updates planned until 2027. The cohort includes data from all CATC clinics' electronic medical records and includes demographic information and OAT clinical indicators.

FINDINGS TO DATE

This cohort profile describes the demographic and clinical characteristics of patients being treated in a large OAT physician network. As well, we report the longitudinal OAT retention by treatment type during a time of increasing exposure to a contaminated dangerous drug supply. Notable findings also include retention differences between methadone (32% of patients at 1 year) and buprenorphine (20% at 1 year). Previously published research from this cohort indicated that patient-level factors associated with retention include geographic location, concurrent substance use and prior treatment attempts. Service-level factors such as telemedicine delivery and frequency of urine drug screenings also influence retention. Additionally, the cohort identified rising OAT participation and a substantial increase in fentanyl use during the COVID-19 pandemic.

FUTURE PLANS

Future research objectives are the longitudinal evaluation of retention and flexible modelling techniques that account for the changes as patients are treated with OAT. Furthermore, future research aims are the use of conditional models, and linkage with provincial-level administrative datasets.

10-year retention of a comprehensive treatment model of buprenorphine for opioid use disorder

BACKGROUND

There has been extensive research demonstrating the effectiveness of medications for opioid use disorder (MOUD) but limited investigation into its long-term retention rate.

OBJECTIVE

Assess the long-term treatment retention of a buprenorphine-based MOUD clinic with additional stratifications by age and gender.

METHODS

This retrospective study analyzed 10-years of data from a MOUD clinic in West Virginia that served 3,255 unique patients during the study period (2009-2019). Retention was measured by summation of total treatment days with a new episode of care defined as re-initiating buprenorphine treatment after 60+ consecutive days of nonattendance. Kaplan-Meier survival analysis, with the log-rank test, was used to compare retention by gender and age.

RESULTS

The mean age was 38 (SD = 10.6) and 95% were non-Hispanic white. Irrespective of treatment episode, 56.8% of patients were retained ≥ 90 days, and the overall median time in treatment was 112 days. Considering only the first treatment episode, 48.4% of 3,255 patients were retained at least 90 days and the overall median was 77 days. Female patients had a ≥ 90 day retention rate of 52.2% for the first admission and 60.1% for multiple admissions, both significantly higher than those of male subjects (44.1% and 53.0%). Additionally, patients ≤ 24 years old had the lowest rate of treatment retention, while patients aged ≥ 35 had the highest.

CONCLUSIONS

This study adds to the limited data regarding long-term retention in MOUD. Our findings indicate gender and age were highly correlated with retention in MOUD treatment.

Identifying the Heterogeneity in the Association between Workforce Diversity and Retention in Opioid Treatment among Black clients

Background

This study investigates the impact of workforce diversity, specifically staff identified as Black/African American, on retention in opioid use disorder (OUD) treatment, aiming to enhance patient outcomes. Employing a novel machine learning technique known as 'causal forest,' we explore heterogeneous treatment effects on retention.

Methods

We relied on four waves of the National Drug Abuse Treatment System Survey (NDATSS), a nationally representative longitudinal dataset of treatment programs. We analyzed OUD program data from the years 2000, 2005, 2014 and 2017 (n = 627). Employing the 'causal forest' method, we analyzed the heterogeneity in the relationship between workforce diversity and retention in OUD treatment. Interviews with program directors and clinical supervisors provided the data for this study.

Results

The results reveal diversity-related variations in the association with retention across 61 out of 627 OUD treatment programs (less than 10%). These programs, associated with positive impacts of workforce diversity, were more likely private-for-profit, newer, had lower percentages of Black and Latino clients, lower staff-to-client ratios, higher proportions of staff with graduate degrees, and lower percentages of unemployed clients.

Conclusions

While workforce diversity is crucial, our findings underscore that it alone is insufficient for improving retention in addiction health services research. Programs with characteristics typically linked to positive outcomes are better positioned to maximize the benefits of a diverse workforce in client retention. This research has implications for policy and program design, guiding decisions on resource allocation and workforce diversity to enhance retention rates among Black clients with OUDs.

Association of random and observed urine drug screening with long-term retention in opioid treatment programs

BACKGROUND

In the US, opioid treatment providers (OTPs) have wide latitude to perform urine drug screening (UDS) and discharge clients for positive results. OTP clients have identified randomized and directly observed UDS as potentially stigmatizing, but little research has examined the association between UDS modality and retention in OTPs.

METHODS

This cross-sectional study uses the 2016-2017 NDATSS wave among OTPs that administered methadone. The exposure was a 4-level variable based on whether OTPs had a high percentage (≥ 90% of clients) who experienced randomized, observed, both, or neither modality of UDS. The outcome was the proportion of clients retained in treatment 1 year or longer (long-term retention). Analyses were conducted using fractional logit regression with survey weighting and presented as percentages and 95% confidence intervals. We also present how policies for involuntary clinic discharge modify these effects.

RESULTS

150 OTPs were eligible with a median of 310 clients. 40 (27%) OTPs did not highly utilize either randomized or observed UDS, 22 (15%) only highly utilized observed UDS, 42 (28%) only highly utilized randomized UDS and 46 (31%) utilized both practices on ≥ 90% of clients. Adjusted estimates for long-term retention ranged from 57.7% in OTPs that conducted both randomized and observed UDS on ≥ 90% of clients and 70.4% in OTPs that did not highly utilize these practices. Involuntary discharge may moderate this relationship.

CONCLUSION

Findings showed an association between high utilization of randomized and observed UDS and decreased long-term retention, suggesting that UDS modality may impact long-term OTP retention.

Wiidookaage'Win: A Community-Based Qualitative Approach to Developing a Facebook Group Intervention for Native Women to Support Recovery From Opioid Use

PURPOSE

To develop a culturally-tailored American Indian/Alaska Native (AI/AN) women's Facebook group supporting opioid recovery as an adjunct to medication.

DESIGN

Community-based, qualitative approach.

SETTING

Minnesota, U.S.

PARTICIPANTS

AI/AN women in opioid recovery, interested parties, and a Community Advisory Committee (CAC) of AI/AN women with lived experience, health care providers, and community members.

INTERVENTION

We developed evidence-based content focusing on stress/trauma and substance use, mindfulness, responding to triggers, and supportive community resources. Additional content centered on AI/AN culture was also selected.

METHOD

Interviews were conducted by two women, then transcribed and coded using content analysis with NVivo software. Results were presented to CAC for further content refinement.

RESULTS

CAC members (n = 10) guided study methods, intervention development, and dissemination activities. 14 AI/AN women (mean age 36.4 years; mean 6.7 months opioid abstinence) and 12 interested parties (7 men, 5 women) were receptive to an AI/AN gender-specific Facebook group, preferring content with AI/AN people and/or text resonating with AI/AN culture (e.g., Native traditions, family, personal stories, historical trauma). Recommendations included (1) protect confidentiality, (2) retain positivity, (3) incorporate resources and exercises to build coping skills, and (4) moderators should be authentic and relatable to build trust.

