Stronger, longer, better opioid antagonists? Nalmefene is NOT a naloxone replacement

The fatal overdose crisis claims nearly 200 lives daily in the United States (U.S). Evolutions in the illicit drug supply, such as the addition of sedative adulterants and a shift to synthetic opioids such as fentanyl, have driven increasing rates of both fatal and non-fatal overdose. Specifically, synthetic opioid usage of fentanyl was implicated in 68 % of the U.S. drug overdose deaths in 2022 alone. This has placed tremendous burden on communities, emergency medical services, and healthcare systems, and contributed to tragedy and grief both in the U.S. and worldwide. Despite the availability of effective opioid antagonist medications and standards of care, there has been increased interest in research and development of alternative opioid overdose reversal agents by the National Institutes of Health (NIH) in partnership with pharmaceutical manufacturers over the last decade. The U.S. Food and Drug Administration (FDA) recently approved nalmefene (Opvee) a mu-opioid receptor antagonist that boasts an extended half-life and stronger mu-receptor affinity compared to the standard of care use of naloxone for opioid reversal. In this article, we explore the medical need and ramifications of the introduction of longer-acting opioid antagonists in the current opioid overdose landscape. Existing data highlight the effectiveness of already available naloxone products as a safe and effective standard of care. These data support the notion that stronger, longer-acting agents may be unnecessary, and their existence may cause undue harm, such as more severe and/or prolonged withdrawal symptoms, lead to challenging patient interactions, and complicate the initiation of medications for opioid use disorder. More evidence is needed before healthcare professionals should implement the use of stronger, longer-acting opioid antagonists for reversing opioid overdose over evidence-based, cost-effective naloxone.

Neighborhood and Individual Disparities in Community-Based Naloxone Access for Opioid Overdose Prevention

Improving access to naloxone for laypersons is a cornerstone of the US strategy to reduce opioid overdose deaths. This study evaluated change in distance to opioid overdose prevention programs (OOPPs) providing walk-in naloxone across two time points. We also explored individual and neighborhood disparities in distance to OOPPs, associations between 2020 OOPP locations and 2018 overdoses, and associations between OOPPs and neighborhood fatal overdose rates. Using fatal opioid overdose locations in 2018 (n = 1167) and 2020 (n = 2045) in New York City, we mapped OOPP locations and fatal overdose locations to visualize areas of unmet naloxone need. We used logistic regression to assess individual (age, sex, race/ethnicity) and neighborhood correlates of odds of an overdose occurring within walking distance (≤ 0.5 miles or 0.8 km) of an OOPP and negative binomial regression to assess the relationship between census tract-level OOPP counts and overdose rates. Distance to OOPPs significantly improved over time, with average distance decreasing by 1.7 miles (2.7 km) (p < 0.001). OOPPs were more likely to be located in neighborhoods with higher poverty in both years and in closer proximity to Latinos in 2020-suggesting improved access for Latinos and in higher poverty neighborhoods. OOPP locations in 2020 were significantly positively associated with overdose locations in 2018. OOPPs were not well-situated in neighborhoods with elevated overdose rates in 2018 but were better situated in 2020, controlling for other neighborhood variables. Community lay naloxone access through OOPPs improved over time and could have promising effects for improved overdose rates in the future.

Intranasal Naloxone for Opioid Overdose

This JAMA Insights describes indications for naloxone use in preventing opioid overdoses and benefits vs barriers to its availability following FDA approval of its availability without a prescription.

Naldemedine-laxative combination: retrospective inpatient study

OBJECTIVES

The initiation of peripherally acting μ-opioid receptor antagonists (PAMORAs) should be considered 2 weeks after conventional laxatives have failed to achieve an adequate response, and affected patients should be evaluated every 2 weeks thereafter. However, this guidance is difficult to implement in acute care hospitals. This study aimed to examine how naldemedine (PAMORA) should be introduced in combination with other laxatives in the acute care setting.

METHODS

This retrospective study evaluated 93 inpatients who received at least four doses of naldemedine. We investigated changes in the average daily defecation counts during the first 7 days after compared with before naldemedine administration and the incidence of diarrhoea.

