Effects of a higher-bioavailability buprenorphine/naloxone sublingual tablet versus buprenorphine/naloxone film for the treatment of opioid dependence during induction and stabilization: a multicenter, randomized trial

Overview of best practices for buprenorphine initiation in the emergency department

In recent decades, opioid overdoses have increased dramatically in the United States and peer countries. Given this, emergency medicine physicians have become adept in reversing and managing complications of acute overdose. However, many remain unfamiliar with initiating medication for opioid use disorder such as buprenorphine, a high-affinity partial opioid agonist. Emergency department-based buprenorphine initiation is supported by a significant body of literature demonstrating a marked reduction in mortality in addition to increased engagement in care. Buprenorphine initiation is also safe, given both the pharmacologic properties of buprenorphine that reduce the risk of diversion or recreational use, and previously published literature demonstrating low rates of respiratory depression, sedation, and precipitated withdrawal. Further, barriers to emergency department-based initiation have been reduced in recent years, with publicly available dosing and up-titration schedules, numerous publications overviewing best practices for managing precipitated withdrawal, and removal of USA policies previously restricting patient access and provider prescribing, with the removal of the X-waiver via the Medication Access and Training Expansion Act. Despite reductions in barriers, buprenorphine initiation in the emergency room remains underutilized. Poor uptake has been attributed to numerous individual and systemic barriers, including inadequate education, provider stigma, and insufficient access to outpatient follow-up care. The following practice innovation aims to summarize previously published evidence-based best practices and provide an accessible, user-friendly initiation guide to increase emergency physician comfortability with buprenorphine initiation going forward.

The Impact of Individual Counseling on Treatment for Opioid Use

ABSTRACT

In 2018, more than 67,000 people died because of drug overdoses, and of that number, approximately 69.5% involved an opioid, making it a leading cause of death in the United States. Additionally concerning is that 40 states have reported increased overdose deaths and opioid-related deaths since the start of the COVID-19 global pandemic. Presently, many insurance companies and healthcare providers require patients to receive counseling during medication treatment for opioid use disorder (OUD), despite the lack of evidence that it is necessary for all patients. To inform policy and improve quality of treatment, this nonexperimental, correlational study examined the relationship between individual counseling status and treatment outcomes in patients receiving medication treatment for OUD. Treatment outcome variables (treatment utilization, medication use, and opioid use) were extracted from the electronic health records of 669 adults who received treatment between January 2016 and January 2018. Study findings suggest women in our sample were more likely to test positive for benzodiazepines (t = -4.3, p < .001) and amphetamines (t = -4.4, p < .001), whereas men used alcohol at higher rates than women (t = 2.2, p = .026). In addition, women were more likely to report having experienced Post-Traumatic Stress Disorder/trauma (χ2 = 16.5, p < .001) and anxiety (χ2 = 9.4, p = .002). Regression analyses revealed concurrent counseling was unrelated to medication utilization and ongoing opioid use. Patients who had prior counseling utilized buprenorphine more frequently (β = 0.13, p < .001) and used opioids less often (β = -0.14, p < .001); however, both relationships were weak. These data do not provide evidence that counseling during OUD outpatient has a significant impact on treatment outcomes. These findings provide further evidence that barriers to medication treatment such as mandatory counseling can and should be removed.

Buprenorphine and its formulations: a comprehensive review

Buprenorphine, a novel long-acting analgesic, was developed with the intention of two purposes: analgesia and opioid use disorder. Regarding its pharmacodynamics, it is a partial agonist at mu receptors, an inverse agonist at kappa receptors, and an antagonist at delta receptors. For the purpose of analgesia, three formulations of buprenorphine were developed: IV/IM injectable formulation (Buprenex®), transdermal patch formulation (Butrans®), and buccal film formulation (Belbuca®). Related to opioid dependence, the formulations developed were subcutaneous extended release (Sublocade®), subdermal implant (Probuphine®), and sublingual tablets (Subutex®). Lastly, in order to avoid misuse of buprenorphine for opioid dependence, two combination formulations paired with naloxone were developed: film formulation (Suboxone®) and tablet formulation (Zubsolv®). In this review, we present details of each formulation along with their similarities and differences between each other and clinical considerations.

A comparison of registered and published primary outcomes in clinical trials of opioid use disorder: ACTTION review and recommendations

BACKGROUND AND AIMS

Prospective trial registration can increase research integrity. This Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) review was designed to compare the primary outcomes (PO) reported in registries with associated publications for opioid use disorder (OUD) clinical trials.