CONCLUSIONS

Our approach provides a model for developing culturally tailored, appealing and effective social media interventions to support AI/AN women in recovery from opioid use disorder.

Latent class analysis of perceived stigma among older adults receiving medications for opioid use disorder

RATIONALE

Public stigma surrounds individuals who use medication for their recovery from a substance use disorder. However, we know little about subgroups of individuals with varying levels of perceived stigma and how these levels may be associated with physical and mental health-related quality of life (HRQOL) and social support.

METHODS

We used latent class analysis to define subgroups of people aged 50-72 years of age (N = 104) who were enrolled in eight medication for opioid use disorder (MOUD) programs to explore subgroupings and correlates of group membership.

RESULTS

We found evidence for three distinct classes of individuals and named the classes 1) the high stigma class, 2) the embarrassed class, and 3) the low stigma class. We found that people in the high-stigma class reported more rejection, more abstinence-based support group involvement, and reduced mental HRQOL.

CONCLUSIONS

Results suggest reducing stigma among people on MOUD may help to boost mental HRQOL and improve social support receipt. The results are consistent with iatrogenic effects of AA/NA support groups such that these treatment modalities may increase stigma due to their focus on abstinence-only treatment for substance use disorders.

Evaluation of opioid use disorder treatment outcomes in patients receiving split daily versus once daily dosing of buprenorphine-naloxone

INTRODUCTION

In clinical practice, sublingual (SL) buprenorphine-naloxone is prescribed as once daily or split daily dosing for the management of opioid use disorder (OUD). Evidence is lacking that assesses how split daily buprenorphine-naloxone affects OUD outcomes. This study aims to evaluate how the dosing frequency of SL buprenorphine-naloxone impacts therapy effectiveness when treating patients with OUD.

METHODS

This retrospective analysis included adult outpatients prescribed treatment with SL buprenorphine-naloxone for OUD between July 1, 2016, and March 1, 2020. The study excluded patients with sickle cell disease, recent methadone treatment, or pregnancy. We characterized study groups by dosing frequency, either once daily or split dosing. The study compared retention in treatment, medication adherence, adherence to treatment program, and hospital encounters between groups.

RESULTS

The study screened eight-hundred and seven patients, and included 250 patients newly prescribed SL buprenorphine-naloxone. Fifty-seven patients (22.8 %) were prescribed once daily dosing and 193 patients (77.2 %) were prescribed split daily dosing. The study found no significant differences noted in 12-month rates of treatment retention (52.6 % vs. 45.6 %, p = .35). These outcomes remained similar when assessed at three and six months. Within a year of buprenorphine-naloxone initiation, the study found no differences in the percentage of patients with hospitalizations (26.3 % vs. 38.3 %, p = .10), median number of hospitalizations (2 vs. 2), or proportion of days covered by a prescription ≥80 % (93.3 % vs. 92.0 %, p = .82).

CONCLUSIONS

In this study, patients receiving once daily buprenorphine-naloxone had similar treatment outcomes to patients receiving split dosing. Further controlled studies are necessary to evaluate which patients are more likely to benefit from split dosing.

A Cost Model for a Low-Threshold Clinic Treating Opioid Use Disorder

The US fee-for-service payment system under-reimburses clinics offering access to comprehensive treatments for opioid use disorder (OUD). The funding shortfall limits a clinic's ability to expand and improve access, especially for socially marginalized patients with OUD. New payment models, however, should reflect the high variation in cost for using a clinic's clinical and voluntary psychosocial and recovery support services. The authors applied time-driven activity-based costing, a patient-level, micro-costing approach, to estimate the cost at an outpatient clinic that delivers medication for opiate used disorder (MOUD) and voluntary psychosocial and recovery support services. Much of the cost variation could be explained by classifying patients into three archetypes: (1) light touch (1-3 visits): no significant co-occurring psychiatric illness, stable housing, and easy to connect for ongoing OUD treatment in a traditional outpatient setting; (2) standard (average of 8 visits): initially requires an integrated team-based care model but soon stabilizes for transition to community-based outpatient care; (3) quad morbidity (> 20 visits): multiple co-occurring substance use disorders, unhoused, co-occurring medical and psychiatric complexity, and limited social supports. With the cost of the initial visit set at an indexed value of 100, an average light touch patient had a cost of 352, a standard patient was 718, and a quad morbidity patient was 1701. The cost structure revealed by this analysis provides the foundation for alternative payment models that would enable new MOUD clinics, staffed with multi-disciplinary care teams, and located for convenient access by high-risk patients, to be established and sustained.

High Interest in Injectable Opioid Agonist Treatment With Hydromorphone Among Urban Syringe Service Program Participants

BACKGROUND

Injectable opioid agonist treatment with hydromorphone (iOAT-H) is effective for persons who inject drugs (PWID) with opioid use disorder (OUD) but remains unavailable in the United States. Our objective was to determine interest in iOAT-H among syringe services program (SSP) participants.

METHODS

We recruited PWID with OUD from SSPs in New York City. Interest in iOAT-H was assessed on a 4-point scale. We compared participants who were and were not interested in iOAT-H regarding sociodemographic characteristics and self-reported variables (past 30 days): heroin use, public injection practices, and participation in illegal activity other than drug possession. Participants reported their preferred OUD treatment and reasons for these preferences.

RESULTS

Of 108 participants, most were male (69%), Hispanic (68%), and median age was 42 years. The median number of prior OUD treatment episodes was 6 (interquartile range: 2-12). Most (65%) were interested in iOAT-H. Interested participants (vs not interested) reported, over the prior 30 days, greater heroin use days (mean, 26.4 vs 22.3), injecting in public more times (median, 15 vs 6), and a higher percentage having participated in illegal activity (40% vs 16%). Preferences for OUD treatment were: iOAT-H (43%), methadone (39%), and buprenorphine (9%). Participants who preferred iOAT-H to conventional OUD treatments reported preferring injection as a route of administration and that available OUD treatments helped them insufficiently.

CONCLUSIONS

SSP participants with OUD reported high interest in iOAT-H. Participants had attempted conventional treatments but still used heroin almost daily. We identified PWID at risk for opioid-related harms who potentially could benefit from iOAT-H.

A Harm Reduction Framework for Integrated Treatment of Co-Occurring Opioid Use Disorder and Trauma-Related Disorders

The opioid epidemic has exposed a gulf in mental health research, treatment, and policy: Most patients with comorbid trauma-related disorder (TRD) and opioid use disorder (OUD) (TRD + OUD) remain undiagnosed or unsuccessfully treated for the combination of TRD symptoms and opioid use. TRD treatments tend to be psychotherapies that are not accessible or practical for many individuals with TRD + OUD, due to TRD treatment models not systematically incorporating principles of harm reduction (HR). HR practices prioritize flexibility and unequivocally improve outcomes and save lives in the treatment of OUD. Considering the urgent need to improve TRD + OUD treatment and outcomes, we propose that the OUD and TRD fields can be meaningfully reconciled by integrating HR principles with classic phasic treatment for TRD. Adding a "prestabilization" phase of treatment for TRD - largely analogous to the precontemplation Stage of Change - creates opportunities to advance research, clinical practice, and policies and potentially improve patient outcomes.

