Sublingual Buprenorphine-naloxone Research Articles

Examination of Correlates of OUD Outcomes in Young Adults: Secondary Analysis From the XBOT Trial.

Opioid use disorder (OUD) treatment outcomes are poorer for young adults than older adults. Developmental differences are broadly implicated, but particular vulnerability factor interactions are poorly understood. This study sought to identify moderators of OUD relapse between age groups. This secondary analysis compared young adults (18-25) to older adults (26+) from a comparative effectiveness trial ("XBOT") that randomized (N = 570) participants to extended-release naltrexone or sublingual buprenorphine-naloxone. We explored the relationship between 25 prespecified patient baseline characteristics and relapse to regular opioid use by age group and treatment condition, using logistic regression. Young adults (n = 111) had higher rates of 24-week relapse than older adults (n = 459) (70.3% vs 58.8%) and differed on a number of specific characteristics, including more smokers, more intravenous opioid use, and more cannabis use. No significant moderators predicted relapse, in either three-way or two-way interactions. No baseline factors were identified as moderating the relationship between age group and opioid relapse, nor any interactions between baseline characteristics, age group, and treatment condition to predict opioid relapse. Poorer treatment outcomes for young adults are likely associated with multiple developmental vulnerabilities rather than any single predominant factor. Although not reaching significance, several characteristics (using heroin, smoking tobacco, high levels of depression/anxiety, or treatment because of family/friends) showed higher odds ratio point estimates for relapse in young adults than older adults. This is the first study to explore moderators of worse OUD treatment outcomes in young adults, highlighting the need to identify predictor variables that could inform treatment enhancements. (Am J Addict 2021;00:1-12).

Buprenorphine Microdose Induction for the Management of Prescription Opioid Dependence.

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

An alternative analysis of illicit opioid use during treatment in a randomized trial of extended-release naltrexone versus buprenorphine-naloxone: A per-protocol and completers analysis

BackgroundThe distinct pharmacological properties and clinical uses of extended-release naltrexone (XR-NTX) and sublingual buprenorphine-naloxone (BUP-NX) present challenges in analyzing patient outcomes. MethodsWe conducted a secondary analysis of a multi-site randomized trial comparing XR-NTX with sublingual BUP-NX treatment for opioid use disorder initiated during inpatient detoxification and continued in outpatient treatment. Urine testing data for non-study opioids from the last 22 weeks of the 24-week trial were analyzed in both a per-protocol sample (n = 474 participants who received at least one dose of medication) and a completers sample (n = 211 participants who received all XR-NTX doses or all BUP-NX prescriptions). The present analyses sought to identify differences in the weekly percentages of opioid-positive urine tests between participants treated with the two medications. ResultsThe proportion of opioid-positive tests in both conditions was less than 20 % for 21 of the 22 weeks in the per-protocol sample and all 22 weeks in the completers sample. Generalized linear mixed model analyses revealed a significant treatment (XR-NTX vs. BUP-NX) X week (weeks 3–24) interaction in the per-protocol sample but not the completers sample. In the per-protocol analysis, the BUP-NX, compared to XR-NTX, had significantly greater proportions of opioid-positive tests in 14 out of the 22 weeks. ConclusionsLongitudinal modeling approaches that utilize flexible procedures for handling missing data can offer a different perspective on study findings. Results from the present analyses suggest that XR-NTX appeared to be somewhat more effective than BUP-NX in reducing illicit opioid use in the per-protocol sample.

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

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

Treatment of Opioid Dependence with Depot Buprenorphine (CAM2038) in Custodial Settings Is Safe, Effective and Cost-Effective

