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

Rotation from methadone to buprenorphine using a micro-dosing regime in patients with opioid use disorder and serious mental illness: A case series

INTRODUCTION

Inducting buprenorphine from methadone has traditionally involved initial opioid withdrawal, with risk of mental state deterioration in patients with serious mental illness (SMI). Micro-dosing of buprenorphine, with small incremental doses, is a novel off-label approach to transitioning from methadone and does not require a period of methadone abstinence. Given the limited literature about buprenorphine microdosing, we aimed to evaluate the feasibility and safety of inducting buprenorphine in a series of patients on methadone with SMI.

METHODS

For this retrospective case series, we reviewed the records of 16 patients with SMI at a Melbourne addiction treatment centre, from January 2021 to July 2022, who transitioned via micro-dosing, from high-dose methadone (>30 mg) to buprenorphine and depot-buprenorphine. Psychiatric diagnoses, mental state, other substance withdrawal, transfer success, transition time, opioid withdrawal symptoms and overall patient experience were collected via objective and subjective reporting.

RESULTS

Methadone to buprenorphine transfer was completed by 88% of patients. Mental health measures remained stable with the exception of mildly increased anxiety. Median transfer time was 6.5 days for inpatients, 9 days for mixed setting and 10 days for outpatients. Most patients (93%) rated their experience 'manageable' reporting mild withdrawal symptoms. One patient met study criteria for precipitated withdrawal.

DISCUSSION AND CONCLUSIONS

This retrospective case series provides evidence that the use of a micro-dosing buprenorphine induction for methadone to buprenorphine transitions, including to depot-buprenorphine, has negligible risk, is tolerated by patients with SMI and is unlikely to precipitate an exacerbation of their mental illness.

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.

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.

Open-label investigation of rapid initiation of extended-release buprenorphine in patients using fentanyl and fentanyl analogs

BACKGROUND AND OBJECTIVES

Synthetic opioids, including fentanyl and fentanyl analogs, account for over 70,000 annual overdose deaths in the United States, but there is limited information examining methods of induction and maintenance outcomes for buprenorphine treatment of patients with opioid use disorder (OUD) using these opioids.

METHODS

A secondary analysis of results grouped by fentanyl use status was completed for an open-label study with rapid induction of extended-release buprenorphine in the inpatient research unit. Eligible participants received a single 4 mg dose of transmucosal buprenorphine (BUP-TM) followed by an extended-release buprenorphine 300 mg injection ([BUP-XR]) after approximately 1 h. An extension study continued follow-up up to 6 months (6 monthly injections).

RESULTS

Among participants with fentanyl-positive urine samples (FEN+; n = 19), all received BUP-TM, 17 received BUP-XR, 13 elected to receive a second BUP-XR injection, and 10 received all six scheduled injections. Among participants with fentanyl-negative samples (FEN-; n = 7), all received BUP-TM and BUP-XR, four elected to receive a second injection, and two participants received all six scheduled injections. Induction day clinical opioid withdrawal scale (COWS) scores were similar for FEN+ and FEN- groups. In the FEN+ group, mean COWS scores fell to below 5 within 24 h of BUP-XR injection.

DISCUSSION AND CONCLUSIONS

The treatment of individuals with OUD using fentanyl with a rapid 1-day induction to BUP-XR 300 mg injection is feasible and well-tolerated.

SCIENTIFIC SIGNIFICANCE

A prospective trial of participants grouped by fentanyl use status at induction demonstrates comparable patient retention and clinical response following single-day induction of BUP-XR in participants who are FEN+ and FEN-.

Use of intravenous buprenorphine microdosing to initiate medication for opioid use disorder in a patient with co-occurring pain: case report

INTRODUCTION

Buprenorphine is used to treat opioid use disorder (OUD). However, therapy is often disrupted during acute pain episodes, and re-initiation is often deferred due to intolerable interruption in opioid analgesics. This case report describes a unique strategy for inducing buprenorphine without stopping opioid analgesics.

CASE

One patient with OUD and acute pain was initiated on buprenorphine using intravenous microdosing without precipitated withdrawal or pain exacerbation. Full agonist opioids were successfully weaned after discharge and the patient was linked with a community-based treatment program.

