Comparative Safety of In Utero Exposure to Buprenorphine Combined With Naloxone vs Buprenorphine Alone.

Importance: Buprenorphine combined with naloxone is commonly used to treat opioid use disorders outside of pregnancy. In pregnancy, buprenorphine alone is generally recommended because of limited perinatal safety data on the combination product. Objective: To compare perinatal outcomes following prenatal exposure to buprenorphine with naloxone vs buprenorphine alone. Design, Settings, and Participants: Population-based cohort study using health care utilization data from Medicaid-insured beneficiaries in the US from 2000 to 2018. The cohort was restricted to pregnant individuals linked to their liveborn infants, with maternal Medicaid enrollment from 3 months before pregnancy to 1 month after delivery and infant enrollment for the first 3 months after birth, unless they died sooner. Exposure: Use of buprenorphine with naloxone vs buprenorphine alone during the first trimester based on outpatient dispensings. Main Outcomes and Measures: Outcomes included major congenital malformations, low birth weight, neonatal abstinence syndrome, neonatal intensive care unit admission, preterm birth, respiratory symptoms, small for gestational age, cesarean delivery, and maternal morbidity. Confounder-adjusted risk ratios were calculated using propensity score overlap weights. Results: This study identified 3369 pregnant individuals exposed to buprenorphine with naloxone during the first trimester (mean [SD] age, 28.8 [4.6] years) and 5326 exposed to buprenorphine alone or who switched from the combination to buprenorphine alone by the end of the first trimester (mean [SD] age, 28.3 [4.5] years). When comparing buprenorphine combined with naloxone with buprenorphine alone, a lower risk for neonatal abstinence syndrome (absolute risk, 37.4% vs 55.8%; weighted relative risk, 0.77 [95% CI, 0.70-0.84]) and a modestly lower risk for neonatal intensive care unit admission (absolute risk, 30.6% vs 34.9%; weighted relative risk, 0.91 [95% CI, 0.85-0.98]) and small for gestational age (absolute risk, 10.0% vs 12.4%; weighted relative risk, 0.86 [95% CI, 0.75-0.98]) was observed. For maternal morbidity, the comparative rates were 2.6% vs 2.9%, respectively, and the weighted relative risk was 0.90 (95% CI, 0.68-1.19). No differences were observed with respect to major congenital malformations overall, low birth weight, preterm birth, respiratory symptoms, or cesarean delivery. Results were consistent across sensitivity analyses. Conclusions and Relevance: There were similar and, in some instances, more favorable neonatal and maternal outcomes for pregnancies exposed to buprenorphine combined with naloxone compared with buprenorphine alone. For the outcomes assessed, compared with buprenorphine alone, buprenorphine with naloxone during pregnancy appears to be a safe treatment option. This supports the view that both formulations are reasonable options for the treatment of opioid use disorder in pregnancy, affirming flexibility in collaborative treatment decision-making.

Assessing predictors of adequate individual buprenorphine maintenance dosage for the treatment of opioid use disorder: Listening to the patient.

OBJECTIVE: Dose optimization plays a key role in determining clinical outcomes in patients on opioid agonist treatment (OAT). The objective of this study was to identify the variables independently associated with buprenorphine/naloxone (B/N) dose adequacy in patients with opiate use disorder (OUD). METHOD: Cross-sectional study of a convenience sample of patients with OUD treated with B/N (n = 315) in four regions in Spain. The Opiate Dosage Adequacy Scale (ODAS) was used to determine B/N dose adequacy. The ODAS evaluate the six components of the "dose adequacy" construct, as follows: continued use of heroin; narcotic blockade or crossed tolerance; objective opioid withdrawal symptoms (OWS); subjective OWS; craving for heroin; and overmedication. A binomial logistic regression analysis was performed to identify the variables associated with the condition "ODAS Adequate B/N dose". Participants completed a battery of instruments to assess sociodemographic, substance use, clinical, and treatment variables. RESULTS: The B/N dose was considered adequate in 231 of the 315 participants (73.3 %). Two variables, satisfaction with B/N as a medication (OR=5.764, 95 % CI=2.211-15.030) and patient-perceived participation in B/N dose decisions (OR=1.790, 95 % CI=1221-2623), were independently, significantly, and positively associated with the "ODAS Adequate B/N dose" condition. While the severity of heroin dependence was significantly associated with buprenorphine dose adequacy in the bivariate analyses, significance was lost in the full regression model. CONCLUSION: Satisfaction with B/N as a medication and patient-perceived involvement in the dose decision are associated with clinician-assessed dose adequacy. In the context of good clinical practice, it is important to take into account both of these variables to individualize the prescribed dose through a shared decision-making process.