Background: Opioid agonist treatment (OAT) is effective but resource intensive to administer safely in custodial settings, leading to significant under-treatment of opioid dependence in these settings worldwide. Methods: This open-label trial compared depot buprenorphine, CAM2038 (weekly for 4 weeks then monthly) to oral methadone ( https://www.anzctr.org.au ACTRN12618000942257). Modelled treatment costs included a comparison group on sublingual buprenorphine-naloxone. Men and women, aged>18 years of various security classifications with a diagnosis of moderate to severe DSM-5 opioid use disorder and a custodial sentence of at least six months were recruited from correctional centres in New South Wales, Australia. Findings: Between November 2018 and July 2019, 67 patients not in OAT treatment at recruitment commenced depot buprenorphine. Sixty-two patients already stable on oral methadone treatment were recruited to the comparison arm. Patients treated with depot buprenorphine commonly reported at least one adverse event related to study drug (63/67, 94%), typically mild and transient. No diversion of depot buprenorphine was identified. Retention in depot buprenorphine treatment was 92%. Self-reported use of non-prescribed opioids (primarily buprenorphine-naloxone) and injecting drug use decreased significantly among depot buprenorphine patients by 16 weeks (p<0·0001). Monthly treatment costs were: $112AUD for injectable depot buprenorphine, $339AUD for oral methadone and $1,299AUD for sublingual buprenorphine-naloxone. Interpretation: The first published study to explore depot buprenorphine in custodial settings shows treatment retention, substance use and safety outcomes comparable to those observed in community settings and for other OAT used in custodial settings, without increased risk of diversion. Depot buprenorphine is a more efficient and less costly OAT delivery method requiring less health and custodial staff resources to administer. Enhanced access to depot buprenorphine should be considered for custodial settings worldwide. Trial Registration: (https://www.anzctr.org.au ACTRN12618000942257). Funding: NSW Health funded the study, and had input into design, data collection, analysis, interpretation and write-up. The JHFMHN provided clinical support for the study. Camurus AB provided CAM2038 for study participants with no right of veto of publication or dissemination of results. Declaration of Interests: AJD reports grants from Braeburn/Camurus AB, to conduct clinical studies with buprenorphine products and travel support to Hunter New England Local Health District, which employs AJD. He is an honorary investigator on an Indivior-funded study of buprenorphine products and has served on an advisory board for Mundipharma. PSH reports grants from Braeburn/Camurus AB, to conduct clinical studies with buprenorphine products and has served on advisory boards for Lundbeck, Indivior, AbbVie and Gilead. NL reports grants from Braeburn and Camurus AB to conduct sponsored, and investigator-led clinical studies with CAM2038. NL served on Advisory Boards for Mundipharma, Indivior and Chiesi Pharmaceuticals. MC was employed by the NSW Ministry of Health, sponsors of the study. All other authors declare no competing interests. Ethics Approval Statement: The trial was approved by JHFMHN and the Aboriginal Health and Medical Research Council (AHMRC) Human Research Ethics Committees (Protocol JH File No G561/17 & HREC/ 18/JH/3), as well as the CSNSW Ethics Committee. Participation was voluntary and written, informed consent was obtained from all participants prior to the conduct of any study procedure.

Patients' perspectives on initiating treatment with extended-release naltrexone (XR-NTX)

BackgroundThe National Drug Abuse Treatment Clinical Trials Network (CTN) multisite comparative-effectiveness study (“X:BOT”) by Lee et al. (2018) found that, once initiated, extended-release naltrexone (XR-NTX) is as similarly safe and effective as sublingual buprenorphine-naloxone (BUP-NX) for the treatment of opioid use disorder (OUD). However, the detoxification hurdle makes XR-NTX much more difficult to initiate than BUP-NX. This hurdle highlights the need to better understand how patients transition from active opioid use to XR-NTX treatment. ObjectiveTo explore patient-identified barriers and facilitators to initiating antagonist treatment (XR-NTX) within the context of an inpatient hospital setting and to reflect postdischarge experiences of those who did and did not initiate XR-NTX treatment. MethodWe used a convenience sampling strategy to identify study candidates, with the intention of recruiting approximately an equal number of medication-initiated and noninitiated patients. Study participants (N = 14) included 13 males and 1 female with OUD randomized to the XR-NTX arm of the X:BOT study at 1 of the 8 study sites. Seven participants in this sample initiated XR-NTX treatment, and seven did not. Each participant completed one semistructured qualitative interview. We analyzed transcripts using deductive and inductive approaches to conventional content analysis. ResultsAlthough the majority of participants viewed opioid blockade, once-monthly dosing, and no dependence or withdrawal as favorable attributes of XR-NTX, participant ambivalence and lack of familiarity with antagonist treatment were barriers to treatment initiation. The long duration of action and the perceived “commitment” to the medication (e.g., “At the time, a month sounded like a year”) compounded the patients' concerns and ambivalence. The majority of those who initiated XR-NTX described it as an effective treatment for OUD, with treatment satisfaction and sustained abstinence emerging as central themes among this population. Some participants who did not successfully initiate XR-NTX expressed regret and a willingness to try XR-NTX in the future. ConclusionAchieving full opioid detoxification is one, but not the only, barrier to initiating treatment with XR-NTX. Additional participant-identified barriers to XR-NTX initiation include fears and ambivalence regarding antagonist treatment. Once initiated, participants perceive XR-NTX to be an effective treatment for maintaining abstinence from opioids. XR-NTX appealed to participants due to the autonomy it affords with once-monthly dosing and no physical dependence.

