Management of opioid use disorders: a national clinical practice guideline

Characteristics of Opioid Toxicity Deaths Among Adolescents and Young Adults in Ontario Prior To and During the COVID-19 Pandemic

PURPOSE

To characterize opioid toxicity deaths among adolescents and young adults in Ontario, Canada, prior to and during the first year of the COVID-19 pandemic.

METHODS

We conducted a descriptive, cross-sectional study of opioid toxicity deaths among individuals aged 15-24 in Ontario in the year prior to (March 17, 2019, to March 16, 2020) and the first year of the pandemic (March 17, 2020, to March 16, 2021) using administrative health databases. We analyzed circumstances surrounding death, substances contributing to death, and health-care encounters prior to death.

RESULTS

We identified 284 deaths among Ontarians aged 15-24, including 115 in the year preceding and 169 in the first year of the pandemic. Fentanyl contributed to 84.3% of deaths in the prepandemic year, rising to 93.5% (p = .012) the following year. Stimulants contributed to approximately half of deaths in both periods (41.7% prepandemic and 49.1% during pandemic). In both periods, roughly one in 4 decedents had a health-care encounter in the week prior to death and less than 20% of those with an opioid use disorder received opioid agonist treatment in the 30 days prior to death.

DISCUSSION

Among young Ontarians, the number of opioid-related deaths increased by 47% in the first year of the COVID-19 pandemic. Fentanyl contributed to the vast majority of deaths, with non-opioid substances (primarily stimulants) also contributing to approximately half of deaths. Patterns of health-care utilization prior to death suggest opportunities to better connect this population to services that address opioid use disorder needs and promote harm reduction.

Feasibility and effectiveness of extended-release buprenorphine (XR-BUP) among correctional populations: a systematic review

Background: Medications for opioid use disorder (MOUD) reduce risks for overdose among correctional populations. Among other barriers, daily dosing requirements hinder treatment continuity post-release. Extended-release buprenorphine (XR-BUP) may therefore be beneficial. However, limited evidence exists.Objectives: To conduct a systematic review examining the feasibility and effectiveness of XR-BUP among correctional populations.Methods: Searches were carried out in Pubmed, Embase, and PsychINFO in October 2023. Ten studies reporting on feasibility or effectiveness of XR-BUP were included, representing n = 819 total individuals (81.6% male). Data were extracted and narratively reported under the following main outcomes: 1) Feasibility; 2) Effectiveness; and 3) Barriers and Facilitators.Results: Studies were heterogeneous. Correctional populations were two times readier to try XR-BUP compared to non-correctional populations. XR-BUP was feasible and safe, with no diversion, overdoses, or deaths; several negative side effects were reported. Compared to other MOUD, XR-BUP significantly reduced drug use, resulted in similar or higher treatment retention rates, fewer re-incarcerations, and was cost-beneficial, with a lower overall monthly/yearly cost. Barriers to XR-BUP, such as side effects and a fear of needles, as well as facilitators, such as a lowered risk of opioid relapse, were also identified.Conclusion: XR-BUP appears to be a feasible and potentially effective alternative treatment option for correctional populations with OUD. XR-BUP may reduce community release-related risks, such as opioid use and overdose risk, as well as barriers to treatment retention. Efforts to expand access to and uptake of XR-BUP among correctional populations are warranted.

A population-based time-series analysis of opioid agonist treatment dispensed during pregnancy

BACKGROUND AND AIMS

Identifying effective opioid treatment options during pregnancy is a high priority due to the growing prevalence of opioid use disorder across North America. We assessed the temporal impact of three population-level interventions on the use of opioid agonist treatment (OAT) during pregnancy in Ontario, Canada.

DESIGN

This was a population-based time-series analysis to identify trends in the monthly prevalence of pregnant people dispensed methadone and buprenorphine. The impact of adding buprenorphine/naloxone to the public drug formulary, the release of pregnancy-specific guidance and the start of the COVID-19 pandemic were assessed.

SETTING AND PARTICIPANTS

The study was conducted in Ontario, Canada between 1 July 2013 and 31 March 2022, comprising people who delivered a live or stillbirth in any Ontario hospital during the study period.

MEASUREMENTS

We identified any prescription for methadone or buprenorphine dispensed between the estimated conception date and delivery date and calculated the monthly prevalence of OAT-exposed pregnancies among all pregnant people in Ontario.

FINDINGS

Overall, rates of OAT during pregnancy have declined since mid-2018. Methadone-exposed pregnancies decreased from 0.46% of all pregnancies in Ontario in 2015 to a low of 0.16% in 2022. In the primary analysis, none of the interventions had a statistically significant impact on overall OAT rates; however, in the stratified analyses, there was a small increase in buprenorphine after the formulary change [0.006%, 95% confidence interval (CI) = 0.0032-0.0081, P < 0.0001] and a decrease in buprenorphine after the release of the 2017 guidelines (-0.005%, 95% CI = -0.0080 to -0.0020, P = 0.001) and the start of the COVID-19 pandemic (-0.003%, 95% CI = -0.0054 to -0.0006, P = 0.015).

CONCLUSION

Despite changes in guidance and funding, opioid agonist treatment during pregnancy has been declining in Ontario, Canada since 2018.

Informing evidence-based medicine for opioid use disorder using pharmacoeconomic studies

INTRODUCTION

The health and economic consequences of inadequately treated opioid use disorder (OUD) are substantial. Healthcare systems in the United States (US) and other countries are facing a growing healthcare crisis due to opioids. Although effective medications for OUD exist, relying solely on clinical information is insufficient for addressing the opioid crisis.

AREAS COVERED

In this review, the role of pharmacoeconomic studies in informing evidence-based medication treatment for OUD is discussed, with a particular emphasis on the US healthcare system, where the economic burden is significantly higher than the global average. The scope/objective of pharmacoeconomics as a distinct scientific research program is briefly defined, followed by a discussion of existing evidence informed by data from systematic reviews, in addition to a convenience sample of recently published pharmacoeconomic studies and protocols. The review also explores the need for methodological advancements in the field.

EXPERT OPINION

Despite the potential of pharmacoeconomic research in shaping evidence-based medicine for OUD, significant challenges limiting its real-world application remain. How to address these challenges are explored, including how to combine cost-effectiveness and budget impact analyses to address the needs of the healthcare system as a whole and specific stakeholders interested in adopting new OUD treatment strategies.

Caring for Hospitalized Adults With Opioid Use Disorder in the Era of Fentanyl: A Review

Importance

The rise of fentanyl and other high-potency synthetic opioids across US and Canada has been associated with increasing hospitalizations and unprecedented overdose deaths. Hospitalization is a critical touchpoint to engage patients and offer life-saving opioid use disorder (OUD) care when admitted for OUD or other medical conditions.

Observations

Clinical best practices include managing acute withdrawal and pain, initiating medication for OUD, integrating harm reduction principles and practices, addressing in-hospital substance use, and supporting hospital-to-community care transitions. Fentanyl complicates hospital OUD care. Fentanyl's high potency intensifies pain, withdrawal, and cravings and increases the risk for overdose and other harms. Fentanyl's unique pharmacology has rendered traditional techniques for managing opioid withdrawal and initiating buprenorphine and methadone inadequate for some patients, necessitating novel strategies. Further, co-use of opioids with stimulants drugs is common, and the opioid supply is unpredictable and can be contaminated with benzodiazepines, xylazine, and other substances. To address these challenges, clinicians are increasingly relying on emerging practices, such as low-dose buprenorphine initiation with opioid continuation, rapid methadone titration, and the use of alternative opioid agonists. Hospitals must also reconsider conventional approaches to in-hospital substance use and expand clinicians' understanding and embrace of harm reduction, which is a philosophy and set of practical strategies that supports people who use drugs to be safer and healthier without judgment, coercion, or discrimination. Hospital-to-community care transitions should ensure uninterrupted access to OUD care after discharge, which requires special consideration and coordination. Finally, improving hospital-based addiction care requires dedicated infrastructure and expertise. Preparing hospitals across the US and Canada to deliver OUD best practices requires investments in clinical champions, staff education, leadership commitment, community partnerships, quality metrics, and financing.

Conclusions and Relevance

The findings of this review indicate that fentanyl creates increased urgency and new challenges for hospital OUD care. Hospital clinicians and systems have a central role in addressing the current drug crisis.

Experience of patients on methadone maintenance treatment receiving take-home methadone doses during COVID-19 pandemic: A multi-site study from India

BACKGROUND

Methadone take-home doses for opioid dependence treatment are strictly regulated due to diversion and overdose concerns, so patients must visit the clinic daily for dispensing. This was also done in India until the COVID-19 pandemic, when lockdown restriction compelled take- home dispensing of methadone. This study examined experience of patients who received take- home methadone during COVID-19 pandemic in India.

METHODS

Observational, cross-sectional design. We contacted all consenting methadone centres in India during the lockdown and selected those that provided take-home doses for the study. Patients who received daily methadone before the lockdown and take-home doses after were interviewed using a study-specific questionnaire.

RESULTS

The study had 210 participants. Take-home methadone was dispensed for 2.5 days on average in each dispensing. When taking methadone at home, 3.3% split their dose 25% took less than the prescribed dose to save it for a rainy days, and 3.3% reported an overdose episode. Adherence improved in 58.6% participants after take-home methadone. Participants perceived many benefits from take-home methadone such as reduced hospital visits and travel time to collect methadone, improvement in work, and financial savings. About 54.3% participants reported storing their take-home doses safely, and 1.9% reported that their family consumed methadone by mistake.