The association of medical providers' attitudes about naloxone and people with opioid use disorder and their self-reported "low-barrier" treatment practices

Opioid-involved overdose deaths continue to climb, in part because of suboptimal access to and retention on medications for opioid use disorder (MOUD), including buprenorphine. Low barrier buprenorphine treatment aims to reduce or eliminate the threshold for getting and staying on medication by providing immediate and long-term access to buprenorphine without strict rules or requirements. This study examines associations between medical providers' beliefs about treating people with opioid use disorder (OUD) and naloxone access with their self-reported low-barrier buprenorphine prescribing practices. We surveyed and analyzed responses from providers (N = 86) who completed X-waiver courses in Missouri between March 2017 and September 2019, of which 55% (n = 47) both completed the full survey and endorsed prescribing buprenorphine since the training. The survey included questions about buprenorphine prescribing behaviors as well as the Naloxone-Related Risk Compensation Beliefs (NaRCC-B) scale and the Attitudes toward Patients with OUD scale. Analyses consisted of a series of linear and logistic regressions with the NaRCC-B and OUD Attitudes scales predicting various domains of low-barrier prescribing behaviors. Findings indicate medical providers' beliefs about treating people with OUD are associated with their practice of addiction medicine, with individuals with more favorable views being more likely to endorse low-barrier buprenorphine prescribing practices including offering telemedicine and at-home inductions, prescribing higher doses of buprenorphine, treating larger caseloads, and discussing overdose risk and protective factors with their patients. Providers' beliefs about naloxone being enabling were less related to their buprenorphine practices but strongly related to their likelihood of providing naloxone. Future research may examine which strategies effectively change prescriber attitudes and their adoption of lower-barrier prescribing practices.

Implementation of medication for opioid use disorder treatment in Indian health clinics in California: A qualitative evaluation

INTRODUCTION

American Indians and Alaska Native (AIAN) populations are disproportionately affected by opioid misuse. Medication for opioid use disorder (MOUD) is essential to decrease overdose events and overdose deaths. AIAN communities can benefit from MOUD programs that are housed within primary care clinics to improve treatment accessibility. This study aimed to gather information on the needs, barriers, and successes related to implementing MOUD programs in Indian health clinics (IHCs) offering primary care.

METHODS

The study used the Reach, Effectiveness, Adoption, Implementation, and Maintenance Qualitative Evaluation for Systematic Translation (RE-AIM QuEST) evaluation framework to structure key informant interviews with clinic staff who received technical assistance for MOUD program implementation. The study incorporated RE-AIM dimensions into a semi-structured interview guide. We developed the coding approach for analyzing interview data using Braun and Clarke's (2006) reflexive thematic analysis in qualitative research.

RESULTS

Eleven clinics participated in the study. The research team conducted twenty-nine interviews with clinic staff. We found that inadequate education about MOUD, scant resources, and limited availability of AIAN providers adversely impacted reach. Challenges with integrating medical and behavioral care, patient-level barriers (e.g., rural conditions, geographical dispersion), and limited workforce capacity impacted MOUD effectiveness. Stigma at the clinic level was detrimental to MOUD adoption. Implementation was challenging due to a limited number of waivered providers, and the need for technical assistance and MOUD policies and procedures. Staff turnover and restricted physical infrastructure negatively influenced MOUD maintenance.

CONCLUSIONS

Clinical infrastructure should be strengthened. The integration of culture into clinic services must be embraced by staff to support MOUD adoption. Increased representation from AIAN clinical staff is needed to appropriately represent the population being served. Stigma at various levels must be addressed, and the multiple barriers that AIAN communities face must be considered in understanding MOUD program implementation and outcomes.

Buprenorphine for Chronic Pain Management: a Narrative Review

PURPOSE OF REVIEW

The aim of this review is to educate healthcare professionals regarding buprenorphine for the use of opioid use disorder (OUD) as well as for chronic pain management. This review provides physicians and practitioners with updated information regarding the distinct characteristics and intricacies of prescribing buprenorphine.

RECENT FINDINGS

Buprenorphine is approved by the US Food and Drug Administration (FDA) for acute pain, chronic pain, opioid use disorder (OUD), and opioid dependence. When compared to most other opioids, buprenorphine offers superior patient tolerability, an excellent half-life, and minimal respiratory depression. Buprenorphine does have notable side effects as well as pharmacokinetic properties that require special attention, especially if patients require future surgical interventions. Many physicians are not trained to initiate or manage patients on buprenorphine. However, buprenorphine offers a potentially safer alternative for medication management for patients who require chronic opioid therapy for pain or have OUD. This review provides updated information on buprenorphine for both chronic pain and OUD.

A Guide to Expanding the Use of Buprenorphine Beyond Standard Initiations for Opioid Use Disorder

Buprenorphine has become an important medication in the context of the ongoing opioid epidemic. However, complex pharmacologic properties and varying government regulations create barriers to its use. This narrative review is intended to facilitate buprenorphine use-including non-traditional initiation methods-by providers ranging from primary care providers to addiction specialists. This article briefly discusses the opioid epidemic and the diagnosis and treatment of opioid use disorder (OUD). We then describe the basic and complex pharmacologic properties of buprenorphine, linking these properties to their clinical implications. We guide readers through the process of initiating buprenorphine in patients using full agonist opioids. As there is no single recommended approach for buprenorphine initiation, we discuss the details, advantages, and disadvantages of the standard, low-dose, bridging-strategy, and naloxone-facilitated initiation techniques. We consider the pharmacology of, and evidence base for, buprenorphine in the treatment of pain, in both OUD and non-OUD patients. Throughout, we address the use of buprenorphine in children and adolescent patients, and we finish with considerations related to the settings of pregnancy and breastfeeding.

Regaining control over opioid use? The potential application of auricular transcutaneous vagus nerve stimulation to improve opioid treatment in China

Opioid use disorder (OUD) is a critical problem in China and is accompanied by depression and deficits in cognitive control. In China, the most successful intervention for OUD is the community drug rehabilitation where methadone maintenance treatment (MMT) plays a key role. Even though methadone for the treatment of OUD can be helpful, it can cause severe somatic side-effects, which limit its effectivity. Even worse, it can have detrimental effects on cognitive control, which is crucial to regain control over drug intake. Here, we consider the potential use of auricular transcutaneous vagus nerve stimulation (atVNS) as an addition to MMT for opioid withdrawal treatment. Compared to other non-invasive brain stimulation methods, atVNS also targets the locus coeruleus (LC) important for noradrenaline (NA) synthesis. NA is an essential neurotransmitter impacted in opioid withdrawal and also critically involved in cognitive control processes. Its ADD-ON to MMT might be a useful mean to improve mood and enhance cognitive control processes impacted in OUD. We discuss the translational advantages of atVNS in China such as the cultural acceptance of the modality of treatment similar to electroacupuncture. Additionally, the wearability of the ear electrode and at-home self-administration without intense medical supervision makes of atVNS a useful tool to enhance clinical and cognitive outcomes especially in everyday life situation. We discuss how atVNS can be integrated in tele-medical health approaches allowing that innovative treatments can widely be disseminated and continued even in situations of restricted medical access.