Variants of opioid genes and response to treatment of opioid use disorder with buprenorphine-naloxone versus extended-release naltrexone in Caucasians

ABSTRACT Background: Sublingual buprenorphine-naloxone (BUP-NX), an FDA-approved treatment for opioid use disorder (OUD), combines buprenorphine (a partial mu/kappa agonist) with naloxone (a mu/ kappa antagonist). Extended-release injection naltrexone (XR-NTX; a mu receptor antagonist and kappa receptor partial agonist) is also an FDA-approved treatment for OUD. However, while some patients respond well to these medications, many others leave treatment and relapse. Objectives: Determine whether gene variants in the opioid gene system are associated with better or worse treatment response. Methods: In a 24-week, multisite, randomized, comparative effectiveness trial of daily, sublingual self-administration of BUP-NX versus monthly injection of XR-NTX conducted in the National Drug Abuse Clinical Trials Network, DNA was collected and four opioid gene variants were evaluated: (1) mu opioid receptor 118A>G; (2) 68-bp repeat in prodynorphin; (3) prodynorphin SNP rs910080; and (4) kappa opioid receptor SNP rs6473797. In non-Hispanic Caucasians (N = 334), two outcomes measures were assessed: received first dose (yes/no) and received last dose (yes/no). Separate logistic regressions were used to model each outcome measure as a function of treatment (XR-NTX vs BUP-NX), each gene variant, and their interaction. Results: There were no significant main effects of gene variant on receiving first dose or last dose. There were also no significant gene variant by treatment interactions. Conclusions: The outcome of treatment of OUD with medications is likely a complex function of multiple factors, including environmental, psychosocial, and possibly genetic, such that major effects of genetic variants may be unlikely.

Kratom Dependence and Treatment Options: A Comprehensive Review of the Literature.

Kratom, or Mitragyna speciosa Korth., is a tropical plant prevalent in Southeast Asia, and it is utilized as a traditional remedy for symptomatic relief of various illnesses. It has been labeled as an atypical opioid with significant narcotic-like properties, capable of inducing kratom dependence among those who misuse or abuse it. The prevalence of kratom use has drastically increased worldwide, raising concerns among healthcare providers, particularly regarding the availability of efficacious treatment options for kratom dependence. This manuscript provides a comprehensive narrative review of literature focusing on the psychoactive alkaloids of kratom, the possible neurobiological and pathophysiological models underlying the occurrence of kratom dependence, and the clinical presentations and effective treatment options available for kratom dependence. The psychoactive alkaloids of kratom, such as mitragynine (MG) and 7-hydroxymitragynine (7-HMG), act as partial mu opioid agonists and induce kratom dependence. As a result, regular kratom use leads to withdrawal symptoms on abstinence, along with craving, tolerance, and cross-tolerance to morphine. The psychological withdrawal symptoms reported include depressed mood, anxiety, restlessness, irritability, and feeling tense, while the physical withdrawal symptoms are myalgia and body ache, joint pain, lacrimation, running nose, yawning, insomnia, diarrhea, feverish sensation, loss of appetite, tremors, itching over the body, loss of concentration, and chills. Neonatal withdrawal symptoms, such as oral intolerance, restlessness, irritability, and vomiting, are also reported in newborns of women who are on regular kratom use. Sublingual buprenorphine-naloxone (Suboxone) is reported as a promising treatment for detoxification and maintenance replacement therapy for kratom-dependent users. Alternative treatments for in-patient detoxification include intravenous clonidine and a combination of oral dihydrocodeine and lofexidine. We conclude by adding a note on the research gap concerning kratom dependence, which future studies should focus on.

Extended-release naltrexone versus buprenorphine-naloxone to treat opioid use disorder among black adults

Few studies examine the effectiveness of treatments for opioid use disorder (OUD) among Black individuals despite recent evidence suggesting opioid overdose death rates are, in some cases, highest and increasing at a faster rate among Black people compared to other racial/ethnic groups. This secondary analysis study investigated treatment preference, retention, and relapse rates amongst a subgroup of 73 Black participants with OUD (81% male, mean age 39.05, SD = 11.80) participating in a 24-week multisite randomized clinical trial (“X:BOT”) comparing the effectiveness of extended-release naltrexone (XR-NTX) and sublingual buprenorphine-naloxone (BUP-NX) between 2014 and 2017. Chi-square analyses were used to investigate treatment preference assessed at baseline, and logistic regression analyses were used to investigate differences in the odds of retention and relapse assessed over the 24-week course of treatment between treatment groups. Our findings suggest no differences in preference for XR-NTX versus BUP-NX. However, similar to the parent trial, there was an induction hurdle such that only 59.5% of those randomized to XR-NTX successfully initiated medication compared to 91.6% of those randomized to BUP-NX (OR = 0.13, 95% CI = 0.04, 0.52). No significant differences were found in treatment retention (intention-to-treat: OR = 1.19, 95% CI = 0.43, 3.28; per-protocol [i.e., those who initiated medication]: OR = 0.60, 95% CI = 0.20, 1.82) or relapse rates between treatment groups (intention-to-treat: OR = 1.53, 95% CI = 0.57, 4.13; per-protocol: OR = 0.69, 95% CI = 0.23, 2.06). Although there is a significant initiation hurdle with XR-NTX, once inducted, both medications appear similar in effectiveness, but as in the main study, dropout rates were high. Future research is needed on how to improve adherence.