Rapid induction of transdermal buprenorphine to subcutaneous extended-release buprenorphine for the treatment of opioid use disorder.

BACKGROUND: Buprenorphine is an effective and safe treatment for opioid use disorder, but the requirement for moderate opioid withdrawal symptoms to emerge prior to initiation is a significant treatment barrier. CASE PRESENTATION: We report on two cases of hospitalized patients with severe, active opioid use disorder, in which we initiated treatment with transdermal buprenorphine over 48 h, followed by the administration of a single dose of sublingual buprenorphine/naloxone and then extended-release subcutaneous buprenorphine. The patients did not experience precipitated withdrawal and only had mild withdrawal symptoms. CONCLUSIONS: This provides preliminary evidence for a rapid induction strategy that may improve tolerability, caregiver burden, and treatment retention as compared to previous induction strategies.

Extended-Release Injection vs Sublingual Buprenorphine for Opioid Use Disorder With Fentanyl Use: A Post Hoc Analysis of a Randomized Clinical Trial.

Importance: Fentanyl has exacerbated the opioid use disorder (OUD) and opioid overdose epidemic. Data on the effectiveness of medications for OUD among patients using fentanyl are limited. Objective: To assess the effectiveness of sublingual or extended-release injection formulations of buprenorphine for the treatment of OUD among patients with and without fentanyl use. Design, Setting, and Participants: Post hoc analysis of a 24-week, randomized, double-blind clinical trial conducted at 35 outpatient sites in the US from December 2015 to November 2016 of sublingual buprenorphine-naloxone vs extended-release subcutaneous injection buprenorphine (CAM2038) for patients with OUD subgrouped by presence vs absence of fentanyl or norfentanyl in urine at baseline. Study visits with urine testing occurred weekly for 12 weeks, then 6 times between weeks 13 and 24. Data were analyzed on an intention-to-treat basis from March 2022 to August 2023. Intervention: Weekly and monthly subcutaneous buprenorphine vs daily sublingual buprenorphine-naloxone. Main Outcomes and Measures: Retention in treatment, percentage of urine samples negative for any opioids (missing values imputed as positive), percentage of urine samples negative for fentanyl or norfentanyl (missing values not imputed), and scores on opiate withdrawal scales and visual analog craving scales. Results: Of 428 participants, 123 (subcutaneous buprenorphine, n = 64; sublingual buprenorphine-naloxone, n = 59; mean [SD] age, 39.1 [10.8] years; 75 men [61.0%]) had evidence of baseline fentanyl use and 305 (subcutaneous buprenorphine, n = 149; buprenorphine-naloxone, n = 156; mean [SD] age, 38.1 [11.1] years; 188 men [61.6%]) did not have evidence of baseline fentanyl use. Study completion was similar between the fentanyl-positive (60.2% [74 of 123]) and fentanyl-negative (56.7% [173 of 305]) subgroups. The mean percentage of urine samples negative for any opioid were 28.5% among those receiving subcutaneous buprenorphine and 18.8% among those receiving buprenorphine-naloxone in the fentanyl-positive subgroup (difference, 9.6%; 95% CI, -3.0% to 22.3%) and 36.7% among those receiving subcutaneous buprenorphine and 30.6% among those receiving buprenorphine-naloxone in the fentanyl-negative subgroup (difference, 6.1%; 95% CI, -1.9% to 14.1%), with significant main associations of baseline fentanyl status and treatment group. In the fentanyl-positive subgroup, the mean percentage of urine samples negative for fentanyl during the study was 74.6% among those receiving subcutaneous buprenorphine vs 61.9% among those receiving sublingual buprenorphine-naloxone (difference, 12.7%; 95% CI, 9.6%-15.9%). Opioid withdrawal and craving scores decreased rapidly after treatment initiation across all groups. Conclusions and Relevance: In this post hoc analysis of a randomized clinical trial of sublingual vs extended-release injection buprenorphine for OUD, buprenorphine appeared to be effective among patients with baseline fentanyl use. Patients with fentanyl use had fewer opioid-negative urine samples during the trial compared with the fentanyl-negative subgroup. These findings suggest that the subcutaneous buprenorphine formulation may be more effective at reducing fentanyl use. Trial Registration: ClinicalTrials.gov Identifier: NCT02651584.