"Safer Drug Supply" Measures in Canada to Reduce the Drug Overdose Fatality Toll: Clarifying Concepts, Practices and Evidence Within a Public Health Intervention Framework

North America has been home to an unprecedented crisis of drug overdose deaths, driven largely by drug users' exposure to highly potent and toxic, illicit opioid drugs (e.g., fentanyl). Although a large and diverse menu of interventions (e.g., targeted prevention or treatment measures) has been implemented or expanded in Canada, these have not effectively managed to revert and reduce this excessive death toll. Given the fact that these interventions do not directly aim to address toxic drug exposure as the primary vector and cause of acute overdose deaths, public health-oriented "safer drug supply" measures have been initiated in local settings across Canada. These safer supply initiatives provide users with prescribed, pharmaceutical-grade drug supply with the aim of reducing overdose and death risks. These measures have been criticized but also misconstrued from several angles, e.g., as representing inadequate medical or even unethical and harmful practice. Related concerns regarding "diversion" have been raised. In this Perspective, we briefly address some of these issues and clarify selected issues of elementary concepts, practices, and evidence related to safer supply measures within a public health-oriented intervention framework. These measures are also discussed in reference to other, comparable types of public health-oriented emergency health or survival care standards, while considering the extreme contexts of an ongoing, acute drug death crisis in Canada.

A conceptual framework for how structural changes in emerging acute substance use service models can reduce stigma of medications for opioid use disorder

Stigma toward people taking medication for opioid use disorder (MOUD) is prevalent, harmful to the health and well-being of this population, and impedes MOUD treatment resource provision, help-seeking, and engagement in care. In recent years, clinicians have implemented new models of MOUD-based treatment in parts of the United States that integrate buprenorphine initiation into emergency departments and other acute general medical settings, with post-discharge linkage to office-based treatment. These service models increase access to MOUD and they have potential to mitigate stigma toward opioid use and MOUD. However, the empirical literature connecting these emerging service delivery models to stigma outcomes remains underdeveloped. This paper aims to bridge the stigma and health service literatures via a conceptual model delineating how elements of emerging MOUD service models can reduce stigma and increase behavior in pursuit of life goals. Specifically, we outline how new approaches to three key processes can counter structural, public, and self-stigma for this population: (1) community outreach with peer-to-peer influence, (2) clinical evaluation and induction of MOUD in acute care settings, and (3) transition to outpatient maintenance care and early recovery. Emerging service models that target these three processes can, in turn, foster patient empowerment and pursuit of life goals. There is great potential to increase the well-being of people who use opioids by reducing stigma against MOUD via these structural changes.

Shared and divergent transcriptomic regulation in nucleus accumbens D1 and D2 medium spiny neurons by cocaine and morphine

Substance use disorders (SUDs) induce widespread molecular dysregulation in the nucleus accumbens (NAc), a brain region pivotal for coordinating motivation and reward. These molecular changes are thought to support lasting neural and behavioral disturbances that promote drug-seeking in addiction. However, different drug classes exert unique influences on neural circuits, cell types, physiology, and gene expression despite the overlapping symptomatology of SUDs. To better understand common and divergent molecular mechanisms governing SUD pathology, our goal was to survey cell-type-specific restructuring of the NAc transcriptional landscape in after psychostimulant or opioid exposure. We combined fluorescence-activated nuclei sorting and RNA sequencing to profile NAc D1 and D2 medium spiny neurons (MSNs) across cocaine and morphine exposure paradigms, including initial exposure, prolonged withdrawal after repeated exposure, and re-exposure post-withdrawal. Our analyses reveal that D1 MSNs display many convergent transcriptional responses across drug classes during exposure, whereas D2 MSNs manifest mostly divergent responses between cocaine and morphine, with morphine causing more adaptations in this cell type. Utilizing multiscale embedded gene co-expression network analysis (MEGENA), we discerned transcriptional regulatory networks subserving biological functions shared between cocaine and morphine. We observed largely integrative engagement of overlapping gene networks across drug classes in D1 MSNs, but opposite regulation of key D2 networks, highlighting potential therapeutic gene network targets within MSNs. These studies establish a landmark, cell-type-specific atlas of transcriptional regulation induced by cocaine and by morphine that can serve as a foundation for future studies towards mechanistic understanding of SUDs. Our findings, and future work leveraging this dataset, will pave the way for the development of targeted therapeutic interventions, addressing the urgent need for more effective treatments for cocaine use disorder and enhancing the existing strategies for opioid use disorder.

Transgender individuals are at higher risk for suicidal ideation and preparation than cisgender individuals in substance use treatment

Introduction

This study describes the differences and similarities in mental health, substance use, and substance use treatment outcomes between people presenting for SUD treatment who identified as transgender and those who identified as cisgender men or women.

Methods

We compared 64 individuals who self-identified as transgender and presented for SUD treatment to samples of cisgender men and women (separately) matched based on propensity scores which were created based on sociodemographic factors known to influence both the nature of substance use and patterns of treatment engagement including age, education, race, stable housing, and employment status. Comparisons were made using χ2 tests and t-tests in over 150 variables collected at treatment intake regarding physical and mental health, substance use patterns, events that led to treatment, reasons for seeking treatment, and treatment outcomes.

Results

The transgender sample endorsed six of the seven suicide-related items more often than at least one of the cisgender-matched samples. Furthermore, the transgender sample remained in treatment significantly longer (M = 32.3, SD = 22.2) than the cisgender male sample (M = 19.5, SD = 26.1, t = 2.17, p = 0.03).

Discussion

This study is a first step into understanding gender minority population experiences during SUD treatment. While there was no significant difference between the cisgender and transgender samples on most variables, there was an elevated prevalence of suicidal ideation and behaviors in the transgender sample, which warrants further investigation.

Economic Evaluation of Extended-Release Buprenorphine for Persons With Opioid Use Disorder

Importance

In 2017, the US Food and Drug Administration (FDA) approved a monthly injectable form of buprenorphine, extended-release buprenorphine; published data show that extended-release buprenorphine is effective compared with no treatment, but its current cost is higher and current retention is lower than that of transmucosal buprenorphine. Preliminary research suggests that extended-release buprenorphine may be an important addition to treatment options, but the cost-effectiveness of extended-release buprenorphine compared with transmucosal buprenorphine remains unclear.

Objective

To evaluate the cost-effectiveness of extended-release buprenorphine compared with transmucosal buprenorphine.