Therapeutic Drug Monitoring in Buprenorphine/Naloxone Treatment for Opioid Use Disorder: Clinical Feasibility and Optimizing Assay Precision.

Compliance with sublingual buprenorphine/naloxone (SL-BUP/NX) is associated with higher abstinence from illicit opioid use. Therapeutic drug monitoring (TDM) has been recommended for adherence monitoring of buprenorphine (BUP) maintenance treatment for opioid use disorder (OUD), but to date there have been no reported clinical applications. In this TDM feasibility study, we investigated BUP assay precision in 15 adults with OUD who had been stabilized on buprenorphine/naloxone. Using solid phase extraction, BUP recovery was contrasted at 100 mMol and 1 Molar of acetic acid wash solution. Precision was determined by applying the condition generating highest recovery using 0.2 ng/mL and 10 ng/mL standards. Four blood samples were drawn to examine the BUP peak and trough plasma concentrations, and BUP elimination rate was estimated. BUP recovery was examined again in a random sample and contrasted with the concentration predicted applying first-order kinetics. Higher BUP recovery was achieved with 1 Molar wash (94.3%; p=0.05). Precision ranged from 15-20%. The estimated limit of detection (LoD) and limit of quantitation (LoQ) were 0.02 and 0.069 ng/mL, respectively. BUP peak and trough concentrations were successfully examined, and BUP trough concentrations were replicated confirming steady state. BUP concentrations were predicted at a variance of -7.20% to 1.54 %. TDM for BUP maintenance treatment of OUD is feasible, and simple adjustment of the assay conditions enhances BUP recovery.

Pharmacogenomics and Opioid Use Disorder: Clinical Decision Support in an African American Cohort

Opioid use disorder (OUD) constitutes a significant public health burden as opioid overdose deaths have continued to rise in the United States. Although treatment modalities are available to manage OUD, some patients experience challenges achieving their OUD management goals. Some of these challenges may be attributable to inherited genetic variations, or polymorphisms, on the genes that code for proteins impacting the pharmacokinetics or pharmacodynamics of medications used in OUD management. Clinical pharmacogenomics testing can elucidate these polymorphisms; however, a lack of real-world evidence for the use of pharmacogenomics in OUD management complicates the implementation process. We conducted a retrospective cohort study of 113 patients undergoing buprenorphine-based OUD management in Northeast Washington D.C. to determine if clinical pharmacogenomics testing for CYP3A4 and CYP3A5 would impact treatment outcomes. Data were collected from the electronic medical record (EMR) from December 30, 2015 to December 31, 2016. Study outcomes were based on presence of withdrawal symptoms, instances of unauthorized substances in urine drug tests (UDTs), and sublingual buprenorphine/naloxone (SBN) dose with standard-of-care (SOC) dosing versus pharmacogenomics (PGx)-based dosing. Pearson correlation tests, Wilcoxon signed rank tests, Wilcoxon rank sum tests, and one-way ANOVA tests were used. Linear and logistic regression analyses were used to assess predictors of withdrawal symptomatology. Kaplan-Meier survival analyses were used to assess time to first withdrawal. Our research suggests that patients with at least one copy of the CYP3A4*1B allele exhibit an accelerated rate of metabolism compared to the wild-type allele CYP3A4*1.