DESIGN

The World Health Organization's International Clinical Trials Registry Platform (ICTRP) was searched for completed trials (2010 through 2019). Associated publications were identified and paired with trial registry data based on the publication date.

MEASUREMENTS

Reviewers independently rated the occurrence of discrepancies between the POs in the registry compared to the publication. An analysis of prospective versus retrospective registration was also completed.

FINDINGS

One-hundred and forty trials were identified in the search, and 43 registry-publication pairs evaluated. Only 34 of the 43 pairs could be examined for discrepancies because nine did not report a PO in registry and publication. Of the 34 pairs, only four met rigorous criteria for prospective trial registration and had an exact match of POs. In contrast, the majority of the 34 trials, or 80%, had inconsistent POs (e.g., registered secondary outcomes published as primary; the timing of PO not specified) and/or were retrospectively registered.

CONCLUSIONS

Many clinical trials focused on OUD have not met the standards of trial registration, such as consistent reporting of POs and prospective registration. Failure to properly register trial characteristics undermines the validity of research findings and can delay the development of life-saving treatments. Recommendations for improving prospective trial reporting practices are provided.

Oromucosal products - Market landscape and innovative technologies: A review

Strategies that rely on oral mucosal administration have increased in the last decade and oromucosal products are paving the way to overcome specific challenges, namely improving drug bioavailability when compared with the conventional oral route, due to a reduction of the hepatic first-pass metabolism and pre-systemic degradation. Overall, the advantages of these products make oromucosal route of administration attractive for the development of value-added medicines, which can address more properly the unmet medical needs of specific patients. Generally, such products have an easy and convenient administration since they do not require water for ingestion, which may be particularly relevant for geriatric and pediatric groups, or non-cooperative patients. Usually, the development of these products aims to provide a faster onset of action, critical for acute or emergency treatments. Although oriented to achieve better therapeutic outcomes, today's drug development is primarily focused on patient-centered care, meaning that patients' specific characteristics/needs are an important driving force behind product-development efforts. In accordance, pharmaceutical innovation can rely not only on new drug substances but also on re-formulation of already approved ones or alternative routes of administration, enhancing patient convenience, treatment efficacy and/or safety. Throughout this review, the oromucosal drug products, approved in the last decade, and a retrospective analysis of their critical quality attributes and specifications will be described. Furthermore, trends and opportunities of the latest technologies in this field, as well as the number of ongoing clinical studies, will be presented and discussed.

Buprenorphine/Naloxone (Zubsolv®): A Review in Opioid Dependence

A new sublingual buprenorphine/naloxone tablet (hereafter referred to as buprenorphine/naloxone; Zubsolv^®), combining a long-acting partial µ receptor agonist and an opioid antagonist, is approved for the treatment of opioid dependence in adults and adolescents aged > 15 years. This formulation has a higher bioavailability, better taste and faster sublingual dissolve time than a reference sublingual buprenorphine/naloxone tablet (Suboxone^®), advantages that provide greater patient preference (potentially improving adherence) and importantly may reduce the risk of buprenorphine parenteral abuse by providing similar buprenorphine exposure at an ≈ 30% lower dosage than reference buprenorphine/naloxone. In large phase III trials of up to 28 days, buprenorphine/naloxone was associated with high treatment retention rates during the induction and stabilization phases, and also reduced opioid craving and opioid withdrawal symptoms. Although noninferiority of buprenorphine/naloxone to sublingual buprenorphine tablet during the 2-day induction phase was only shown in one of the two similarly designed trials, pooled analyses confirmed that treatment retention rates were similar in the buprenorphine/naloxone and buprenorphine groups. Where evaluated, noninferiority of buprenorphine/naloxone to sublingual buprenorphine/naloxone film (only approved in the USA) was also demonstrated at 15 days in the stabilization phase. During the 24-week extension study, buprenorphine/naloxone maintenance therapy sustained improvements in opioid craving and addiction severity scores. Buprenorphine/naloxone was generally well tolerated, displaying a tolerability profile that was generally consistent with that seen with reference buprenorphine/naloxone. In conclusion, with potentially greater patient preference and a lower potential for parenteral buprenorphine abuse than reference buprenorphine/naloxone, buprenorphine/naloxone expands the treatment options available for adults and adolescent (aged > 15 years) patients with opioid dependence.

