Buprenorphine treatment of opioid dependence: clinical trial of daily versus alternate-day dosing

Diversity inclusion in United States opioid pharmacological treatment trials: A systematic review

Pharmacological treatments for opioid use disorders (OUDs) may have mixed efficacy across diverse groups, i.e., sex/gender, race/ethnicity, and socioeconomic status (SES). The present systematic review aims to examine how diverse groups have been included in U.S. randomized clinical trials examining pharmacological treatments (i.e., methadone, buprenorphine, or naltrexone) for OUDs. PubMed was systematically searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The initial search yielded 567 articles. After exclusion of ineligible articles, 50 remained for the present review. Of the included articles, 14.0% (n = 7) reported both full (i.e., accounting for all participants) sex/gender and race/ethnicity information; only two of those articles also included information about any SES indicators. Moreover, only 22.0% (n = 11) reported full sex/gender information, and 42.0% (n = 21) reported full racial/ethnic information. Furthermore, only 10.0% (n = 5) reported that their lack of subgroup analyses or diverse samples was a limitation to their studies. Particularly underrepresented were American Indian/Alaska Native (AI/AN), Asian, Native Hawaiian/Other Pacific Islander (NH/OPI), and multiracial individuals. These results also varied by medication type; Black individuals were underrepresented in buprenorphine randomized controlled trials (RCTs) but were well represented in RCTs for methadone and/or naltrexone. In conclusion, it is critical that all people receive efficacious pharmacological care for OUDs given the ongoing opioid epidemic. Findings from the present review, however, support that participants from diverse or marginalized backgrounds are underrepresented in treatment trials, despite being at increased risk for disparities related to OUDs. Suggestions for future research are advanced. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A buprenorphine-validated rat model of opioid use disorder optimized to study sex differences in vulnerability to relapse

RATIONALE

Opioid use disorder (OUD) is a major epidemic in the USA. Despite evidence indicating that OUD may be particularly severe for women, preclinical models have yet to establish sex as a major factor in OUD.

OBJECTIVES

Here, we examined sex differences in vulnerability to relapse following intermittent access fentanyl self-administration and protracted abstinence and used buprenorphine, the FDA-approved treatment for OUD, to test the validity of our model.

METHODS

Following acquisition of fentanyl self-administration under one of two training conditions, male and female rats were given extended, 24-h/day access to fentanyl (0.25 μg/kg/infusion, 10 days) using an intermittent access procedure. Vulnerability to relapse was assessed using an extinction/cue-induced reinstatement procedure following 14 days of abstinence; buprenorphine (0 or 3 mg/kg/day) was administered throughout abstinence.

RESULTS

Levels of drug-seeking were high following extended-access fentanyl self-administration and abstinence; buprenorphine markedly decreased drug-seeking supporting the validity of our relapse model. Females self-administered more fentanyl and responded at higher levels during subsequent extinction testing. Buprenorphine was effective in both sexes and eliminated sex and estrous phase differences in drug-seeking. Interestingly, the inclusion of a time-out during training had a major impact on later fentanyl self-administration in females, but not males, indicating that the initial exposure conditions can persistently impact vulnerability in females.

CONCLUSIONS

These findings demonstrate the utility of this rat model for determining sex and hormonal influences on the development and treatment of OUD.

Pharmacological therapies for management of opium withdrawal

BACKGROUND

Pharmacologic therapies for management of heroin withdrawal have been studied and reviewed widely. Opium dependence is generally associated with less severe dependence and milder withdrawal symptoms than heroin. The evidence on withdrawal management of heroin might therefore not be exactly applicable for opium.

OBJECTIVES

To assess the effectiveness and safety of various pharmacologic therapies for the management of the acute phase of opium withdrawal.

SEARCH METHODS

We searched the following sources up to September 2017: CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, regional and national databases (IMEMR, Iranmedex, and IranPsych), main electronic sources of ongoing trials, and reference lists of all relevant papers. In addition, we contacted known investigators to obtain missing data or incomplete trials.