CONCLUSIONS

Take-home methadone was found to be beneficial to most participants in terms of time saved and improved productivity. Preconceived concerns of providing take-home methadone in terms of its overdose, diversion, or accidental ingestion by others are not commonly seen when individuals are provided take-home doses of methadone.

Examining inequities in access to opioid agonist treatment (OAT) take-home doses (THD): A Canadian OAT guideline synthesis and systematic review

BACKGROUND

Daily supervised Opioid Agonist Treatment (OAT) medication has been identified as a barrier to treatment retention. Canadian OAT guidelines outline take-home dose (THD) criteria, yet, OAT prescribers use their clinical judgement to decide whether an individual is 'clinically stable' to receive THD. There is limited information regarding whether these decisions may result in inequitable access to THD, including in the context of updated COVID-19 guidance. The current Canadian OAT THD guideline synthesis and systematic review aimed to address this knowledge gap.

METHODS

This systematic review included a two-pronged approach. First, we searched available academic literature in Embase, Medline, and PsychINFO up until October 12th, 2022, to identify studies that compared characteristics of individuals on OAT who had and had not been granted access to THD to explore potential inequities in access. Next, we identified all Canadian national and provincial OAT guidelines through a semi-structured grey literature search (conducted between September-October 2022) and extracted all THD 'stability' and allowances/timeline criteria to compare against characteristics identified in the literature search. Data from both review arms were synthesized and narratively presented.

RESULTS

A total of n = 56 guidelines and n = 7 academic studies were included. The systematic review identified a number of patient characteristics such as age, sex, race/ethnicity, marital status, housing, employment, neighborhood income, drug use, mental health, health service utilization, as well as treatment duration that were associated with differential access to THD. The Canadian OAT THD guideline synthesis identified many of these same characteristics as 'stability' criteria, underscoring the potential for Canadian OAT guidelines to result in inequitable access to THD.

CONCLUSIONS

This two-pronged literature review demonstrated that current guidelines likely contribute to inequitable OAT THD access due primarily to inconsistent 'stability' criteria across guidelines. More research is needed to understand differential OAT THD access with a focus on prescriber decision-making and evaluating associated treatment and safety outcomes. The development of a client-centered, equity-focused, and evidence-informed decision making framework that incorporates more clear definitions of 'stability' criteria and indications for prescriber discretion is warranted.

Building Capacity for Injectable Diacetylmorphine and Hydromorphone for the Treatment of Opioid Use Disorder: Identifying Typical Doses

Identifying typical doses of existing opioid use disorder medications, such as injectable opioid agonist treatment (iOAT), can support client and program needs, and potentially increase iOAT expansion. Longitudinal data from participants in a cohort study (n = 131), along with clinic dispensation records from August 2014 to April 2020, were used to examine physician prescribed as well as used doses of injectable diacetylmorphine and hydromorphone. Dosage groups, by medication and prescribed dose per session, were created for both hydromorphone and diacetylmorphine. A total of 534, 522 injections were registered during the study period among 129 participants. Mean received diacetylmorphine doses ranged from 106 to 989 mg per day, with most clients using 125-262 mg per session (mean 192.99 mg) and attending 2.40 sessions per day. Mean received hydromorphone doses ranged from 51.09 to 696.06 mg per day, with the majority using 88-154 mg per session (mean 121.32 mg; 2.43 sessions). Average daily doses remained stable overtime and, while mid-range doses were most typical, participants used the whole spectrum of allowable dose prescriptions. Evidence supporting typical doses of iOAT can be integrated into program planning to better allow providers and prescribers to anticipate program needs and engage in individualized care.

The current state of knowledge on care for co-occurring chronic pain and opioid use disorder: A scoping review

BACKGROUND AND AIMS

Opioid use disorder often co-occurs with chronic pain but assessment and treatment of these co-occurring disorders is complex. This review aims to identify current treatments and delivery models for co-occurring chronic pain and opioid use disorder (OUD) documented in the scientific literature.

DESIGN

Scoping review.

METHODS

The review was conducted in six databases in June 2022 (no time limit): CINAHL, PsycINFO, Web of Science, Cochrane, PubMed and Embase. The PRISMA-ScR checklist was used to guide reporting.

RESULTS

Forty-seven publications addressing the issue of co-occurring chronic pain and OUD management were included. Randomized controlled trials provide evidence for the effectiveness of opioid agonist treatments (OAT) such as methadone or buprenorphine/naloxone, as well as for combining OAT with Mindfulness-Oriented Recovery Enhancement or cognitive behavioural therapy. A number of other pharmacological treatments (opioid and nonopioid), nonpharmacological treatments (e.g. physiotherapy) and service delivery models (e.g. simultaneous treatment of comorbidities, interdisciplinary and interprofessional collaboration) are also underlined. In most cases, authors recommend a combination of strategies to meet patient needs.

CONCLUSIONS

The scoping review reveals gaps in evidence-based knowledge to effectively care for co-occurring chronic pain and OUD, but several experts recommend the uptake of known 'best' practices such as integrated treatment of the multiple biopsychosocial dimensions of the co-occurring disorders as well as collaborative interdisciplinary work.

CLINICAL RELEVANCE

Improving services is dependent on alleviating barriers such as working in silos, the costs associated with nonpharmacological treatments, and the double stigma associated with pain in people with a substance use disorder.

Sexually transmitted and blood-borne infection risk reduction with methadone and buprenorphine/naloxone among people with prescription-type opioid use disorder: Findings from a Canadian pragmatic randomized trial

INTRODUCTION

People who use drugs are disproportionally affected by sexually transmitted and blood-borne infections (STBBIs). While the benefits of methadone in reducing injecting-risk behaviours are well documented, less is known on its impacts on sexual-related risks, as well as its comparative effectiveness to buprenorphine/naloxone, particularly in the context of highly potent opioids. The aim of this study was to estimate the relative effects of buprenorphine/naloxone and methadone on injecting and STBBI risks among people with prescription-type opioid use disorder (POUD).

METHODS

Secondary analysis of a pan-Canadian pragmatic 24-week randomized clinical trial comparing methadone and buprenorphine/naloxone models of care among 272 people with POUD (including licit or illicit opioid analgesics, fentanyl). The Risk Behaviour Survey was used to collect injecting and sexual risks at baseline, and weeks 12 and 24.

RESULTS

In total, 210 participants initiated treatment (103 buprenorphine/naloxone and 107 methadone). At baseline, 113/205 (55.1%) participants reported recently injecting drugs, 37/209 (17.7%) unsafe injection practices and 67/162 (41.4%) high-risk sex. Both methadone and buprenorphine/naloxone were associated with reductions in the prevalence of injection drug use and high-risk sex at weeks 12 and 24 with no interactions between treatment arm and time.

CONCLUSION

Methadone and buprenorphine/naloxone were similarly effective in reducing injecting and sexual risk behaviours among people with POUD.

CLINICAL TRIALS REGISTRATION

clinicaltrials.gov NCT03033732.

Discontinuation of psychotropic medication: a synthesis of evidence across medication classes

Pharmacotherapy is an effective treatment modality across psychiatric disorders. Nevertheless, many patients discontinue their medication at some point. Evidence-based guidance for patients, clinicians, and policymakers on rational discontinuation strategies is vital to enable the best, personalized treatment for any given patient. Nonetheless, there is a scarcity of guidelines on discontinuation strategies. In this perspective, we therefore summarize and critically appraise the evidence on discontinuation of six major psychotropic medication classes: antidepressants, antipsychotics, benzodiazepines, mood stabilizers, opioids, and stimulants. For each medication class, a wide range of topics pertaining to each of the following questions are discussed: (1) Who can discontinue (e.g., what are risk factors for relapse?); (2) When to discontinue (e.g., after 1 year or several years of antidepressant use?); and (3) How to discontinue (e.g., what's the efficacy of dose reduction compared to full cessation and interventions to mitigate relapse risk?). We thus highlight how comparing the evidence across medication classes can identify knowledge gaps, which may pave the way for more integrated research on discontinuation.

Patient's and healthcare provider's experiences with Opioid Maintenance Treatment (OMT): a qualitative evidence synthesis

BACKGROUND

Opioid Maintenance Treatment (OMT) is the gold standard for people with opioid dependence. However, drop-out rates are high, and many patients do not reach desired outcomes. Understanding patients' and healthcare providers' experiences with the treatment can provide valuable information to improve the quality of OMT and to increase acceptability and accessibility of services. The aim of this systematic review is to explore and synthesise the experiences of OMT among persons with opioid dependence and health care providers, to inform policy makers and practitioners on how to improve OMT outcomes.

METHODS

We conducted a qualitative evidence synthesis. We systematically searched in electronic databases (CINAHL, Embase, MEDLINE, and nordic databases) and searched for grey literature. As we identified many studies that met our inclusion criteria, we purposively sampled a manageable number of studies to include in this review. Two researchers independently extracted and coded data from the included studies and used the Andersen's healthcare utilization model to organize and develop codes. We assessed the methodological limitations of the studies, and our confidence in the findings using GRADE CERQual.

RESULTS

We retrieved 56 relevant studies and purposively sampled 24 qualitative studies of patients' and healthcare providers' experiences with OMT. Our analyses resulted in six main themes: (1) External stigma prevents engagement and retention in treatment, (2) Being identified as in OMT contributed to an increased experience of stigma (3) Inadequate knowledge and expertise among healthcare providers affected patients' treatment experiences, (4) Quality of communication between personnel and patients impacts patients' engagement with treatment and treatment outcomes, (5) Patients wanted help with many aspects of their lives not just medication, and (6) Balancing positive expectations of OMT with treatment stigma. We found that stigma was an overarching theme across these themes.

