Using quality improvement approaches to increase emergency department provider engagement in research participant enrollment during COVID-19 and opioid overdose public health emergencies.

PURPOSE: We utilized quality improvement (QI) approaches to increase emergency department (ED) provider engagement with research participant enrollment during the opioid crisis and coronavirus disease (COVID-19) pandemic. The context of this work is the Evaluating Microdosing in the Emergency Department (EMED) study, a randomized trial offering buprenorphine/naloxone to ED patients through randomization to standard or microdosing induction. Engaging providers is crucial for participant recruitment to our study. Anticipating challenges sustaining long-term engagement after a 63% decline in provider referrals four months into enrollments, we applied Plan-Do-Study-Act (PDSA) cycles to develop and implement an engagement strategy to increase and sustain provider engagement by 50% from baseline within 9 months. METHODS: Our engagement strategy was centered on Coffee Carts rounds: 5-min study-related educational presentations for providers on shift; and a secondary initiative, a Suboxone Champions program, to engage interested providers as study-related peer educators. We used provider referrals to our team as a proxy for study engagement and report the percent change in mean weekly referrals across two PDSA cycles relative to our established referral baseline. RESULTS: A QI approach afforded real-time review of interventions based on research and provider priorities, increasing engagement via mean weekly provider referrals by 14.5% and 49% across two PDSA cycles relative to baseline, respectively. CONCLUSIONS: Our Coffee Carts and Suboxone Champions program are efficient, low-barrier, educational initiatives to convey study-related information to providers. This work supported our efforts to maximally engage providers, minimize burden, and provide life-saving buprenorphine/naloxone to patients at risk of fatal overdose.

RéSUMé: BUT: Nous avons utilisé des approches d'amélioration de la qualité (AQ) pour accroître l'engagement des fournisseurs des services d'urgence (SU) avec l'inscription des participants à la recherche pendant la crise des opioïdes et la pandémie de maladie à coronavirus (COVID-19). Le contexte de ce travail est l'étude Evaluating Microdosing in the Emergency Department (EMED), un essai randomisé offrant de la buprénorphine/naloxone aux patients aux urgences par randomisation à l'induction standard ou au microdosage. L'engagement des fournisseurs est crucial pour le recrutement des participants à notre étude. En anticipant les difficultés à maintenir un engagement à long terme après une baisse de 63 % des recommandations de fournisseurs quatre mois après les inscriptions, nous avons appliqué le Plan-Do-Study-Act (PDSA) cycles d'élaboration et de mise en œuvre d'une stratégie d'engagement visant à accroître et à maintenir l'engagement des fournisseurs de 50 % par rapport au niveau de référence dans les neuf mois. MéTHODES: Notre stratégie de mobilisation était axée sur les tournées de Coffee Carts : des présentations éducatives de cinq minutes sur l'étude pour les fournisseurs sur le quart de travail; et une initiative secondaire, un programme Suboxone Champions, pour mobiliser les fournisseurs intéressés en tant que pairs éducateurs liés à l'étude. Nous avons utilisé les recommandations des fournisseurs à notre équipe comme indicateur de la participation à l'étude et nous avons signalé le pourcentage de changement dans les recommandations hebdomadaires moyennes pour deux cycles PDSA par rapport à notre base de référence établie. RéSULTATS: Une approche d'AQ a permis d'examiner en temps réel les interventions en fonction des priorités de la recherche et des fournisseurs, ce qui a augmenté l'engagement par l'intermédiaire des recommandations hebdomadaires moyennes des fournisseurs de 14,5 % et de 49 % au cours de deux cycles de PDSA par rapport au niveau de référence, respectivement. CONCLUSION: Notre programme Coffee Carts and Suboxone Champions est une initiative éducative efficace et peu contraignante qui permet de transmettre aux fournisseurs des renseignements sur les études. Ce travail a appuyé nos efforts visant à mobiliser au maximum les fournisseurs, à réduire au minimum le fardeau et à fournir de la buprénorphine/naloxone vitale aux patients à risque de surdose mortelle.

A qualitative study of experiences with physical activity among people receiving opioid agonist therapy.