SELECTION CRITERIA

Controlled clinical trials and randomised controlled trials on pharmacological therapies, compared with no intervention, placebo, other pharmacologic treatments, different doses of the same drug, and psychosocial intervention, to manage acute withdrawal from opium in a maximum duration of 30 days.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 13 trials involving 1096 participants. No pooled analysis was possible. Studies were carried out in three countries, Iran, India, and Thailand, in outpatient and inpatient settings. The quality of the evidence was generally very low.When the mean of withdrawal symptoms was provided for several days, we mainly focused on day 3. The reason for this was that the highest severity of opium withdrawal is in the second to fourth day.Comparing different pharmacological treatments with each other, clonidine was twice as good as methadone for completion of treatment (risk ratio (RR) 2.01, 95% confidence interval (CI) 1.69 to 2.38; 361 participants, 1 study, low-quality evidence). All the other results showed no differences between the considered drugs: baclofen versus clonidine (RR 1.06, 95% CI 0.63 to 1.80; 66 participants, 1 study, very low-quality evidence); clonidine versus clonidine plus amantadine (RR 1.03, 95% CI 0.86 to 1.24; 69 participants, 1 study); clonidine versus buprenorphine in an inpatient setting (RR 1.04, 95% CI 0.90 to 1.20; 1 study, 35 participants, very low-quality evidence); methadone versus tramadol (RR 0.95, 95% CI 0.65 to 1.37; 1 study, 72 participants, very low-quality evidence); methadone versus methadone plus gabapentin (RR 1.17, 95% CI 0.96 to 1.43; 1 study, 40 participants, low-quality evidence), and tincture of opium versus methadone (1 study, 74 participants, low-quality evidence).Comparing different pharmacological treatments with each other, adding amantadine to clonidine decreased withdrawal scores rated at day 3 (mean difference (MD) -3.56, 95% CI -5.97 to -1.15; 1 study, 60 participants, very low-quality evidence). Comparing clonidine with buprenorphine in an inpatient setting, we found no difference in withdrawal symptoms rated by a physician (MD -1.40, 95% CI -2.93 to 0.13; 1 study, 34 participants, very low-quality evidence), and results in favour of buprenorpine when rated by participants (MD -11.80, 95% CI -15.56 to -8.04). Buprenorphine was superior to clonidine in controlling severe withdrawal symptoms in an outpatient setting (RR 0.35, 95% CI 0.19 to 0.64; 1 study, 76 participants). We found no difference in the comparison of methadone versus tramadol (MD 0.04, 95% CI -2.68 to 2.76; 1 study, 72 participants) and in the comparison of methadone versus methadone plus gabapentin (MD -2.20, 95% CI -6.72 to 2.32; 1 study, 40 participants).Comparing clonidine versus buprenorphine in an outpatient setting, more adverse effects were reported in the clonidine group (1 study, 76 participants). Higher numbers of participants in the clonidine group experienced hypotension at days 5 to 8, headache at days 1 to 8, sedation at days 5 to 8, dizziness and dry mouth at days 1 to 10, and nausea at days 1 to 9. Sweating was reported in a significantly higher number of participants in the buprenorphine group at days 1 to 10. We found no difference between groups for all the other comparisons considering this outcome.Comparing different dosages of the same pharmacological detoxification treatment, a high dose of clonidine (1 to 1.2 mg/day) did not differ from a low dose of clonidine (0.5 to 0.6 mg/day) in completion of treatment in an inpatient setting (RR 1.00, 95% CI 0.84 to 1.19; 1 study, 68 participants), however a higher number of participants with hypotension was reported in the high-dose group (RR 3.25, 95% CI 1.77 to 5.98). Gradual reduction of methadone was associated with more adverse effects than abrupt withdrawal of methadone (RR 2.25, 95% CI 1.02 to 4.94; 1 study, 20 participants, very low-quality evidence).