Treating Chronic Pain: An Overview of Clinical Studies Centered on the Buprenorphine Option

The buprenorphine receptor binding profile is unique in that it binds to all three major opioid receptors (mu, kappa, delta), and also binds to the orphan-like receptor, the receptor for orphanin FQ/nociceptin, with lower affinity. Within the mu receptor group, buprenorphine analgesia in rodents is dependent on the recently discovered arylepoxamide receptor target in brain, which involves a truncated 6-transmembrane mu receptor gene protein, distinguishing itself from morphine and most other mu opioids. Although originally designed as an analgesic, buprenorphine has mainly been used for opioid maintenance therapy and only now is increasingly recognized as an effective analgesic with an improved therapeutic index relative to certain potent opioids. Albeit a second-, third-, or fourth-line analgesic, buprenorphine is a reasonable choice in certain clinical situations. Transdermal patches and buccal film formulations are now commercially available as analgesics. This review discusses buprenorphine pharmacodynamics and pharmacokinetics, use in certain populations, and provides a synopsis of systematic reviews and randomized analgesic trials. We briefly discuss postoperative management in patients receiving buprenorphine maintenance therapy, opioid equivalence to buprenorphine, rotations to buprenorphine from other opioids, and clinical relevance of buprenorphine-related QTc interval changes.

Pharmacokinetic and pharmaceutical properties of a novel buprenorphine/naloxone sublingual tablet for opioid substitution therapy versus conventional buprenorphine/naloxone sublingual tablet in healthy volunteers

PURPOSE

A novel sublingual buprenorphine/naloxone rapidly-dissolving tablet (BNX-RDT) for opioid substitution therapy has been developed for improved bioavailability, rapid disintegration and improved taste masking. We compared the bioavailability and pharmaceutical properties of BNX-RDT with conventional buprenorphine/naloxone sublingual tablets (BNX).

METHODS

Fasting, open-label, randomized, single-dose, two-cohort crossover study in healthy volunteers under naltrexone block. Cohort 1 (high-dose, N = 64) received BNX-RDT 11.4/2.9 mg and BNX 16/4 mg. Cohort 2 (low-dose, N = 61) received BNX-RDT 2.9/0.71 mg and BNX 4/1 mg. Plasma samples were collected over 72 h. Relative systemic exposures of buprenorphine and naloxone were assessed using standard statistical models for bioequivalence analysis. Pharmaceutical assessments included dissolve time, taste and mouthfeel assessments, and overall preference.

RESULTS

BNX-RDT 11.4/2.9 mg provided equivalent buprenorphine and naloxone exposure to BNX 16/4 mg. BNX-RDT 2.9/0.71 mg provided ~20% lower buprenorphine and 35% lower naloxone exposure compared with BNX 4/1 mg. The comparison of BNX-RDT 2.9/0.71 mg with BNX 4/1 mg did not fully meet equivalence criteria. BNX-RDT was associated with improved dose proportionality across strengths compared with BNX (post hoc analysis), resulting in lower exposure from BNX-RDT relative to BNX at the lower strength. Median perceived dissolve times were significantly shorter for BNX-RDT than BNX at high (8.5 versus 16.2 min) and low (7.6 versus 9.1 min) doses. Taste and mouthfeel were rated significantly more pleasant than BNX, with ~78% of subjects preferring BNX-RDT.

CONCLUSION

BNX-RDT provided improved buprenorphine absorption compared to a conventional sublingual tablet, with shorter dissolve times and improved taste and mouthfeel, resulting in a high preference for the novel formulation.

Safety of a Rapidly Dissolving Buprenorphine/Naloxone Sublingual Tablet (BNX-RDT) for Treatment of Opioid Dependence: A Multicenter, Open-label Extension Study

Objective:

To assess the safety of rapidly dissolving buprenorphine/naloxone sublingual tablets (BNX-RDT) in opioid-dependent patients.

Methods:

This open-label, 24-week extension study enrolled patients who completed primary trials of BNX-RDT. Daily tablet doses ranged from 5.7 to 17.1 mg. The primary endpoint was safety; secondary assessments included opioid cravings, addiction severity, health-related quality of life (QOL), and workplace productivity at screening (final day of the primary trials) through study end, with changes measured from baseline of the primary trials.

Results:

In all, 665 patients received treatment; 292 (43.9%) completed the study. A total of 258 patients (38.8%) reported 557 treatment-emergent adverse events, most commonly headache (3.2%) and constipation (3.0%). Craving scores showed continued improvement on 100-mm visual analog scale (mean change from primary trial baseline, −52.8 at screening; mean change from extension trial baseline, −60.5 at week 24). Reductions in addiction severity from baseline of both the primary and extension trial were maintained through week 24 on multiple assessments, as were improvements in QOL on Short Form 36. Employment increased by 15% and mean (SD) hours worked per week increased by 4.6 (20.1) from baseline to study end. Mean (SD) scores for impact of opioid dependence on work productivity improved from 4.7 (3.0) at baseline to 0.9 (1.8) at study end (11-point scale).

