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.

Providing medication for opioid use disorder and HIV pre-exposure prophylaxis at syringe services programs via telemedicine: a pilot study.

BACKGROUND: People who inject drugs (PWID) are at high risk for opioid overdose and infectious diseases including HIV. We piloted PARTNER UP, a telemedicine-based program to provide PWID with medication for opioid use disorder (MOUD) with buprenorphine/naloxone (bup/nx) and oral pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate/emtricitabine through two syringe services programs (SSP) in North Carolina. We present overall results from this project, including participant retention rates and self-reported medication adherence. METHODS: Study participants met with a provider for an initial in-person visit at the SSP, followed by weekly telemedicine visits in month 1 and then monthly until program end at month 6. Participants were asked to start both MOUD and PrEP at initiation but could choose to discontinue either at any point during the study. Demographics and health history including substance use, sexual behaviors, and prior use of MOUD/PrEP were collected at baseline. Follow-up surveys were conducted at 3- and 6-months to assess attitudes towards MOUD and PrEP, change in opioid use and sexual behaviors, and for self-reported medication adherence. Participant retention was measured by completion of visits; provider notes were used to assess whether the participant reported continuation of medication. RESULTS: Overall, 17 persons were enrolled and started on both bup/nx and PrEP; the majority self-identified as white and male. At 3 months, 13 (76%) remained on study; 10 (77%) reported continuing with both MOUD and PrEP, 2 (15%) with bup/nx only, and 1 (8%) with PrEP only. At 6 months, 12 (71%) remained on study; 8 (67%) reported taking both bup/nx and PrEP, and 4 (33%) bup/nx only. Among survey participants, opioid use and HIV risk behaviors decreased. Nearly all reported taking bup/nx daily; however, self-reported daily adherence to PrEP was lower and declined over time. The most common reason for not continuing PrEP was feeling not at risk for acquiring HIV. CONCLUSIONS: Our study results show that MOUD and PrEP can be successfully administered via telemedicine in SSPs. PrEP appears to be a lower priority for participants with decreased continuation and adherence. Low perception of HIV risk was a reason for not continuing PrEP, possibly mitigated by MOUD use. Future studies including helping identify PWID at highest need for PrEP are needed. TRIAL REGISTRATION: Providing Suboxone and PrEP Using Telemedicine, NCT04521920. Registered 18 August 2020. https://clinicaltrials.gov/study/NCT04521920?term=mehri%20mckellar&rank=2 .

Factors associated with frequent buprenorphine / naloxone initiation in a national survey of Canadian emergency physicians.

OBJECTIVE: To identify individual and site-related factors associated with frequent emergency department (ED) buprenorphine/naloxone (BUP) initiation. BUP initiation, an effective opioid use disorder (OUD) intervention, varies widely across Canadian EDs. METHODS: We surveyed emergency physicians in 6 Canadian provinces from 2018 to 2019 using bilingual paper and web-based questionnaires. Survey domains included BUP-related practice, demographics, attitudes toward BUP, and site characteristics. We defined frequent BUP initiation (the primary outcome) as at least once per month, high OUD prevalence as at least one OUD patient per shift, and high OUD resources as at least 3 out of the following 5 resources: BUP initiation pathways, BUP in ED, peer navigators, accessible addiction specialists, and accessible follow-up clinics. We excluded responses from sites with <50% participation (to minimize non-responder bias) and those missing the primary outcome. We used univariate analysis to identify associations between frequent BUP initiation and factors of interest, stratifying by OUD prevalence. RESULTS: We excluded 3 responses for missing BUP initiation frequency and 9 for low response rate at one ED. Of the remaining 649 respondents from 34 EDs, 374 (58%) practiced in metropolitan areas, 384 (59%) reported high OUD prevalence, 312 (48%) had high OUD resources, and 161 (25%) initiated BUP frequently. Age, gender, board certification and years in practice were not associated with frequent BUP initiation. Site-specific factors were associated with frequent BUP initiation (high OUD resources [OR 6.91], high OUD prevalence [OR 4.45], and metropolitan location [OR 2.39],) as were individual attitudinal factors (willingness, confidence, and responsibility to initiate BUP.) Similar associations persisted in the high OUD prevalence subgroup. CONCLUSIONS: Individual attitudinal and site-specific factors were associated with frequent BUP initiation. Training to increase physician confidence and increasing OUD resources could increase BUP initiation and benefit ED patients with OUD.