AUTHORS' CONCLUSIONS

Results did not support using any specific pharmacological approach for the management of opium withdrawal due to generally very low-quality evidence and small or no differences between treatments. However, it seems that opium withdrawal symptoms are significant, especially at days 2 to 4 after discontinuation of opium. All of the assessed medications might be useful in alleviating symptoms. Those who receive clonidine might experience hypotension.

Buprenorphine/Naloxone Maintenance Therapy: an Observational Retrospective Report on the Effect of Dose on 18 months Retention in an Office-Based Treatment Program

CONTEXT AND OBJECTIVE

Buprenorphine has been available with few reports of the dose range necessary to adequately maintain patients. We report on the effect of 8 mg/d versus 16 mg/d of buprenorphine on long-term patient retention in office-based opioid maintenance (OBOMT).

DESIGN SETTING AND PARTICIPANTS

Case series, at an urban hospital-based primary care clinic providing OBOMT to 157 opiate-dependent, low socioeconomic status, uninsured, nonhomeless patients.

INTERVENTION

The OBOMT program operated by a comprehensive sobriety treatment program experienced State funding cuts. Thus, after 2 years, the program was required by the State funder to decrease the buprenorphine maintenance dose from 16 to 8 mg/d for all new admissions. We report on patient retention before and after dose reduction.

MAIN OUTCOME MEASURES

The primary outcomes of this study were to measure and compare patient retention in the 2 cohorts at each point of treatment transition over the 18 months following OBOMT initiation.

RESULTS

No significant differences in patient retention were observed between the 16 and 8 mg/d patient cohorts. Lower dose buprenorphine maintenance (8 mg/d) in uninsured patients enrolled in publicly funded long-term OBOMT combined with comprehensive sobriety counseling was as effective as higher dose therapy (16 mg/d) in promoting patient retention throughout the study period. This lower dose resulted in a substantial saving to the public funding agency.

CONCLUSIONS

In an observational retrospective report, retention in treatment of opiate-addicted patients was the same at 8 and 16 mg/d buprenorphine doses after 18 months. These data have implications for public and managed care funding of OBOMT, for the general prescribing of buprenorphine in outpatient care, and may be instructive in the ongoing debate about the relationship between buprenorphine dose.

Research Note — Review of Corrections-Based Therapy for Opiate-Dependent Patients: Implications for Buprenorphine Treatment among Correctional Populations

Inmates with a history of opiate dependence represent a substantial proportion of the correctional population in the United States. Opiate use has negative consequences for both the inmate and society, including increased recidivism rates, increased infectious disease prevalence, avoidable emergency room use, decreased access to primary care services, and overdose. While there have been great successes in community-based treatment of opiate dependence, these successes have not yet been achieved in correctional settings. This paper reviews the pharmacological treatment options for opiate-dependent inmates, along with potential application for community-to-correctional approaches. The recent approval by the Food and Drug Administration (FDA) of physician-prescribed buprenorphine and the new opportunities it presents to corrections-based treatment are also explored in depth. Successful implementation of such strategies is likely to result in desirable health and social outcomes for both the inmate and the community at large.

Buprenorphine maintenance versus placebo or methadone maintenance for opioid dependence

BACKGROUND

Buprenorphine maintenance treatment has been evaluated in randomised controlled trials against placebo medication, and separately as an alternative to methadone for management of opioid dependence.

OBJECTIVES

To evaluate buprenorphine maintenance compared to placebo and to methadone maintenance in the management of opioid dependence, including its ability to retain people in treatment, suppress illicit drug use, reduce criminal activity, and mortality.