Design, Setting, and Participants

This economic evaluation used a state transition model starting in 2019 to simulate the lifetime of a closed cohort of individuals with OUD presenting for evaluation for opioid agonist treatment with buprenorphine. The data sources used to estimate model parameters included cohort studies, clinical trials, and administrative data. The model relied on pharmaceutical costs from the Federal Supply Schedule and health care utilization costs from published studies. Data were analyzed from September 2021 to January 2023.

Interventions

No treatment, treatment with transmucosal buprenorphine, or treatment with extended-release buprenorphine.

Main Outcomes and Measures

Mean lifetime costs per person, discounted quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).

Results

The simulated cohort included 100 000 patients with OUD receiving (61% male; mean [SD] age, 38 [11] years) or not receiving medication treatment (58% male, mean [SD] age, 48 [18] years). Compared with no medication treatment, treatment with transmucosal buprenorphine yielded an ICER of $19 740 per QALY. Compared with treatment with transmucosal buprenorphine, treatment with extended-release buprenorphine yielded lower effectiveness by 0.03 QALYs per person at higher cost, suggesting that treatment with extended-release buprenorphine was dominated and not preferred. In probabilistic sensitivity analyses, treatment with transmucosal buprenorphine was the preferred strategy 60% of the time. Treatment with extended-release buprenorphine was cost-effective compared with treatment with transmucosal buprenorphine at a $100 000 per QALY willingness-to-pay threshold only after substantial changes in key parameters.

Conclusions and Relevance

In this economic evaluation of extended-release buprenorphine compared with transmucosal buprenorphine for the treatment of OUD, extended-release buprenorphine was not associated with efficient allocation of limited resources when transmucosal buprenorphine was available. Future initiatives should aim to improve retention rates or decrease costs associated with extended-release buprenorphine.

Prescription analgesic medication use among osteoarthritis patients

OBJECTIVE

Pharmacotherapy is the most common strategies to reduce pain for osteoarthritis (OA) patients. To analyze the trend and pattern of prescription analgesic medication use in American OA patients. Besides, our study also tried to figure out the demographic characteristics of opioid use among OA population which may helpful for managing the use of opioids.

METHODS

We included 2214 OA patients from 2007 to 2018. We extracted data from National Health and Nutrition Examination Survey (NHANES) database. We compared analgesics and anti-depression medications use by category between survey participants with OA and without.

RESULTS

For OA patients, NSAIDs, acetaminophen and gabapentinoid were the mostly highly used analgesics (10.2%, 9.0% and 8.9%, respectively). However, we also found that opioids use was very common in OA patients (7.7%) and the duration of opioids use was significantly long. In addition, the opioids use did not decrease from 2007 to 2018, while gabapentinoid increased rapidly from recent decade (From 5.0% to 12.1%). The common analgesic combination used by OA population was opioids with acetaminophen and gabapentinoid with selective serotonin reuptake inhibitors (SSRIs) (2.9% and 2.7%, respectively).

CONCLUSION

The use of gabapentinoid increased rapidly from recent decade, while opioids use did not decrease. The long-term excessive use of opioids was also a serious problem for OA pain control. More improvements such as focusing more on healthcare education and paying more attention on non-pharmacotherapy and the psychological situation of patients are needed.

Predictors of treatment retention and survival among methadone-maintained patients: A possible role for a functional delta opioid receptor gene variant

BACKGROUND

Variants in the delta opioid receptor gene, OPRD1, were associated with opioid use disorder and response to treatment. The study goal was to assess whether OPRD1 variants predict survival and retention in methadone maintenance treatment (MMT).

METHODS

Retention and survival time since admission (June 1993 - June 2022) until leaving treatment (for retention), or at the end of follow-up (Dec 2022) (for retention and survival) were analyzed in 488 patients. Vital data was taken from a national registry. Predictors were estimated using Kaplan-Meier and Cox regression models.

RESULTS

Longer retention and survival were found for carriers of the T allele of SNP rs204076. This SNP is associated with OPRD1 expression in cortex (GTEx). Carriers of the T allele (n = 251) survived longer compared to non-carriers (24.7 vs. 20.2 years, p = 0.005) and had longer retention (11.2 vs. 8.8 years, p = 0.04). Multivariate analysis identified the T allele as an independent predictor of longer survival time (p = 0.003) and retention (p = 0.009). Additional predictors for survival were no benzodiazepine use after one year in MMT, no hepatitis C, <20 years of opioid usage, and admission at age < 30. Additional predictors for longer retention were no use of other drugs except opioids on admission, and no drugs at one year, as well as methadone dose ≥ 100mg/d at one year and axis I & II DSM-5 psychiatric diagnosis.

CONCLUSIONS

The OPRD1 SNP rs204076 and non-genetic predictors contribute to survival time and retention in MMT patients.

A TLR7/8 agonist increases efficacy of anti-fentanyl vaccines in rodent and porcine models

Opioid use disorders (OUD) and overdose are public health threats worldwide. Widespread access to highly potent illicit synthetic opioids such as fentanyl is driving the recent rise in fatal overdoses. Vaccines containing fentanyl-based haptens conjugated to immunogenic carrier proteins offer a long-lasting, safe, and cost-effective strategy to protect individuals from overdose upon accidental or deliberate exposure to fentanyl and its analogs. Prophylactic or therapeutic active immunization with an anti-fentanyl vaccine induces the production of fentanyl-specific antibodies that bind the drug in the blood and prevent its distribution to the brain, which reduces its reinforcing effects and attenuates respiratory depression and bradycardia. To increase the efficacy of a lead anti-fentanyl vaccine, this study tested whether the incorporation of synthetic toll-like receptor (TLR) 4 and TLR7/8 agonists as vaccine adjuvants would increase vaccine efficacy against fentanyl challenge, overdose, and self-administration in either rats or Hanford miniature pigs. Formulation of the vaccine with a nucleolipid TLR7/8 agonist enhanced its immunogenicity and efficacy in preventing fentanyl-induced respiratory depression, analgesia, bradycardia, and self-administration in either rats or mini-pigs. These studies support the use of TLR7/8 adjuvants in vaccine formulations to improve their clinical efficacy against OUD and potentially other substance use disorders (SUD).

Transcriptional signatures of heroin intake and relapse throughout the brain reward circuitry in male mice

Opioid use disorder (OUD) looms as one of the most severe medical crises facing society. More effective therapeutics will require a deeper understanding of molecular changes supporting drug-taking and relapse. Here, we develop a brain reward circuit-wide atlas of opioid-induced transcriptional regulation by combining RNA sequencing (RNA-seq) and heroin self-administration in male mice modeling multiple OUD-relevant conditions: acute heroin exposure, chronic heroin intake, context-induced drug-seeking following abstinence, and relapse. Bioinformatics analysis of this rich dataset identified numerous patterns of transcriptional regulation, with both region-specific and pan-circuit biological domains affected by heroin. Integration of RNA-seq data with OUD-relevant behavioral outcomes uncovered region-specific molecular changes and biological processes that predispose to OUD vulnerability. Comparisons with human OUD RNA-seq and genome-wide association study data revealed convergent molecular abnormalities and gene candidates with high therapeutic potential. These studies outline molecular reprogramming underlying OUD and provide a foundational resource for future investigations into mechanisms and treatment strategies.