BACKGROUND: Physical or mental health comorbidities are common among people with substance use disorders undergoing opioid agonist therapy. As both a preventive and treatment strategy, exercise offers various health benefits for several conditions. Exercise interventions to people with substance use disorders receiving opioid agonist therapy are limited. This study aims to explore experiences with physical activity, perceived barriers, and facilitators among people receiving opioid agonist therapy. METHOD: Fourteen qualitative interviews were conducted with individuals receiving opioid agonist therapy in outpatient clinics in Western Norway. RESULTS: Most were males in the age range 30 to 60 years. Participants had diverse and long-term substance use histories, and most received buprenorphine-based opioid agonist therapy. The identified themes were (1) Physical limitations: Participants experienced health-related problems like breathing difficulties, pain, and reduced physical function. (2) Social dynamics: Social support was essential for participating in physical activities and many argued for group exercises, but some were concerned about the possibility of meeting persons influenced by substances in a group setting, fearing temptations to use substances. (3) Shift in focus: As participants felt the weight of the health burden, their preference for activities shifted from sports aiming for "adrenaline" to a health promoting focus. (4) COVID-19's impact on exercise: because of the pandemic, group activities were suspended, and participants described it as challenging to resume. (5) Implementation preferences in clinics: Not interfering with opioid medication routines was reported to be essential. CONCLUSION: This study offers valuable insights for the development of customized exercise interventions aimed at enhancing the health and well-being of patients undergoing opioid agonist therapy. These findings underscore the significance of addressing social dynamics, overcoming physical limitations, and implementing a practical and effective exercise regimen.

Abnormal Morphology and Synaptogenic Signaling in Astrocytes Following Prenatal Opioid Exposure.

In recent decades, there has been a dramatic rise in the rates of children being born after in utero exposure to drugs of abuse, particularly opioids. Opioids have been shown to have detrimental effects on neurons and glia in the central nervous system (CNS), but the impact of prenatal opioid exposure (POE) on still-developing synaptic circuitry is largely unknown. Astrocytes exert a powerful influence on synaptic development, secreting factors to either promote or inhibit synapse formation and neuronal maturation in the developing CNS. Here, we investigated the effects of the partial µ-opioid receptor agonist buprenorphine on astrocyte synaptogenic signaling and morphological development in cortical cell culture. Acute buprenorphine treatment had no effect on the excitatory synapse number in astrocyte-free neuron cultures. In conditions where neurons shared culture media with astrocytes, buprenorphine attenuated the synaptogenic capabilities of astrocyte-secreted factors. Neurons cultured from drug-naïve mice showed no change in synapses when treated with factors secreted by astrocytes from POE mice. However, this same treatment was synaptogenic when applied to neurons from POE mice, indicating a complex neuroadaptive response in the event of impaired astrocyte signaling. In addition to promoting morphological and connectivity changes in neurons, POE exerted a strong influence on astrocyte development, disrupting their structural maturation and promoting the accumulation of lipid droplets (LDs), suggestive of a maladaptive stress response in the developing CNS.

Managing emergency department patients with opioid use disorder.

As the United States continues to grapple with the opioid crisis, emergency clinicians are on the front lines of managing patients with opioid use disorder. This issue reviews tools and best practices in emergency department management of patients with opioid overdose and opioid withdrawal, and how substance use history will inform treatment planning and disposition. As growing evidence shows that medications for opioid use disorder (MOUD)- buprenorphine, methadone, and naltrexone-can have lasting impacts on patients' addiction recovery, strategies for assessing patient readiness for MOUD and overcoming barriers to emergency department initiation of these medications are reviewed. Newer approaches to buprenorphine dosing (high-dose, low-dose, home induction, and long-acting injectable dosing) are also reviewed.

Buprenorphine Prescribing and Challenges Faced Among National Health Service Corps Clinicians.