SEARCH METHODS

We searched the following databases to January 2013: Cochrane Drugs and Alcohol Review Group Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Current Contents, PsycLIT, CORK, Alcohol and Drug Council of Australia, Australian Drug Foundation, Centre for Education and Information on Drugs and Alcohol, Library of Congress, reference lists of identified studies and reviews. We sought published/unpublished randomised controlled trials (RCTs) from authors.

SELECTION CRITERIA

Randomised controlled trials of buprenorphine maintenance treatment versus placebo or methadone in management of opioid-dependent persons.

DATA COLLECTION AND ANALYSIS

We used Cochrane Collaboration methodology.

MAIN RESULTS

We include 31 trials (5430 participants), the quality of evidence varied from high to moderate quality.There is high quality of evidence that buprenorphine was superior to placebo medication in retention of participants in treatment at all doses examined. Specifically, buprenorphine retained participants better than placebo: at low doses (2 - 6 mg), 5 studies, 1131 participants, risk ratio (RR) 1.50; 95% confidence interval (CI) 1.19 to 1.88; at medium doses (7 - 15 mg), 4 studies, 887 participants, RR 1.74; 95% CI 1.06 to 2.87; and at high doses (≥ 16 mg), 5 studies, 1001 participants, RR 1.82; 95% CI 1.15 to 2.90. However, there is moderate quality of evidence that only high-dose buprenorphine (≥ 16 mg) was more effective than placebo in suppressing illicit opioid use measured by urinanalysis in the trials, 3 studies, 729 participants, standardised mean difference (SMD) -1.17; 95% CI -1.85 to -0.49, Notably, low-dose, (2 studies, 487 participants, SMD 0.10; 95% CI -0.80 to 1.01), and medium-dose, (2 studies, 463 participants, SMD -0.08; 95% CI -0.78 to 0.62) buprenorphine did not suppress illicit opioid use measured by urinanalysis better than placebo.There is high quality of evidence that buprenorphine in flexible doses adjusted to participant need,was less effective than methadone in retaining participants, 5 studies, 788 participants, RR 0.83; 95% CI 0.72 to 0.95. For those retained in treatment, no difference was observed in suppression of opioid use as measured by urinalysis, 8 studies, 1027 participants, SMD -0.11; 95% CI -0.23 to 0.02 or self report, 4 studies, 501 participants, SMD -0.11; 95% CI -0.28 to 0.07, with moderate quality of evidence.Consistent with the results in the flexible-dose studies, in low fixed-dose studies, methadone (≤ 40 mg) was more likely to retain participants than low-dose buprenorphine (2 - 6 mg), (3 studies, 253 participants, RR 0.67; 95% CI: 0.52 to 0.87). However, we found contrary results at medium dose and high dose: there was no difference between medium-dose buprenorphine (7 - 15 mg) and medium-dose methadone (40 - 85 mg) in retention, (7 studies, 780 participants, RR 0.87; 95% CI 0.69 to 1.10) or in suppression of illicit opioid use as measured by urines, (4 studies, 476 participants, SMD 0.25; 95% CI -0.08 to 0.58) or self report of illicit opioid use, (2 studies, 174 participants, SMD -0.82; 95% CI -1.83 to 0.19). Similarly, there was no difference between high-dose buprenorphine (≥ 16 mg) and high-dose methadone (≥ 85 mg) in retention (RR 0.79; 95% CI 0.20 to 3.16) or suppression of self-reported heroin use (SMD -0.73; 95% CI -1.08 to -0.37) (1 study, 134 participants).Few studies reported adverse events ; two studies compared adverse events statistically, finding no difference between methadone and buprenorphine, except for a single result indicating more sedation among those using methadone.

AUTHORS' CONCLUSIONS

Buprenorphine is an effective medication in the maintenance treatment of heroin dependence, retaining people in treatment at any dose above 2 mg, and suppressing illicit opioid use (at doses 16 mg or greater) based on placebo-controlled trials.However, compared to methadone, buprenorphine retains fewer people when doses are flexibly delivered and at low fixed doses. If fixed medium or high doses are used, buprenorphine and methadone appear no different in effectiveness (retention in treatment and suppression of illicit opioid use); however, fixed doses are rarely used in clinical practice so the flexible dose results are more relevant to patient care. Methadone is superior to buprenorphine in retaining people in treatment, and methadone equally suppresses illicit opioid use.