CONCLUSION

Our findings suggest that OMT could be more beneficial for patients if treatment programs prioritize efforts to diminish societal and OMT provider stigma and find strategies to better address patient needs. Initiatives should focus on improving treatment knowledge among providers, encouraging the use of client perspectives, considering the context of family members, and establishing a more holistic and flexible treatment environment.

The Association Between Self-Reported Anxiety and Retention in Opioid Agonist Therapy: Findings From a Canadian Pragmatic Trial

BACKGROUND

Prescription-type opioid use disorder (POUD) is often accompanied by comorbid anxiety, yet the impact of anxiety on retention in opioid agonist therapy (OAT) is unclear. Therefore, this study investigated whether baseline anxiety severity affects retention in OAT and whether this effect differs by OAT type (methadone maintenance therapy (MMT) vs. buprenorphine/naloxone (BNX)).

METHODS

This secondary analysis used data from a pan-Canadian randomized trial comparing flexible take-home dosing BNX and standard supervised MMT for 24 weeks. The study included 268 adults with POUD. Baseline anxiety was assessed using the Beck Anxiety Inventory (BAI), with BAI ≥ 16 indicating moderate-to-severe anxiety. The primary outcomes were retention in assigned and any OAT at week 24. In addition, the impact of anxiety severity on retention was examined, and assigned OAT was considered an effect modifier.

RESULTS

Of the participants, 176 (65%) reported moderate-to-severe baseline anxiety. In adjusted analyses, there was no significant difference in retention between those with BAI ≥ 16 and those with BAI < 16 assigned (29% vs. 28%; odds ratio (OR) = 2.03, 95% confidence interval (CI) = 0.94-4.40; P = 0.07) or any OAT (35% vs. 34%; OR = 1.57, 95% CI = 0.77-3.21; P = 0.21). In addition, there was no significant effect modification by OAT type for retention in assigned (P = 0.41) or any OAT (P = 0.71). In adjusted analyses, greater retention in treatment was associated with BNX (vs. MMT), male gender identity (vs. female, transgender, or other), enrolment in the Quebec study site (vs. other sites), and absence of a positive urine drug screen for stimulants at baseline.

CONCLUSIONS

Baseline anxiety severity did not significantly impact retention in OAT for adults with POUD, and there was no significant effect modification by OAT type. However, the overall retention rates were low, highlighting the need to develop new strategies to minimize the risk of attrition from treatment.

CLINICAL TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (NCT03033732).

Comparative Analysis of Instrumental Variables on the Assignment of Buprenorphine/Naloxone or Methadone for the Treatment of Opioid Use Disorder

BACKGROUND

Instrumental variable (IV) analysis provides an alternative set of identification assumptions in the presence of uncontrolled confounding when attempting to estimate causal effects. Our objective was to evaluate the suitability of measures of prescriber preference and calendar time as potential IVs to evaluate the comparative effectiveness of buprenorphine/naloxone versus methadone for treatment of opioid use disorder (OUD).

METHODS

Using linked population-level health administrative data, we constructed five IVs: prescribing preference at the individual, facility, and region levels (continuous and categorical variables), calendar time, and a binary prescriber's preference IV in analyzing the treatment assignment-treatment discontinuation association using both incident-user and prevalent-new-user designs. Using published guidelines, we assessed and compared each IV according to the four assumptions for IVs, employing both empirical assessment and content expertise. We evaluated the robustness of results using sensitivity analyses.

RESULTS

The study sample included 35,904 incident users (43.3% on buprenorphine/naloxone) initiated on opioid agonist treatment by 1585 prescribers during the study period. While all candidate IVs were strong (A1) according to conventional criteria, by expert opinion, we found no evidence against assumptions of exclusion (A2), independence (A3), monotonicity (A4a), and homogeneity (A4b) for prescribing preference-based IV. Some criteria were violated for the calendar time-based IV. We determined that preference in provider-level prescribing, measured on a continuous scale, was the most suitable IV for comparative effectiveness of buprenorphine/naloxone and methadone for the treatment of OUD.

CONCLUSIONS

Our results suggest that prescriber's preference measures are suitable IVs in comparative effectiveness studies of treatment for OUD.

Access challenges to opioid use disorder treatment among individuals experiencing homelessness: Voices from the streets

BACKGROUND

Achieving equitable access to medications for opioid use disorder (MOUD) such as buprenorphine is a pressing issue. Evidence suggests disparities in MOUD access based on race and socioeconomic status, further exacerbated by the COVID-19 pandemic. However, the drivers behind this access gap remain poorly understood. This study explores barriers to treatment access among individuals with opioid use disorder (OUD) experiencing homelessness.

METHODS

We interviewed 28 individuals in and around the Boston Public Health Commission (BPHC) Engagement Center, an area known for its high density of active substance use and homelessness. We asked about people's experiences, perceptions, and attitudes toward OUD treatment. We conducted a thematic analysis of our interview data.

RESULTS

Fifty-four percent of participants sampled were not prescribed MOUD. None of the participants reported having an active prescription of sublingual buprenorphine or buprenorphine/naloxone. White participants were more likely to have been prescribed buprenorphine in the past compared to participants of other races even in this socioeconomically homogeneous sample. Themes that emerged in our data included challenges to accessing MOUD due to reduced services during the COVID-19 pandemic, lost or stolen medications, fewer inpatient withdrawal management beds for women, transportation challenges, fear of adverse effects of MOUD, the perception that taking MOUD replaces one addiction for another, and community disapproval of MOUD. Participants also reported stigma and discrimination based on race, gender, and socioeconomic status.

CONCLUSION

Systems and individual-level factors contribute to the MOUD treatment gap across race and socioeconomic status. The COVID-19 pandemic posed additional access challenges. This study provides important, actionable insights about the barriers faced by a particularly vulnerable population of individuals with OUD experiencing homelessness.

Perceptions in orthopedic surgery on the use of cannabis in treating pain: a survey of patients with spine pain (POSIT Spine)

BACKGROUND

Back pain is the leading cause of disability worldwide. Despite guidelines discouraging opioids as first-line treatment, opioids remain the most prescribed drugs for back pain. There is renewed interest in exploring the potential medical applications of cannabis, and with the recent changes in national legislation there is a unique opportunity to investigate the analgesic properties of cannabis.

METHODS

This was a multi-center survey-based study examining patient perceptions regarding cannabis for spine pain. We included patients presenting with back or neck pain to one of three Orthopedic clinics in Ontario. Our primary outcome was perceived effect of cannabis on back pain, while secondary outcomes were perceptions regarding potential applications and barriers to cannabis use.

RESULTS

259 patients participated in this study, 35.3% (90/255) stating they used cannabis medically. Average pain severity was 6.5/10 ± 0.3 (95% CI 6.2-6.8). Nearly three-quarters were prescribed opioids (73.6%, 148/201), with oxycodone/oxycontin (45.9% 68/148) being the most common, and almost half of (49.3%, 73/148) had used an opioid in the last week. Patients estimated cannabis could treat 54.3% ± 4.0 (95% CI 50.3-58.3%) of their spine pain and replace 46.2% ± 6. 6 (95% CI 39.6-52.8%) of their current analgesics. Age (β = - 0.3, CI - 0.6-0.0), higher pain severity (β = 0.4, CI 0.1-0.6) and previous cannabis use (β = 14.7, CI 5.1-24.4) were associated with a higher perceived effect of cannabis. Patients thought cannabis would be beneficial to treat pain (129/146, 88.4%), and reduce (116/146, 79.5%) or eliminate opioids (102/146, 69.9%). Not considering using cannabis for medical purposes (65/150, 43.3%) was the number one reported barrier.

CONCLUSIONS

Patients estimated medical cannabis could treat more than half of their spine pain, with one in three patients already using medical cannabis. 79% of patients also believe cannabis could reduce opioid usage. This data will help support more research into cannabis for musculoskeletal pain.

Low-dose Initiation of Buprenorphine/naloxone for the Management of Chronic Non-cancer Pain in Patients on Long-term Opioid Therapy: A Case Series

Background

Buprenorphine may provide superior analgesia to full opioid agonist therapy and reverse the effects of opioid-induced hyperalgesia, while having a favorable safety profile and fewer adverse effects, in chronic non-cancer pain treatment. Low-dose initiation of buprenorphine is a useful strategy for patients on long-term opioid therapy because it avoids the need for moderate opioid withdrawal required for traditional buprenorphine initiations. However, there are few published reports of low-dose initiation regimens in the setting of chronic pain.

Aims

The aim of the study was to describe a case series of individuals living with chronic pain who were transitioned from long-term full opioid agonist therapy onto sublingual buprenorphine/naloxone using low-dose initiation regimens.

Methods

This study is a retrospective case series that included all patients who received care at an outpatient chronic pain clinic and were scheduled for low-dose initiation of buprenorphine/naloxone between March 2020 and December 2022. Data were collected through a retrospective review of electronic medical records and results were analyzed using descriptive statistics.

Results

Eighteen patients underwent transitions from their baseline opioids onto buprenorphine/naloxone using a low-dose initiation regimen. Of those patients, 17 successfully completed the initiation (94.44%), 12 experienced adverse effects during the initiation (66.67%), with only one patient requiring treatment discontinuation, and all adverse effects resolved once maintenance doses of buprenorphine/naloxone were established. The mean Clinical Global Impression-Improvement score after initiation was 2 (1-5).

Conclusion

Low-dose initiation is an effective approach to transition patients with chronic non-cancer pain from long-term opioid therapy to buprenorphine/naloxone without major complications or worsening pain.