Neurobehavioral outcomes of infants exposed to buprenorphine-naloxone compared with naltrexone during pregnancy.

BACKGROUND: Naltrexone is a medication used to treat both opioid and alcohol use disorder with limited experience in pregnant individuals, particularly in comparison to more commonly utilized treatments such as buprenorphine-naloxone. The long-term outcomes of infants exposed to naltrexone has not been previously examined. AIMS: To compare the neurobehavioral outcomes of naltrexone versus buprenorphine-naloxone exposed infants. STUDY DESIGN: Multi-centered prospective cohort study. SUBJECTS: Pregnant people on prescribed buprenorphine-naloxone or naltrexone were enrolled during pregnancy and the dyad followed until 12 months after delivery. OUTCOME MEASURES: Infants were evaluated at 4-6 weeks corrected gestational age (CGA) using the NICU Neonatal Neurobehavioral Scale (NNNS) and at the 12-month CGA visit using the Ages and Stages Questionnaire, Third Edition (ASQ-3). RESULTS: There were 7 dyads in the naltrexone group and 34 in the buprenorphine-naloxone group. On the NNNS, infants exposed to naltrexone had higher median scores for arousal and excitability, and lower median scores for attention and regulation at 4-6 weeks CGA compared to the buprenorphine-naloxone group. None of the infants in the naltrexone group were monitored for NOWS and had shorter length of hospital stay compared with the buprenorphine-naloxone group. Although no statistically significant differences were observed, more infants in the buprenorphine-naloxone group were identified as at risk for development delays in the communication, problem solving, and personal social domains of the ASQ-3 at 12 months CGA. Results should be interpreted with caution given this study's small sample size and lack of a prospective comparison cohort. CONCLUSIONS: In this small cohort, there are differences noted in infant neurobehavior by NNNS at 4-6 weeks of age when comparing the buprenorphine-naloxone and naltrexone groups. At 12 months, ASQ-3 scores were similar but with percentage differences in potential development delay risk observed between the two groups. Larger cohort studies are needed to determine the long-term child outcomes after naltrexone exposure in pregnancy.

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..

Characterizing acute and postsurgical pain management in patients receiving buprenorphine or buprenorphine/naloxone.

