Rapid Transition From Methadone to Buprenorphine Utilizing a Micro-dosing Protocol in the Outpatient Veteran Affairs Setting

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.

Case report: Successful induction of buprenorphine in medically complex patients concurrently on opioids: a case series at a tertiary care center

Effective pain management is essential for optimal surgical outcomes; however, it can be challenging in patients with a history of opioid use disorder (OUD). Buprenorphine, a partial opioid agonist, is a valuable treatment option for patients with OUD. Initiating buprenorphine treatment in patients concurrently taking opioids can be complex due to potential adverse outcomes like precipitated withdrawal. Evolving guidelines suggest there are benefits to continuing buprenorphine for surgical patients throughout the perioperative period, however situations do arise when buprenorphine has been discontinued. Typically, in this scenario patients would be restarted on buprenorphine after they have fully recovered from post-surgical pain and no longer require opioids for pain control. Unfortunately, holding MOUD may expose the patient to risks such as opioid induced respiratory depression or addiction relapse. In this case series, we discuss a novel method to restart buprenorphine in small incremental doses, known as micro-dosing, while the patient is still taking opioids for pain. We will present two complex clinical cases when this method was used successfully at a tertiary care hospital system.

Low Dose Buprenorphine Initiation: A Guide for the Inpatient Clinician

Low dose buprenorphine initiation (LDBI) is a dosing strategy used to transition patients from full opioid agonists to buprenorphine. The purpose of LDBI is to circumvent obstacles associated with disruption in analgesia, precipitated withdrawal, and prerequisite opioid withdrawal prior to initiating buprenorphine, as not all patients are able to tolerate physical withdrawal symptoms recommended by national guidelines. No literature exists directly comparing traditional buprenorphine initiation to LDBI. Until information on long-term outcomes is available, these dosing strategies should be reserved for patients unable to tolerate traditional buprenorphine initiation. Available published research suggests LDBI strategies will allow some patients to successfully transition to buprenorphine with minimal or no symptoms of withdrawal. Ensuring access to pharmacotherapy during hospital admission is a crucial time for potential intervention and should be considered when appropriate. This narrative review discusses the background of LDBI strategies as well as practical clinical and operational considerations for the inpatient clinician.

Transitioning From High-dose Methadone to Buprenorphine Using a Microdosing Approach: Unique Considerations at ASAM Level 3 Facilities

Transitions from high-dose methadone to buprenorphine for treatment of opioid use disorder (OUD) present risk of precipitated withdrawal related to the introduction of a high-affinity partial agonist at the mu-opioid receptor after occupancy by a lower-affinity full agonist. Various strategies have been explored to maintain patient stability during this process, including microdosing buprenorphine. Current literature lacks consensus on an optimal setting and strategy for initiating a buprenorphine microdosing protocol and gives little detail on patients' conditions after the acute transition period. We report a 6-day microdosing transition from methadone 100 mg directly to sublingual buprenorphine, followed by a 20-day period of monitoring and additional treatment. This patient tolerated a sublingual buprenorphine microdosing protocol while using supportive medications with a peak Clinical Opiate Withdrawal Scale score of 6. The patient's most significant withdrawal symptoms occurred several days after completion of the microdosing process. This case demonstrates the feasibility of using a transmucosal buprenorphine formulation in microdosing transitions from high-dose methadone directly to buprenorphine, and highlights the utility of a medically monitored intensive inpatient setting (American Society of Addiction Medicine level 3.7) in providing appropriate monitoring and treatment during and after a microdosing transition.

48-hour Induction of Transdermal Buprenorphine to Sublingual Buprenorphine/Naloxone: The IPPAS Method

Buprenorphine is an effective medication for the treatment of opioid use disorder. However, the traditional method of buprenorphine induction requires a period of abstinence and the development of at least moderate withdrawal, which can be barriers in starting treatment. We present the case of a hospitalized patient with opioid use disorder using unregulated fentanyl, who underwent a transdermal buprenorphine induction over 48 hours to initiate sublingual buprenorphine/naloxone on the third day. The patient experienced minimal levels of withdrawal and did not experience precipitated withdrawal. The ease of use of this novel induction method over previously published induction protocols can greatly improve the accessibility of buprenorphine for patients and healthcare staff.

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.

Development of an intravenous low-dose buprenorphine initiation protocol

BACKGROUND

Buprenorphine is a life-saving treatment for opioid use disorder (OUD). Low-dose initiation (LDI) is an emerging buprenorphine initiation strategy that circumvents barriers associated with standard initiation. This study aims to describe tolerability and completion of LDI using intravenous (IV) buprenorphine and to define dosing protocols in a cohort of patients hospitalized in an urban academic hospital.