A double blind, within subject comparison of spontaneous opioid withdrawal from buprenorphine versus morphine

Preliminary evidence suggests that there is minimal withdrawal after the cessation of chronically administered buprenorphine and that opioid withdrawal symptoms are delayed compared with those of other opioids. The present study compared the time course and magnitude of buprenorphine withdrawal with a prototypical μ-opioid agonist, morphine. Healthy, out-of-treatment opioid-dependent residential volunteers (N = 7) were stabilized on either buprenorphine (32 mg/day i.m.) or morphine (120 mg/day i.m.) administered in four divided doses for 9 days. They then underwent an 18-day period of spontaneous withdrawal, during which four double-blind i.m. placebo injections were administered daily. Stabilization and spontaneous withdrawal were assessed for the second opioid using the same time course. Opioid withdrawal measures were collected eight times daily. Morphine withdrawal symptoms were significantly (P < 0.05) greater than those of buprenorphine withdrawal as measured by mean peak ratings of Clinical Opiate Withdrawal Scale (COWS), Subjective Opiate Withdrawal Scale (SOWS), all subscales of the Profile of Mood States (POMS), sick and pain (0-100) Visual Analog Scales, systolic and diastolic blood pressure, heart rate, respiratory rate, and pupil dilation. Peak ratings on COWS and SOWS occurred on day 2 of morphine withdrawal and were significantly greater than on day 2 of buprenorphine withdrawal. Subjective reports of morphine withdrawal resolved on average by day 7. There was minimal evidence of buprenorphine withdrawal on any measure. In conclusion, spontaneous withdrawal from high-dose buprenorphine appears subjectively and objectively milder compared with that of morphine for at least 18 days after drug cessation.

An intronic variant in OPRD1 predicts treatment outcome for opioid dependence in African-Americans

Although buprenorphine and methadone are both effective treatments for opioid dependence, their efficacy can vary significantly among patients. Genetic differences may explain some of the variability in treatment outcome. Understanding the interactions between genetic background and pharmacotherapy may result in more informed treatment decisions. This study is a pharmacogenetic analysis of the effects of genetic variants in OPRD1, the gene encoding the δ-opioid receptor, on the prevalence of opioid-positive urine tests in African-Americans (n=77) or European-Americans (n=566) undergoing treatment for opioid dependence. Patients were randomly assigned to treatment with either methadone or buprenorphine/naloxone (Suboxone) over a 24-week open-label clinical trial, in which illicit opioid use was measured by weekly urinalysis. In African-Americans, the intronic SNP rs678849 predicted treatment outcome for both medications. Methadone patients with the CC genotype were less likely to have opioid-positive urine tests than those in the combined CT and TT genotypes group (relative risk (RR)=0.52, 95% confidence interval (CI)=0.44-0.60, p=0.001). In the buprenorphine treatment group, however, individuals with the CC genotype were more likely to have positive opioid drug screens than individuals in the combined CT and TT genotypes group (RR=2.17, 95% CI=1.95-2.68, p=0.008). These findings indicate that the genotype at rs678849 predicts African-American patient response to two common treatments for opioid dependence, suggesting that matching patients to treatment type based on the genotype at this locus may improve overall treatment efficacy. This observation requires confirmation in an independent population.