Perioperative opioid requirements of patients receiving sublingual buprenorphine-naloxone: a case series

BackgroundBuprenorphine, a partial opioid agonist, displaces full opioid agonists from receptors and may impede surgical pain management. We report the effects of a sublingual formulation of buprenorphine-naloxone, Suboxone (SL-BUP), on perioperative pain management.MethodsWe identified all adult surgical patients from December 31, 2004, to January 1, 2016, who received SL-BUP within 30 days prior to procedures performed with general, regional, or combined general/regional anesthesia. We recorded opioid use during the procedure, in the post-anesthesia care unit (PACU), and during the 24 h following PACU discharge. We also examined opioid use in those who continued SL-BUP until the day of surgery vs those who preoperatively discontinued SL-BUP.ResultsThirty-two patients were treated preoperatively with SL-BUP. Three patients had regional anesthesia only, and opioid requirements were case dependent. Requirements were minimal for creation of an arteriovenous fistula and high following knee replacement and cesarean section. Twelve patients received combined general/regional anesthesia, and 17 received general anesthesia only. Intraoperative and PACU opioid use in these 2 groups were not significantly different (P = .10 and P = .93, respectively). In both groups opioid use increased after discharge from the PACU, and remained comparable between the general and combined general/regional group through the first 24 h after PACU discharge (P = .78). Although median [interquartile range] 24-h opioid doses were higher among patients who discontinued SL-BUP, the difference was not statistically significant in the general anesthesia–only group (SL-BUP discontinued, 199 [110–411] mg IV-MEq [intravenous morphine equivalent] vs SL-BUP continued, 106 [58–160] mg IV-MEq; P = .15) or in the combined general/regional group (SL-BUP discontinued, 140 [100–157] mg IV-MEq vs SL-BUP continued, 100 [73–203] mg IV-MEq; P = .94).ConclusionsRegardless of the type of anesthesia used, physicians treating patients with SL-BUP must be prepared to administer large doses of opioids during the early postoperative period. No difference in opioid requirements was noted between patients who perioperatively stopped SL-BUP versus those who continued SL-BUP.

Decline in Buprenorphine/Naloxone Prescriptions in a State Medicaid Population Following Formulary Conversion from Suboxone to Bunavail.

A large, statewide, fee-for-service Medicaid plan recently (October 2015) executed a complete switch from sublingual buprenorphine-naloxone [(SLBN), Suboxone®] to buccal buprenorphine-naloxone [(BBN), Bunavail®] on its preferred drug formulary. This complete formulary switch provided an opportunity to assess dynamic changes in prescribing patterns, patient/physician acceptance, and indices of potential misuse/diversion. For the period January 1, 2015 through December 31, 2016, two datasets were analyzed: prescriptions and associated costs for buprenorphine-naloxone (BN) products and urine toxicology test results for patients in the Medicaid plan. The dataset comprised 1370 unique providers ordering 643,225 prescriptions for opioid addiction therapy. Patient and order volumes, and the rate of monthly positive laboratory values for opioid molecules and cocaine were reviewed. A targeted survey of physicians treating opioid-dependent patients with state Medicaid plan coverage was also conducted. Upon plan conversion to BBN, there was a rapid increase in monthly BBN prescriptions mirrored by a rapid decrease in SLBN prescriptions. Peak in BBN prescriptions (2633 in November 2015) was approximately 60% lower than peak in SLBN prescriptions (6531 in July 2015). An unexpected finding was a 68% reduction of the overall BN market, indicating that many BN prescriptions were abandoned. The reduction was associated with quarterly cost savings to the Medicaid plan of approximately $3.5 million. Toxicology results indicated a reduction in drug positivity (defined as positivity for cocaine and/or any opioids except buprenorphine and methadone) from 13-16% in 2015 to less than 10% in 2016. Heroin positivity decreased from approximately 9% in December 2015 to an average of less than 1% during the last quarter of 2016, while positivity for norbuprenorphine, the major metabolite of buprenorphine, showed a marked increase in 2016 vs 2015. Among physicians who responded to the targeted survey most rated BBN as more difficult to abuse or misuse than SLBN. The rapid reduction in the overall BN market following a complete formulary switch from SLBN to BBN was associated with quarterly savings of $3.5 million for the state Medicaid plan. Toxicology data suggest that this cost saving was realized in the context of improved physician and patient adherence to treatment protocols. The changing market dynamics can potentially be explained by a number of contributory factors, including a reduction of diversion and illicit distribution of BN following formulary conversion. These results are considered hypothesis-generating and future research should systematically compare the propensity for diversion and abuse of BN products using various epidemiological tracking tools. BioDelivery Sciences International, Inc.