Importance: The National Health Service Corps (NHSC) Loan Repayment Program (LRP) expansion in fiscal year (FY) 2019 intended to improve access to medication for opioid use disorder (MOUD) by adding more clinicians who could prescribe buprenorphine. However, some clinicians still face barriers to prescribing, which may vary between rural and nonrural areas. Objective: To examine the growth in buprenorphine prescribing by NHSC clinicians for Medicaid beneficiaries during the NHSC LRP expansion and describe the challenges to prescribing that persist in rural and nonrural areas. Design, Setting, and Participants: This cross-sectional study analyzed preexpansion and postexpansion Medicaid claims data to evaluate the percentage of prescriptions of buprenorphine filled during FY 2017 through 2021. This study also analyzed challenges and barriers to prescribing MOUD between rural and urban areas, using results from annual surveys conducted with NHSC clinicians and sites from FY 2019 through FY 2021. Exposure: Prescribing of buprenorphine by NHSC clinicians. Main Outcomes and Measures: The main outcomes were the percentage and number of Medicaid beneficiaries with opioid use disorder (OUD) who filled a prescription for buprenorphine before and after the LRP expansion and the challenges NHSC clinicians and sites faced in providing substance use disorder and OUD services. Survey results were analyzed using descriptive statistics. Results: During FYs 2017 through 2021, 7828 NHSC clinicians prescribed buprenorphine (standard LRP: mean [SD] age, 38.1 [8.4] years and 4807 females [78.9%]; expansion LRPs: mean [SD] age, 39.4 [8.1] years and 1307 females [75.0%]). A total of 3297 NHSC clinicians and 4732 NHSC sites responded to at least 1 survey question to the 3 surveys. The overall percentage of Medicaid beneficiaries with OUD who filled a prescription for buprenorphine during the first 2.5 years post expansion increased significantly from 18.9% before to 43.7% after expansion (an increase of 123 422 beneficiaries; P < .001). The percentage more than doubled among beneficiaries living in areas with a high Social Vulnerability Index score (from 17.0% to 36.7%; an increase of 31 964) and among beneficiaries living in rural areas (from 20.8% to 55.7%; an increase of 45 523). However, 773 of 2140 clinicians (36.1%; 95% CI, 33.6%-38.6%) reported a lack of mental health services to complement medication for OUD treatment, and 290 of 1032 clinicians (28.1%; 95% CI, 24.7%-31.7%) reported that they did not prescribe buprenorphine due to a lack of supervision, mentorship, or peer consultation. Conclusions and Relevance: These findings suggest that although the X-waiver requirement has been removed and Substance Abuse and Mental Health Services Administration guidelines encourage all eligible clinicians to screen and offer patients with OUD buprenorphine, as permissible by state law, more trained health care workers and improved care coordination for counseling and referral services are needed to support comprehensive OUD treatment.

Barriers to Buprenorphine Dispensing by Medicaid-Participating Community Retail Pharmacies.

Importance: Controlled substances have regulatory requirements under the US Federal Controlled Substance Act that must be met before pharmacies can stock and dispense them. However, emerging evidence suggests there are pharmacy-level barriers in access to buprenorphine for treatment for opioid use disorder even among pharmacies that dispense other opioids. Objective: To estimate the proportion of Medicaid-participating community retail pharmacies that dispense buprenorphine, out of Medicaid-participating community retail pharmacies that dispense other opioids and assess if the proportion dispensing buprenorphine varies by Medicaid patient volume or rural-urban location. Design, Setting, and Participants: This serial cross-sectional study included Medicaid pharmacy claims (2016-2019) data from 6 states (Kentucky, Maine, North Carolina, Pennsylvania, Virginia, West Virginia) participating in the Medicaid Outcomes Distributed Research Network (MODRN). Community retail pharmacies serving Medicaid-enrolled patients were included, mail-order pharmacies were excluded. Analyses were conducted from September 2022 to August 2023. Main Outcomes and Measures: The proportion of pharmacies dispensing buprenorphine approved for opioid use disorder among pharmacies dispensing an opioid analgesic or buprenorphine prescription to at least 1 Medicaid enrollee in each state. Pharmacies were categorized by median Medicaid patient volume (by state and year) and rurality (urban vs rural location according to zip code). Results: In 2016, 72.0% (95% CI, 70.9%-73.0%) of the 7038 pharmacies that dispensed opioids also dispensed buprenorphine to Medicaid enrollees, increasing to 80.4% (95% CI, 79.5%-81.3%) of 7437 pharmacies in 2019. States varied in the percent of pharmacies dispensing buprenorphine in Medicaid (range, 73.8%-96.4%), with significant differences between several states found in 2019 (χ2 P < .05), when states were most similar in the percent of pharmacies dispensing buprenorphine. A lower percent of pharmacies with Medicaid patient volume below the median dispensed buprenorphine (69.1% vs 91.7% in 2019), compared with pharmacies with above-median patient volume (χ2 P < .001). Conclusions and Relevance: In this serial cross-sectional study of Medicaid-participating pharmacies, buprenorphine was not accessible in up to 20% of community retail pharmacies, presenting pharmacy-level barriers to patients with Medicaid seeking buprenorphine treatment. That some pharmacies dispensed opioid analgesics but not buprenorphine suggests that factors other than compliance with the Controlled Substance Act influence pharmacy dispensing decisions.