A phase 1 randomized, placebo-controlled study to investigate potential interactions between ASP8062, a positive allosteric modulator of the GABAB receptor, and morphine in recreational opioid users

BACKGROUND

Recent increases in opioid use and subsequent opioid use disorder are a major public health crisis in the United States.

AIMS

This phase 1 randomized, placebo-controlled study investigated the safety, tolerability, and pharmacokinetics (PKs) of ASP8062, a γ-aminobutyric acid B receptor-positive allosteric modulator, with and without administration of morphine in participants who used opioids recreationally.

METHODS

Participants were randomly assigned (2:1) to daily dosing with ASP8062 25 mg or placebo on days 1-10. On day 10, all participants received morphine as a single oral dose of 45 mg; assessments were performed on days 11-16. The primary end point was safety, evaluated as the nature, frequency, and severity of adverse events, and end-tidal CO₂ levels. PK end points were a secondary outcome measure.

RESULTS

A total of 24 participants (aged 21-54 years) received ASP8062 (n = 16) or placebo (n = 8). There were no deaths or serious adverse events leading to treatment discontinuation during the study. Most adverse events were mild, with numerically lower absolute number of adverse events reported with ASP8062 plus morphine versus placebo plus morphine. ASP8062 plus morphine did not increase respiratory depression, potential drug abuse- or withdrawal-related adverse events. There were no significant PK interactions.

CONCLUSIONS

In this phase 1 study, we did not observe any unexpected safety signals or notable PK interactions with concomitant morphine administration. These data suggest a potentially low risk for an increase in drug abuse- or withdrawal-related adverse events or respiratory distress in participants exposed to ASP8062 and morphine.

Association of receiving opioid medication-assisted treatment with sexual identity and mental health/substance use disorder symptoms in a nationally representative sample of adults

Background

Although the literature suggests that medication-assisted treatment (MAT) is an effective treatment for opioid use disorder, limited studies have assessed the prevalence or the association between MAT use and sexual identity, mental health, or substance use disorder among a nationally representative sample. We assessed the prevalence and association of opioid MAT use between sexual identity, depressive disorder symptoms, alcohol use dependence, and marijuana use dependence in the United States.

Methods

We used the 2019 National Survey on Drug Use and Health public-use data on adults aged 18-64 years (N = 38,841) to conduct a weighted multivariable logistic regression analysis.

Results

A total of 4.80% and 2.32% of the population identified as bisexual and lesbian/gay, respectively. About 0.31% (612,750 people) of the population reported receiving opioid MAT, 3.73% had alcohol use dependence, 1.42% had marijuana use dependence, and 9.13% had major depressive episode (MDE) symptoms. Of those who had received opioid MAT, 0.57% were bisexuals and 1.07% were lesbians/gays, 0.65% were people with alcohol use dependence, 2.32% with marijuana use dependence, and 1.59% with MDE symptoms. Lesbian/gay individuals were more likely to receive opioid MAT (AOR = 3.43, 95% CI = 1.42, 8.25) compared to heterosexual individuals. The odds were higher for people with marijuana use dependence (AOR = 3.44, 95% CI = 1.47, 8.06) and MDE symptoms (AOR = 5.22, 95% CI = 3.46, 7.89) than their counterparts.

Conclusions

In this study, sexual minorities, people with MDE symptoms, and those dependent on marijuana use were more likely to receive opioid MAT, suggesting the need to investigate further opioid use disorder symptoms and their risk factors among these populations.

Malmö Treatment Referral and Intervention Study (MATRIS)-36-month follow-up on retention and substance use among patients referred from needle exchange to opioid agonist treatment-The role of stimulant use at baseline

INTRODUCTION

Opioid use disorder (OUD) is the leading cause of overdose morbidity and mortality globally. Retention in opioid agonist treatment (OAT) is crucial as it effectively reduces overdose mortality among individuals suffering from OUD. Previous research on treatment retention among heroin-dependent individuals referred from needle exchange programs (NEP) to OAT is scarce, and with predictors for retention in OAT being somewhat inconclusive, further investigations into this subject is of great interest. The aim of our study was to assess 36-month treatment outcomes-defined as retention and illicit drug abstinence-and predictors of OAT discontinuation.

METHODS

This is a longitudinal cohort study of 71 study subjects successfully referred from a NEP to OAT. Participants were included between October 2011 and April 2013 and followed for 36 months. The study collected data from a structured baseline interview and from patient records, including laboratory data.

RESULTS

At the 36-month follow-up, retention was 51 % (n = 36), with mean days in treatment of 422 for those who discontinued treatment. Amphetamine use during the 30 days before inclusion was positively correlated with treatment discontinuation (AOR 1.22 [95 % CI 1.02-1.46]). No statistically significant association with retention was seen for gender, age, suicide attempt prior to treatment, or benzodiazepine use during 30 days prior to treatment. Opiate use and use of other substances were reduced over time, with major reductions occurring during the first 6 months.

CONCLUSIONS

Hitherto, baseline factors predicting retention in OAT have been insufficiently demonstrated. Active referral from NEP to OAT is effective when it comes to long-term retention and reduction of substance use while in treatment. Except from use of amphetamine, the use of other substances prior to OAT was not associated with treatment discontinuation. Further and in-depth analyses of baseline predictors are of importance for OAT retention.

Heroin and its metabolites: relevance to heroin use disorder

Heroin is an opioid agonist commonly abused for its rewarding effects. Since its synthesis at the end of the nineteenth century, its popularity as a recreational drug has ebbed and flowed. In the last three decades, heroin use has increased again, and yet the pharmacology of heroin is still poorly understood. After entering the body, heroin is rapidly deacetylated to 6-monoacetylmorphine (6-MAM), which is then deacetylated to morphine. Thus, drug addiction literature has long settled on the notion that heroin is little more than a pro-drug. In contrast to these former views, we will argue for a more complex interplay among heroin and its active metabolites: 6-MAM, morphine, and morphine-6-glucuronide (M6G). In particular, we propose that the complex temporal pattern of heroin effects results from the sequential, only partially overlapping, actions not only of 6-MAM, morphine, and M6G, but also of heroin per se, which, therefore, should not be seen as a mere brain-delivery system for its active metabolites. We will first review the literature concerning the pharmacokinetics and pharmacodynamics of heroin and its metabolites, then examine their neural and behavioral effects, and finally discuss the possible implications of these data for a better understanding of opioid reward and heroin addiction. By so doing we hope to highlight research topics to be investigated by future clinical and pre-clinical studies.