Buprenorphine and buprenorphine/naloxone diversion, misuse, and illicit use: an international review

The diversion, misuse, and non-medically supervised use of buprenorphine and buprenorphine/naloxone by opioid users are reviewed. Buprenorphine and buprenorphine/naloxone are used globally as opioid analgesics and in the treatment of opioid dependency. Diversion of buprenorphine and buprenorphine/naloxone represents a complex medical and social issue, and has been widely documented in various geographical regions throughout the world. We first discuss the clinical properties of buprenorphine and its abuse potential. Second, we discuss its diversion and illicit use on an international level, as well as motivations for those activities. Third, we examine the medical risks and benefits of buprenorphine's non-medically supervised use and misuse. These risks and benefits include the effect of buprenorphine's use on HIV risk and the risk of its concomitant use with other medications and drugs of abuse. Finally, we discuss the implications of diversion, misuse, and non-medically supervised use (including potential measures to address issues of diversion); and potential areas for further research.

Gender issues in the pharmacotherapy of opioid-addicted women: buprenorphine

Gender, a biological determinant of mental health and illness, plays a critical role in determining patients' susceptibility, exposure to mental health risks, and related outcomes. Regarding sex differences in the epidemiology of opioid dependence, one third of the patients are women of childbearing age. Women have an earlier age of initiation of substance use and a more rapid progression to drug involvement and dependence than men. Generally few studies exist which focus on the special needs of women in opioid maintenance therapy. The aim of this paper is to provide an overview of treatment options for opioid-dependent women, with a special focus on buprenorphine, and to look at recent findings related to other factors that should be taken into consideration in optimizing the treatment of opioid-dependent women. Issues addressed include the role of gender in the choice of medication assisted treatment, sex differences in pharmacodynamics and pharmacokinetics of buprenorphine drug interactions, cardiac interactions, induction of buprenorphine in pregnant patients, the neonatal abstinence syndrome and breastfeeding. This paper aims to heighten the awareness for the need to take gender into consideration when making treatment decisions in an effort to optimize services and enhance the quality of life of women suffering from substance abuse.

Diversion of buprenorphine/naloxone coformulated tablets in a region with high prescribing prevalence

The purpose of this article was to characterize practices of buprenorphine/naloxone (B/N) diversion in a region with a high prescribing prevalence. A cross-sectional, open-ended survey was administered to individuals entering opioid addiction treatment programs in two New England states. The authors obtained formative information about the knowledge, attitudes, beliefs, practices, and street economy of B/N diversion. The authors interviewed 51 individuals, 49 of which were aware of B/N medication. Of that number, 100% had diverted B/N to modulate opiate withdrawal symptoms arising from attempted "self-detoxification," insufficient funds to purchase preferred illicit opioids, or inability to find a preferred source of drugs. Thirty of 49 (61%) participants obtained the illicit drug from an individual holding a legitimate prescription for B/N. A high proportion of individuals in the study locations who sought treatment for opioid addiction self-reported the purchase and use of diverted B/N. The diversion of B/N may be minimized by modifying educational, treatment, monitoring, and dispensing practices.

Psychopharmacologic management of opioid-dependent women during pregnancy

Illicit drug use during pregnancy presents complex clinical challenges, including reducing drug use and treating psychiatric disorders. Pharmacologic treatment of psychiatric disorders in a pregnant woman requires an evaluation of the balance between potential clinical benefit and the risk of potential neonatal consequences. This study describes psychiatric symptoms in 111 opioid-dependent pregnant women and their prescribed psychotropic medications. Hypomania, generalized anxiety disorder and depression were the most common disorders for which psychiatric symptoms were endorsed. Over half of women studied were prescribed some form of psychoactive medication during pregnancy. Pharmacologic vs. non-pharmacologic treatment approaches in this patient population are discussed.

Buprenorphine maintenance versus placebo or methadone maintenance for opioid dependence

BACKGROUND

Buprenorphine has been reported as an alternative to methadone for maintenance treatment of opioid dependence, but differing results are reported concerning its relative effectiveness indicating the need for an integrative review.

OBJECTIVES

To evaluate the effects of buprenorphine maintenance against placebo and methadone maintenance in retaining patients in treatment and in suppressing illicit drug use.