Changes in Buprenorphine Prescribing in Community Health Centers.

This cohort study characterizes changes in buprenorphine prescribing among community health center clinicians between 2016 and 2021.

Impact of jail-based methadone or buprenorphine treatment on non-fatal opioid overdose after incarceration.

BACKGROUND: Non-fatal overdose is a leading predictor of subsequent fatal overdose. For individuals who are incarcerated, the risk of experiencing an overdose is highest when transitioning from a correctional setting to the community. We assessed if enrollment in jail-based medications for opioid use disorder (MOUD) is associated with lower risk of non-fatal opioid overdoses after jail release among individuals with opioid use disorder (OUD). METHODS: This was a retrospective, observational cohort study of adults with OUD who were incarcerated in New York City jails and received MOUD or did not receive any MOUD (out-of-treatment) within the last three days before release to the community in 2011-2017. The outcome was the first non-fatal opioid overdose emergency department (ED) visit within 1 year of jail release during 2011-2017. Covariates included demographic, clinical, incarceration-related, and other characteristics. We performed multivariable cause-specific Cox proportional hazards regression analysis to compare the risk of non-fatal opioid overdose ED visits within 1 year after jail release between groups. RESULTS: MOUD group included 8660 individuals with 17,119 incarcerations; out-of-treatment group included 10,163 individuals with 14,263 incarcerations. Controlling for covariates and accounting for competing risks, in-jail MOUD was associated with lower non-fatal opioid overdose risk within 14 days after jail release (adjusted HR=0.49, 95% confidence interval=0.33-0.74). We found no significant differences 15-28, 29-56, or 57-365 days post-release. CONCLUSION: MOUD group had lower risk of non-fatal opioid overdose immediately after jail release. Wider implementation of MOUD in US jails could potentially reduce post-release overdoses, ED utilization, and associated healthcare costs.

Growing importance of high-volume buprenorphine prescribers in OUD treatment: 2009-2018.

BACKGROUND: We examined the number and characteristics of high-volume buprenorphine prescribers and the nature of their buprenorphine prescribing from 2009 to 2018. METHODS: In this observational cohort study, IQVIA Real World retail pharmacy claims data were used to characterize trends in high-volume buprenorphine prescribers (clinicians with a mean of 30 or more active patients in every month that they were an active prescriber) during 2009-2018. Very high-volume prescribing (mean of 100+ patients per month) was also examined. RESULTS: Overall, 94,491 clinicians prescribed buprenorphine dispensed during 2009-2018. The proportion of active prescribers meeting high-volume criteria increased from 7.4 % in 2009 to 16.7 % in 2018. High-volume prescribers accounted for 80 % of dispensed buprenorphine prescriptions during 2009-2018; very high-volume prescribers accounted for 26 %. Adult primary care physicians consistently comprised the majority of high-volume prescribers. Addiction specialists were much more likely to be high-volume prescribers compared to other specialties, including psychiatrists and pain specialists. By 2018, the proportion of prescriptions from high-volume prescribers paid by Medicaid had doubled to 40 %, accompanied by a decline in both self-pay and commercial insurance. High-volume prescribers were overwhelmingly concentrated in urban counties with the highest fatal overdose rates. In 2018, the highest density of high-volume prescribers was in New England and the mid-Atlantic region. CONCLUSIONS: Growth in high-volume prescribers outpaced the overall growth in buprenorphine prescribers across 2009-2018. High-volume prescribers play an increasingly central role in providing medication for OUD in the U.S., yet results indicate key regional variation in the availability of high-volume buprenorphine prescribers.