CONCLUSION

This case describes use of intravenous buprenorphine to treat OUD and acute pain without adverse consequences.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Survey of Buprenorphine Low-dose Regimens Used by Healthcare Institutions

BACKGROUND

Buprenorphine microdosing ("low-dosing") allows for initiation of buprenorphine without requiring patients to endure withdrawal. Case studies suggest its favorable utility as an alternative to conventional buprenorphine induction. However, published regimens vary in duration, dosage forms used, and timing of full opioid agonist discontinuation.

METHODS

This cross-sectional survey study sought to determine how buprenorphine low-dosing is approached by medical institutions across the United States. The primary end point was characterization of inpatient buprenorphine low-dosing regimens. Situations and types of patients in which low-dosing is used and obstacles to institutional protocol development were also collected. An online survey was disseminated through professional pharmacy organizations and personal contacts. Responses were collected over 4 weeks.

RESULTS

Twenty-three unique protocols were collected from 25 institutions. Most protocols used buccal (8 protocols) or transdermal (8 protocols) buprenorphine as first doses before transitioning to sublingual buprenorphine. The most common starting doses were buprenorphine 20 μg/h transdermal, 150 μg buccal, and 0.5 mg sublingual. Patients unable to tolerate conventional buprenorphine induction or those who potentially used fentanyl nonmedically were most likely to be prescribed low-dosing. The most common obstacle to developing an internal low-dosing protocol was lack of existing consensus guidelines.

CONCLUSIONS

Similar to published regimens, internal protocols are variable. Buccal first doses may be used more commonly in practice based on survey results, while transdermal first doses are more commonly reported in publications. More research is needed to determine whether differences in starting formulations impact safety and efficacy of buprenorphine low-dosing in the inpatient setting.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Howard Street Method: A Community Pharmacy-led Low Dose Overlap Buprenorphine Initiation Protocol for Individuals Using Fentanyl

OBJECTIVES

Buprenorphine treatment significantly reduces morbidity and mortality for people with opioid use disorder. Fear of precipitated withdrawal remains a barrier to starting buprenorphine for patients who use synthetic opioids, particularly fentanyl. We aim to evaluate the development and implementation of a buprenorphine low dose overlap initiation (LDOI) protocol in an urban public health community pharmacy.

METHODS

We performed a retrospective chart review of patients with nonprescribed fentanyl use (N = 27) to examine clinical outcomes of a buprenorphine LDOI schedule, named the Howard Street Method, dispensed from a community pharmacy in San Francisco from January to December 2020.

RESULTS

Twenty-seven patients were prescribed the Howard Street Method. Twenty-six patients picked up the prescription and 14 completed the protocol. Of those who completed the protocol, 11 (79%) reported no symptoms of withdrawal and 3 (21%) reported mild symptoms. Four patients (29%) reported cessation of full opioid agonist use and 10 (71%) reported reduction in their use by the end of the protocol. At 30 days, 12 patients (86%) were retained in care and 10 (71%) continued buprenorphine. At 180 days, 6 patients (43%) were retained in care and 2 (14%) were still receiving buprenorphine treatment.

CONCLUSIONS

We found that a LDOI blister-pack protocol based at a community pharmacy was a viable intervention for starting buprenorphine treatment and a promising alternative method for buprenorphine initiation in an underresourced, safety-net population of people using fentanyl.

Low dose IV buprenorphine inductions for patients with opioid use disorder and concurrent pain: a retrospective case series

BACKGROUND

Hospitalizations are a vital opportunity for the initiation of life-saving opioid agonist therapy (OAT) for patients with opioid use disorder. A novel approach to OAT initiation is the use of IV buprenorphine for low dose induction, which allows patients to immediately start buprenorphine at any point in a hospitalization without stopping full agonist opioids or experiencing significant withdrawal.