SEARCH STRATEGY

We searched the following databases up to October 2006: Cochrane Drugs and Alcohol Review Group Register, the Cochrane Controlled Trials Register, MEDLINE, EMBASE, Current Contents, Psychlit, CORK , Alcohol and Drug Council of Australia, Australian Drug Foundation, Centre for Education and Information on Drugs and Alcohol, Library of Congress databases, reference lists of identified studies and reviews, authors were asked about any other published or unpublished relevant RCT.

SELECTION CRITERIA

Randomised clinical trials of buprenorphine maintenance versus placebo or methadone maintenance.

DATA COLLECTION AND ANALYSIS

Authors separately and independently evaluated the papers and extracted data for meta-analysis.

MAIN RESULTS

Twenty four studies met the inclusion criteria (4497 participants), all were randomised clinical trials, all but six were double-blind. The method of allocation concealment was not clearly described in the majority (20) of the studies, but where it was reported the methodological quality was good. Buprenorphine was statistically significantly superior to placebo medication in retention of patients in treatment at low doses (RR=1.50; 95% CI: 1.19 - 1.88), medium (RR=1.74; 95% CI: 1.06 - 2.87), and high doses (RR=1.74; 95% CI: 1.02 - 2.96). The high statistical heterogeneity prevented the calculation of a cumulative estimate. However, only medium and high dose buprenorphine suppressed heroin use significantly above placebo. Buprenorphine given in flexible doses was statistically significantly less effective than methadone in retaining patients in treatment (RR= 0.80; 95% CI: 0.68 - 0.95), but no different in suppression of opioid use for those who remained in treatment. Low dose methadone is more likely to retain patients than low dose buprenorphine (RR= 0.67; 95% CI: 0.52 - 0.87). Medium dose buprenorphine does not retain more patients than low dose methadone, but may suppress heroin use better. There was no advantage for medium dose buprenorphine over medium dose methadone in retention (RR=0.79; 95% CI:0.64 - 0.99) and medium dose buprenorphine was inferior in suppression of heroin use.

AUTHORS' CONCLUSIONS

Buprenorphine is an effective intervention for use in the maintenance treatment of heroin dependence, but it is less effective than methadone delivered at adequate dosages.

Pharmacologic treatments for opioid dependence: detoxification and maintenance options

While opioid dependence has more treatment agents available than other abused drugs, none are curative. They can, however, markedly diminish withdrawal symptoms and craving, and block opioid effects due to lapses.

The most effective withdrawal method is substituting and tapering methadone or buprenorphine, α-2 Adrenergic agents can ameliorate untreated symptoms or substitute for agonists if not available. Shortening withdrawal by precipitating it with narcotic antagonists has been studied, but the methods are plagued by safety issues or persisting symptoms. Neither the withdrawal agents nor the methods are associated with better long-term outcome, which appears mostly related to post-detoxification treatment.

Excluding those with short-term habits, the best outcome occurs with long-term maintenance on methadone or buprenorphine accompanied by appropriate psychosocial interventions. Those with strong external motivation may do well on the antagonist naltrexone. Currently, optimum duration of maintenance on either is unclear. Better agents are needed to impact the brain changes related to addiction.

Multi-centre observational study of buprenorphine use in 32 Italian drug addiction centres

AIM

To examine how buprenorphine is currently being used across Italy, and to identify simultaneously best practice protocols to guide physicians in optimising the safety and efficacy of this treatment option.

DESIGN

Retrospective, observational, multi-centre study.

PARTICIPANTS

A total of 979 opioid-dependent patients were included from 32 centres involving the initiation of 1122 treatments.