LatinX harm reduction capital, medication for opioid use disorder, and nonfatal overdose: A structural equation model analysis among people who use drugs in Massachusetts.

BACKGROUND: We introduce the concept of harm reduction capital (HRCap) as the combination of knowledge, resources, and skills related to substance use risk reduction, which we hypothesize to predict MOUD use and opioid overdose. In this study, we explored the interrelationships between ethnicity, HRCap, nonfatal overdose, and MOUD use among PWUD. METHODS: Between 2017 and 2019, people who currently or in the past used opioids and who lived in Massachusetts completed a one-time survey on substance use history, treatment experiences, and use of harm reduction services. We fit first-order measurement constructs for positive and negative HRCap (facilitators and barriers). We used generalized structural equation models to examine the inter-relationships of the latent constructs with LatinX self-identification, past year overdose, and current use of MOUD. RESULTS: HRCap barriers were positively associated with past-year overdose (b=2.6, p<0.05), and LatinX self-identification was inversely associated with HRCap facilitators (b=-0.49, p<0.05). There was no association between overdose in the past year and the current use of MOUD. LatinX self-identification was positively associated with last year methadone treatment (b=0.89, p<0.05) but negatively associated with last year buprenorphine treatment (b=-0.68, p<0.07). Latinx PWUD reported lower positive HRCap than white non-LatinX PWUD and had differential utilization of MOUD. CONCLUSION: Our findings indicate that a recent overdose was not associated with the current use of MOUD, highlighting a severe gap in treatment utilization among individuals at the highest risk. The concept of HRCap and its use in the model highlight substance use treatment differences, opportunities for intervention, and empowerment.

Concomitant use of pre-emptive analgesia with local and general anesthesia in rat uterine pain surgical model.

Preemptive analgesia is used for postoperative pain management, providing pain relief with few adverse effects. In this study, the effect of a preemptive regime on rat behavior and c-fos expression in the spinal cord of the uterine surgical pain model was evaluated. It was a lab-based experimental study in which 60 female Sprague-Dawley rats; eight to 10 weeks old, weighing 150-300 gm were used. The rats were divided into two main groups: (i) superficial pain group (SG) (with skin incision only), (ii) deep pain group (with skin and uterine incisions). Each group was further divided into three subgroups based on the type of preemptive analgesia administered i.e., "tramadol, buprenorphine, and saline subgroups." Pain behavior was evaluated using the "Rat Grimace Scale" (RGS) at 2, 4, 6, 9 and 24 h post-surgery. Additionally, c-fos immunohistochemistry was performed on sections from spinal dorsal horn (T12-L2), and its expression was evaluated using optical density and mean cell count 2 hours postoperatively. Significant reduction in the RGS was noted in both the superficial and deep pain groups within the tramadol and buprenorphine subgroups when compared to the saline subgroup (p ≤ .05). There was a significant decrease in c-fos expression both in terms of number of c-fos positive cells and the optical density across the superficial laminae and lamina X of the spinal dorsal horn in both SD and DG (p ≤ .05). In contrast, the saline group exhibited c-fos expression primarily in laminae I-II and III-IV for both superficial and deep pain groups and lamina X in the deep pain group only (p ≤ .05). Hence, a preemptive regimen results in significant suppression of both superficial and deep components of pain transmission. These findings provide compelling evidence of the analgesic efficacy of preemptive treatment in alleviating pain response associated with uterine surgery.

Extended-release versus oral buprenorphine as opioid maintenance treatment during pregnancy-maternal and neonatal outcomes.