METHODS

This is a retrospective case series of 33 patients with opioid use disorder concurrently treated with full agonist opioids for pain who voluntarily underwent low dose induction at a tertiary academic medical center. Low dose induction is the process of initiating very low doses of buprenorphine at fixed intervals with gradual dose increases in patients who recently received or are simultaneously treated with full opioid agonists. Our study reports one primary outcome: successful completion of the low dose induction (i.e. transitioned from low dose IV buprenorphine to sublingual buprenorphine-naloxone) and three secondary outcomes: discharge from the hospital with buprenorphine-naloxone prescription, self-reported pain scores, and nursing-assessed clinical opiate withdrawal scale (COWS) scores over a 6-day period, using descriptive statistics. COWS and pain scores were obtained from day 0 (prior to starting the low dose induction) to day 5 to assess the effect on withdrawal symptoms and pain control.

RESULTS

Thirty patients completed the low dose induction (30/33, 90.9%). Thirty patients (30/33, 90.9%) were discharged with a buprenorphine prescription. Pain and COWS scores remained stable over the course of the study period. Mean COWS scores for all patients were 2.6 (SD 2.8) on day 0 and 1.6 (SD 2.6) on day 5. Mean pain scores for all patients were 4.4 (SD 2.1) on day 0 and 3.5 on day 5 (SD 2.1).

CONCLUSIONS

This study found that an IV buprenorphine low dose induction protocol was well-tolerated by a group of 33 hospitalized patients with opioid use disorder with co-occurring pain requiring full agonist opioid therapy. COWS and pain scores improved for the majority of patients. This is the first case series to report mean daily COWS and pain scores over an extended period throughout a low dose induction process.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Developing A Rapid Transfer from Opioid Full Agonist to Buprenorphine: "Ultrarapid Micro-Dosing" Proof of Concept

Buprenorphine/naloxone has been shown to be effective for treating opioid use disorder (OUD). However, the traditional method of induction requires a patient to be in moderate-to-severe withdrawal, which is challenging, time-consuming, and a common reason for leaving against medical advice. Induction strategies that minimize the severity and duration of patient discomfort while enabling patients to reach therapeutic doses during short hospital admissions can mitigate difficulties when inducing a patient on buprenorphine/naloxone. This case-series illustrates two patients with OUD using illicit fentanyl, who were successfully started on buprenorphine/naloxone using 24-hour and 6-hour micro-dosing induction protocol. During induction, the patients were up-titrated to a therapeutic dose through ultrarapid micro-dosing with ongoing use of short-acting opioids. Both patients reached therapeutic doses experiencing minimal levels of withdrawal. This case-series is a proof of concept for the use of a buprenorphine/naloxone ultrarapid micro-induction protocol for inpatients with OUD. By reducing the length of induction and precluding the need for withdrawal, this method offers several advantages over previously published inductions protocols and can improve the accessibility of buprenorphine/naloxone to patients with OUD.

Successful conversion from butorphanol nasal spray to buprenorphine/naloxone using a low-dose regimen to assist with opioid tapering in the setting of chronic pain and migraine management in an older adult patient: A case report

Background

Butorphanol is marketed as a treatment for migraines; however, evidence suggests that the harms of its use exceed the benefits. The short half-life of butorphanol places patients at high risk for opioid dependence and makes tapering a challenge. Buprenorphine/naloxone has unique pharmacological properties that are beneficial in chronic pain treatment. At this time there is limited published data on the use of micro-dosing initiation regimens in patients with chronic pain, especially in older adult patients.

Aims

This article presents the case of an older adult patient for whom a buprenorphine/naloxone micro-dosing regimen was successfully utilized to aid discontinuation of butorphanol nasal spray, assist with opioid tapering, and manage chronic pain.

Methods

This case took place in an outpatient setting while the patient was receiving care from an interprofessional chronic pain service. The electronic medical record was reviewed to obtain a summary of the case data. Informed patient consent was obtained.

Results

We present a case of an older adult patient who had been using butorphanol nasal spray for migraine and general pain management for over 20 years. The risks of ongoing use of butorphanol (i.e., inter-dose-related pain, opioid dependence, possible opioid-induced hyperalgesia, and fall risk) no longer exceeded any perceived benefit. The patient was successfully transitioned onto sublingual buprenorphine/naloxone using a micro-dosing regimen.