Initiation of opioid agonist therapy after hospital visits for opioid poisonings in Ontario

BACKGROUND

Emergency department visits and hospital admissions for opioid toxicity are opportunities to initiate opioid agonist therapy (OAT), which reduces morbidity and mortality in patients with opioid use disorder (OUD). The study objectives were to evaluate OAT initiation rates after a hospital encounter for opioid toxicity in Ontario, Canada, and determine whether publication of a 2018 Canadian OUD management guideline was associated with increased initiation.

METHODS

We conducted a retrospective, population-based serial cross-sectional study of hospital encounters for opioid toxicity among patients with OUD between Jan. 1, 2013, and Mar. 31, 2020, in Ontario, Canada. The primary outcome was OAT initiation (methadone, buprenorphine-naloxone, or slow-release oral morphine) within 7 days of discharge, measured quarterly. We examined the impact of the release of the OUD management guideline on OAT initiation rates using Autoregressive Integrated Moving Average models.

RESULTS

Among 20 702 hospital visits for opioid toxicity among patients with OUD, the median age was 35 years, and 65.1% were male. Over the study period, the percentage of visits leading to OAT initiation within 7 days rose from 1.7% or less (Q1 2013) to 5.6% (Q1 2020); however, the publication of the Canadian OUD management guideline was not associated with a significant increase in these rates (0.14% slope change, 95% confidence interval -0.11% to 0.38%; p = 0.3).

INTERPRETATION

Among hospital encounters for opioid toxicity, despite rising prevalence over time, only 1 in 18 patients were dispensed OAT within a week of discharge in early 2020. These findings highlight missed opportunities to initiate therapies proven to reduce mortality in patients with OUD.

Managing substance use in patients receiving therapeutic repetitive transcranial magnetic stimulation: A scoping review

Repetitive Transcranial Magnetic Stimulation (rTMS) is an invaluable treatment option for neuropsychiatric disorders. Co-occurring recreational and nonmedical substance use can be common in those presenting for rTMS treatment, and it is unknown how it may affect the safety and efficacy of rTMS for the treatment of currently approved neuropsychiatric indications. This scoping review aimed to map the literature on humans receiving rTMS and had a history of any type of substance use. The search identified 274 articles providing information on inclusion/exclusion criteria, withdrawal criteria, safety protocols, type of rTMS and treatment parameters, adverse events and effect on primary outcomes that related to substance use. There are neurophysiological effects of substance use on cortical excitability, although the relevance to clinical rTMS practice is unknown. The current literature supports the safety and feasibility of delivering rTMS to those who have co-occurring neuropsychiatric disorder and substance use. However, specific details on how varying degrees of substance use alters the safety, efficacy, and mechanisms of rTMS remains poorly described.

Guideline No. 443a: Opioid Use Throughout Women's Lifespan: Fertility, Contraception, Chronic Pain, and Menopause

OBJECTIVE

To provide health care providers with the best evidence on opioid use and women's health. Areas of focus include general patterns of opioid use and safety of use; care of women who use opioids; stigma, screening, brief intervention, and referral to treatment; hormonal regulation; reproductive health, including contraception and fertility; sexual function; perimenopausal and menopausal symptoms; and chronic pelvic pain syndromes.

TARGET POPULATION

The target population includes all women currently using or contemplating using opioids.

OUTCOMES

Open, evidence-informed dialogue about opioid use will lead to improvements in patient care and overall health.

BENEFITS, HARMS, AND COSTS

Exploring opioid use through a trauma-informed approach offers the health care provider and patient with an opportunity to build a strong, collaborative, and therapeutic alliance. This alliance empowers women to make informed choices about their own care. It also allows for the diagnosis and possible treatment of opioid use disorders. Use should not be stigmatized, as stigma leads to poor "partnered care" (i.e., the partnership between the patient and care provider). Therefore, health care providers and patients must understand the potential role of opioids in women's health (both positive and negative) to ensure informed decision-making.

EVIDENCE

A literature search was designed and carried out in PubMed and the Cochrane Library databases from August 2018 until March 2023 using following MeSH terms and keywords (and variants): opioids, illicit drugs, fertility, pregnancy, breastfeeding, and aging.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

All health care providers who care for women.

TWEETABLE ABSTRACT

Opioid use can affect female reproductive function; health care providers and patients must understand the potential role of opioids in women's health to ensure informed decision-making.

SUMMARY STATEMENTS

RECOMMENDATIONS.

"I thought it was for guys that did needles": Medication perceptions and lay expertise among medical research participants

INTRODUCTION

Although randomized controlled trials (RCTs) examine "objective" indicators of safety and efficacy of investigational drugs, participants may not perceive study medications as neutral entities. Some medications are imbued with social and cultural meaning, such as stigmatized medications for opioid use disorders. Such perceptions surrounding substance use treatments can extend to the research context and shape RCT participants' experiences with and adherence to study medications.

METHODS

Considering these complexities in substance use research, we conducted a nested qualitative study within a multi-site, pragmatic RCT in Canada testing two treatments (methadone versus buprenorphine/naloxone) for opioid use disorder. Between 2017 and 2020, we conducted 115 interviews with 75 RCT participants across five trial sites in British Columbia, Alberta, Ontario, and Quebec.

RESULTS

Using an abductive coding approach, we characterized participants by their previous experience with medication for opioid use disorder and by their exposure to drug culture and drug scenes. Across these experience types, we identified systematic differences around participants' perceptions of the study medications, sources of information and expertise, and medication stigma.

CONCLUSION

Our findings illustrate the critical importance of social context in shaping medication beliefs and study experiences among people who use drugs, with implications for the conduct of future RCTs in substance use.

'I don't chase drugs as much anymore, and I'm not dead': Client reported outcomes associated with safer opioid supply programs in Ontario, Canada

INTRODUCTION

The ongoing opioid overdose crisis, which has killed over 30,000 people in Canada since 2016, is driven by the volatility of an unregulated opioid drug supply comprised primarily of fentanyl. The Canadian government has recently funded safer opioid supply (SOS) programs, which include off-label prescriptions of pharmaceutical-grade opioids to high risk individuals with the goal of reducing overdose deaths.

METHODS

In 2021, we examined the implementation and adaption of four SOS programs in Ontario. These programs use a primary care model and serve communities experiencing marginalisation. We conducted semi-structured interviews with program clients. We present the results of a thematic analysis with the aim of describing clients' self-reported impact of these programs on their health and well-being.

RESULTS

We interviewed 52 clients between June and October 2021 (mean age 47 years, 56% men, 17% self-identified Indigenous, 14% living with HIV). Our results indicate multifaceted pathways to improved self-reported health and well-being among clients including changes to drug use practices, fewer overdoses, reduced criminalised activity, improved trust and engagement in health care, and increased social stability (e.g., housing).

DISCUSSION AND CONCLUSION

Most clients reported that the intervention saved their life because of the reduced frequency of overdoses. Findings suggest that SOS programs improved clients' health outcomes and increase opportunities for engagement in health services. Our results provide insight into the mechanisms behind some of the emergent evidence on the impact of safer supply prescribing.

Guideline No. 443b: Opioid Use Throughout Women's Lifespan: Opioid Use in Pregnancy and Breastfeeding

OBJECTIVE

To provide health care providers the best evidence on opioid use and women's health. Areas of focus include pregnancy and postpartum care.

TARGET POPULATION

The target population includes all women currently using or contemplating using opioids.

OUTCOMES

Open, evidence-informed dialogue about opioid use will improve patient care.

BENEFITS, HARMS, AND COSTS

Exploring opioid use through a trauma-informed approach provides the health care provider and patient with an opportunity to build a strong, collaborative, and therapeutic alliance. This alliance empowers women to make informed choices about their own care. It also allows for the diagnosis and possible treatment of opioid use disorders. Opioid use should not be stigmatized, as stigma leads to poor "partnered care" (i.e., the partnership between the patient and care provider). Health care providers need to understand the effect opioids can have on pregnant women and support them to make knowledgeable decisions about their health.

EVIDENCE

A literature search was designed and carried out in PubMed and the Cochrane Library databases from August 2018 until March 2023 using following MeSH terms and keywords (and variants): opioids, opioid agonist therapy, illicit drugs, fertility, pregnancy, fetal development, neonatal abstinence syndrome, and breastfeeding.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

All health care providers who care for pregnant and/or post-partum women and their newborns.

TWEETABLE ABSTRACT

Opioid use during pregnancy often co-occurs with mental health issues and is associated with adverse maternal, fetal, and neonatal outcomes; treatment of opioid use disorder with agonist therapy for pregnant women can be safe during pregnancy where the risks outnumber the benefits.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Directive clinique no 443b : Opioïdes aux différentes étapes de la vie des femmes : Grossesse et allaitement

OBJECTIF

Présenter aux professionnels de la santé les données probantes concernant l'utilisation des opioïdes et la santé des femmes. Les domaines d'intérêt sont la grossesse et les soins post-partum.