METHODS

Data was collected via retrospective chart review for IV buprenorphine LDI cases initiated between September 1, 2020 and February 28, 2021. Cases were excluded if diagnostic criteria for OUD was not met, Clinical Opiate Withdrawal Scale (COWS) scores were not recorded, or sublingual (SL) buprenorphine was given within 24 h before IV buprenorphine. Completion of LDI and COWS data were assessed for all cases. Cases were categorized based on adherence to a dosing strategy and LDI indication, including OUD and acute pain, non-prescribed fentanyl exposure, and transition from methadone.

RESULTS

Seventy-two cases were identified, and thirteen cases were excluded, leaving 59 cases in the population. Of these cases, 72.9% (43/59) tolerated LDI, and 91.5% (54/59) completed buprenorphine initiation. Forty-four (44/59, 75%) cases were adherent. Median duration of LDI within the adherent group was 23.7 h (IQR 22.8-27.0), 37.1 h (IQR 36.2-40.9), and 48.8 h (IQR 47.0-52.4) for the "rapid," "moderate," and "slow" dosing strategies, respectively.

CONCLUSIONS

IV buprenorphine LDI was tolerated and completed in a majority of patients. Dosing protocols allowed for rapid transition to sublingual buprenorphine. Acute pain or recent methadone or fentanyl exposure may inform IV LDI dosing strategy selection.

Outpatient Microdose Induction with Transdermal Buprenorphine: A Case Series

Transdermal buprenorphine is FDA approved for chronic severe pain but has an increasing amount of data supporting its use to transition patients from full opioid agonists to sublingual buprenorphine via a microdose strategy. The literature has primarily focused on patients with a pain diagnosis or who have been prescribed opioids in inpatient units. This case series reviews the use of transdermal buprenorphine to transition patients from methadone and illicit opioids to sublingual buprenorphine. The authors identified seven patients from an outpatient opiate treatment program who received the transdermal buprenorphine protocol. All patients were prescribed methadone and used illicit heroin prior to and during the transition. Five patients (71.4%) successfully completed the transition to sublingual buprenorphine, with all five patients reporting no or mild withdrawal symptoms. These findings suggest that transdermal buprenorphine is a potentially safe and effective microdose induction method for patients who use illicit substances in an outpatient setting.

Microdose Induction of Buprenorphine in a Patient Using Tianeptine

BACKGROUND

Opioids and opioid alternatives are a serious threat to public health in the United States and other countries. Patients are looking to the internet increasingly as a source of opioid alternatives to self-treat addiction or other psychiatric conditions. It is imperative that patients receive proper treatment to prevent morbidity and mortality related to opioid use disorder.

CASE SUMMARY

We report a case of a middle-aged male with a 3-year history of tianeptine use who presented to an outpatient clinic looking for addiction treatment options after failed attempts at tapering his daily dosage of approximately 10 grams per day. The patient underwent a microdose induction of sublingual buprenorphine over a 7-day period (0.25-12 mg) while continuing tianeptine use, and self-monitored for withdrawal symptoms daily using the Clinical Opiate Withdrawal Scale. The patient was seen over the course of treatment by a board-certified toxicologist and addiction specialist on day 2, 5, 6, and 14 to ensure patient safety and treatment adherence. After 14 days of treatment, the patient was able to stop tianeptine use without any major symptoms of withdrawal, anxiety, or depression.

DISCUSSION

This case report highlights the effectiveness of buprenorphine in the treatment of opioid use disorder in a patient using tianeptine and further exemplifies the utility of buprenorphine in an outpatient setting.

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.

Clinical Case Conference: Strategies for Transferring From Methadone to Buprenorphine

The mainstay of treatment for opioid use disorder are medications, methadone (a full opioid agonist), or buprenorphine (a partial opioid agonist), in conjunction with psychosocial interventions. Both treatments are effective but safety, efficacy, and patient preference can lead to a decision to change from one treatment to the other. Transfer from buprenorphine to methadone is not clinically challenging; however, changing from methadone to buprenorphine is more complex. Published reports describe varied approaches to manage this transfer to both minimize patient symptoms associated with withdrawal from methadone and reduce risk of precipitating withdrawal symptoms with introduction of the partial agonist buprenorphine [Lintzeris et al. J Addict Med. 2020; in press]. There is no single approach for methadone to buprenorphine that is superior to others and no approach that is suitable for all case presentations. This case conference describes three different approaches to achieve a successful methadone to buprenorphine transfer and provides commentary on how the case may be managed based on published transfer "strategies."

Transdermal buprenorphine for in-hospital transition from full agonist opioids to sublingual buprenorphine: a retrospective observational cohort study

INTRODUCTION

Patients with opioid use disorder may have difficulty transitioning from full-agonist opioids to sublingual buprenorphine due to the risk of precipitated opioid withdrawal. Novel strategies have been developed to facilitate this transition, including the use of micro-dosing with transdermal buprenorphine. We began using a transdermal buprenorphine transition strategy at our hospital in 2019.