Conclusions

This case provides an example of the potential benefit buprenorphine/naloxone can have for patients with chronic pain and previous opioid exposure, especially older adults at risk of central adverse effects of opioids.

Current and emerging pharmacotherapies for opioid dependence treatments in adults: a comprehensive update

INTRODUCTION

Opioid use disorder (OUD) is characterized by compulsive opioid seeking and taking, intense drug craving, and intake of opioids despite negative consequences. The prevalence of OUDs has now reached an all-time high, in parallel with peak rates of fatal opioid-related overdoses, where 15 million individuals worldwide meet the criteria for OUD. Further, in 2020, 120,000 opioid-related deaths were reported worldwide with over 75,000 of those deaths occurring within the United States.

AREAS COVERED

In this review, we highlight pharmacotherapies utilized in patients with OUDs, including opioid replacement therapies, and opioid antagonists utilized for opioid overdoses and deterrent of opioid use. We also highlight newer treatments, such as those targeting the neuroimmune system, which are potential new directions for research given the recently established role of opioids in activating neuroinflammatory pathways, as well as over the counter remedies, including kratom, that may mitigate withdrawal.

EXPERT OPINION

To effectively treat OUDs, a deeper understanding of the current therapeutics being utilized, their additive effects, and the added involvement of the neuroimmune system are essential. Additionally, a complete understanding of opioid-induced neuronal alterations and therapeutics that target these abnormalities - including the neuroimmune system - is required to develop effective treatments for OUDs.

Pharmacotherapy of Opioid Use Disorder-Update and Current Challenges

The incidence of opioid use disorder (OUD) and overdose deaths is rising yearly within the United States. Many cases are associated with illicitly manufactured fentanyl use. In addition to offering patients medications for OUD (methadone, buprenorphine, and naltrexone), the approach to this epidemic should involve increasing provider awareness and education about substance use disorders, expanding urine toxicology screens to test for fentanyl, and using low-threshold treatment approaches.

A Plea From People Who Use Drugs to Clinicians: New Ways to Initiate Buprenorphine Are Urgently Needed in the Fentanyl Era

With the worst opioid overdose death crisis in the United States history, urgent new approaches to assist people who use drugs onto medication for opioid use disorder are necessary. In this commentary, addiction medicine clinicians and drug user union representatives align to argue that conventional ways of buprenorphine initiation that require periods of withdrawal must be augmented with additional novel approaches to initiation. In the fentanyl era, members of the New England Users Union and Portland Users Union report encountering precipitated withdrawal, being unable to stop using full agonist opioids for a required period of time, and difficulty initiating this medication that could offer them some stability and life-saving treatment. People who use drugs should be involved at all levels with ongoing research, clinical and policy efforts to improve buprenorphine initiation as their lives and their suffering are at stake.

Buprenorphine initiation strategies for opioid use disorder and pain management: A systematic review

Buprenorphine possesses many unique attributes that make it a practical agent for adults and adolescents with opioid use disorder (OUD) and/or acute or chronic pain. Sublingual buprenorphine has been the standard of care for treating OUD, but its use in pain management is not as clearly defined. Current practice guidelines recommend a period of mild‐to‐moderate withdrawal from opioids before transitioning to buprenorphine due to its ability to displace full agonists from the μ‐opioid receptor. However, this strategy can lead to negative physical and psychological outcomes for patients. Novel initiation strategies suggest that concomitant administration of small doses of buprenorphine with opioids can avoid the unwanted withdrawal associated with buprenorphine initiation. We aim to systematically review the buprenorphine initiation strategies that have emerged in the last decade. Embase, PubMed, and Cochrane Databases were searched for relevant literature. Studies were included if they were published in the English language and described the transition to buprenorphine from opioids. Data were collected from each study and synthesized using descriptive statistics. This review included 7 observational studies, 1 feasibility study, and 39 case reports/series which included 924 patients. The strategies utilized between the literature included traditional initiation (47.9%), microdosing with various buprenorphine formulations (16%), and miscellaneous methods (36.1%). Traditional initiation and microdosing initiation were compared in the data synthesis and analysis; miscellaneous methods were omitted given the high variability between methods. Overall, 95.6% of patients in the traditional initiation group and 96% of patients in the microdosing group successfully rotated to sublingual buprenorphine. Initiation regimens can vary widely depending on patient‐specific factors and buprenorphine formulation. A variety of buprenorphine transition strategies are published in the literature, many of which were effective for patients with OUD, pain, or both.