POPULATION CIBLE

Toutes les femmes qui utilisent des opioïdes. RéSULTATS: Un dialogue ouvert et éclairé sur l'utilisation des opioïdes améliorera les soins aux patientes. BéNéFICES, RISQUES ET COûTS: L'exploration de l'utilisation d'opioïdes par une approche tenant compte des traumatismes antérieurs donne au professionnel de la santé et à la patiente l'occasion de bâtir une alliance solide, collaborative et thérapeutique. Cette alliance permet aux femmes de faire des choix éclairés. Elle favorise le diagnostic et le traitement possible du trouble lié à l'utilisation d'opioïdes. L'utilisation ne doit pas être stigmatisée, puisque la stigmatisation affaiblit le partenariat (le partenariat entre patiente et professionnel de la santé). Les professionnels de la santé ceus-ci doivent comprendre l'effet potentiel des opioïdes sur la santé les femmes enceintes et les aider à prendre des décisions éclairées sur leur santé. DONNéES PROBANTES: Une recherche a été conçue puis effectuée dans les bases de données PubMed et Cochrane Library pour la période d'août 2018 à mars 2023 des termes MeSH et mots clés suivants (et variantes) : opioids, opioid agonist therapy, illicit drugs, fertility, pregnancy, fetal development, neonatal abstinence syndrome et breastfeeding. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Tous les professionnels de la santé qui prodiguent des soins aux femmes et aux nouveaux-nés. RéSUMé POUR TWITTER: La consommation d'opioïdes pendant la grossesse coïncide souvent avec des problèmes de santé mentale et est associée à des conséquences néfastes pour la mère, le fœtus et le nouveau-né ; le traitement des troubles liés à la consommation d'opioïdes par agonistes peut être sûr pendant la grossesse lorsque les risques sont plus nombreux que les avantages. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Real-world Evidence for Impact of Opioid Agonist Therapy on Nonfatal Overdose in Patients with Opioid Use Disorder during the COVID-19 Pandemic

OBJECTIVES

The primary objectives of this study were to describe the demographics and clinical characteristics of patients who were treated with buprenorphine extended-release versus buprenorphine-naloxone sublingual tablets versus methadone in a real-world setting and to evaluate the difference in nonfatal overdose events between treatment cohorts.

METHODS

This study was a retrospective chart review of patients with opioid use disorder initiating opioid agonist therapy in Canada during the outset of the COVID-19 pandemic (March 11, 2020 to October 31, 2021). Three treatment cohorts were defined by the initial prescribed opioid agonist therapy regimen: buprenorphine extended-release, buprenorphine-naloxone sublingual tablets, and methadone. Baseline characteristics, as well as treatment status, overdose events, and substance use 6 months after treatment initiation were collected using a standardized form.

RESULTS

Nine clinics provided data on 379 patient cases. The incidence rate (number of events per 100 person-years) for a self-reported nonfatal overdose was 46.8 (n = 18), 19.3 (n = 10), and 1.7 (n = 1) in the methadone, buprenorphine-naloxone sublingual tablets, and buprenorphine extended-release cohorts, respectively. The risk-adjusted difference for the proportion of patients with nonfatal overdose was 8.59% (95% confidence interval, 3.10-14.08%; P = 0.0022) for methadone versus buprenorphine extended-release and 6.51% (95% confidence interval, 1.46-11.56%; P = 0.0115) for buprenorphine-naloxone sublingual tablets versus buprenorphine extended-release.

CONCLUSIONS

Buprenorphine extended-release was associated with lower rates of nonfatal overdose events compared with daily opioid agonist therapy. Given the limitations of this naturalistic, retrospective design, further prospective studies are needed to validate these findings and demonstrate the potential for long-acting opioid agonist therapy in addressing the opioid crisis.

Postoperative buprenorphine continuation in stabilized buprenorphine patients: A population cohort study

BACKGROUND AND AIMS

Sudden discontinuation of buprenorphine in the treatment of opioid use disorder can increase the risk of subsequent relapse and overdose. Little is known about buprenorphine use in the perioperative period. The aim of this study was to determine the rate of buprenorphine continuation after hospital discharge following surgery and factors associated with continuation.

DESIGN

A population-based retrospective cohort study was conducted using administrative data from Ontario, Canada, between 2012 and 2018. The cohort included individuals on continuous buprenorphine prior to surgery. Logistic regression modeling was used to estimate the association of buprenorphine continuation with demographic, opioid agonist treatment, surgical and health service use factors.

SETTING

Administrative databases from Institute for Clinical Evaluative Sciences (ICES) were used, which capture the Ontario, Canada, population. The data sets describe physician billing, monitoring of controlled substances and hospital discharges.

PARTICIPANTS

Adults (≥ 18 years, n = 2176) had received a buprenorphine/naloxone product continuously for at least 60 days for the treatment of opioid use disorder and subsequently underwent a surgical procedure.

MEASUREMENTS

Continuation (versus discontinuation) of buprenorphine prescriptions in the 14 days after surgical discharge was recommended. Exposures included demographic, comorbidity, opioid agonist treatment, surgical and health service use characteristics.

FINDINGS

About 176 (8.1%) of the 2176 patients discontinued buprenorphine after surgery. Inpatient surgery (versus ambulatory) was associated with reduced odds of continuation, with an unadjusted odds ratio (OR) of 0.17 [95% confidence interval (CI) = 0.12-0.25] and an adjusted OR of 0.16 (95% CI = 0.11-0.23) after accounting for age, sex, rural residence, neighborhood income quintile, Charlson comorbidity index, psychiatric hospitalizations in the past 5 years and recent dispensed supply of buprenorphine (number needed to harm of 6.6).

CONCLUSIONS

In Ontario, Canada, from 2012 to 2018, most patients receiving continuous preoperative buprenorphine therapy continued buprenorphine use after surgery. Inpatient surgery was a strong predictor of discontinuation compared with ambulatory procedures.

Academy of Breastfeeding Medicine Clinical Protocol #21: Breastfeeding in the Setting of Substance Use and Substance Use Disorder (Revised 2023)

Background: The Academy of Breastfeeding Medicine (ABM) revised the 2015 version of the substance use disorder (SUD) clinical protocol to review the evidence and provide updated literature-based recommendations related to breastfeeding in the setting of substance use and SUD treatments. Key Information: Decisions around breastfeeding are an important aspect of care during the peripartum period, and there are specific benefits and risks for substance-exposed mother-infant dyads. Recommendations: This protocol provides breastfeeding recommendations in the setting of nonprescribed opioid, stimulant, sedative-hypnotic, alcohol, nicotine, and cannabis use, and SUD treatments. Additionally, we offer guidance on the utility of toxicology testing in breastfeeding recommendations. Individual programs and institutions should establish consistent breastfeeding approaches that mitigate bias, facilitate consistency, and empower mothers with SUD. For specific breastfeeding recommendations, given the complexity of breastfeeding in mothers with SUD, individualized care plans should be created in partnership with the patient and multidisciplinary team with appropriate clinical support and follow-up. In general, breastfeeding is recommended among mothers who stop nonprescribed substance use by the time of delivery, and they should continue to receive ongoing postpartum care, such as lactation support and SUD treatment. Overall, enhancing breastfeeding education regarding substance use in pregnancy and lactation is essential to allow for patient-centered guidance.

Preexisting mental health disorders and risk of opioid use disorder in young people: A case-control study

AIM

Opioid use disorder (OUD) is a leading cause of preventable mortality amongst young people worldwide. Early identification and intervention of modifiable risk factors may reduce future OUD risk. The aim of this study was to explore whether the onset of OUD is associated with preexisting mental health conditions such as anxiety and depressive disorders in young people.

METHODS

A retrospective, population-based case-control study was conducted from 31 March 2018 until 01 January 2002. Provincial administrative health data were collected from Alberta, Canada.

CASES

Individuals 18-25 years on 01 April 2018, with a previous record of OUD.

CONTROLS

Individuals without OUD were matched to cases, on age/sex/index date. Conditional logistic regression analysis was used to control for additional covariates (e.g., alcohol-related disorders, psychotropic medications, opioid analgesics, and social/material deprivation).

RESULTS

We identified N = 1848 cases and N = 7392 matched controls. After adjustment, OUD was associated with the following preexisting mental health conditions: Anxiety disorders, aOR = 2.53 (95% CI = 2.16-2.96); depressive disorders, aOR = 2.20 (95% CI = 1.80-2.70); alcohol-related disorders, aOR = 6.08 (95% CI, 4.86-7.61); anxiety and depressive disorders, aOR = 1.94 (95% CI = 1.56-2.40); anxiety and alcohol-related disorders, aOR = 5.22 (95% CI = 4.03-6.77); depressive and alcohol-related disorders, aOR = 6.47 (95% CI = 4.73-8.84); anxiety, depressive and alcohol-related disorders, aOR = 6.09 (95% CI = 4.41-8.42).

DISCUSSION

Preexisting mental health conditions such as anxiety and depressive disorders are risk factors for future OUD in young people. Preexisting alcohol-related disorders showed the strongest association with future OUD and demonstrated an additive risk when concurrent with anxiety/depression. As not all plausible risk factors could be examined, more research is still needed.

A comparative study of the efficacy of venlafaxine and naltrexone for relapse prevention in patients with opioid use disorder attributed to tramadol

Tramadol and venlafaxine share similar pharmacological characteristics that may allow for overlapping therapeutic indications for them. The objective of this study was to compare the efficacy of venlafaxine and naltrexone in the treatment of tramadol abuse. This comparative trial included 95 patients with tramadol abuse who were detoxified for 2 weeks. Twenty-eight participants underwent the maintenance phase, while the remaining participants (n = 67) dropped out. The patients were randomized to use 50 mg/day of naltrexone or 225 mg/day of venlafaxine for 8 weeks. All participants were interviewed using SCID-I (DSM-IV-TR) criteria for diagnosing substance use and other psychiatric disorders. The proportion of relapsed patients was comparable between the naltrexone and venlafaxine groups (29.4% vs. 30.4%, P = 0.9). However, participants in the venlafaxine group stayed in treatment longer than participants in the naltrexone group, and the difference was significant (22.9 ± 7.89 days vs. 16.9 ± 3.4 days, P = 0.01). Only psychiatric comorbidity was found to be significantly associated with retention in treatment (80% vs. 22%, P = 0.005). Venlafaxine is as effective as naltrexone in preventing relapse in patients with tramadol abuse. Venlafaxine was more effective than naltrexone in treatment retention.