Heroin assisted treatment for key health outcomes in people with chronic heroin addictions: A context-focused systematic review

BACKGROUND AND AIMS

Randomised controlled trials in Europe and Canada have shown that supervised heroin assisted treatment (HAT) is an effective treatment option for people with long-term heroin addictions for whom the standard opioid substitution treatments (OST) have not been effective. This review aims to evaluate the effectiveness of supervised HAT and analyse the significance of context and implementation in the design of successful HAT programmes.

METHODS

PubMed, CENTRAL, Embase, and Web of Science were searched to identify randomised controlled trials (RCT) and systematic reviews evaluating supervised HAT compared to any other OST. Studies were eligible for inclusion if they were published in English, evaluated a supervised form of HAT, and included illegal drug use and/or health as a primary outcome measure. There were no restrictions on publication date. The following outcomes of the included studies were analysed using narrative synthesis and meta-analysis where possible: retention, street drug use, health, and social functioning.

RESULTS

Nine randomised controlled trials spanning eight studies (n = 2331) and three systematic reviews met the inclusion criteria. Seven of the eight studies compared HAT to methadone maintenance treatment (MMT). One study compared HAT to injectable hydromorphone in a double-blind non-inferiority trial. Meta-analysis was performed on pooled results of retention across all included studies and found that HAT has a statistically significant effect on retention [Z = 7.65 (P > 0.0001)]. Five of the eight included studies found that supervised HAT reduces participants' use of illegal drugs more significantly than MMT. Evidence of improved health in participants receiving supervised HAT compared to other OSTs was inconsistent; positive effects were observed in three of the included studies (n = 1626).

CONCLUSION

When compared to methadone maintenance treatment (MMT), heroin assisted treatment (HAT) more consistently retains people with heroin addictions in treatment and reduces their consumption of illicit drugs.

TRIAL REGISTRATION

PROSPERO registration: CRD42022341306.

Endomorphin analog ZH853 shows low reward, tolerance, and affective-motivational signs of withdrawal, while inhibiting opioid withdrawal and seeking

Currently available μ-opioid receptor agonist pharmacotherapies for opioid use disorder possess adverse effects limiting their use and, despite treatment, rates of relapse remain high. We previously showed that endomorphin analog ZH853 had no effect in rodent models that predict abuse liability in humans. Here we extended these findings by examining dependence liability and reinforcing properties in female rats and male rats with previous opioid exposure. The potential use of ZH853 in managing opioid use disorder was evaluated by examining its effect on opioid-seeking behavior and withdrawal. We found that ZH853 did not induce locomotor activation in male and female mice and was not self-administered by female rats. Relative to morphine, ZH853 led to similar somatic signs of withdrawal, but low affective-motivational signs of withdrawal, and absent changes in ventral tegmental area K(+)-Cl(-) co-transporter expression associated with reward dysregulation. The low abuse liability of ZH853 was further supported in oxycodone self-administering male rats, where ZH853 substitution extinguished opioid-seeking behavior. ZH853 priming also did not reinstate morphine conditioned place preference. Lastly, ZH853 inhibited oxycodone-seeking behavior during relapse after forced abstinence and decreased the expression of morphine withdrawal. These findings suggest the potential use of ZH853 as a safer opioid medication for long-term treatment of pain and opioid use disorder.

Transcriptional signatures of heroin intake and seeking throughout the brain reward circuit

Opioid use disorder (OUD) looms as one of the most severe medical crises currently facing society. More effective therapeutics for OUD requires in-depth understanding of molecular changes supporting drug-taking and relapse. Recent efforts have helped advance these aims, but studies have been limited in number and scope. Here, we develop a brain reward circuit-wide atlas of opioid-induced transcriptional regulation by combining RNA sequencing (RNAseq) and heroin self-administration in male mice modeling multiple OUD-relevant conditions: acute heroin exposure, chronic heroin intake, context-induced drug-seeking following prolonged abstinence, and heroin-primed drug-seeking (i.e., "relapse"). Bioinformatics analysis of this rich dataset identified numerous patterns of molecular changes, transcriptional regulation, brain-region-specific involvement in various aspects of OUD, and both region-specific and pan-circuit biological domains affected by heroin. Integrating RNAseq data with behavioral outcomes using factor analysis to generate an "addiction index" uncovered novel roles for particular brain regions in promoting addiction-relevant behavior, and implicated multi-regional changes in affected genes and biological processes. Comparisons with RNAseq and genome-wide association studies from humans with OUD reveal convergent molecular regulation that are implicated in drug-taking and relapse, and point to novel gene candidates with high therapeutic potential for OUD. These results outline broad molecular reprogramming that may directly promote the development and maintenance of OUD, and provide a foundational resource to the field for future research into OUD mechanisms and treatment strategies.

Trends and Characteristics of Buprenorphine-Involved Overdose Deaths Prior to and During the COVID-19 Pandemic

Importance

Buprenorphine remains underused in treating opioid use disorder, despite its effectiveness. During the onset of the COVID-19 pandemic, the US government implemented prescribing flexibilities to support continued access.

Objective

To determine whether buprenorphine-involved overdose deaths changed after implementing these policy changes and highlight characteristics and circumstances of these deaths.

Design, Setting, and Participants

This cross-sectional study used data from the State Unintentional Drug Overdose Reporting System (SUDORS) to assess overdose deaths in 46 states and the District of Columbia occurring July 2019 to June 2021. Data were analyzed from March 7, 2022, to June 30, 2022.

Main Outcomes and Measures

Buprenorphine-involved and other opioid-involved overdose deaths were examined. Monthly opioid-involved overdose deaths and the percentage involving buprenorphine were computed to assess trends. Proportions and exact 95% CIs of drug coinvolvement, demographics, and circumstances were calculated by group.

Results

During July 2019 to June 2021, 32 jurisdictions reported 89 111 total overdose deaths and 74 474 opioid-involved overdose deaths, including 1955 buprenorphine-involved overdose deaths, accounting for 2.2% of all drug overdose deaths and 2.6% of opioid-involved overdose deaths. Median (IQR) age was similar for buprenorphine-involved overdose deaths (41 [34-55] years) and other opioid-involved overdose deaths (40 [31-52] years). A higher proportion of buprenorphine-involved overdose decedents, compared with other opioid-involved decedents, were female (36.1% [95% CI, 34.2%-38.2%] vs 29.1% [95% CI, 28.8%-29.4%]), non-Hispanic White (86.1% [95% CI, 84.6%-87.6%] vs 69.4% [95% CI, 69.1%-69.7%]), and residing in rural areas (20.8% [95% CI, 19.1%-22.5%] vs 11.4% [95% CI, 11.2%-11.7%]). Although monthly opioid-involved overdose deaths increased, the proportion involving buprenorphine fluctuated but did not increase during July 2019 to June 2021. Nearly all (92.7% [95% CI, 91.5%-93.7%]) buprenorphine-involved overdose deaths involved at least 1 other drug; higher proportions involved other prescription medications compared with other opioid-involved overdose deaths (eg, anticonvulsants: 18.6% [95% CI, 17.0%-20.3%] vs 5.4% [95% CI, 5.2%-5.5%]) and a lower proportion involved illicitly manufactured fentanyls (50.2% [95% CI, 48.1%-52.3%] vs 85.3% [95% CI, 85.1%-85.5%]). Buprenorphine decedents were more likely to be receiving mental health treatment than other opioid-involved overdose decedents (31.4% [95% CI, 29.3%-33.5%] vs 13.3% [95% CI, 13.1%-13.6%]).