BACKGROUND: There is currently a clinical dilemma in treating acute pain in patients receiving long-term buprenorphine products. METHODS: This is a retrospective cohort review involving patients receiving long-term buprenorphine therapy who either underwent a surgical procedure or presented to an emergency department (ED) for acute pain between January 1, 2012 and January 1, 2022. Patients were excluded if opioids were prescribed 30 days before the index date. Chart reviews were conducted to characterize buprenorphine treatment strategies and the addition of new pain medications. Chart review revealed (1) incidence of opioid use disorder (OUD) relapse, (2) hospital re-presentation for pain or OUD, (3) fatal and non-fatal overdose, and (4) all-cause mortality and suicidality. Descriptive statistics were used to analyze results. RESULTS: A total of 70 of 259 screened patients met inclusion criteria. The mean (±SD) age was 50.3 ± 13 years, 92.9% male, 64.3% White, and 78.6% had an OUD diagnosis. While 84.3% presented to the ED, 15.7% underwent surgical procedures. For the primary endpoint, the total daily dose of buprenorphine or buprenorphine/naloxone from index date to discharge was continued in 90.0%, increased in 2.9%, decreased in 1.4%, and discontinued in 5.7% of cases. At discharge, 46.2% were prescribed an additional pain medication. A total of 7.1% re-presented for pain or OUD relapse, 15.7% experienced an OUD relapse, 1.4% experienced new-onset suicidality, and 1.4% experience all-cause mortality within 90 days of the index date. No fatal or non-fatal opioid overdoses were observed. CONCLUSION: The most commonly observed practice was continuing buprenorphine doses in patients with acute or postsurgical pain, which was effective and safe. Although further data is necessary to fully elucidate these findings, the data herein may suggest that clinicians can safely continue buprenorphine doses in the acute pain setting in patients receiving these products chronically.

Association Between Sublingual Buprenorphine-Naloxone Exposure and Dental Disease.

This study examines the association of sublingual buprenorphine/naloxone and dental adverse events using the IQVIA health claims database.

A cross-sectional survey on buprenorphine-naloxone practice and attitudes in 22 Canadian emergency physician groups: a cross-sectional survey.

BACKGROUND: Buprenorphine-naloxone (BUP) initiation in emergency departments improves follow-up and survival among patients with opioid use disorder. We aimed to assess self-reported BUP-related practices and attitudes among emergency physicians. METHODS: We designed a cross-sectional physician survey by adapting a validated questionnaire on opioid harm reduction practices, attitudes and barriers. We recruited physician leads from 6 Canadian provinces to administer surveys to the staff physicians in their emergency department groups between December 2018 and November 2019. We included academic and community non-locum emergency department staff physicians. We excluded responses from emergency department groups with response rates less than 50% to minimize nonresponse bias. Primary (BUP prescribing practices) and secondary (willingness and attitudes) outcomes were analyzed using descriptive statistics. RESULTS: After excluding 1 group for low response (9/26 physicians), 652 of 798 (81.7%) physicians responded from 22 groups serving 34 emergency departments. Among respondents, 64.1% (95% confidence interval [CI] 60.4%-67.8%, emergency department group range 7.1%-100.0%) had prescribed BUP at least once in their career, 38.4% had prescribed it for home initiation and 24.8% prescribed it at least once a month. Overall, 68.9% (95% CI 65.3%-72.4%, emergency department group range 24.1%-97.6%) were willing to administer BUP, 64.2% felt it was a major responsibility and 37.1% felt they understood people who use drugs. Respondents most frequently rated lack of adequate training (58.2%) and lack of time (55.2%) as very important barriers to BUP initiation. INTERPRETATION: Two-thirds of the emergency physicians surveyed prescribed BUP, although only one-quarter did so regularly and one-third prescribed it for home initiation; wide variation between emergency department groups existed. Strategies to increase BUP initiation must address physicians' lack of time and training for BUP initiation and improve their understanding of people who use drugs.

Comparison of Treatment Retention of Adults With Opioid Addiction Managed With Extended-Release Buprenorphine vs Daily Sublingual Buprenorphine-Naloxone at Time of Release From Jail.