Comparative effectiveness of extended-release naltrexone versus buprenorphine-naloxone for opioid relapse prevention (X:BOT): a multicentre, open-label, randomised controlled trial

Extended-release naltrexone (XR-NTX), an opioid antagonist, and sublingual buprenorphine-naloxone (BUP-NX), a partial opioid agonist, are pharmacologically and conceptually distinct interventions to prevent opioid relapse. We aimed to estimate the difference in opioid relapse-free survival between XR-NTX and BUP-NX. We initiated this 24 week, open-label, randomised controlled, comparative effectiveness trial at eight US community-based inpatient services and followed up participants as outpatients. Participants were 18 years or older, had Diagnostic and Statistical Manual of Mental Disorders-5 opioid use disorder, and had used non-prescribed opioids in the past 30 days. We stratified participants by treatment site and opioid use severity and used a web-based permuted block design with random equally weighted block sizes of four and six for randomisation (1:1) to receive XR-NTX or BUP-NX. XR-NTX was monthly intramuscular injections (Vivitrol; Alkermes) and BUP-NX was daily self-administered buprenorphine-naloxone sublingual film (Suboxone; Indivior). The primary outcome was opioid relapse-free survival during 24 weeks of outpatient treatment. Relapse was 4 consecutive weeks of any non-study opioid use by urine toxicology or self-report, or 7 consecutive days of self-reported use. This trial is registered with ClinicalTrials.gov, NCT02032433. Between Jan 30, 2014, and May 25, 2016, we randomly assigned 570 participants to receive XR-NTX (n=283) or BUP-NX (n=287). The last follow-up visit was Jan 31, 2017. As expected, XR-NTX had a substantial induction hurdle: fewer participants successfully initiated XR-NTX (204 [72%] of 283) than BUP-NX (270 [94%] of 287; p<0·0001). Among all participants who were randomly assigned (intention-to-treat population, n=570) 24 week relapse events were greater for XR-NTX (185 [65%] of 283) than for BUP-NX (163 [57%] of 287; hazard ratio [HR] 1·36, 95% CI 1·10-1·68), most or all of this difference accounted for by early relapse in nearly all (70 [89%] of 79) XR-NTX induction failures. Among participants successfully inducted (per-protocol population, n=474), 24 week relapse events were similar across study groups (p=0·44). Opioid-negative urine samples (p<0·0001) and opioid-abstinent days (p<0·0001) favoured BUP-NX compared with XR-NTX among the intention-to-treat population, but were similar across study groups among the per-protocol population. Self-reported opioid craving was initially less with XR-NTX than with BUP-NX (p=0·0012), then converged by week 24 (p=0·20). With the exception of mild-to-moderate XR-NTX injection site reactions, treatment-emergent adverse events including overdose did not differ between treatment groups. Five fatal overdoses occurred (two in the XR-NTX group and three in the BUP-NX group). In this population it is more difficult to initiate patients to XR-NTX than BUP-NX, and this negatively affected overall relapse. However, once initiated, both medications were equally safe and effective. Future work should focus on facilitating induction to XR-NTX and on improving treatment retention for both medications. NIDA Clinical Trials Network.

Effectiveness and cost-effectiveness of unsupervised buprenorphine-naloxone for the treatment of heroin dependence in a randomized waitlist controlled trial

BackgroundAccess to opioid agonist treatment can be associated with extensive waiting periods with significant health and financial burdens. This study aimed to determine whether patients with heroin dependence dispensed buprenorphine-naloxone weekly have greater reductions in heroin use and related adverse health effects 12-weeks after commencing treatment, compared to waitlist controls and to examine the cost-effectiveness of this strategy. MethodsAn open-label waitlist RCT was conducted in an opioid treatment clinic in Newcastle, Australia. Fifty patients with DSM-IV-TR heroin dependence (and no other substance dependence) were recruited. The intervention group (n=25) received take-home self-administered sublingual buprenorphine-naloxone weekly (mean dose, 22.7±5.7mg) and weekly clinical review. Waitlist controls (n=25) received no clinical intervention. The primary outcome was heroin use (self-report, urine toxicology verified) at weeks four, eight and 12. The primary cost-effectiveness outcome was incremental cost per additional heroin-free-day. ResultsOutcome data were available for 80% of all randomized participants. Across the 12-weeks, treatment group heroin use was on average 19.02days less/month (95% CI −22.98, −15.06, p<0.0001). A total 12-week reduction in adjusted costs including crime of $A5,722 (95% CI 3299, 8154) in favor of treatment was observed. Excluding crime, incremental cost per heroin-free-day gained from treatment was $A18.24 (95% CI 4.50, 28.49). ConclusionWhen compared to remaining on a waitlist, take-home self-administered buprenorphine-naloxone treatment is associated with significant reductions in heroin use for people with DSM-IV-TR heroin dependence. This cost-effective approach may be an efficient strategy to enhance treatment capacity.