RESULTS

Daily defecation counts during the first 7 days after compared with before naldemedine administration were greater in both the naldemedine, magnesium oxide (MgO) and another laxative group, and in the naldemedine and another laxative other than MgO group than in the naldemedine only group. The incidence rates of diarrhoea were significantly higher in the naldemedine, MgO, and another laxative group, and in the naldemedine and another laxative other than MgO group than in the naldemedine only group.

CONCLUSIONS

The introduction of naldemedine alone or in combination with MgO should be considered.

Naldemedine versus placebo in opioid-induced constipation: a meta-analysis

OBJECTIVE

Opioid-induced constipation (OIC) is a frequent adverse event among patients receiving chronic pain therapy that is requiring opioids. Naldemedine was approved by the Food and Drug Administration to treat OIC and appears to be more efficient than any other peripherally acting µ-opioid receptor antagonist. This meta-analysis aimed at assessing the available data on naldemedine in terms of efficacy.

METHODS

We searched the Cochrane Library, PubMed and ClinicalTrials on 24 May 2022 to identify randomised controlled trials (RCTs) comparing naldemedine to placebo among patients reporting OIC.

RESULTS

Evaluation of 6 RCTs enrolling 2769 participants showed significantly greater respondence to treatment (OR=2.48; 95% CI: 2.02 to 3.06; p<0.00001), change in weekly spontaneous bowel movements (SBMs) (mean difference=1.45; 95% CI: 1.14 to 1.76; p<0.00001), complete SBMs (mean difference=0.89; 95% CI: 0.62 to 1.17; p<0.00001) and SBMs without straining (mean difference=0.89; 95% CI: 0.61 to 1.17; p<0.00001) for patients treated with naldemedine. We found no difference in numeric pain rating scales after one (mean difference=0.05; 95% CI: -0.22 to 0.31; p=0.73) and two weeks of treatment (mean difference= -0.04; 95% CI: -0.31 to 0.22; p=0.75). Funding and clinical diversity were possible risks of bias.

CONCLUSIONS

Naldemedine improves a variety of bowel function parameters while preserving analgesia, confirming its efficacy for patients with OIC. However, head-to-head trials are needed to establish naldemedine as treatment of first choice for laxative-refractory OIC.

PROSPERO REGISTRATION NUMBER

CRD42022281353.

Distribution of intranasal naloxone to potential opioid overdose bystanders in Sweden: effects on overdose mortality in a full region-wide study

OBJECTIVES

Distribution of take-home naloxone is suggested to reduce opioid-related fatalities, but few studies have examined the effects on overdose deaths in the general population of an entire community. This study aimed to assess the effects on overdose deaths of a large-scale take-home naloxone programme starting in June 2018, using an observational design with a historic control period.

DESIGN

From the national causes of death register, deaths diagnosed as X42 or Y12 (International Classification of Diseases, 10th revision, ICD-10) were registered as overdoses. Numbers of overdoses were calculated per 100 000 inhabitants in the general population, and controlled for data including only individuals with a prior substance use disorder in national patient registers, to focus on effects within the primary target population of the programme. The full intervention period (2019-2021) was compared with a historic control period (2013-2017).

SETTING

Skåne county, Sweden.

PARTICIPANTS

General population.

INTERVENTIONS

Large-scale take-home naloxone distribution to individuals at risk of overdose.

PRIMARY AND SECONDARY OUTCOME MEASURES

Decrease in overdose deaths per 100 000 inhabitants, in total and within the population with substance use disorder diagnosis.

RESULTS

Annual average number of overdose deaths decreased significantly from 3.9 to 2.8 per 100 000 inhabitants from the control period to the intervention period (a significant decrease in men, from 6.7 to 4.3, but not in women, from 1.2 to 1.3). Significant changes remained when examining only prior substance use disorder patients, and decreases in overdose deaths could not be attributed to a change in treatment needs for opioid use disorders in healthcare and social services.