A Case report of a continuous ambulatory drug delivery (CADD) pump to deliver opioid agonist treatment in an acute care setting

BACKGROUND

People with substance use disorder are at risk of complications of drug use and frequent hospitalization and may continue to use substances during admission to acute care. Acute care harm reduction strategies including oral or injectable prescription opioids may aid in care retention and improve health outcomes in this patient population.

CASE PRESENTATION

A 58-year-old woman with refractory opioid use disorder was admitted to hospital for management of dysphagia secondary to esophageal stricture. She received injectable opioid agonist therapy using a continuous ambulatory drug delivery (CADD) pump in order to facilitate completion of her hospital admission.

CONCLUSIONS

The patient successfully received acute medical care with the use of a CADD pump for consistent, patient-controlled opioid administration, with the support of an interdisciplinary team and by respecting the patient's own substance use goals.

Associations of methadone and buprenorphine-naloxone doses with unregulated opioid use, treatment retention, and adverse events in prescription-type opioid use disorders: Exploratory analyses of the OPTIMA study

BACKGROUND AND OBJECTIVES

Buprenorphine/naloxone (BUP-NX) and methadone are used to treat opioid use disorder (OUD), yet there is insufficient evidence on the impact of doses on interventions' effectiveness and safety when treating OUD attributable to other opioids than heroin.

METHODS

We explored associations between methadone and BUP-NX doses and treatment outcomes using data from OPTIMA, a 24-week, pragmatic, open-label, multicenter, pan-Canadian, randomized controlled, two-arm parallel trial with participants (N = 272) with OUD who primarily use opioids other than heroin. Participants were randomized to receive flexible take-home BUP-NX (n = 138) or standard supervised methadone treatment (n = 134). We examined associations between highest BUP-NX and methadone doses, and (1) percentage of opioid-positive urine drug screens (UDS); (2) retention in the assigned treatment; and (3) adverse events (AEs).

RESULTS

The mean (SD) highest BUP-NX and methadone dose were 17.31 mg/day (8.59) and 67.70 mg/day (34.70). BUP-NX and methadone doses were not associated with opioid-positive UDS percentages or AEs. Methadone dose was associated with higher retention in treatment (odds ratio [OR]: 1.025; 95% confidence interval [CI]: 1.010; 1.041), while BUP-NX dose was not (OR: 1.055; 95% CI: 0.990; 1.124). Higher methadone doses (70-110 mg/day) offered higher odds of treatment retention.

DISCUSSION AND CONCLUSION

Methadone dose was associated with higher retention, which may be related to its full µ-opioid receptor agonism. Future research should notably ascertain the effect of pace of titration on a wide range of outcomes.

SCIENTIFIC SIGNIFICANCE

Our results extend previous findings of high doses of methadone increasing retention to be applied in our population using opioids other than heroin, including highly potent opioids.

Noninferiority Clinical Trial of Adapted START NOW Psychotherapy for Outpatient Opioid Treatment

Background

Medications for opioid use disorder (MOUD) such as buprenorphine is effective for treating opioid use disorder (OUD). START NOW (SN) is a manualized, skills-based group psychotherapy originally developed and validated for the correctional population and has been shown to result in reduced risk of disciplinary infractions and future psychiatric inpatient days with a dose response effect. We investigate whether adapted START NOW is effective for treating OUD in a MOUD office-based opioid treatment (OBOT) setting in this non-inferiority clinical trial.

Methods

Patients enrolled in once weekly buprenorphine/suboxone MOUD OBOT were eligible for enrollment in this study. Participants were cluster-randomized, individually-randomized, or not randomized into either START NOW psychotherapy or treatment-as-usual (TAU) for 32 weeks of therapy. Treatment effectiveness was measured as the number of groups attended, treatment duration, intensity of attendance, and overall drug use as determined by drug screens.

Results

137 participants were quasi-randomized to participate in SN (n = 79) or TAU (n = 58). Participants receiving START NOW psychotherapy, when compared to TAU, had comparable number of groups attended (16.5 vs. 16.7, p = 0.80), treatment duration in weeks (24.1 vs. 23.8, p = 0.62), and intensity defined by number of groups attended divided by the number of weeks to last group (0.71 vs. 0.71, p = 0.90). SN compared to TAU also had similar rates of any positive drug screen result (81.0% vs. 91.4%, p = 0.16). This suggests that adapted START NOW is noninferior to TAU, or the standard of care at our institution, for treating opioid use disorder.

Conclusion

Adapted START NOW is an effective psychotherapy for treating OUD when paired with buprenorphine/naloxone in the outpatient group therapy setting. Always free and publicly available, START NOW psychotherapy, along with its clinician manual and training materials, are easily accessible and distributable and may be especially useful for low-resource settings in need of evidence-based psychotherapy.

Crystal methamphetamine use and methadone maintenance treatment dissatisfaction: A prospective cohort study in Vancouver, Canada

BACKGROUND

Patient satisfaction is key to the success of methadone maintenance treatment (MMT), and yet how MMT satisfaction is affected by the increasingly common use of crystal methamphetamine among people receiving opioid treatment remains poorly understood. We aimed to assess the association between crystal methamphetamine use and MMT dissatisfaction.

METHODS

We employed generalized estimating equations to examine the relationship between crystal methamphetamine use and MMT dissatisfaction among patients receiving MMT within two prospective cohorts in Vancouver, Canada, between December 2016 and March 2020.

RESULTS

Of the 836 participants receiving MMT, the median age was 47 years, and 55.3 % self-identified as male at baseline. In a multivariable model, those reporting more than weekly crystal methamphetamine use were more likely to report MMT dissatisfaction (Odds ratio: 1.40, 95 % confidence interval: 1.05-1.86) compared to those reporting less than monthly crystal methamphetamine use.

CONCLUSIONS

Among our sample of people receiving MMT, we noted a positive association of frequent crystal methamphetamine use with MMT dissatisfaction. Our study suggests a need for novel strategies to better understand and address frequent methamphetamine use among those receiving MMT, particularly given recent shifts in substance use patterns involving the rising co-use of methamphetamines and opioids.

Cognitive impairment in opioid use disorders: Is there a case for use of nootropics?

Opioid Use Disorders (OUDs) are often associated with cognitive impairments, which may lead to an increased risk of relapse. These cognitive deficits do not resolve with abstinence or medication-assisted treatment and may require targeted management. While psychotherapies and neuromodulation techniques have been studied for their effectiveness, they have certain limitations and challenges. Cognition enhancing prescription drugs like donepezil and memantine, which are used in dementias, have shown promise in a small number of studies examining their role in the reversal of opioid-induced cognitive deficits. The authors explore the potential role of nootropics in improvement of cognitive decline associated with OUDs.

Clinical practice guideline for deprescribing opioid analgesics: summary of recommendations

INTRODUCTION

Long term opioids are commonly prescribed to manage pain. Dose reduction or discontinuation (deprescribing) can be challenging, even when the potential harms of continuation outweigh the perceived benefits. The Evidence-based clinical practice guideline for deprescribing opioid analgesics was developed using robust guideline development processes and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, and contains deprescribing recommendations for adults prescribed opioids for pain.

MAIN RECOMMENDATIONS

Eleven recommendations provide advice about when, how and for whom opioid deprescribing should be considered, while noting the need to consider each person's goals, values and preferences. The recommendations aim to achieve: implementation of a deprescribing plan at the point of opioid initiation; initiation of opioid deprescribing for persons with chronic non-cancer or chronic cancer-survivor pain if there is a lack of overall and clinically meaningful improvement in function, quality of life or pain, a lack of progress towards meeting agreed therapeutic goals, or the person is experiencing serious or intolerable opioid-related adverse effects; gradual and individualised deprescribing, with regular monitoring and review; consideration of opioid deprescribing for individuals at high risk of opioid-related harms; avoidance of opioid deprescribing for persons nearing the end of life unless clinically indicated; avoidance of opioid deprescribing for persons with a severe opioid use disorder, with the initiation of evidence-based care, such as medication-assisted treatment of opioid use disorder; and use of evidence-based co-interventions to facilitate deprescribing, including interdisciplinary, multidisciplinary or multimodal care.

CHANGES IN MANAGEMENT AS A RESULT OF THESE GUIDELINES

To our knowledge, these are the first evidence-based guidelines for opioid deprescribing. The recommendations intend to facilitate safe and effective deprescribing to improve the quality of care for persons taking opioids for pain.

Assessing the impact of the slow-release oral morphine drug shortages in Ontario, Canada: A population-based time series analysis

BACKGROUND

Slow-release oral morphine (SROM) is used to manage pain, and as opioid agonist treatment (OAT). Between 2017 and 2021 in Canada, several drug shortages occurred for Kadian© (SROM-24). The purpose of this study was to evaluate the impact of these shortages on people's ability to remain on this medication.

METHODS

We conducted a retrospective population-based time series analysis of SROM-24 dispensed between January 1, 2014, and December 31, 2021, in Ontario, Canada. Using interventional autoregressive integrated moving average models (ARIMA) models, we evaluated the association between SROM-24 drug shortages and treatment discontinuation. Analyses were also stratified by the SROM-24 indication (pain or OAT).

RESULTS

We identified 22,479 SROM-24 recipients, of which one-third (33.9%) were aged 65 or above and just over half (51.9%) were female. In our primary analysis of monthly SROM-24 discontinuation, we observed a significant sustained monthly increase following the shortages in November 2019 (+0.29%/month; 95% CI: 0.16%, 0.43%; p < .001) with significant sudden, temporary changes following the shortages in March 2020 (+2.00%; 95% CI: 0.95%, 3.05%; p < .001), July 2021 (+3.53%; 95% CI: 2.20%, 4.86%; p < .001), and August 2021 (+4.98%; 95% CI: 3.49%, 6.47%; p < .001). Similar results were observed in our stratified analyses, with sustained high rates of discontinuation among people accessing SROM-24 as OAT.