Mobile Medication Adherence Platform for Buprenorphine (MAP4BUP): A Phase I feasibility, usability and efficacy pilot randomized clinical trial.

BACKGROUND/AIM: Poor medication adherence is one of the main barriers to the long-term efficacy of buprenorphine/naloxone (BUP/NAL). The aims of this pilot investigation were to examine if a Bluetooth-enabled pill cap and mobile application is a feasible, usable tool for increasing BUP/NAL adherence among people with an opioid use disorder. METHODS: This pilot randomized clinical trial (RCT; total n = 41) lasted 12 weeks and was conducted in two office-based BUP/NAL provider locations in Spokane, WA and Coeur d'Alene, ID from January 2020 to September of 2021 with an 11-month gap due to COVID-19. Patients receiving BUP/NAL who consented to participate were randomized to receive the pill cap device (PLY group; n = 19) or a service as usual (SAU group; n = 22) group that included an identical but inactive cap for their bottle. The PLY group received reminders via text and voice, and the support of a "helper" (e.g., friend) to monitor pill cap openings. RESULTS: Most participants in PLY group found the device both feasible (92.86 %) and usable (78.57 %). Most participants liked using the device (92.86 %) and were satisfied with the device (85.71 %). While not statistically different from one another, medication adherence per the Medication Possession Ratio was 75 % in the SAU group and 84 % in the PLY group. Pill cap openings were significantly higher in the PLY group with an average of 91.8 openings versus the SAU group's average of 56.7 (p < 0.05). CONCLUSION: The devices was feasible, usable, and patients had high levels of satisfaction. The device was associated with increased pill openings.

Associations of Methadone and BUP/NX Dose Titration Patterns With Retention in Treatment and Opioid Use in Individuals With Prescription-Type Opioid Use Disorder: Secondary Analysis of the OPTIMA Study.

INTRODUCTION: Methadone and buprenorphine/naloxone (BUP/NX) titration parameters (eg, range, duration, and rate) can vary during opioid use disorder (OUD) treatment. We describe methadone and BUP/NX titration patterns and their associations with treatment outcomes among individuals with a prescription-type OUD. METHODS: We used data from a 24-week open-label, multicenter randomized controlled trial, including N = 167 participants aged 18-64 years old with prescription-type OUD who received at least a first dose of treatment. Descriptive analyses of methadone and BUP/NX titration patterns were conducted, that is, range and duration from first to maximum dose, and rate (range/duration ratio). Outcomes included percentage of opioid-positive urine drug screens (UDS) and treatment retention. Adjusted linear and logistic regressions were used to study associations between titration patterns and percentage of opioid-positive UDS and treatment retention. RESULTS: Methadone doses were increased by a mean dose range of 42.4 mg over a mean duration of 42.2 days. BUP/NX doses were increased by a mean dose range of 8.4 mg over a mean duration of 28.7 days. Only methadone dose titration range (odds ratio: 1.03; 95% CI, 1.01 to 1.05) and duration (odds ratio: 1.03; 95% CI, 1.01 to 1.05) were associated with higher retention. Only methadone dose titration rate was associated with lower percentage of opioid-positive UDS at weeks 12-24 ( B : -2.77; 95% CI, -4.72 to -0.81). CONCLUSIONS: Specific parameters of methadone titration were associated with treatment outcomes and may help in personalizing treatment schedules. Sustained methadone dose titration, when indicated, may help increase retention, whereas faster dose titration for methadone may help decrease opioid use.

There goes the neighborhood? The public safety enhancing effects of a mobile harm reduction intervention.