OBJECTIVE: To get information on subcutaneous extended-release buprenorphine as opioid maintenance treatment during pregnancy, we compared it to orally administered buprenorphine and buprenorphine-naloxone treatments. We hypothesized that maternal and neonatal outcomes do not differ between the treatment groups. Study design In this population-based cohort study, 60 pregnant individuals receiving non-changed opioid maintenance treatment for opioid use disorder with a buprenorphine product from the time before conception to the time after delivery and their newborns were included. They were divided into three groups based on the pharmacotherapy with subcutaneous extended-release buprenorphine, sublingual buprenorphine, or buprenorphine-naloxone. Statistical analyses were conducted using Fischer's exact tests, ANOVA tests, and Kruskal-Wallis tests. All the statistical tests were two-tailed. RESULTS: The frequency of pregnancy or delivery complications did not significantly differ between the group receiving extended-release buprenorphine and the other groups. During pregnancy, 38 % of the women used illicit drugs concomitantly, with equal frequency in the extended-release buprenorphine group and the other groups. Of the neonates, 93 % were born full-term and 90 % got at least eight Apgar points in one minute age, without significant differences between the groups (p = 0.57). The need for pharmacotherapy for neonatal opioid withdrawal syndrome was the lowest in the extended-release buprenorphine group (25 %) and highest in the sublingual buprenorphine group (67 %). Still, the difference between the treatment groups did not reach statistical significance (p = 0.17). Among all neonates, the breastfed infants were less likely to receive pharmacotherapy for withdrawal symptoms than the formula-fed ones (p = 0.048). CONCLUSIONS: Extended-release buprenorphine with steady drug concentration seems to be a promising pharmacotherapy option during pregnancy for mothers. Maternal health during pregnancy may contribute to the well-being of newborns. Larger trials are urgently needed to confirm these results..

High-Dose Buprenorphine Initiation in the Management of Opioid Use Disorder in Pregnancy.

Buprenorphine is commonly used as a treatment for opioid use disorder (OUD). Transition to buprenorphine traditionally has been done using a low-dose initiation regimen due to concerns surrounding precipitated withdrawal. There are increasing data supporting use of a high-dose initiation regimen in the nonpregnant population. This retrospective case series describes six individuals with OUD who underwent high-dose buprenorphine initiation in pregnancy. There were no instances of sedation, respiratory depression, supplemental oxygen use, or death. All individuals were successfully transitioned to buprenorphine. These findings provide support for high-dose buprenorphine initiation in pregnancy, but future large studies are needed.

Barriers and facilitators for family physicians prescribing opioid agonist therapy in Saskatchewan.

OBJECTIVE: To explore barriers and facilitators for family physicians in Saskatchewan prescribing opioid agonist therapy (OAT). DESIGN: Self-administered postal survey. SETTING: Family medicine practices in Saskatchewan. PARTICIPANTS: A total of 218 Saskatchewan family physicians who were not authorized to prescribe OAT as of June 2022. MAIN OUTCOME MEASURES: Descriptive and inferential statistics of physicians' self-reported barriers to and facilitators of prescribing OAT for opioid use disorder (OUD). RESULTS: Most respondents (84.8%) had some comfort with diagnosing OUD. However, more than half (58.3%) did not feel confident or knowledgeable about prescribing OAT. Barriers to OAT prescribing included lack of time, incomplete training requirements, lack of interest, insufficient funding or support, feeling overwhelmed, and perceiving that OAT does not work and thus is not necessary. Physicians working in core neighbourhoods and those receiving fee-for-service compensation reported the least available time to prescribe OAT. Conversely, physicians working in interdisciplinary team settings had increased time for OAT prescribing compared with physicians in other settings. Having a close personal relationship with someone with OUD was correlated with increased comfort in diagnosing OUD as well as with knowledge about and confidence in prescribing OAT. Themes identified as facilitators to increasing OAT prescribing included the addition of resources and supports, increased training, more awareness about OUD and OAT, enhanced compensation, and altered prescribing regulations. CONCLUSION: Despite the presence of several real and perceived barriers limiting OAT prescribing by Saskatchewan family physicians, there are family physicians interested in providing this therapy. Increased clinical resources and support, including increased interdisciplinary practice, are actionable steps that should be considered by policy decision makers to address this issue. Additionally, increased OUD and OAT education, which includes the perspectives of those with lived experience of OUD, would help address physician confidence, knowledge, and awareness in this area.