Importance: Extended-release buprenorphine (XRB), a monthly injectable long-acting opioid use disorder (OUD) treatment, has not been studied for use in corrections facilities. Objective: To compare treatment retention following release from jail among adults receiving daily sublingual buprenorphine-naloxone (SLB) vs those receiving XRB. Design, Setting, and Participants: This open-label, randomized comparative effectiveness study included 52 incarcerated adults in New York City observed for 8 weeks postrelease between June 2019 and May 2020. Participants were soon-to-be-released volunteers from 1 men's and 1 women's jail facility who had OUDs already treated with SLB. Follow-up treatment was received at a primary care clinic in Manhattan. Data were analyzed between June 2020 and December 2020. Interventions: XRB treatment was offered prior to release and continued monthly through 8 weeks after release. SLB participants continued to receive daily directly observed in-jail SLB administration, were provided a 7-day SLB supply at jail release, and followed up at a designated clinic (or other preferred clinics). Main Outcomes and Measures: Buprenorphine treatment retention at 8 weeks postrelease. Results: A total of 52 participants were randomized 1:1 to XRB (26 participants) and SLB (26 participants). Participants had a mean (SD) age of 42.6 (10.0) years; 45 participants (87%) were men; and 40 (77%) primarily used heroin prior to incarceration. Most participants (30 [58%]) reported prior buprenorphine use; 18 (35%) reported active community buprenorphine treatment prior to jail admission. Twenty-one of 26 assigned to XRB received 1 or more XRB injection prior to release; 3 initiated XRB postrelease; and 2 did not receive XRB. Patients in the XRB arm had fewer jail medical visits compared with daily SLB medication administration (mean [SD] visits per day: XRB, 0.11 [0.03] vs SLB, 1.06 [0.08]). Community buprenorphine treatment retention at week 8 postrelease was 18 participants in the XRB group (69.2%) vs 9 in the SLB group (34.6%), and rates of opioid-negative urine tests were 72 of 130 tests in the XRB group (55.3%) and 50 of 130 tests in the SLB group (38.4%). There were no differences in rates of serious adverse events, no overdoses, and no deaths. Conclusions and Relevance: XRB was acceptable among patients currently receiving SLB, and patients had fewer in-jail clinic visits and increased community buprenorphine treatment retention when compared with standard daily SLB treatment. These results support wider use and further study of XRB as correctional and reentry OUD treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT03604159.

Sublingual Buprenorphine-Naloxone Compared With Injection Naltrexone for Opioid Use Disorder: Potential Utility of Patient Characteristics in Guiding Choice of Treatment.

OBJECTIVE: Sublingual buprenorphine-naloxone and extended-release injection naltrexone are effective treatments, with distinct mechanisms, for opioid use disorder. The authors examined whether patients' demographic and clinical characteristics were associated with better response to one medication or the other. METHODS: In a multisite 24-week randomized comparative-effectiveness trial of assignment to buprenorphine-naloxone (N=287) compared with extended-release naltrexone (N=283) comprising inpatients planning to initiate medication treatment for opioid use disorder, 50 demographic and clinical characteristics were examined as moderators of the effect of medication assignment on relapse to regular opioid use and failure to initiate medication. Moderator-by-medication interactions were estimated using logistic regression with correction for multiple testing. RESULTS: In the intent-to-treat sample, patients who reported being homeless had a lower relapse rate if they were assigned to receive extended-release naltrexone (51.6%) compared with buprenorphine-naloxone (70.4%) (odds ratio=0.45, 95% CI=0.22, 0.90); patients who were not homeless had a higher relapse rate if they were assigned to extended-release naltrexone (70.9%) compared with buprenorphine-naloxone (53.1%) (odds ratio=2.15, 95% CI=1.44, 3.21). In the subsample of patients who initiated medication, the interaction was not significant, with a similar pattern of lower relapse with extended-release naltrexone (41.4%) compared with buprenorphine (68.6%) among homeless patients (odds ratio=0.32, 95% CI=0.15, 0.68) but less difference among those not homeless (extended-release naltrexone, 57.2%; buprenorphine, 52.0%; odds ratio=1.24, 95% CI=0.80, 1.90). For failure to initiate medication, moderators were stated preference for medication (failure was less likely if the patient was assigned to the medication preferred), parole and probation status (fewer failures with extended-release naltrexone for those on parole or probation), and presence of pain and timing of randomization (more failure with extended-release naltrexone for patients endorsing moderate to severe pain and randomized early while still undergoing medically managed withdrawal). CONCLUSIONS: Among patients with opioid use disorder admitted to inpatient treatment, homelessness, parole and probation status, medication preference, and factors likely to influence tolerability of medication initiation may be important in matching patients to buprenorphine or extended-release naltrexone.