BACKGROUND: Buprenorphine is a gold-standard treatment for opioid use disorders, but most people with these disorders do not access it. Barriers to treatment access may be diminished by low-threshold mobile treatment programs but concern regarding their impact on local public safety challenges their adoption. METHODS: This quasi-experimental study uses difference-in-differences analyses to measure the impact of four mobile buprenorphine clinics in Pittsburgh on neighborhood arrest rates. The study period spans 2018 to 2022, with a pre-intervention period of 11 to 12 quarters and a post-intervention period of 7 to 8 quarters (dependent on neighborhood). A treatment group of 84 census block groups in the areas surrounding clinics during the time period after their establishment were compared to a control group of city census blocks not within one mile of a clinic plus treated block groups in the two years prior to clinic establishment. Outcome variables include drug, non-drug, and total arrests, measured quarterly per 100 in population. RESULTS: Compared to block groups further than 1 mile from a clinic, arrests fell by 34.13 % (b = -0.358, 95 % CI = -0.557, -0.158), drug arrests by 33.85 % (b = -0.087, 95 % CI = -0.151, -0.023), and non-drug related arrests by 22.29 % (b = -0.179, 95 % CI = -0.302, -0.057). Drug arrests declined significantly on days when the clinics were not present (b = -0.015, 95 % CI = -0.025, -0.006), with no significant change on clinic operational days (b = -0.002, 95 % CI = -0.016, -0.013). Total arrests declined significantly on days when clinics were and were not present (b = -0.045, 95 % CI = -0.078, -0.012; and b = -0.052, CI = -0.082, -0.023, respectively). CONCLUSIONS: Mobile clinics providing medication for opioid use disorders were associated with reduced neighborhood arrest rates. Expansion of mobile services could promote health equity and public safety.

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.

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).

Pharmacogenetics of Biochemically Verified Abstinence in an Opioid Agonist Therapy Randomized Clinical Trial of Methadone and Buprenorphine/Naloxone.

Methadone and buprenorphine/naloxone are opioid agonist therapies for opioid use disorder treatment. Genetic factors contribute to individual differences in opioid response; however, little is known regarding genetic associations with clinical outcomes in people receiving opioid agonist therapies. Participants diagnosed with opioid use disorder, principally consisting of prescription opioids (licit or illicit), were randomized to methadone or buprenorphine/naloxone for 24 weeks of daily treatment (NCT03033732). Urine was collected at 12 biweekly study visits and analyzed for non-treatment opioids. Variants in genes involved in methadone metabolism (CYP2B6, CYP2C19, and CYP3A4), buprenorphine metabolism (CYP3A4 and UGT2B7), and µ-opioid receptor function (OPRM1) were genotyped and analyzed for their association with the number of non-treatment opioid-free urine screens. Primary analyses focused on the last 12 weeks (6 study visits, post-titration) of treatment among those reporting White ethnicity. Additional sensitivity and exploratory analyses were performed. Among methadone-treated participants (n = 52), the OPRM1 rs1799971 AA genotype (vs. G-genotypes, i.e., having one or two G alleles) was associated with greater opioid-free urine screens (incidence rate ratio = 5.24, 95% confidence interval (CI) = 2.43-11.26, P = 0.000023); longitudinal analyses showed a significant genotype-by-time interaction over the full 24 weeks (12 study visits, ß = -0.28, 95% CI = -0.45 to -0.11, P = 0.0015). Exploratory analyses suggest an OPRM1 rs1799971 genotype effect on retention. No evidence of association was found between other genetic variants, including in metabolic variants, and non-treatment opioid-free urine screens in the methadone or buprenorphine/naloxone arms. Those with the OPRM1 rs1799971 G-genotypes may have a poorer response to methadone maintenance treatment, an effect that persisted through 24 weeks of treatment.

Buprenorphine-Naloxone Maintenance and Lactation.

BACKGROUND: Breastfeeding among lactating people with opioid use disorder taking buprenorphine monotherapy is generally accepted, as low concentrations of buprenorphine and metabolites in human milk have been well-established. The use of buprenorphine-naloxone for pregnant and lactating people with opioid use disorder is expanding and there is no information available regarding the concentrations of naloxone and their metabolites in human milk to recommend the use of this combination medication during lactation. RESEARCH AIMS: To determine the concentrations of buprenorphine and naloxone and their primary metabolites in human milk, maternal plasma, and infant plasma, among lactating buprenorphine-naloxone maintained people and their infants. METHODS: Four lactating buprenorphine-naloxone maintained people provided plasma and human milk samples on Days 2, 3, 4, 14, and 30 postpartum. Infant plasma was obtained on Day 14. RESULTS: Concentrations of buprenorphine, norbuprenorphine and their glucuronide metabolites were present in maternal plasma and human milk at low concentrations, consistent with previous research in lactating buprenorphine monotherapy participants. Naloxone was not detected, or was detected at concentrations below the limit of quantification, in maternal plasma and in all except one human milk sample at Day 30. Naloxone was not detected or detected at concentrations below the limit of quantification in all infant plasma samples. CONCLUSION: Results support the use of buprenorphine-naloxone by lactating people who meet appropriate criteria for breastfeeding.