Conclusions:

Extended treatment with BNX-RDT demonstrated a safety profile similar to other BNX formulations, reduced opioid cravings, and improved both QOL and work productivity. Continued treatment may enable patients to advance in recovery and return to normal functioning.

Pharmacogenomics-guided policy in opioid use disorder (OUD) management: An ethnically-diverse case-based approach

INTRODUCTION

Opioid use disorder (OUD) is characterized by a problematic pattern of opioid use leading to clinically-significant impairment or distress. Opioid agonist treatment is an integral component of OUD management, and buprenorphine is often utilized in OUD management due to strong clinical evidence for efficacy. However, interindividual genetic differences in buprenorphine metabolism may result in variable treatment response, leaving some patients undertreated and at increased risk for relapse. Clinical pharmacogenomics studies the effect that inherited genetic variations have on drug response. Our objective is to demonstrate the impact of pharmacogenetic testing on OUD management outcomes.

METHODS

We analyzed a patient who reported discomfort at daily buprenorphine dose of 24 mg, which was a mandated daily maximum by the pharmacy benefits manager. Regular urine screenings were conducted to detect the presence of unauthorized substances, and pharmacogenetic testing was used to determine the appropriate dose of buprenorphine for OUD management.

RESULTS

At the 24 mg buprenorphine daily dose, the patient had multiple relapses with unauthorized substances. Pharmacogenetic testing revealed that the patient exhibited a cytochrome P450 3A4 ultrarapid metabolizer phenotype, which necessitated a higher than recommended daily dose of buprenorphine (32 mg) for adequate OUD management. The patient exhibited a reduction in the number of relapses on the pharmacogenetic-based dose recommendation compared to standard dosing.

CONCLUSION

Pharmacogenomic testing as clinical decision support helped to individualize OUD management. Collaboration by key stakeholders is essential to establishing pharmacogenetic testing as standard of care in OUD management.

Impact of a Mandated Change in Buprenorphine Formulation

OBJECTIVE

This study examines the impact of an insurance-mandated change in formulation of buprenorphine/naloxone (BNX) for patients with opioid use disorder treated in a primary care clinic.

METHODS

A retrospective cohort study was conducted to determine the proportion of patients who were switched back to the previous BNX formulation and rates of aberrant urine drug tests for the 3 months before and 3 months after a mandated change in BNX from the sublingual film to the rapidly dissolving tablet (BNX-RDT). Aberrant urine drug tests were defined as the presence of cocaine, nonprescribed opioids/benzodiazepines, or the absence of buprenorphine.

RESULTS

In all, 186 patients were included in the analysis. At 3 months after the change, 36.0% of patients remained on BNX-RDT at equivalent dose, 9.1% were prescribed a higher dose of BNX-RDT, 52.7% were switched back to their previous formulation after a trial of BNX-RDT, and 2.2% dropped out of care. There was no significant change in the rates of aberrant urine drug tests pre and postchange (36.6% vs 33.7%; P = 0.27) or in any individual component of urine drug testing. Age, sex, and starting dose were not associated with remaining on BNX-RDT at equivalent dose, compared with increasing dose or changing formulation.

CONCLUSIONS

Most patients were dissatisfied with the change in formulation and requested a return to the previous formulation. This change did not appear to impact drug use; however, the flexibility that permitted patients to switch back to their previous BNX formulation likely attenuated the policy's impact.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Randomised Comparison of a Novel Buprenorphine Oral Lyophilisate versus Existing Buprenorphine Sublingual Tablets in Opioid-Dependent Patients: A First-in-Patient Phase II Randomised Open Label Safety Study

AIMS

To test the safety of new buprenorphine oral lyophilisate wafer ("bup-lyo") versus standard sub-lingual buprenorphine ("bup-SL").

DESIGN

Randomised (2:1) open-label study; opioid-dependent subjects; subsequent partial cross-over.

SETTINGS

Specialised clinical trials facility and addictions treatment facility.

PARTICIPANTS

Opioid-dependent subjects (n = 36) commencing buprenorphine maintenance (personalised dose-titration) including patients co-using alcohol, cocaine and benzodiazepines (below thresholds).

MEASUREMENTS

Respiratory function (respiratory rate, pulse-oximetry); medication hold and dose adequacy; opiate withdrawal signs and symptoms; tablet disintegration times; treatment retention. Pharmacokinetics (PK) for plasma buprenorphine and norbuprenorphine (n = 11).