Comparing rapid micro-induction and standard induction of buprenorphine/naloxone for treatment of opioid use disorder: protocol for an open-label, parallel-group, superiority, randomized controlled trial.

BACKGROUND: Buprenorphine/naloxone (Suboxone) is a current first-line treatment for opioid use disorder (OUD). The standard induction method of buprenorphine/naloxone requires patients to be abstinent from opioids and therefore experience withdrawal symptoms prior to induction, which can be a barrier in starting treatment. Rapid micro-induction (micro-dosing) involves the administration of small, frequent does of buprenorphine/naloxone and removes the need for a period of withdrawal prior to the start of treatment. This study aims to compare the effectiveness and safety of rapid micro-induction versus standard induction of buprenorphine/naloxone in patients with OUD. METHODS: This is a randomized, open-label, two-arm, superiority, controlled trial comparing the safety and effectiveness of rapid micro-induction versus standard induction of buprenorphine/naloxone for the treatment of OUD. A total of 50 participants with OUD will be randomized at one Canadian hospital. The primary outcome is the completion of buprenorphine/naloxone induction with low levels of withdrawal. Secondary outcomes are treatment retention, illicit drug use, self-reported drug use behaviour, craving, pain, physical health, safety, and client satisfaction. DISCUSSION: This is the first randomized controlled trial to compare the effectiveness and safety of rapid micro-induction versus standard induction of buprenorphine/naloxone. This study will thereby generate evidence for a novel induction method which eliminates substantial barriers to the use of buprenorphine/naloxone in the midst of the ongoing opioid crisis. Trial registration ClinicalTrials.gov, NCT04234191; date of registration: January 21, 2020; https://clinicaltrials.gov/ct2/show/NCT04234191.

Buprenorphine Microdose Induction for the Management of Prescription Opioid Dependence.

Prescription opioid dependence remains a major source of morbidity and mortality in the United States. Patients previously on high-dose opioids may poorly tolerate opioid tapers. Current guidelines support the use of buprenorphine therapy in opioid-tapering protocols, even among patients without a diagnosis of opioid use disorder. Buprenorphine microinduction protocols can be used to transition patients to buprenorphine therapy without opioid withdrawal. From November 2019 to April 2020, we transitioned 8 patients on high-dose prescribed opioids for pain to sublingual buprenorphine-naloxone using a microdose protocol without any evidence of precipitated withdrawal. Six of these patients remain on buprenorphine-naloxone and report improved analgesia. Because of its simplicity, the buprenorphine microinduction protocol can be easily adapted for telemedicine and may help to prevent unnecessary clinic visits and opioid-related admissions in the setting of social distancing regulations during the coronavirus 2019 pandemic.

Does XR injectable naltrexone prevent relapse as effectively as daily sublingual buprenorphine-naloxone?

YES. MONTHLY EXTENDED-RELEASE INJECTABLE NALTREXONE (XR-NTX) TREATS OPIOID USE DISORDER AS EFFECTIVELY AS DAILY SUBLINGUAL BUPRENORPHINE-NALOXONE (BUP-NX) WITHOUT CAUSING ANY INCREASE IN SERIOUS ADVERSE EVENTS OR FATAL OVERDOSES. (STRENGTH OF RECOMMENDATION: A, 2 GOOD-QUALITY RCTS).

Use of Sublingual Nitrates for Management of Limb Ischemia Secondary to Inadvertent Intra-Arterial Buprenorphine/Naloxone (Suboxone®) Film Injection.

Multiple case reports have signaled a rise in buprenorphine abuse in the US, particularly among inmates. We present the case of limb ischemia secondary to accidental intra-arterial buprenorphine/naloxone film injection successfully treated with sublingual nitroglycerin. A 39-year-old man with history of intravenous drug use presented sudden severe left hand pain since three days prior to evaluation. Pain was preceded by self-injection of dissolved buprenorphine/naloxone sublingual film onto the affected arm. An arteriogram suggested severe vasoconstriction in the absence of frank thrombosis. Patient was initially treated with continuous heparin infusion and nifedipine. Forty-eight hours later, due to poor response, sublingual nitroglycerin was added to therapy. Digits regained color, sensation, and pain resolved within 15 minutes of administration of sublingual nitroglycerin. The presence of acute limb ischemia caused by prolonged vasospasm is a very rare complication. A normal angiogram should raise suspicion regarding vasospasm as the mechanism of ischemia, and prompt nitroglycerin therapy.