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.

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.

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

INTRODUCTION: In clinical practice, sublingual (SL) buprenorphine-naloxone is prescribed as once daily or split daily dosing for the management of opioid use disorder (OUD). Evidence is lacking that assesses how split daily buprenorphine-naloxone affects OUD outcomes. This study aims to evaluate how the dosing frequency of SL buprenorphine-naloxone impacts therapy effectiveness when treating patients with OUD. METHODS: This retrospective analysis included adult outpatients prescribed treatment with SL buprenorphine-naloxone for OUD between July 1, 2016, and March 1, 2020. The study excluded patients with sickle cell disease, recent methadone treatment, or pregnancy. We characterized study groups by dosing frequency, either once daily or split dosing. The study compared retention in treatment, medication adherence, adherence to treatment program, and hospital encounters between groups. RESULTS: The study screened eight-hundred and seven patients, and included 250 patients newly prescribed SL buprenorphine-naloxone. Fifty-seven patients (22.8 %) were prescribed once daily dosing and 193 patients (77.2 %) were prescribed split daily dosing. The study found no significant differences noted in 12-month rates of treatment retention (52.6 % vs. 45.6 %, p = .35). These outcomes remained similar when assessed at three and six months. Within a year of buprenorphine-naloxone initiation, the study found no differences in the percentage of patients with hospitalizations (26.3 % vs. 38.3 %, p = .10), median number of hospitalizations (2 vs. 2), or proportion of days covered by a prescription ≥80 % (93.3 % vs. 92.0 %, p = .82). CONCLUSIONS: In this study, patients receiving once daily buprenorphine-naloxone had similar treatment outcomes to patients receiving split dosing. Further controlled studies are necessary to evaluate which patients are more likely to benefit from split dosing.

Nonprescription use of buprenorphine tablets among patients at a tertiary care addictive disorder treatment center in India: Observa-tions and implications.

OBJECTIVE: Nonprescribed use of drugs is a clinical and public health challenge fueled by diversion of controlled opioids like buprenorphine. In this study, we report the nonprescription use of buprenorphine and buprenorphine-naloxone for the first time in India. DESIGN: A cross-sectional observational study utilizing semistructured interviews. SETTING: A tertiary care addictive disorder treatment center in India, which provides inpatient and outpatient medically oriented care that includes agonist treatment (buprenorphine) or detoxification and antagonist treatment (naltrexone). PARTICIPANTS: Patients aged 18-65 years, registered at the center, and who had a history of current (within the past 6 months) nonprescription use of buprenorphine tablets were recruited. MAIN OUTCOME MEASURES: Participants were questioned about demographic and clinical factors and details of nonprescription use of buprenorphine and buprenorphine-naloxone using a structured questionnaire. Since both buprenorphine with naloxone and buprenorphine without naloxone are available and transacted on the street "loose" out of the blister packs, we were unable to differentiate the use of plain buprenorphine and a combination of buprenorphine- naloxone. RESULTS: A majority of the participants used nonprescribed tablets buprenorphine and buprenorphine-naloxone with an intent to control the withdrawal symptoms, and the reason for this use was that other patients shared their prescriptions of these medications. About half of the participants injected the tablets, and liquid pheniramine was most commonly used as the solvent for dissolving the tablets. A "high" was perceived by around half of those who injected. Participants reported knowing, on an average, around 13 peers who injected the tablet buprenorphine or -buprenorphine-naloxone. CONCLUSION: Nonprescription use of tablets buprenorphine and -buprenorphine-naloxone is a clinical concern and also an important public health issue. Geographical and systemic expansions of the availability of buprenorphine may reduce the "demand" for nonprescribed buprenorphine, while the opportunities for diversion from treatment centers can be minimized through more careful clinical prescriptions and monitoring practices.

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.

Decline in Prenatal Buprenorphine/Naloxone Fills during the COVID-19 Pandemic in the United States.