Conclusions and Relevance

The findings of this cross-sectional study suggest that actions to facilitate access to buprenorphine-based treatment for opioid use disorder during the COVID-19 pandemic were not associated with an increased proportion of overdose deaths involving buprenorphine. Efforts are needed to expand more equitable and culturally competent access to and provision of buprenorphine-based treatment.

Modulation of 5-HT release by dynorphin mediates social deficits during opioid withdrawal

Social isolation during opioid withdrawal is a major contributor to the current opioid addiction crisis. We find that sociability deficits during protracted opioid withdrawal in mice require activation of kappa opioid receptors (KORs) in the nucleus accumbens (NAc) medial shell. Blockade of release from dynorphin (Pdyn)-expressing dorsal raphe neurons (DRPdyn), but not from NAcPdyn neurons, prevents these deficits in prosocial behaviors. Conversely, optogenetic activation of DRPdyn neurons reproduced NAc KOR-dependent decreases in sociability. Deletion of KORs from serotonin (5-HT) neurons, but not from NAc neurons or dopamine (DA) neurons, prevented sociability deficits during withdrawal. Finally, measurements with the genetically encoded GRAB5-HT sensor revealed that during withdrawal KORs block the NAc 5-HT release that normally occurs during social interactions. These results define a neuromodulatory mechanism that is engaged during protracted opioid withdrawal to induce maladaptive deficits in prosocial behaviors, which in humans contribute to relapse.

Awareness, perception and utilization of a mobile health clinic by people who use drugs

INTRODUCTION

People who use drugs (PWUD) face a multitude of barriers to accessing healthcare and other services. Mobile health clinics (MHC) are an innovative, cost-effective health care delivery approach that increases healthcare access to vulnerable populations and medically underserved areas. There is limited understanding, however, of how PWUD perceive and experience MHCs.

METHODS

Semi-structured interviews were conducted with 31 PWUD - 16 who had received care (clients) on an MHC (The Spot) and 15 who had not (non-clients) - to explore their perceptions and utilization of an MHC partnered with a mobile syringe services program in Baltimore, Maryland. Data analysis of the text was conducted using an iterative thematic constant comparison process informed by grounded theory.

RESULTS

Clients and non-clients, once aware of the MHC, had positive perceptions of The Spot and its benefits for their individual health as well as for the wellbeing of their community. These sentiments among clients were largely driven by access to low-barrier buprenorphine and service delivery without stigma around drug use. However, lack of general awareness of the spot and specific service offering were barriers to its use among non-clients.

DISCUSSION

MHCs provide an important opportunity to engage PWUD in healthcare and to expand buprenorphine use; however, even with accessibility near where PWUD access injection equipment, barriers to its use remain. Peer dissemination may be able to facilitate program information sharing and recruitment.KEY MESSAGESPeople who use drugs perceive a mobile health clinic in their neighbourhood as a benefit to their communities and themselves by improving access to healthcare services, providing access to low-threshold buprenorphine dispensation, and offering services without drug use stigma.People who use drugs learned about a mobile health clinic in their neighbourhood largely through word-of-mouth. As a result, people received limited information about the mobile health clinic services creating a barrier to its use.

Preclinical Characterization and Development on NAQ as a Mu Opioid Receptor Partial Agonist for Opioid Use Disorder Treatment

Mu opioid receptor (MOR) selective antagonists and partial agonists have clinical utility for the treatment of opioid use disorders (OUDs). However, the development of many has suffered due to their poor pharmacokinetic properties and/or rapid metabolism. Our recent efforts to identify MOR modulators have provided 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6α-(isoquinoline-3-carboxamido)morphinan (NAQ), a low-efficacy partial agonist, that showed sub-nanomolar binding affinity to the MOR (K i 0.6 nM) with selectivity over the delta opioid receptor (δ/μ 241) and the kappa opioid receptor (κ/μ 48). Its potent inhibition of the analgesic effect of morphine (AD50 0.46 mg/kg) and precipitation of significantly less withdrawal symptoms even at 100-fold greater dose than naloxone represents a promising molecule for further development as a novel OUD therapeutic agent. Therefore, further in vitro and in vivo characterization of its pharmacokinetics and pharmacodynamics properties was conducted to fully understand its pharmaceutical profile. NAQ showed favorable in vitro ADMET properties and no off-target binding to several classes of GPCRs, enzymes, and ion channels. Following intravenous administration, 1 mg/kg dose of NAQ showed a similar in vivo pharmacokinetic profile to naloxone; however, orally administered 10 mg/kg NAQ demonstrated significantly improved oral bioavailability over both naloxone and naltrexone. Abuse liability assessment of NAQ in rats demonstrated that NAQ functioned as a less potent reinforcer than heroin. Chronic 5 day NAQ pretreatment decreased heroin self-administration in a heroin-vs-food choice procedure similar to the clinically used MOR partial agonist buprenorphine. Taken together, these studies provide evidence supporting NAQ as a promising lead to develop novel OUD therapeutics.

Multi-omics study reveals associations among neurotransmitter, extracellular vesicle-derived microRNA and psychiatric comorbidities during heroin and methamphetamine withdrawal

Despite decades of research in the field of substance withdrawal, molecular biomarkers and related mechanistic study have generally been lacking. In addition to known neurotransmitters, circulating miRNAs are found in small vesicles known as exosomes within blood that have diagnostic potential and are known to contribute to psychiatric disorders. The aim of this work was to characterize the changes in neurotransmitter and exosomal miRNA profiles during heroin and methamphetamine withdrawal using a cross-sectional study design, and to determine their associations to psychiatric comorbidities in a large group of patients with substance use disorders (SUDs). Using weighted gene co-expression network analysis, a series of known, conserved, and novel exosomal miRNAs were identified as being associated with the severity of anxiety and depression, as well as the concentrations of neurotransmitters GABA, choline, and serotonin. Bioinformatics analyses established that the differences in the miRNA profile target signaling pathways are significantly associated with developmental and intellectual abnormalities. Notably, a set of dysregulated miRNA signatures including hsa-mia-451a and hsa-mir-21a resulted in an AUC of 0.966 and 0.861, respectively, for predicting the patients with SUDs. Furthermore, hsa-miR-744a-5p was positively correlated with serotonin, and its important role in maintaining neuronal development and function was revealed using an in vitro human induced pluripotent stem cells derived neuronal model. Our results suggest that the miRNA content of circulating exosomes represent a biomolecular "fingerprint" of the progression of substance withdrawal and may uncover the putative mechanism of how these exosomal miRNAs contribute to psychiatric symptoms.