Use of a novel prescribing approach for the treatment of opioid use disorder: Buprenorphine/naloxone micro-dosing - a case series.

INTRODUCTION AND AIMS: Buprenorphine/naloxone is an evidence-based treatment for opioid use disorder, but an identified limitation is the period of required opioid abstinence prior to induction on the medication. 'Micro-dosing', or using incrementally increasing doses of buprenorphine/naloxone over time, may be a way to overcome this challenge as it can be done in parallel with the ongoing use of other opioids (either illicit or prescribed). DESIGN AND METHODS: A retrospective case series (January to December 2018) was completed of seven participants who underwent buprenorphine/naloxone induction using micro-dosing at two outpatient addiction clinics in Vancouver, Canada. RESULTS: Seven participants completed a 7-day buprenorphine/naloxone micro-dosing protocol. Prior to and during the induction, one participant was prescribed methadone, three were prescribed slow release oral morphine and three used only illicit fentanyl. Participants were prescribed sublingual buprenorphine/naloxone: 0.5 mg once daily (day 1), 0.5 mg twice daily (BID; day 2), 1 mg BID (day 3), 2 mg BID (day 4), 3 mg BID (day 5), 4 mg BID (day 6) and 12 mg once daily (day 7). On day 7, all prescribed or illicit full opioid agonists were discontinued. Buprenorphine/naloxone was subsequently titrated to a daily dose of between 12 and 32 mg. All patients reported success with buprenorphine/naloxone induction with no precipitated withdrawal. DISCUSSION AND CONCLUSIONS: Buprenorphine/naloxone micro-dosing may offer a promising alternative approach for successful induction for individuals with opioid use disorder who desire treatment with buprenorphine/naloxone, and further research to determine effectiveness is warranted.

Towards a common metric for assessing heroin-dependent patient satisfaction with medications: Testing methadone and buprenorphine-naloxone.

BACKGROUND: Patient satisfaction with methadone or buprenorphine-naloxone can be multidimensionally and specifically assessed by using, respectively, the Scale to Assess Satisfaction with Medications for Addiction Treatment-Methadone for Heroin addiction (SASMAT-METHER) or the SASMAT-Buprenorphine-Naloxone for Heroin addiction (SASMAT-BUNHER). The factor structures of the SASMAT-METHER and SASMAT-BUNHER show substantial commonalities. The objective of the present study is to evaluate the replicability of the SASMAT-METHER factor structure using data from the SASMAT-BUNHER development study in order to obtain an instrument that can be used to compare patient satisfaction with methadone vs. buprenorphine-naloxone. METHOD: Secondary analysis of SASMAT-BUNHER data provided by 205 participants in the original validation study of that scale (Pérez de los Cobos et al., 2018). Using the SASMAT-METHER component solution (17 items, 3 factors) as the target structure, a principal component analysis was performed on the data set comprised of the corresponding 17 SASMAT-BUNHER items using an oblique semi-specified Procrustean rotation. Additionally, Tucker congruence coefficients were computed to examine the correspondence between the two solutions. RESULT: The factor structures of SASMAT-METHER and the 17-item version of the SASMAT-BUNHER can be considered equal given that the overall Tucker's congruence coefficient of factorial similarity was 0.972, with individual component congruencies ranging from 0.960 to 0.995. CONCLUSIONS: The SASMAT-METHER component solution can serve as a single common tool to compare methadone vs. buprenorphine-naloxone in terms of patient satisfaction. This finding supports the feasibility of using a common metric to specifically assess satisfaction with medications to treat heroin dependence.