OBJECTIVES: Pregnancy provides a critical opportunity to engage individuals with opioid use disorder in care. However, before the COVID-19 pandemic, there were multiple barriers to accessing buprenorphine/naloxone during pregnancy. Care disruptions during the pandemic may have further exacerbated these existing barriers. To quantify these changes, we examined trends in the number of individuals filling buprenorphine/naloxone prescriptions during the COVID-19 pandemic. METHODS: We estimated an interrupted time series model using linked national pharmacy claims and medical claims data from prepandemic (May 2019 to February 2020) to the pandemic period (April 2020 to December 2020). We estimated changes in the growth rate in the monthly number of individuals filling buprenorphine/naloxone prescriptions in the 6 months preceding a delivery claim, per 100,000 pregnancies, during the COVID-19 pandemic. RESULTS: We identified 2947 pregnant individuals filling buprenorphine/naloxone prescriptions. Before the pandemic, there was positive growth in the monthly number of individuals filling buprenorphine/naloxone prescriptions (4.83%; 95% confidence interval [CI], 3.82-5.84%). During the pandemic, this monthly growth rate declined for both individuals on commercial insurance and individuals on Medicaid (all payers: -5.53% [95% CI, -6.65% to -4.41%]; Medicaid: -7.66% [95% CI, -10.14% to -5.18%]; Commercial: -3.59% [95% CI, -5.32% to -1.87%]). CONCLUSION: The number of pregnant individuals filling buprenorphine/naloxone prescriptions was increasing, but this growth has been lost during the pandemic.

Risk of relapse to non-opioid addictive substances among opioid dependent patients treated with an opioid receptor antagonist or a partial agonist: A randomized clinical trial.

BACKGROUND AND OBJECTIVE: First study to assess any compensatory increase in use of non-opioid illicit substances and alcohol in opioid dependent patients randomized to treatment with extended-release naltrexone (XR-NTX) or buprenorphine-naloxone (BP-NLX) and in longer term treatment with extended-release naltrexone. METHOD: A multicenter, outpatient, open-label randomized clinical trial where patients received intramuscular extended-release naltrexone hydrochloride, 380 mg/month, or daily sublingual buprenorphine-naloxone 8-24/2-6 mg for 12 weeks, and an option to continue with extended-release naltrexone for an additional 36 week follow-up. The study was conducted at five urban addiction clinics and detoxification units in Norway between November 2012, and July 2016. RESULTS: Among the 143 patients, 106 men and 37 women, there were no significant differences between those randomized to XR-NTX or BP-NLX in the risk of first relapse to alcohol (HR 1.31; 0.68-2.53), amphetamines (HR 0.88; 0.43-1.80), benzodiazepines (HR 1.24; 0.74-2.09) or cannabis (HR 1.55; 0.83-2.89). Also in the 36-week (12-48 weeks) follow-up period we found no significant differences between patients continuing with XR-NTX compared to those switching to XR-NTX after the randomized period in risk of first relapse to any non-opioid substance. In both study periods, the mean time in the study were longer among those relapsing to non-opioid addictive substances than those who did not. There was no significant association between first relapse to illicit opioids and first relapse to non-opioid addictive substances. CONCLUSION: There was no increase in the risk of relapse to non-opioid addictive substances neither in short term nor longer-term treatment with extended-release naltrexone. Trial registrationclinicaltrials.gov Identifier: NCT01717963.

Medicare coverage of buprenorphine-naloxone film surrounding generic entry.

OBJECTIVES: To investigate trends in Medicare coverage of buprenorphine-naloxone film before and after the FDA approval of its first generic versions. STUDY DESIGN: This study used data from the Part D Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files from 2015 to 2022, which provide information on all stand-alone Medicare/Medicare Advantage Prescription Drug Plans. METHODS: We examined the percentage of plans that provided coverage of brand-name and generic buprenorphine-naloxone films with strength 8 mg/2 mg during 2015-2022. Median out-of-pocket (OOP) cost for a 30-day supply was estimated among all plans that provided coverage. RESULTS: Generic buprenorphine-naloxone film was covered by 82% of Medicare Part D plans in 2020, 2 years after market entry. Coverage of brand-name Suboxone film decreased from 76% in 2019 to 42% in 2020. The median OOP cost of buprenorphine-naloxone films faced by Medicare enrollees decreased from $99 in 2019 to $42 in 2020, driven by the lower price of generic films. In contrast, the OOP cost for brand-name buprenorphine-naloxone film increased gradually from $85 in 2015 to $100 in 2022. CONCLUSIONS: Medicare Part D plan formularies replaced brand-name buprenorphine-naloxone films with the newly approved generic versions. This was accompanied by a substantial decrease in estimated OOP cost faced by Part D enrollees. These changes could potentially increase access to buprenorphine among Medicare enrollees with opioid use disorder.