CONCLUSIONS

The present study, involving 3 years of take-home naloxone distribution, demonstrated a decreased overdose mortality in the population, however, only in men. The findings call for further implementation of naloxone programmes, and for further studies of potential effects and barriers in women.

TRIAL REGISTRATION NUMBER

NCT03570099.

Does the advent of depot therapy represent a step change in our understanding of opioid use disorder and its treatment?

After years of minimal innovation in pharmacotherapeutics, impressive outcomes in the treatment of opioid use disorder are being obtained from a new way of delivering an old medication; long-acting injectable formulations of buprenorphine appear to produce compelling reductions in relapse to illicit opioid use not only during use but also following depot discontinuation. This commentary discusses potential mechanisms behind this observation, asks if the removal of the need for daily oral opioid agonist dosing furthers our understanding of addiction treatment and whether we should therefore consider expanding access to depot formulations.

Remaking the 'angry Narcanned subject': Affording new subject positions through take-home naloxone training

Naloxone is a medication used to reverse opioid overdose. Alongside its lifesaving effects, it also has a reputation for producing distress, aggression and occasionally violence upon administration. This article analyses how take-home naloxone (THN) training initiatives address naloxone's reputation for producing aggression and conflict, and how new subject positions emerge in the context of this training. While the role of naloxone in producing aggression has been discussed in a range of research, this work emphasises that such conflict is neither inevitable nor even likely because it is contingent on several other issues such as administration practices. Building on this scholarship, we work with Bruno Latour's theorisation of technological 'affordances' to analyse THN as a socially co-produced technology that, rather than either determining or neutrally communicating actions and effects, 'affords' possibilities, capacities and subjects. Analysing data drawn from observations of THN training in Victoria, Australia, and in-depth interviews with training participants, we argue that the issue of conflict upon revival affords a subject position we term the 'angry Narcanned subject'. This subject, we note, has come to hold a powerful position in understandings of naloxone, not least because it tends to accord with stereotypes of antisocial drug users. From here, we argue that a much of THN training is focused on challenging and reframing naloxone's reputation for conflict and questioning related subject positions, especially that of the angry Narcanned subject. We argue that this process of challenging and reframing affords two new subject positions for consumers: the 'capable administrator' and the 'calmer revivee'. We conclude that while THN training affords multiple, potentially positive, subject positions, unless these initiatives are accompanied by broader interventions such as decriminalisation campaigns, they may inadvertently responsibilise people who consume opioids for addressing overdose and erase the role of prohibition, criminalisation and stigmatisation in producing overdose events.

Opioid Misuse Harm Reduction

BACKGROUND/AIMS

The misuse of opioids by the public is a major health issue. Prescription opioids and nonprescription opioids, such as heroin and opium, are misused in epidemic proportions. When opioids are used incorrectly or illegally, they can lead to drug dependence, addiction, morbidity, and mortality. This program is in collaboration with the Jolt Foundation that provides resources to prevent opioid overdose deaths.

DESIGN/METHODS

This program involves community education on the dangers of opioid use and training on the use of naloxone rescue procedures to prevent overdose deaths. A pretest-posttest design was employed to determine if participants gained knowledge regarding the naloxone administration procedures.

PARTICIPANTS

The researcher presented 10 community naloxone trainings that included staff from 20 different social service agencies, two schools, and three local churches. Each agency received at least one naloxone kit.

FINDINGS

The outcomes were met and included educating 137 participants on the risk factors and signs and symptoms of opioid overdose and the proper procedure to administer naloxone. One hundred twenty-eight posttests were returned and showed that the objectives for the project were met. The overall mean score for the pretests was 65.00 ( n = 126) with a standard deviation of 19.01, and the overall mean for the posttests was 86.64 ( n = 128) with a standard deviation of 14.60.

CONCLUSIONS

Community social service agency staff were successfully educated to respond appropriately to overdose situations in a group training setting as evidenced by significant posttest scores.