Community based buprenorphine micro-induction in the context of methadone maintenance treatment and fentanyl - Case report

INTRODUCTION

The micro-induction method of initiating buprenorphine is becoming a popular method for initiating buprenorphine in patients with Opioid Use Disorder, who are on full opioid agonists, either prescribed or non-prescribed, in order to avoid precipitated withdrawal. Given the rising concerns around illicit fentanyl use, this method of initiating buprenorphine has become another tool for clinicians to help patients with Opioid Use Disorder, even when multiple full opioid agonists are involved. While the process for initiating buprenorphine through this process is well studied, the characteristics of patients who are able to tolerate this initiation method in an outpatient setting is not.

CASE(S)

We present the cases of two patients with Opioid Use Disorder in a community-based methadone maintenance program in whom micro-induction methods were used to initiate buprenorphine without lowering the methadone dose. Both patients successfully transitioned to buprenorphine without precipitated withdrawal. One of the patients was also using fentanyl at the time of induction and was able to abstain from fentanyl use following the induction process.

CONCLUSION

Initiating Buprenorphine using micro-induction strategies in a community based outpatient clinic in patients who are already on full opioid agonists is feasible, in these particular cases, the methadone dose or concurrent fentanyl use did not affect the outcome. We present the characteristics of the patient and the community clinic hoping that this helps more clinicians in replicating this induction strategy.

Low-dose Buprenorphine Initiation in Hospitalized Adults With Opioid Use Disorder: A Retrospective Cohort Analysis

OBJECTIVES

Patients with opioid use disorder (OUD) can initiate buprenorphine without requiring a withdrawal period through a low-dose (sometimes referred to as "micro-induction") approach. Although there is growing interest in low-dose buprenorphine initiation, current evidence is limited to case reports and small case series.

METHODS

We performed a retrospective cohort study of patients with OUD seen by a hospital-based addiction medicine consult service who underwent low-dose buprenorphine initiation starting during hospital admission. We then integrated our practice-based experiences with results from the existing literature to create practice considerations.

RESULTS

Sixty-eight individuals underwent 72 low-dose buprenorphine initiations between July 2019 and July 2020. Reasons for low-dose versus standard buprenorphine initiation included co-occurring pain (91.7%), patient anxiety around the possibility of withdrawal (69.4%), history of precipitated withdrawal (9.7%), opioid withdrawal intolerance (6.9%), and other reason/not specified (18.1%). Of the 72 low-dose buprenorphine initiations, 50 (69.4%) were completed in the hospital, 9 (12.5%) transitioned to complete as an outpatient, and 13 (18.1%) were terminated early. We apply our experiences and findings from literature to recommendations for varied clinical scenarios, including acute illness, co-occurring pain, opioid withdrawal intolerance, transition from high dose methadone to buprenorphine, history of precipitated withdrawal, and rapid hospital discharge. We share a standard low-dose initiation protocol with potential modifications based on above scenarios.

CONCLUSIONS

Low-dose buprenorphine initiation offers a well-tolerated and versatile approach for hospitalized patients with OUD. We share lessons from our experiences and the literature, and provide practical considerations for providers.

Challenges with buprenorphine inductions in the context of the fentanyl overdose crisis: A case series

INTRODUCTION AND AIMS

North America is currently experiencing an epidemic of opioid overdose deaths, driven by the proliferation of fentanyl in the street drug market. Although buprenorphine/naloxone (BUP/NX) is an evidence-based, first-line opioid agonist for the management of opioid use disorder, a key challenge in its prescribing lies in the fact that it can precipitate opioid withdrawal during its initial induction process. At this time, there is minimal literature on the BUP/NX induction process in individuals who use illicit fentanyl regularly.