Mediating effect of craving on the impact of buprenorphine/naloxone and methadone treatment on opioid use: Results from a randomized controlled trial.

BACKGROUND: The relationship between opioid craving and opioid use is unclear. We sought to determine to what extent craving mediated the relationship between opioid agonist therapy and changes in opioid use. METHODS: Data came from a pragmatic, 24-week, pan-Canadian, multi-centric, open-label, randomized controlled trial comparing flexible buprenorphine/naloxone take-home doses to standard supervised methadone models of care for the treatment of prescription-type opioid use disorder. Participants were randomly allocated to buprenorphine/naloxone or methadone models of care. 270 people with prescription-type opioid use disorder were included in analyses. There were 93 women (34.4%) and 2 transgender (0.7%) participants. Most participants were white (67.4%), 45.9% reported unstable living conditions, and 44.8% had psychiatric comorbidities. Generalized linear mixed models followed by mediation analysis estimated the direct effect of treatment group on Timeline Followback-reported next-week opioid use and the indirect effect through past 24-hour opioid craving measured using the Brief Substance Craving Scale at week 2, 6, 10, 14, 18 and 22. RESULTS: Upon mediation analysis, the average direct effect of treatment on opioid use was 0.465 (95 % CI = 0.183 to 0.751, p < 0.001). The average causal mediated effect was 0.144 (95 % CI = 0.021 to 0.110; p < 0.001). Craving accounted for 23.6 % of the effect of treatment on opioid use (p < 0.001). CONCLUSIONS: Past 24-hour craving was associated with increased next-week opioid use; however, craving only partially mediated the effect of buprenorphine/naloxone and methadone on next-week opioid use. Research is needed to develop a comprehensive understanding of factors mediating opioid use during opioid agonist therapy.

Withdrawal during outpatient low dose buprenorphine initiation in people who use fentanyl: a retrospective cohort study.

BACKGROUND: Buprenorphine is an effective treatment for opioid use disorder (OUD); however, buprenorphine initiation can be complicated by withdrawal symptoms including precipitated withdrawal. There has been increasing interest in using low dose initiation (LDI) strategies to reduce this withdrawal risk. As there are limited data on withdrawal symptoms during LDI, we characterize withdrawal symptoms in people with daily fentanyl use who underwent initiation using these strategies as outpatients. METHODS: We conducted a retrospective chart review of patients with OUD using daily fentanyl who were prescribed 7-day or 4-day LDI at 2 substance use disorder treatment clinics in San Francisco. Two addiction medicine experts assessed extracted chart documentation for withdrawal severity and precipitated withdrawal, defined as acute worsening of withdrawal symptoms immediately after taking buprenorphine. A third expert adjudicated disagreements. Data were analyzed using descriptive statistics. RESULTS: There were 175 initiations in 126 patients. The mean age was 37 (SD 10 years). 71% were men, 26% women, and 2% non-binary. 21% identified as Black, 16% Latine, and 52% white. 60% were unstably housed and 75% had Medicaid insurance. Substance co-use included 74% who used amphetamines, 29% cocaine, 22% benzodiazepines, and 19% alcohol. Follow up was available for 118 (67%) initiations. There was deviation from protocol instructions in 22% of these initiations with follow up. 31% had any withdrawal, including 21% with mild symptoms, 8% moderate and 2% severe. Precipitated withdrawal occurred in 10 cases, or 8% of initiations with follow up. Of these, 7 had deviation from protocol instructions; thus, there were 3 cases with follow up (3%) in which precipitated withdrawal occurred without protocol deviation. CONCLUSIONS: Withdrawal was relatively common in our cohort but was mostly mild, and precipitated withdrawal was rare. Deviation from instructions, structural barriers, and varying fentanyl use characteristics may contribute to withdrawal. Clinicians should counsel patients who use fentanyl that mild withdrawal symptoms are likely during LDI, and there is still a low risk for precipitated withdrawal. Future studies should compare withdrawal across initiation types, seek ways to support patients in initiating buprenorphine, and qualitatively elicit patients' withdrawal experiences.