Evaluation of an injectable monthly extended-release buprenorphine program in a low-barrier specialty addiction medicine clinic

INTRODUCTION

Monthly injectable extended-release buprenorphine (XR-BUP) can address several systemic and individual barriers to consistent sublingual buprenorphine treatment for patients with opioid use disorder (OUD). Real-world evaluations of XR-BUP in the outpatient addiction treatment setting are limited. The purpose of this study was to compare 6-month treatment retention and urine drug tests between patients who initiated XR-BUP compared to those who were prescribed but did not initiate XR-BUP in a low-barrier addiction medicine specialty clinic.

METHODS

We conducted a retrospective cohort study of adults with OUD prescribed XR-BUP between 12/1/2018 and 12/31/2020 in a low-barrier addiction medicine specialty clinic to compare 6-month treatment retention between patients who initiated XR-BUP and those who were prescribed but did not initiate XR-BUP (comparison group). Secondary outcomes included percent of urine toxicology tests negative for non-prescribed opioids. Multivariable logistic regression models evaluated factors associated with 6-month treatment retention and XR-BUP initiation.

RESULTS

Of the 233 patients prescribed XR-BUP, 148 (63.8 %) identified as non-Hispanic white, 218 (93.6 %) were insured by public insurance (Medicare/Medicaid), and nearly two-thirds were prescribed XR-BUP due to unstable OUD. Approximately 50 % of patients initiated XR-BUP treatment (mean number of injections = 3.7). About 60 % of XR-BUP-treated patients received supplemental sublingual buprenorphine and nearly two-thirds received a 300 mg maintenance dose. Six-month treatment retention was greater in the XR-BUP treatment versus comparison group (70.3 % vs. 36.5 %, p < 0.001). The XR-BUP treatment group had a higher percentage of opioid-negative urine toxicology tests versus the comparison group (67.2 % vs. 36.3 %, p < 0.001). Receipt of XR-BUP was an independent predictor of 6-month treatment retention (OR 5.40, 95 % CI 2.18-13.38). Those prescribed XR-BUP due to unstable OUD had lower odds of treatment retention (OR 0.41, 95 % CI 0.24-0.98) after controlling for receipt of XR-BUP and other variables known to impact retention.

CONCLUSIONS

XR-BUP improved 6-month treatment retention and resulted in a greater proportion of opioid-negative urine toxicology tests compared to a comparison group of patients who were prescribed but did not initiate XR-BUP. Patients with unstable OUD had lower odds of XR-BUP initiation, suggesting the need for targeted interventions to increase XR-BUP uptake in this high-risk population.

Individual-Level Risk Prediction of Return to Use During Opioid Use Disorder Treatment

Importance

No existing model allows clinicians to predict whether patients might return to opioid use in the early stages of treatment for opioid use disorder.

Objective

To develop an individual-level prediction tool for risk of return to use in opioid use disorder.

Design, Setting, and Participants

This decision analytical model used predictive modeling with individual-level data harmonized in June 1, 2019, to October 1, 2022, from 3 multicenter, pragmatic, randomized clinical trials of at least 12 weeks' duration within the National Institute on Drug Abuse Clinical Trials Network (CTN) performed between 2006 and 2016. The clinical trials covered a variety of treatment settings, including federally licensed treatment sites, physician practices, and inpatient treatment facilities. All 3 trials enrolled adult participants older than 18 years, with broad pragmatic inclusion and few exclusion criteria except for major medical and unstable psychiatric comorbidities.

Intervention

All participants received 1 of 3 medications for opioid use disorder: methadone, buprenorphine, or extended-release naltrexone.

Main Outcomes and Measures

Predictive models were developed for return to use, which was defined as 4 consecutive weeks of urine drug screen (UDS) results either missing or positive for nonprescribed opioids by week 12 of treatment.

Results

The overall sample included 2199 trial participants (mean [SD] age, 35.3 [10.7] years; 728 women [33.1%] and 1471 men [66.9%]). The final model based on 4 predictors at treatment entry (heroin use days, morphine- and cocaine-positive UDS results, and heroin injection in the past 30 days) yielded an area under the receiver operating characteristic curve (AUROC) of 0.67 (95% CI, 0.62-0.71). Adding UDS in the first 3 treatment weeks improved model performance (AUROC, 0.82; 95% CI, 0.78-0.85). A simplified score (CTN-0094 OUD Return-to-Use Risk Score) provided good clinical risk stratification wherein patients with weekly opioid-negative UDS results in the 3 weeks after treatment initiation had a 13% risk of return to use compared with 85% for those with 3 weeks of opioid-positive or missing UDS results (AUROC, 0.80; 95% CI, 0.76-0.84).