DESIGN, METHODS AND RESULTS

A case series from a Vancouver, Canada addiction medicine clinic of three fentanyl-exposed patients who experienced unexpected, precipitated withdrawal when initiating BUP/NX.

DISCUSSION AND CONCLUSION

These cases describe incidents of precipitated opioid withdrawal occurring after unusually long periods of fentanyl abstention. Although fentanyl is experienced as a short-acting opioid, the drug persists much longer in the body's peripheral tissues. Here, we highlight the new challenges fentanyl may pose to current BUP/NX induction strategies, and explore the possibility of a long-acting pharmacokinetic effect of fentanyl in the setting of repeated illicit use.

Buprenorphine Microdosing for the Pain and Palliative Care Clinician

Buprenorphine (BUP) can be a safe and effective alternative to traditional opioids for many patients with chronic pain. For patients on higher doses of opioids, rotation to BUP is complicated by the requirement of an opioid-free interval or withdrawal during the transition. Microdosing inductions, in which BUP is gradually titrated, while full agonist opioids are continued, are a viable alternative to traditional inductions. The objective of this article is to review the current literature on BUP microdosing induction, with a focus on patients using opioids for pain. A literature review of the PubMed database was performed in the United States on articles published from inception to May 2021. A total of 34 publications were included. The most commonly utilized microdosing strategy involved administering divided doses of sublingual (SL) products marketed for opioid use disorder treatment, with 25 (73.5%) articles reporting use of partial SL tablets or films (ranging from 1/8 to 1/2 of a 2 mg product) at some point during the induction. Transdermal patches, low-dose SL BUP available in Europe, intravenous BUP, and buccal BUP have also been used. Beyond the products used, the speed of the microinduction, setting, final BUP dosing, and management of concomitant full agonists vary widely in the literature. Microdosing regimens should be individualized based on local guidelines and patient-specific factors. Further studies comparing the safety and efficacy of different protocols are warranted.

Low Dose Initiation of Buprenorphine: A Narrative Review and Practical Approach

Low dose buprenorphine initiation, is an alternative method of initiating buprenorphine in which the starting dose is very low and gradually increased to therapeutic levels over a period of days. This method takes advantage of slow displacement of the full opioid agonist from mu-opioid receptors, avoiding the need for a person with opioid use disorder to experience opioid withdrawal symptoms before initiating buprenorphine, while also minimizing the risk of precipitated opioid withdrawal. With this initiation method, full opioid agonists can be continued as buprenorphine is initiated, expanding the population to which buprenorphine can be offered. To date, the literature on low dose initiation is primarily case-based but rapidly growing. While evidence emerges, guidance for the use of low dose initiation is clearly desired and urgently needed in the context of an increasingly risky and contaminated opioid drug supply, particularly with high potency synthetic opioids, driving overdose deaths. Despite limited evidence, several principles to guide low dose initiation have been identified including: (1) choosing the appropriate clinical situation, (2) initiating at a low buprenorphine dose, (3) titrating the buprenorphine dose gradually, (4) continuing the full opioid agonist even if it is nonmedical, (5) communicating clearly with frequent monitoring, (6) pausing or delaying buprenorphine dose changes if opioid withdrawal symptoms occur, and (7) prioritizing care coordination. We review a practical approach to low dose initiation in hospital-based and outpatient settings guided by the current evidence.

Rapid Transition to Buprenorphine in a Patient With Methadone-Related QTc Interval Prolongation

BACKGROUND

Patients with opioid use disorder (OUD) who are managed on methadone often require transition to buprenorphine therapy. Current recommendations require months to gradually taper off of methadone; however, in some cases, the need to transition is urgent. Only a few rapid methadone-to-buprenorphine transitions have been reported and there are no established protocols to guide clinicians in these cases.