CONCLUSIONS

The SROM-24 shortages resulted in significant treatment disruptions across all recipients. These findings have important implications for those with few treatment alternatives, including people using SROM-24 as OAT who are at risk of adverse outcomes following treatment disruptions.

Buprenorphine/naloxone initiation and referral as a quality improvement intervention for patients who live with opioid use disorder: quantitative evaluation of provincial spread to 107 rural and urban Alberta emergency departments

OBJECTIVES

Opioid use disorder is a major public health concern that accounts for a high number of potential years of life lost. Buprenorphine/naloxone is a recommended treatment for opioid use disorder that can be started in the emergency department (ED). We developed an ED-based program to initiate buprenorphine/naloxone for eligible patients who live with opioid use disorder, and to provide unscheduled, next-day follow-up referrals to an opioid use disorder treatment clinic (in person or virtual) for continuing patient care throughout Alberta.

METHODS

In this quality improvement initiative, we supported local ED teams to offer buprenorphine/naloxone to eligible patients presenting to the ED with suspected opioid use disorder and refer these patients for follow-up care. Process, outcome, and balancing measures were evaluated over the first 2 years of the initiative (May 15, 2018-May 15, 2020).

RESULTS

The program was implemented at 107 sites across Alberta during our evaluation period. Buprenorphine/naloxone initiations in the ED increased post-intervention at most sites with baseline data available (11 of 13), and most patients (67%) continued to fill an opioid agonist prescription at 180 days post-ED visit. Of the 572 referrals recorded at clinics, 271 (47%) attended their first follow-up visit. Safety events were reported in ten initiations and were all categorized as no harm to minimal harm.

CONCLUSIONS

A standardized provincial approach to initiating buprenorphine/naloxone in the ED for patients living with opioid use disorder was spread to 107 sites with dedicated program support staff and adjustment to local contexts. Similar quality improvement approaches may benefit other jurisdictions.

Opioid agonist therapy switching among individuals with prescription-type opioid use disorder: Secondary analysis of a pragmatic randomized trial

BACKGROUND

Engagement and retention in opioid agonist therapy (OAT) remains a challenge. This study evaluated the impact of initial randomized OAT allocation on subsequent switching among people with prescription-type opioid use disorder (POUD).

METHODS

Secondary analysis of a 24-week Canadian multicenter, pragmatic, randomized trial conducted between 2017 and 2020 comparing flexible take-home buprenorphine/naloxone versus supervised methadone models of care for POUD. We used Cox Proportional Hazards modeling to assess for impact of treatment assignment on time to OAT switching, adjusting for important confounders. For clinical correlates, we analyzed data from baseline questionnaires on demographic, substance use, and health factors as well as urine drug screen.

RESULTS

Of 272 randomized participants, 210 initiated OAT within 14 days per trial protocol, of whom 103 participants were randomized to buprenorphine/naloxone and 107 to methadone. Within 24-week follow-up, 41 (20.5%) of all participants switched OAT with 25 (24.3%, median 27 days, 88.4 per 100 person-years) and 16 participants (15.0%, median 53.5 days, 46.1 per 100 person-years) switching from buprenorphine/naloxone and methadone arms, respectively. In adjusted analysis, allocation to buprenorphine/naloxone was associated with significantly higher risk of switching (aHR = 2.31, 95% CI 1.22 - 4.38).

CONCLUSIONS

OAT switching was common in this sample of individuals with POUD, with individuals randomly allocated to buprenorphine/naloxone being more than twice as likely to switch versus methadone. This may reflect a stepped care approach in OUD management. More research is needed to evaluate overall retention and outcomes with the different observed risks of switching between methadone and buprenorphine/naloxone.

The four-factor personality model and its qualitative correlates among opioid agonist therapy clients

Background

The Four Factor Personality Vulnerability model identifies four specific personality traits (e.g., sensation seeking [SS], impulsivity [IMP], anxiety sensitivity [AS], and hopelessness [HOP]) as implicated in substance use behaviors, motives for substance use, and co-occurring psychiatric conditions. Although the relationship between these traits and polysubstance use in opioid agonist therapy (OAT) clients has been investigated quantitatively, no study has examined the qualitative expression of each trait using clients' voice.

Method

Nineteen Methadone Maintenance Therapy (MMT) clients (68.4% male, 84.2% white, mean age[SD] = 42.71 [10.18]) scoring high on one of the four personality traits measured by the Substance Use Risk Profile Scale [SURPS] completed a semi-structured qualitative interview designed to explore their lived experience of their respective trait. Thematic analysis was used to derive themes, which were further quantified using content analysis.

Results

Themes emerging from interviews reflected (1) internalizing and externalizing symptoms, (2) adversity experiences, and (3) polysubstance use. Internalizing symptoms subthemes included symptoms of anxiety, fear, stress, depression, and avoidance coping. Externalizing subthemes included anger, disinhibited cognitions, and anti-social and risk-taking behaviors. Adverse experiences subthemes included poor health, poverty, homelessness, unemployment, trauma, and conflict. Finally, polysubstance use subthemes include substance types, methods of use, and motives. Differences emerged between personality profiles in the relative endorsement of various subthemes, including those pertaining to polysubstance use, that were largely as theoretically expected.

Conclusion

Personality is associated with unique cognitive, affective, and behavioral lived experiences, suggesting that personality may be a novel intervention target in adjunctive psychosocial treatment for those undergoing OAT.

First-line opioid agonist treatment as prevention against assisting others in initiating injection drug use: A longitudinal cohort study of people who inject drugs in Vancouver, Canada

Background

Among people who inject drugs, frequent injecting and experiencing withdrawal are associated with facilitating others' first injections. As these factors may reflect an underlying substance use disorder, we investigated whether first-line oral opioid agonist treatment (OAT; methadone or buprenorphine/naloxone) reduces the likelihood that people who inject drugs help others initiate injecting.

Methods

We used questionnaire data from semi-annual visits between December 2014-May 2018 on 334 people who inject drugs with frequent non-medical opioid use in Vancouver, Canada. We estimated the effect of current first-line OAT on subsequent injection initiation assistance provision (i.e., helped someone initiate injecting in the following six months) using inverse-probability-weighted estimation of repeated measures marginal structural models to reduce confounding and informative censoring by time-fixed and time-varying covariates.

Results

By follow-up visit, 54-64% of participants reported current first-line OAT whereas 3.4-6.9% provided subsequent injection initiation assistance. Per the primary weighted estimate (n = 1114 person-visits), participants currently on first-line OAT (versus no OAT) were 50% less likely, on average, to subsequently help someone initiate injecting (relative risk [RR]=0.50, 95% CI=0.23-1.11). First-line OAT was associated with reduced risk of subsequent injection initiation assistance provision in participants who, at baseline, injected opioids less than daily (RR=0.15, 95% CI=0.05-0.44) but not in those who injected opioids daily (RR=0.86, 95% CI=0.35-2.11).

Conclusions

First-line OAT seemingly reduces the short-term likelihood that people who inject drugs facilitate first injections. However, the extent of this potential effect remains uncertain due to imprecise estimation and observed heterogeneity by baseline opioid injecting frequency.

Women's experiences in injectable opioid agonist treatment programs in Vancouver, Canada

BACKGROUND

Injectable opioid agonist treatment (iOAT) has recently been expanded in some geographical contexts in Canada as part of a response to the escalating overdose crisis. Complex gendered dynamics, including power differentials, violence, and social norms, shape the overdose crisis and drug treatment programs which can adversely impact women's experiences. This qualitative study examines how social (e.g., gender, income, housing) and structural factors (e.g., program policies) impact women's experiences of iOAT.

METHODS

Qualitative interviews were completed with 16 women enrolled in four iOAT programs in Vancouver, Canada. Approximately 50 hours of ethnographic observations were conducted. Interview transcripts and ethnographic fieldnotes were analyzed using a critical feminist lens by applying the concepts of embodiment, relationality, and social control to understand women's engagement and self-reported treatment outcomes.

RESULTS

Initial iOAT engagement was a relational process, including initiating treatment with a partner and engaging with iOAT to (re)build personal relationships. Relationships with iOAT providers, including flexibility and support with medication administration, were important to women, providing an affirming embodied experience and a greater sense of agency. However, program operations (e.g., mandated daily attendance, program crowding) incompatible with women's needs (e.g., employment) could undermine these positive experiences. Women's reported outcomes highlight a tension between achieving more agency and the constraints of intensive and stigmatized treatment.

CONCLUSION

This study highlights how iOAT is both a source of care and control for women from a relational and embodied perspective. Findings underscore the need for gender-attentive and flexible drug treatment services to meet the varied needs of women and the importance of providing relational care for women accessing iOAT.

Interest in using buprenorphine-naloxone among a prospective cohort of street-involved young people in Vancouver, Canada

INTRODUCTION

Limited research examines buprenorphine-naloxone interest among adolescents and young adults (AYA). This longitudinal study examined factors associated with initial buprenorphine-naloxone interest and the time to a positive change in buprenorphine-naloxone interest or enrollment, in addition to identifying reasons for buprenorphine-naloxone disinterest.

METHODS

The study derived data from a cohort of street-involved AYA in Vancouver, Canada between December 2014 and June 2018. The analysis was restricted to AYA who reported weekly or daily illicit opioid use in the last six months but had not initiated buprenorphine-naloxone. The study examined factors associated with initial buprenorphine-naloxone interest using multivariable logistic regression, while multivariable Cox regression identified factors associated with the time to a positive change in buprenorphine-naloxone interest or actual enrollment over follow-up among AYA initially disinterested in buprenorphine-naloxone.