Ethical and clinical safety considerations in the design of an effectiveness trial: A comparison of buprenorphine versus naltrexone treatment for opioid dependence

We examine ethical challenges encountered in the design of an effectiveness trial (CTN-0051; X:BOT), comparing sublingual buprenorphine-naloxone (BUP-NX), an established treatment for opioid dependence, to the newer extended-release injectable naltrexone (XR-NTX). Ethical issues surrounded: 1) known poor effectiveness of one possible, commonly used treatment as usual control condition—detoxification followed by counseling without medication; 2) the role of patients' preferences for treatments, given that treatments were clinically approved and available to the population; 3) differences between the optimal “usual treatment” clinical settings for different treatments making it challenging to design a fair comparison; 4) vested interest groups favoring different treatments exerting potential influence on the design process; 5) potentially vulnerable populations of substance users and prisoners; 6) potential therapeutic misconception in the implementation of safety procedures; and 7) high cost of a large trial limiting questions that could be addressed. We examine how the design features underlying these ethical issues are characteristic of effectiveness trials, which are often large trials that compare treatments with varying degrees of existing effectiveness data and familiarity to patients and clinicians, in community-based treatment settings, with minimal exclusion criteria that could involve vulnerable populations. Hence, investigators designing effectiveness trials may wish to remain alert to the possibility of similar ethical issues.

Opioid-induced constipation: rationale for the role of norbuprenorphine in buprenorphine-treated individuals

Buprenorphine and buprenorphine–naloxone fixed combinations are effective for managing patients with opioid dependence, but constipation is one of the most common side effects. Evidence indicates that the rate of constipation is lower when patients are switched from sublingual buprenorphine–naloxone tablets or films to a bilayered bioerodible mucoadhesive buccal film formulation, and while the bilayered buccal film promotes unidirectional drug flow across the buccal mucosa, the mechanism for the reduced constipation is unclear. Pharmacokinetic simulations indicate that chronic dosing of sublingually administered buprenorphine may expose patients to higher concentrations of norbuprenorphine than buprenorphine, while chronic dosing of the buccal formulation results in higher buprenorphine concentrations than norbuprenorphine. Because norbuprenorphine is a potent full agonist at mu-opioid receptors, the differences in norbuprenorphine exposure may explain the observed differences in treatment-emergent constipation between the sublingual formulation and the buccal film formulation of buprenorphine–naloxone. To facilitate the understanding and management of opioid-dependent patients at risk of developing opioid-induced constipation, the clinical profiles of these formulations of buprenorphine and buprenorphine-naloxone are summarized, and the incidence of treatment-emergent constipation in clinical trials is reviewed. These data are used to propose a potential role for exposure to norbuprenorphine, an active metabolite of buprenorphine, in the pathophysiology of opioid-induced constipation.

New developments in the management of opioid dependence: focus on sublingual buprenorphine-naloxone.

Opioid maintenance therapy is a well-established first-line treatment approach in opioid dependence. Buprenorphine, a partial opioid agonist, has been found by numerous studies to be an effective and safe medication in the treatment of opioid dependence. At present, buprenorphine is available as a monodrug or in a fixed 4:1 ratio combination with naloxone. A diminished risk of diversion and abuse for the buprenorphine–naloxone combination is likely but not firmly established. Conventional formulations are given sublingually to avoid the hepatic first-pass effect. A novel film tablet is available only in the US and Australia. Other novel, sustained-release formulations (implant, depot) are currently being developed and tested. Recent studies, including a Cochrane meta-analysis, suggest that the retention with buprenorphine is lower than for methadone, but that buprenorphine may be associated with less drug use. Higher doses of buprenorphine are associated with better retention rates. Buprenorphine has a ceiling effect at the opioid receptor with regard to respiratory depression, and may cause fewer fatal intoxications than methadone. Possible antidepressant effects of buprenorphine and its use in comorbid psychiatric patients has not been studied in much detail. Clinical implications are discussed.

Parenteral buprenorphine–naloxone abuse is a major cause of fatal buprenorphine-related poisoning