FINDINGS

Oral lyophilised buprenorphine ("bup-lyo") completely dissolved within 2 min for 58 vs. 5% for "bup-SL." Dose titration resulted in similar maintenance dosing (10.8 vs. 9.6 mg). There were no significant between-group differences in opiate-withdrawal phenomena, craving, adequacy of "hold," respiratory function. No serious adverse events (AEs), nor "severe" AEs, although more AEs and Treatment-Emergent AEs with "bup-lyo" (mostly "mild"). PK found greater bioavailability of buprenorphine with "bup-lyo" (but not norbuprenorphine).

CONCLUSIONS

Orally disintegrating buprenorphine oral lyophilisate wafer disintegrated rapidly. No increased respiratory depression was found and clinically no difference between medications was observed. PK found substantially increased bioavailability of buprenorphine (but not of nor-buprenorphine) with "bup-lyo" relative to "bup-SL." In supervised dosing contexts, rapidly disintegrating formulations may enable wider buprenorphine prescribing.

Efficacy of Buprenorphine/Naloxone Rapidly Dissolving Sublingual Tablets (BNX-RDT) After Switching From BNX Sublingual Film

OBJECTIVES

The aim of the study was to evaluate treatment retention, efficacy, and preference ratings among opioid-dependent patients transitioning between a buprenorphine/naloxone rapidly dissolving sublingual tablet formulation (BNX-RDT) and BNX film.

METHODS

After a 2-day, blinded, fixed-dose induction with BNX-RDT (5.7/1.4 mg and 5.7/1.4 or 11.4/2.8 mg, respectively) or buprenorphine (8 mg and 8 or 16 mg, respectively), patients received open-label titrated doses of BNX-RDT or BNX film (generic buprenorphine induction group) during days 3 to 14. On day 15, patients switched treatment (using a conversion ratio of 5.7-8 mg) and continued switched treatment through day 22. Assessments included treatment retention, opioid withdrawal (Clinical and Subjective Opiate Withdrawal scales), opioid cravings (0-100 visual analog scale [VAS]), and preference ratings.

RESULTS

Of the 287 patients who switched from BNX-RDT to BNX film and 279 patients who switched from BNX film to BNX-RDT at day 15, 8.7% and 6.1% withdrew, respectively. Reductions in opioid withdrawal and cravings were similar with both formulations through day 15; after switching treatment, reductions were maintained through day 22 in both groups. Preference ratings at day 22 (patients had received both formulations) favored BNX-RDT for taste, mouthfeel, ease of administration, and overall preference (all P < 0.0001).

CONCLUSIONS

In both patient groups who switched treatment at day 15, more than 90% were retained in treatment, and reductions in opioid withdrawal and cravings were sustained. A significant majority of patients preferred BNX-RDT over BNX film, the clinical impact of which requires further study.

Efficacy of Buprenorphine/Naloxone Rapidly Dissolving Sublingual Tablets (BNX-RDT) After Switching From BNX Sublingual Film

OBJECTIVES

The aim of the study was to evaluate treatment retention, efficacy, and preference ratings among opioid-dependent patients transitioning between a buprenorphine/naloxone rapidly dissolving sublingual tablet formulation (BNX-RDT) and BNX film.

METHODS

After a 2-day, blinded, fixed-dose induction with BNX-RDT (5.7/1.4 mg and 5.7/1.4 or 11.4/2.8 mg, respectively) or buprenorphine (8 mg and 8 or 16 mg, respectively), patients received open-label titrated doses of BNX-RDT or BNX film (generic buprenorphine induction group) during days 3 to 14. On day 15, patients switched treatment (using a conversion ratio of 5.7-8 mg) and continued switched treatment through day 22. Assessments included treatment retention, opioid withdrawal (Clinical and Subjective Opiate Withdrawal scales), opioid cravings (0-100 visual analog scale [VAS]), and preference ratings.

RESULTS

Of the 287 patients who switched from BNX-RDT to BNX film and 279 patients who switched from BNX film to BNX-RDT at day 15, 8.7% and 6.1% withdrew, respectively. Reductions in opioid withdrawal and cravings were similar with both formulations through day 15; after switching treatment, reductions were maintained through day 22 in both groups. Preference ratings at day 22 (patients had received both formulations) favored BNX-RDT for taste, mouthfeel, ease of administration, and overall preference (all P < 0.0001).

CONCLUSIONS

In both patient groups who switched treatment at day 15, more than 90% were retained in treatment, and reductions in opioid withdrawal and cravings were sustained. A significant majority of patients preferred BNX-RDT over BNX film, the clinical impact of which requires further study.