METHODS

We performed a retrospective observational cohort study of patients treated with transdermal buprenorphine to facilitate transition from full-agonist opioids (prescribed or recreational) while hospitalized between January 2019 and December 2020. Patients were excluded if transdermal buprenorphine was given for pain, if they did not receive at least one dose of sublingual buprenorphine while hospitalized, or if their clinical course precluded analysis of their tolerance of the transition protocol. Data on the doses and timing of medications, symptoms during transition, and hospital outcomes were abstracted from the electronic medical record.

RESULTS

We identified 41 cases that satisfied inclusion and exclusion criteria. Thirty-five cases involved a transition from medically indicated opioids; of these, 8 cases involved a transition from methadone. Six cases involved a transition from illicit opioids used prior to hospital presentation. For patient transitioning from medically indicated opioids, the median milligram morphine equivalent (MME) on the day prior to transdermal buprenorphine application was 63.8 (range 0-900, IQR 153.8) and the median MME on the day of transdermal buprenorphine application was 34.5 (range 0-600, IQR 65.3). The median initial dose of sublingual buprenorphine administered was 8 mg (range 2-8mg, IQR 6mg), the median total first-day dose was 16mg (range 2-24mg, IQR 16mg), and the median total daily dose on the last day of follow-up was 16mg (range 2-24mg, IQR 16mg). In 38 cases, patients completed the transition to sublingual buprenorphine and were still taking buprenorphine at the time they left the hospital. The transition protocol was fairly well-tolerated, with 59% of cases tolerating it well and 32% tolerating it fairly.

DISCUSSION

Our findings suggest that the use of transdermal buprenorphine to facilitate transition to sublingual buprenorphine is generally well-tolerated, and may be helpful in hospitalized patients. We identified several areas for improvement in future practice by reviewing the clinical courses of patients who tolerated transition poorly. Limitations of the study include its retrospective chart review design, the lack of a standardized transition protocol during the study period, and the lack of standardized data in the medical record regarding patients' tolerance of the transition protocol. Future research should include prospective studies using a standardized protocol and structured, pre-planned assessments of opioid withdrawal during the transition period.

CONCLUSION

The use of transdermal buprenorphine to facilitate induction of sublingual buprenorphine therapy in hospitalized patients with OUD was generally well-tolerated in this single-center retrospective observational study. Further prospective research is needed to demonstrate efficacy and optimize treatment protocols.

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.

Transition From Full Mu Opioid Agonists to Buprenorphine in Opioid Dependent Patients-A Critical Review

Methadone, a full opioid agonist at the mu-, kappa-, and delta-receptor, and buprenorphine, a partial agonist at the mu receptor, are first-line medications in opioid maintenance treatment. Transition from methadone to buprenorphine may precipitate withdrawal, and no accepted algorithm for this procedure has been developed. Current treatment strategies recommend transfer from methadone to buprenorphine predominantly in patients at low doses of methadone (30-40 mg/day). There are some reports indicating that transition from higher doses of methadone may be possible. A number of dosing strategies have been proposed to soften withdrawal symptoms and facilitate transfer including use of other opioids or medications and especially microdosing techniques for buprenorphine. The case series and studies available thus far are reviewed.

Treating Chronic Pain with Buprenorphine-The Practical Guide

OPINION STATEMENT

Buprenorphine has unique and favorable pharmacological properties that make it useful in a variety of clinical scenarios. It has been recommended to consider buprenorphine first-line opioid for chronic pain, especially in the elderly as it may be associated with less cognitive impairment, falls, sexual dysfunction, and sarcopenia when compared with schedule II opioids. It may be useful in patients with comorbid substance use disorder or non-medical opioid use, as there is less risk of misuse, euphoria and it may improve mood. When used to treat opioid use disorder, the training and waiver was recently waived for licensed practitioners with a DEA and any provider may prescribe buprenorphine. For many reasons outlined in this article, the popularity of using buprenorphine for analgesia continues to grow and a practitioner should consider this as an excellent and safe option for chronic pain.

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.

Ambulatory microdose induction of buprenorphine-naloxone in two adolescent patients with sickle cell disease

Sickle cell disease (SCD) is a hematologic disorder defined by presence of sickle-shaped red blood cells that can occlude blood vessels and cause tissue ischemia and pain. Treating SCD pain adequately and safely is difficult given today's opioid climate. Buprenorphine-naloxone has been described as an alternative option to treat chronic pain in the adult literature; however, it historically required discontinuation of full-agonist opioids before initiation, resulting in opioid withdrawal. Herein we present two adolescents with SCD who successfully weaned off large doses of full-agonist opioids by using microdose induction of buprenorphine-naloxone in clinic, without experiencing significant opioid withdrawal. Ambulatory microdose induction may remove hurdles that otherwise would discourage patients from trying this regimen while still controlling pain safely.