RESULTS

Of 281 participants who reported weekly illicit opioid use but were not on buprenorphine-naloxone, 52 (18.5 %) AYA reported initial buprenorphine-naloxone interest, while 68 (24.2 %) AYA who were initially disinterested in buprenorphine-naloxone reported interest or enrollment over follow-up. In multivariable logistic regression, initial interest was positively associated with older age (Adjusted Odds Ratio [AOR] = 1.09, 95 % Confidence Interval [CI]: 1.03-1.15), but negatively associated with self-reported Indigenous identity (AOR = 0.22, 95 % CI: 0.07-0.68). In multivariable Cox regression, recent detoxification program access (Adjusted Hazard Ratio [AHR] = 0.85, 95 % CI: 0.73-0.98) was positively associated with the time to a positive change in buprenorphine-naloxone interest or enrollment. Common reasons for buprenorphine-naloxone disinterest included not wanting opioid agonist treatments (OAT) (initial n = 67, follow-up n = 105); not wanting to experience precipitated withdrawal (initial n = 42, follow-up n = 54), being satisfied with or preferring other OAT (initial n = 33, follow-up n = 52), not knowing what buprenorphine-naloxone is (initial n = 27, follow-up n = 9), previous negative treatment experiences (initial n = 19, follow-up n = 20), and wanting to continue opioid use (initial n = 13, follow-up n = 9), among others.

CONCLUSIONS

We documented persistent disinterest in buprenorphine-naloxone among AYA, though participants' reasons for disinterest provide insight into the potential benefits of expanding micro-dosing induction; ensuring treatment is culturally safe; and communicating changes in buprenorphine-naloxone programming to AYA. Nevertheless, a need remains to improve the continuum of harm reduction and treatment supports for AYA.

Substance use severity as a predictor for receiving medication for opioid use disorder among adolescents: An analysis of the 2019 TEDS

BACKGROUND

Medication for opioid use disorder (MOUD) is vastly underutilized in adolescents. Existing treatment guidelines for OUD largely focus on adults, providing limited guidance for pediatric populations. Limited information is known about use of MOUD in adolescents based on substance use severity.

METHODS

This secondary data analysis examined how patient-level variables influenced the receipt of MOUD in adolescents aged 12-17 (n = 1866) using the Treatment Episode Data Set (TEDS) 2019 Discharge data set. A crosstabulation and chi-square statistic evaluated the relationship between a proxy for clinical need based on high-risk opioid use (either reporting daily opioid use within the past 30 days and/or history of injection opioid use) for MOUD in states with and without adolescents receiving MOUD (n = 1071). A two-step logistic regression analysis in states with any adolescents receiving MOUD examined the explanatory power of demographic, treatment intake, and substance use characteristics.

RESULTS

Completion of 12th grade, a GED, or beyond, decreased the likelihood of receiving MOUD (odds ratio [OR]= 0.38, p = 0.017), as did being female (OR = 0.47, p = .006). None of the remaining clinical criteria were significantly associated with MOUD, although a history of one or more arrests increased the likelihood of MOUD (OR = 6.98, p = 0.06). Only 13% of individuals who met criteria for clinical need received MOUD.

CONCLUSIONS

Lower education could serve as a proxy for substance use severity. Guidelines and best practices are needed to ensure the proper distribution of MOUD to adolescents based on clinical need.

Cost-effectiveness of flexible take-home buprenorphine-naloxone versus methadone for treatment of prescription-type opioid use disorder

BACKGROUND

Our objective was to examine the cost-effectiveness of flexible take-home buprenorphine-naloxone (BNX) versus methadone alongside the OPTIMA trial in Canada.

METHODS

The OPTIMA study was a pragmatic, open-label, noninferiority, two-arm randomized controlled trial, to assess the comparative effectiveness of flexible take-home BNX vs. methadone in routine clinical care for individuals with prescription-type opioid use disorder. We evaluated cost-effectiveness using a semi-Markov cohort model. Probabilities of overdose were calibrated, accounting for fentanyl prevalence and other overdose risk factors such as naloxone availability. We considered health sector and societal cost perspectives, including costs (2020 CAD) for treatment, health resource use, criminal activity, and health state-specific preference weights as outcomes to calculate incremental cost-effectiveness ratios. Six-month and lifetime (3% annual discount rate) time-horizons were explored.

RESULTS

Over a lifetime time horizon, individuals accumulated -0.144 [CI: -0.302, -0.025] incremental quality-adjusted life years (QALYs) in BNX compared with methadone. Incremental costs were -$2047 [CI: -$39,197, $24,250] from a societal perspective, and -$4549 [CI: -$6332, -$3001] from a health sector perspective. Over a six-month time-horizon, individuals accumulated 0.002 [credible interval (CI): -0.011, 0.016] incremental QALYs in BNX compared with methadone. Incremental costs were -$307 [CI: -$10,385, $8466] from a societal perspective and -$1111 [CI: -$1517, -$631] from a health sector perspective. BNX was dominated (costlier, less effective) in 49.7% of simulations when adopting a societal perspective over a lifetime time horizon.

CONCLUSIONS

Flexible take-home BNX was not cost-effective versus methadone over a lifetime time horizon, resulting from better treatment retention in methadone compared to BNX.

Evaluation of the gap in delivery of opioid agonist therapy among individuals with opioid-related health problems: a population-based retrospective cohort study

AIMS

Although opioid-related harms have reached new heights across North America, the size of the gap in opioid agonist therapy (OAT) delivery for opioid-related health problems is unknown in most jurisdictions. This study sought to characterize the gap in OAT treatment using a cascade of care framework, and determine factors associated with engagement and retention in treatment.

DESIGN

A population-based retrospective cohort study.

SETTING

Ontario, Canada.

PARTICIPANTS

Individuals who sought medical care for opioid-related health problems or died from an opioid-related cause between 2005 and 2019.

MEASUREMENTS

Monthly treatment status for buprenorphine/naloxone or methadone OAT between 2013 and 2019 (i.e. 'off OAT', 'retained on OAT < 6 months', 'retained on OAT ≥ 6 months').

FINDINGS

Of 122 811 individuals in the cohort, 97 516 (79.4%) received OAT at least once during the study period. There was decreasing 6-month treatment retention over time. Model results indicated that males had higher odds of being on OAT each month [odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.23-1.28] but lower odds of OAT retention (OR = 0.90, 95% CI = 0.88-0.92), while the reverse was observed for older individuals (monthly: OR = 0.76 per 10-year increase, 95% CI = 0.76-0.77; retention: OR = 1.36 per 10-year increase, 95% CI = 1.34-1.38) and individuals with higher neighbourhood income (e.g. highest income quintile, monthly: OR = 0.79, 95% CI = 0.77-0.82; highest income quintile, retention: OR = 1.15, 95% CI = 1.11-1.20). Individuals residing in rural areas and with a history of mental health diagnoses had poorer outcomes overall, including lower odds of being on OAT each month (rural: OR = 0.75, 95% CI = 0.73-0.78; mental health: OR = 0.89, 95% CI = 0.87-0.92) and OAT retention (rural: OR = 0.79, 95% CI = 0.77-0.82; mental health: OR = 0.81, 95% CI = 0.78-0.83), as well as higher risk of starting/stopping OAT [rural, starting OAT: hazard ratio (HR) = 1.07, 95% CI = 1.05-1.10; mental health, starting OAT: HR = 1.20, 95% CI: 1.18-1.23; rural, stopping OAT: HR = 1.24, 95% CI: = 1.22-1.26; mental health, stopping OAT: HR = 1.11, 95% CI = 1.09-1.13]. Individuals with a history of mental health diagnoses also had a higher risk of death, regardless of OAT status (off OAT death: HR = 1.49, 95% CI = 1.33-1.66; on OAT death: HR = 1.20, 95% CI = 1.09-1.31).

CONCLUSIONS

Factors influencing engagement and declining retention in treatment with opioid agonist therapy in Ontario's health system include age, sex and neighbourhood income, as well as mental health diagnoses or residing in rural regions.

Machine-learning analysis of opioid use disorder informed by MOR, DOR, KOR, NOR and ZOR-based interactome networks

Opioid use disorder (OUD) continuously poses major public health challenges and social implications worldwide with dramatic rise of opioid dependence leading to potential abuse. Despite that a few pharmacological agents have been approved for OUD treatment, the efficacy of said agents for OUD requires further improvement in order to provide safer and more effective pharmacological and psychosocial treatments. Proteins including mu, delta, kappa, nociceptin, and zeta opioid receptors are the direct targets of opioids and play critical roles in therapeutic treatments. The protein-protein interaction (PPI) networks of the these receptors increase the complexity in the drug development process for an effective opioid addiction treatment. The report below presents a PPI-network informed machine-learning study of OUD. We have examined more than 500 proteins in the five opioid receptor networks and subsequently collected 74 inhibitor datasets. Machine learning models were constructed by pairing gradient boosting decision tree (GBDT) algorithm with two advanced natural language processing (NLP)-based autoencoder and Transformer fingerprints for molecules. With these models, we systematically carried out evaluations of screening and repurposing potential of more than 120,000 drug candidates for four opioid receptors. In addition, absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties were also considered in the screening of potential drug candidates. Our machine-learning tools determined a few inhibitor compounds with desired potency and ADMET properties for nociceptin opioid receptors. Our approach offers a valuable and promising tool for the pharmacological development of OUD treatments.