Conclusions and Relevance

The prediction model described in this study may be a universal risk measure for return to opioid use by treatment week 3. Interventions to prevent return to regular use should focus on this critical early treatment period.

48-hour Induction of Transdermal Buprenorphine to Extended-release Buprenorphine

ABSTRACT

Buprenorphine extended-release (BUP-XR) provides sustained delivery of buprenorphine to control withdrawal and craving symptoms in the form of a monthly injectable and has been shown to improve health outcomes in patients with opioid use disorder. It is recommended that patients are stabilized with a transmucosal buprenorphine product, for at least 7 days per the product monograph; however, clinically, this timeline may be expedited. We report a case of a hospitalized patient with unregulated fentanyl use who underwent a successful transdermal buprenorphine induction for 48 hours to initiate BUP-XR with minimal levels of withdrawal and without precipitating opioid withdrawal. The approach described could provide a practical, patient-centered, accelerated induction strategy that, once independently validated, could considerably facilitate the use of BUP-XR.

Missed Opportunities: Substance Use Hotline Operator Uncertainty of State Buprenorphine Prescribing via Telemedicine

OBJECTIVES

We examined substance use hotline operator certainty of each US state and Washington, DC's endorsement of buprenorphine (initiation and continuation) prescribing via telemedicine.

METHODS

Between March and May 2021, we called hotlines in 50 US states and Washington, DC, requesting information on whether practitioners in that state could initiate or continue buprenorphine treatment for opioid use disorder (OUD) via telephone or video conference. We compared operator responses to state implementation of buprenorphine telemedicine initiation. This study was designated as not human subjects research by the Boston University Institutional Review Board.

RESULTS

We spoke with operators in 47 states and Washington, DC. Operators could not be reached in Alaska, California, and Montana. Most operators were uncertain (don't know, probably yes, probably no) whether the state permitted buprenorphine initiation (81%, n = 39) or continuation (83%, n = 40) via telemedicine. Practitioners could initiate buprenorphine prescribing via telemedicine in 7 states (100%) where operators were certain practitioners could initiate buprenorphine, 1 state (100%) where the operator was certain practitioners could not, and 6 states (86%) where operators indicated practitioners probably could not.

CONCLUSIONS

Most US states and Washington, DC, expanded the role of telemedicine in OUD treatment. However, most operators expressed uncertainty and sometimes communicated inaccurate information regarding whether practitioners could initiate buprenorphine treatment via telemedicine. There is an urgent need for policy mandates institutionalizing the role of telemedicine, and of buprenorphine specifically, in OUD treatment and for resources to train and support substance use hotline operators in this evolving policy environment.

Repeated measures analysis of opioid use disorder treatment on clinical opiate withdrawal scale in a randomized clinical trial: sex differences

PURPOSE

Sex differences may exist in opioid use disorder (OUD) treatment. This study examined the treatment effects of buprenorphine/naloxone (BUP/NX) and methadone (MET) on the Clinical Opiate Withdrawal Scale (COWS) score in individuals with OUD and tested whether the associations differ by sex.

METHOD

We performed a secondary analysis of the data from the National Drug Abuse Treatment Clinical Trials Network (CTN) protocol-0027. A total of 1269 participants (861 males and 408 females) being aged 18 or older with OUD were randomly assigned to receive BUP/NX (n = 740) or MET (n = 529). The paired t test was initially used to compare the COWS scores between pre-dose and post-dose for BUP/NX and MET treatments, separately. The linear mixed model was used to examine the changes in COWS score adjusted for baseline demographic, substance use, and mental health disorders. The interaction of sex and treatment was detected and stratified analysis by sex was conducted.