Buprenorphine (BPN) medication for opioid maintenance treatment in Finland consists predominantly of buprenorphine–naloxone (BNX). Both BPN and BNX are associated with diversion, abuse and non-medically supervised use worldwide. Our purpose was to estimate the proportion of BNX to all BPN-related fatalities. The material consisted of 225 deceased drug abusers in Finland from January 2010 to June 2011 with a positive BPN and/or norbuprenorphine (NOR) and/or naloxone (NX) finding in urine. The data were divided into three groups based on the urine NX and BPN concentrations. The “Parenteral BNX” group (>100μg/l NX) was presumed to consist of injecting or snorting BNX abusers and the “Parenteral BPN” group (>50μg/l BPN, 0μg/l NX) of injecting or snorting BPN abusers, while the “Other BNX or BPN” group (≤100μg/l NX, or ≤50μg/l BPN combined with 0μg/l NX) was presumed to consist of mainly sublingual BNX or BPN users. In 12.4% of cases the NX urine concentration was higher than the threshold 100μg/l. In fatal BPN poisonings, the proportion of parenteral BNX was 28.4%. In the “Parenteral BNX”, “Parenteral BPN” and “Other BNX or BPN” groups, the proportion of fatal BPN poisonings was 67.9, 31.0 and 22.6%, respectively. BNX abuse can be fatal. Among the 225 BPN-related fatalities, parenteral abuse of BNX was shown to be common (12.4%) and BNX poisoning was the underlying cause of death in 8.4%. Parenteral BNX caused fatal BPN poisoning proportionally more often than parenteral BPN.

Conversion of Chronic Pain Patients from FullOpioid Agonists to Sublingual Buprenorphine

Background: Sublingual buprenorphine-naloxone (buprenorphine SL) is a preparation that is used to treat opioid dependence. In addition, the Drug Enforcement Administration (DEA) has acknowledged the legality of an off-label use to treat pain with a sublingual buprenorphine preparation. Buprenorphine SL is unique among the opioid class of analgesics; this compound has a high affinity for the mu-receptor, yet only partially activates it. Thus, buprenorphine SL can provide analgesia, yet minimize opioid side effects. Many patients on high doses of traditional opioid medication develop tolerance. Despite escalating medication dosage, a subset of patients had a paradoxical increase in pain, which has been characterized as opioid-induced hyperalgesia (OIH). Buprenorphine SL, on the other hand, may even be anti-hyperalgesic and may have utility in treating these challenging patients. Objective: To determine the effectiveness of converting patients from traditional full agonist opioid medication to sublingual buprenorphine, as well as to identify patient groups that are most likely to benefit from this therapy. Patients who underwent conversion either had developed tolerance with diminished analgesia or were experiencing side effects on their opioid medications. Study Design: An observational report of outcomes assessment. Setting: An interventional pain management practice setting in the United States. Methods: Retrospective data from clinical records was compiled on 104 de-identified chronic pain patients whose personal information had been redacted (60 men and 44 women, aged 21-78) and who had previously been treated with opioid-agonist drugs; they were converted to buprenorphine SL in tablet form during the study. Chronic pain was defined as persistent pain for at least 6 months. Data collected from patient profiles included age, sex, diagnosis, medication history, pre-induction opioid intake, reason for detoxification, preinduction Clinical Opiate Withdrawal Score (COWS), and if applicable, cause of buprenorphine SL cessation. Pain levels and Quality of Life scores were recorded before and after conversion to buprenorphine SL. Outcome Measures: Level of analgesia for patients who continued conversion to sublingual buprenorphine for more than 2 months. Results: After initiation of buprenorphine SL therapy for more than 2 months, the mean pain scores on a scale from 0-10 decreased by 2.3 points (P &lt; 0.001). Patient Quality of Life (QoL scale) was not significantly affected by buprenorphine SL therapy (P = 0.14). The success rate was highest for patients using morphine, oxycodone, and fentanyl before buprenorphine SL induction. These patient groups had a 3.7 point decrease in pain for those taking morphine, a 2.5 point decrease in pain for those taking oxycodone, and a 2.2 point decrease for those taking fentanyl. The smallest pain reduction was seen in the patient group using oxymorphone before conversion with a 1.1 point decrease in pain. Patients taking between 100-199 mg morphine equivalent per day experienced the greatest reduction (2.7 points) in pain scores. Patients taking between 200 and 299 mg morphine equivalent before buprenorphine SL induction exhibited a decrease of over 2 points on average. Patients taking &gt; 400mg morphine equivalent reported the smallest reduction in pain scores, on average a 1.1 point decrease. Limitations: This study is limited by its observational nature. Conclusions: Patients continuing buprenorphine SL therapy for more than 60 days reported significant decreases in pain (2.3 points). Patients on doses of opioid medication between 100-199 mg morphine equivalents seemed to fare better with conversion to buprenorphine SL than patients on the highest doses (&gt; 400 mg morphine equivalents). The opioid drug used by the patient before buprenorphine SL induction appears to have some effect on buprenorphine SL conversion success. Patients previously taking morphine, oxycodone, and fentanyl had the greatest decrease in pain after conversion to buprenorphine SL. Key Words: Sublingual buprenorphine-naloxone, buprenorphine, buprenorphine SL, opioid dependence, opioid conversion, opioid-induced hyperalgesia, analgesia, full agonist opioids, opioid tolerance.