CASE PRESENTATION

A 43-year-old man on 95 mg methadone for opioid use disorder experienced cardiac arrest attributable to ventricular fibrillation caused by QTc interval prolongation from methadone. In the hospital, a gradual taper of methadone was initiated but proved intolerable; the patient requested to restart his home dose of methadone and leave against medical advice. A rapid transition was initiated instead. Naltrexone (25 mg) was used to precipitate acute withdrawal followed 1 hour later by a "rescue" with buprenorphine/naloxone (16 mg/4 mg). The Clinical Opiate Withdrawal Score (COWS) peaked at 21 post-naltrexone and fell quickly to 15 within a half-hour of buprenorphine/naloxone administration. The patient was maintained on a total daily dose of 16 mg/4 mg buprenorphine/naloxone through the time of discharge.

CONCLUSIONS

A patient requiring an urgent taper off of methadone due to adverse cardiac effects successfully transitioned to buprenorphine/naloxone within 2 hours by using naltrexone to precipitate withdrawal followed by a "rescue" with buprenorphine/naloxone. A relatively high dose of 16 mg/4 mg buprenorphine/naloxone successfully arrested withdrawal symptoms. With further refinement, this protocol may be an important technique for urgent methadone-to-buprenorphine transitions in the inpatient setting.

Rapid buprenorphine microdosing for opioid use disorder in a hospitalized patient receiving very high doses of full agonist opioids for acute pain management: Titration, implementation barriers, and strategies to overcomes

Background: Conventional buprenorphine inductions for OUD are clinically useful but require patients to experience mild to moderate opioid withdrawal symptoms to avoid precipitated withdrawal. This may be intolerable/unreasonable for some, which may have precluded successful buprenorphine treatment in the past. Microdosing buprenorphine, allowing for full agonist opioid overlap, has emerged as a clinically useful strategy for those unable to complete conventional buprenorphine induction. However, many questions remain such as preclusions regarding the amount of full agonist opioid overlap, speed of buprenorphine microdose titration, and overcoming implementation barriers in U.S. hospitals. Case presentation: A female between the ages of 30 and 40 with severe OUD admitted to the hospital for IDU-related osteomyelitis wished to begin buprenorphine for OUD. Her hospitalization was subject to premature discharge at any time due to competing interests of potential foreclosure on her home, so buprenorphine needed to be started rapidly for safety and improved outcomes. Due to her significant acute pain requirements managed with full agonist opioids, it was unreasonable to consider conventional buprenorphine induction. Buprenorphine microdose strategy was employed at more rapid titration and previously described in the literature, starting at 1 mg TDD on day 1, 3 mg TDD on day 2, and 8 mg TDD on day 3 with full agonist opioid overlap starting at 1,944 MME tapered down to 473 MME. The patient prematurely left the hospital, at which time buprenorphine 8 mg TDD was held at this dose for days 3-8 while full agonist opioid was tapered from 473 MME to 117 MME. BUP was then further titrated to 8 mg TID. This patient tolerated buprenorphine microdosing well, without any treatment-emergent opioid symptoms or worsening of baseline symptoms. Discussion: This case demonstrates the success of buprenorphine microdose induction despite very high doses of full agonist opioid overlap and demonstrates the ability to titrate buprenorphine microdoses faster than originally described. Strategies to overcoming implementation barriers are also discussed.

The Pharmacology of Buprenorphine Microinduction for Opioid Use Disorder

Although expanding the availability of buprenorphine—a first-line pharmacotherapy for opioid-use disorder (OUD)—has increased the capacity of healthcare systems to offer treatment, starting this medication is fraught with significant barriers. Standard induction regimens require persons with OUD to taper and discontinue full opioid agonists and experience opioid withdrawal prior to the first dose of buprenorphine. Further, emerging evidence indicates that precipitated withdrawal during induction may impact long-term treatment outcomes. Microinduction is a novel approach that, by harnessing buprenorphine’s unique pharmacological profile, may allow circumventing the needed for prolonged opioid tapers, and reduce the risk of precipitated withdrawal—holding promise to enhance treatment access. In this review, we examine the pharmacological basis for microinduction and appraise the evidence of this approach to improve clinical outcomes among persons with OUD. First, we highlight the potential dose-dependent effects of buprenorphine on two key neuroadaptations at the mu-opioid receptor (MOR)—resensitization and upregulation. We then focus on how microinduction may reverse these chronic MOR neuroadaptations, allowing the maintenance of an adequate opioid tone, and thereby potentially circumventing opioid withdrawal. Second, we describe the clinical evidence available, derived from observational reports and open-label studies, examining the potential efficacy of microinduction. Despite significant heterogeneity—exemplified by variable buprenorphine formulations, daily doses, and schedules of administration—these data provide preliminary support for the feasibility of microinduction. Finally, we provide new mechanistic, methodological, and clinical insights to guide future translational research, as well as randomized, placebo-controlled clinical trials in this compelling agenda of pharmacotherapy development.