RESULTS

The paired t test showed that both BUP/NX and MET treatments significantly reduced the COWS scores (p values <0.0001). BUP/NX revealed higher COWS scores than MET (p = 0.0008) and females demonstrated significantly higher COWS scores than males (p = 0.0169). Stratified by sex, BUP/NX compared with MET revealed higher COWS scores only in males (p = 0.0043), whereas baseline amphetamines use disorder and major depressive disorder were significantly associated with COWS scores in females (p = 0.0158 and 0.0422, respectively).

CONCLUSIONS

Both BUP/NX and MET are effective in decreasing opioid withdrawal symptoms via COWS scores, however, treatment plans for OUD by clinical providers should consider sex differences.

Action Plan and Model to Reduce Potential Opioid Overdose Deaths on K-12 Campuses

School communities are not immune to the alarming increase in opioid-related deaths occurring in the United States during the past decade. The purpose of this article is to share how a middle school in New York State, beginning in the late fall of 2022, successfully implemented a program to reduce the likelihood of opioid overdose deaths in their building through expansion of the accessibility of and education and training in use of naloxone, an opioid antagonist. The program is applicable for all K-12 campuses and follows the Model of Greater Awareness, Improved Training, and Increased Availability of and Accessibility to Intervention Devices, based on the steps successfully used for out-of-hospital cardiac arrest emergencies. Because opioid addiction does not discriminate, it is confidently projected that these targeted actions will proactively and positively reduce the likelihood of opioid overdose deaths in our school setting, including for students, faculty, staff, administrators, and visitors, when and should they occur.

Extended-release Buprenorphine Administered at Discharge in Hospitalized Persons With Opioid Use Disorder: A Case Series

INTRODUCTION

Monthly subcutaneous injectable buprenorphine (XR-Bup) is an option for treatment of opioid use disorder (OUD) that addresses some sublingual buprenorphine adherence barriers and is infrequently offered to hospitalized patients with OUD.

METHODS

A retrospective case series was performed for patients receiving XR-Bup upon discharge from 1 academic medical center. Demographic information, diagnoses, follow-up, and documented factors informing the selection of XR-Bup were extracted from the electronic health record.

RESULTS

In 1 year, 37 hospitalized patients with OUD received XR-Bup at discharge. The average age was 37.6 years, and patients were primarily Medicaid insured with an injection-related infection. The most common documented factors informing the selection of XR-Bup were as follows: previous sublingual buprenorphine adherence barriers, concurrent stimulant use disorder, and patient preference. Sixty-four percent of patients scheduled for follow-up attended appointments, and 55% received a second dose of XR-Bup.

CONCLUSIONS

Subcutaneous injectable buprenorphine is an option for OUD treatment among hospitalized patients providing 30 or more days of buprenorphine coverage in the postdischarge period.

What impacts the acceptability of wearable devices that detect opioid overdose in people who use opioids? A qualitative study

INTRODUCTION

Drug-related deaths involving an opioid are at all-time highs across the United Kingdom. Current overdose antidotes (naloxone) require events to be witnessed and recognised for reversal. Wearable technologies have potential for remote overdose detection or response but their acceptability among people who use opioids (PWUO) is not well understood. This study explored facilitators and barriers to wearable technology acceptability to PWUO.

METHODS

Twenty-four participants (79% male, average age 46 years) with current (n = 15) and past (n = 9) illicit heroin use and 54% (n = 13) who were engaged in opioid substitution therapy participated in semi-structured interviews (n = 7) and three focus groups (n = 17) in London and Nottingham from March to June 2022. Participants evaluated real devices, discussing characteristics, engagement factors, target populations, implementation strategies and preferences. Conversations were recorded, transcribed and thematically analysed.

RESULTS

Three themes emerged: device-, person- and environment-specific factors impacting acceptability. Facilitators included inconspicuousness under the device theme and targeting subpopulations of PWUO at the individual theme. Barriers included affordability of devices and limited technology access within the environment theme. Trust in device accuracy for high and overdose differentiation was a crucial facilitator, while trust between technology and PWUO was a significant environmental barrier.