Short communication: Systematic review on effectiveness of micro-induction approaches to buprenorphine initiation

BACKGROUND/OBJECTIVES

Micro-induction is a novel buprenorphine induction approach that seeks to avoid withdrawal and minimize precipitated withdrawal, both barriers to standard inductions. We aimed to synthesize evidence on micro-induction effectiveness, and regimens described.

METHODS

We searched scientific databases and grey literature for studies including adolescents or adults with opioid use disorder who received buprenorphine micro-induction. Study selection, data extraction and quality assessments occurred in duplicate. We narratively synthesized results.

RESULTS

We screened 4,752 citations and included 19 case studies/series and one feasibility study (n = 57 patients; mean age 38 years [SD 12.0]; 57.9% male [33/57]). Studies described 26 regimens; starting and maintenance doses ranged from 0.03 to 1.0 mg, and 8 to 32 mg, respectively. We calculated rate of increase to 8 mg. All patients achieved the desired maintenance dose. Among 54 patients in whom precipitated withdrawal was not reported, mean increases were 1.36 mg/day (SD 0.41). For three patients in whom precipitated withdrawal was specifically reported, mean increase was 1.17 mg/day (SD 0.11). All studies were low quality.

DISCUSSION

Described regimens are highly variable. Inconsistent reporting, selection bias, and poor quality evidence limit conclusions regarding optimal dosing, and patient characteristics and clinical settings in which micro-induction is likely beneficial.

CONCLUSIONS

This systematic review provides the most up-to-date synthesis on buprenorphine micro-induction regimens. Rigorous studies evaluating effectiveness and safety of micro-induction, and patient and clinical factors influencing its success, are needed.

Microdosing and standard-dosing take-home buprenorphine from the emergency department: A feasibility study

OBJECTIVE

Emergency department (ED)-initiated buprenorphine may prevent overdose. Microdosing is a novel approach that does not require withdrawal, which can be a barrier to standard inductions. We aimed to evaluate the feasibility of an ED-initiated buprenorphine/naloxone program providing standard-dosing and microdosing take-home packages and of randomizing patients to either intervention.

METHODS

We broadly screened patients ≥18 years old for opioid use disorder at a large, urban ED. In a first phase, we provided consecutive patients with 3-day standard-dosing packages, and then we provided a subsequent group with 6-day microdosing packages. In a second phase, we randomized patients to standard dosing or microdosing. We attempted 7-day telephone follow-ups and 30-day in-person community follow-ups. The primary feasibility outcome was number of patients enrolled and accepting randomization. Secondary outcomes were numbers screened, follow-up rates, and 30-day opioid agonist therapy retention.

RESULTS

We screened 3954 ED patients and identified 94 with opioid use disorders. Of the patients, 26 (27.7%) declined participation: 10 identified a negative prior experience with buprenorphine/naloxone as the reason, 5 specifically cited precipitated withdrawal, and none cited randomization. We enrolled 68 patients. A total of 14 left the ED against medical advice, 8 were excluded post-enrollment, 21 received standard dosing, and 25 received microdosing. The 7-day and 30-day follow-up rates were 9/46 (19.6%) and 15/46 (32.6%), respectively. At least 5/21 (23.8%) provided standard dosing and 8/25 (32.0%) provided microdosing remained on opioid agonist therapy at 30 days.

CONCLUSIONS

ED-initiated take-home standard-dosing and microdosing buprenorphine/naloxone programs are feasible, and a randomized controlled trial would be acceptable to our target population.