DISCUSSION AND CONCLUSIONS

Determinants of acceptability can be categorised into device, person and environmental factors. PWUO, on the whole, require devices that are inconspicuous, comfortable, accessible, easy to use, controlled by trustworthy organisations and highly accurate. Device developers must consider how the type of end-user and their environment moderate acceptability of the device.

Characteristics, treatment patterns and retention with extended-release subcutaneous buprenorphine for opioid use disorder: A population-based cohort study in Ontario, Canada

BACKGROUND

Uptake and retention for opioid agonist treatment (OAT) remains low. Novel extended-release formulations may improve OAT accessibility by reducing the frequency of healthcare visits. Our aim was to examine uptake, characteristics, treatment patterns and retention of individuals initiating extended-release subcutaneous buprenorphine (BUP-ER), a monthly injectable OAT.

METHODS

We conducted a population-based cohort study among adults aged 18+ initiated on BUP-ER between February 3, 2020 and March 31, 2022 in Ontario, Canada. Using administrative health data, we defined continuous BUP-ER use based on repeat injections within a 56-day period and used Kaplan-Meier curves to estimate time on treatment. Among new BUP-ER recipients, we described individual and prescriber characteristics, healthcare utilization and treatment patterns.

RESULTS

2366 individuals initiated BUP-ER. The median time to BUP-ER discontinuation was 183 days (interquartile range: 66-428 days) and 52.0% of individuals were co-prescribed buprenorphine/naloxone at least once throughout the period of BUP-ER receipt. Among individuals who initiated on a dose of 300mg BUP-ER and had three or more injections, 18.8% continued to receive only 300mg doses (N=276 of 1470). Furthermore, 28.6% of those whose dose was reduced to 100mg (N=341 of 1194) had a subsequent dose increase to 300mg.

CONCLUSIONS

On average, people initiating BUP-ER discontinue within the first 6 months of treatment. While BUP-ER is likely providing an important OAT option, the high occurrence of discontinuation, supplementation with buprenorphine/naloxone, and frequent dose increases suggest inadequacy of current dosing recommendations among a proportion of individuals.

Association of Fentanyl Test Strip Use, Perceived Overdose Risk, and Naloxone Possession among People Who Use Drugs

Background: As opioid overdoses continue rising, interventions are needed to expand naloxone carriage, an opioid overdose reversal agent. Use of fentanyl test strips (FTS) might promote naloxone carriage. This study examines the relationship between FTS use, perceived overdose risk, and naloxone carriage in Wisconsin, United States. Methods: In a survey of people who use drugs (n = 341) in southern Wisconsin, respondents were asked about FTS use, perceived overdose risk, and how often they (1) have naloxone, (2) have more than one dose of naloxone, and (3) the number of naloxone doses possessed currently. Likert responses were mapped to an integer scale. Ordinal and linear multivariable regression examined the relationship between FTS use and study outcomes while adjusting for respondent characteristics. Results: Most respondents were male (59.6%), identified heroin as their drug of choice (70.7%) and reported intravenous use (87.9%). In unadjusted models, FTS use was associated with more often having naloxone (OR: 2.10; p = 0.005), more often having multiple naloxone doses (OR: 2.98; p < 0.001), and possessing a greater number of naloxone doses (dose count difference: 2.85; p = 0.001). In adjusted models, FTS use was associated with more often having multiple naloxone doses (OR: 2.29; p = 0.005) and possessing a greater number of naloxone doses (dose count difference: 2.25, p = 0.020). Conclusions: Individuals who use FTS more often carry multiple doses relative to individuals who do not use FTS. Given that naloxone carriage is critical for reducing opioid overdose risk, expanding FTS use may offer a strategy to reduce opioid overdose rates via improved naloxone carriage.

The Perceived Role of Withdrawal in Maintaining Opioid Addiction among Adults with Untreated Opioid Use Disorder: A Survey of Syringe Exchange Program Participants

Background: Withdrawal is believed to play a central role in the brain disease model of addiction. However, little research describes withdrawal-motives among untreated individuals in community settings. Methods: This cross-sectional study surveyed syringe exchange program participants (n = 139) with untreated opioid use disorder (OUD) in Columbus, Ohio from January 10th to March 25th, 2023, to assess their perceptions of the role of withdrawal in OUD maintenance, treatment delay, and OUD's refractoriness to buprenorphine. Participants responded to a survey including DSM-5 OUD criteria, demographics, and questions about substance use and opioid withdrawal. Participant ages ranged from 21 to 65 years with a mean age of 37.5 years and standard deviation of 8.1. The racial distribution of the sample was as follows: 81% White/Caucasian, 12% Black/African American, 3% Native American or Alaskan Native. Results: Sixty-six percent of participants agreed, or strongly agreed that opioid withdrawal was "the most important reason" they had been unable to stop using opioids. Almost seventy-one percent agreed, or strongly agreed that worry about opioid withdrawal had caused them to "put off or delay" OUD treatment. Although all participants had active, untreated OUD at the time of recruitment, most (85%) had previously tried buprenorphine, and the majority (78%) reported having experienced buprenorphine-precipitated withdrawal. Conclusions: Among this community sample of individuals with untreated OUD, withdrawal was perceived to have an important role in maintaining OUD, including by motivating OUD treatment delay. Prior buprenorphine-precipitated withdrawal was common, suggesting aversion to withdrawal might possibly be associated with OUD's refractoriness to buprenorphine.

Opioid-induced constipation: a stepwise treatment algorithm feasibility study

BACKGROUND

Opioid-induced constipation (OIC) is frequently undertreated in patients with advanced cancer. Our hypothesis is that the use of a stepwise treatment algorithm, supported by regular patient-reported outcome measures, should improve the management of OIC. The aim of this feasibility study was to determine whether a definitive study could be successfully completed.

METHODS

Patients with OIC (Rome Foundation diagnostic criteria positive), and a Bowel Function Index (BFI) score of ≥30, were recruited to the study. The study involved weekly assessments, and decisions about management were based on the current BFI score (and the tolerability of the current treatment). Management was based on a four-step treatment algorithm, developed from recent international guidelines.

RESULTS

One hundred patients entered the study, and 79 patients completed the study. Fifty-seven (72%) participants responded to treatment, with 34 (43%) participants having a 'complete' response (ie, final BFI<30) and 23 (29%) participants having a 'partial' response (ie, change in BFI≥12). In participants with a complete response, 73.5% were prescribed conventional laxatives, 12% were prescribed a peripherally acting mu-opioid receptor antagonist (PAMORA) and 14.5% were prescribed a PAMORA and conventional laxative.

DISCUSSION

The feasibility study suggests that a definitive study can be successfully completed. However, we will amend the methodology to try to improve participant recruitment, participant retention and adherence to the treatment algorithm. The feasibility study also suggests that the use of the BFI to monitor OIC, and the use of a treatment algorithm to manage OIC, can result in clinically important improvements in OIC.Trial registration number NCT04404933.

Efficacy of Naldemedine on Intestinal Hypomotility and Adhesions in Rodent Models of Postoperative Ileus

Postoperative ileus (POI) often decreases patients' QOL because of prolonged hospitalization and readmission. Alvimopan, a peripheral μ-opioid receptor antagonist, is currently the only therapeutic drug for POI. The aim of this study was to examine the efficacy of naldemedine (a peripheral μ-opioid receptor antagonist with a non-competitive pharmacological profile different from that of alvimopan) on postoperative intestinal hypomotility and adhesion in rodent models, and compare it with the effects of alvimopan. Oral administration of naldemedine (0.3 mg/kg) and alvimopan (3 mg/kg) significantly inhibited the decrease in intestinal motility induced by mechanical irritation in mice (p < 0.01, for both). Naldemedine (1 mg/kg) significantly shortened the adhesion length in chemical-induced postoperative adhesion model rats (p < 0.05). Alvimopan (3 mg/kg) also significantly reduced the adhesion ratio (p < 0.01). These findings suggest that naldemedine is effective for postoperative intestinal hypomotility and adhesions in rodents (i.e., as for alvimopan). Thus, naldemedine may be a useful option for the treatment of POI.