FINDINGS

During the study period 33.4% of patients relapsed during the induction phase. Lower induction doses resulted in markedly higher relapse rates (51.2% of those who received 2 mg versus 20.6% of those who received 10mg of buprenorphine relapsed). Over 89% of patients who received 16 mg of buprenorphine during the induction phase successfully went on to maintenance treatment. The percentage of drug-positive urines also decreased over time on buprenorphine treatment (cocaine-positive urines decreased from 25.8% at study entrance to 0% at 24 months). Psychosocial support in addition to buprenorphine pharmacotherapy further decreased the risk of relapse and was associated with lower levels of heroin craving. Retention in treatment was increased by less-than-daily dosing of buprenorphine.

CONCLUSIONS

Higher induction doses of buprenorphine significantly decreased relapse rates and increased the percentage of patients achieving maintenance treatment. Psychosocial support and/or less-than-daily dosing also appeared to promote positive treatment outcomes.

Substance use and quality of life over 12 months among buprenorphine maintenance-treated and methadone maintenance-treated heroin-addicted patients

The purpose of this study was to investigate the effects of methadone treatment and buprenorphine treatment on retention in treatment, urine drug testing results, psychiatric status, social adjustment, and quality of life among patients involved in long-term treatment with the cited medications. Two hundred thirteen patients (106 on buprenorphine treatment and 107 on methadone treatment) were enrolled in this open study at the 3rd month of their treatment and followed up until the 12th month; those who left the program before the end of the 3rd month of their treatment were not included in the study sample. The results of this study show statistically significant improvements in opioid use, psychiatric status, and quality of life between the 3rd and 12th months for both medications. This study suggests the long-term efficacy of methadone treatment and buprenorphine treatment on symptoms of opioid addiction and quality of life.

Clinical care of the HIV-infected drug user

HIV/AIDS and chemical dependency, the latter often intertwined with mental illness, are complex, overlapping spheres that adversely influence each other and the overall clinical outcomes of the affected individual. Each disorder individually impact tens of millions of people adversely, with explosive epidemics described worldwide. This article addresses the adverse consequences of HIV/AIDS, drug injection, the secondary comorbidities of both, and the impact of immunosuppression on presentation of disease as well as approaches to managing the HIV-infected drug user.

Buprenorphine duration of action: mu-opioid receptor availability and pharmacokinetic and behavioral indices

BACKGROUND

Buprenorphine (BUP) is effective in the treatment of opioid dependence when given on alternating days, probably as a result of long-lasting occupation of micro opioid receptors (microORs). This study examined the duration of action of BUP at microORs and correlations with pharmacokinetic and pharmacodynamic outcomes in 10 heroin-dependent volunteers.

METHODS

Availability of microOR (measured with positron emission tomography and [(11)C]-carfentanil), plasma BUP concentration, opioid withdrawal symptoms, and blockade of hydromorphone (HYD; heroin-like agonist) effects were measured at 4, 28, 52, and 76 hours after omitting the 16 mg/d dose of BUP in a study reported elsewhere.

RESULTS

Relative to heroin-dependent volunteers maintained on BUP placebo, whole-brain microOR availability was 30%, 54%, 67%, and 82% at 4, 28, 52, and 76 hours after BUP. Regions of interest showed similar effects. Plasma concentrations of BUP were time dependent, as were withdrawal symptoms, carbon dioxide sensitivity and extent of HYD blockade. Availability of microOR was also correlated with BUP plasma concentration, withdrawal symptoms, and HYD blockade.

CONCLUSIONS

Together with our previous findings, it appears that microOR availability predicts changes in pharmacokinetic and pharmacodynamic measures and that about 50%-60% BUP occupancy is required for adequate withdrawal symptom suppression (in the absence of other opioids) and HYD blockade.

Opioid Dependence: Rationale for and Efficacy of Existing and New Treatments

Opioid dependence is a chronic and relapsing medical disorder with a well-established neurobiological basis. Opioid agonist treatments, such as methadone and the recently approved buprenorphine, stabilize opioid receptors and the intracellular processes that lead to opioid withdrawal and craving. Both methadone and buprenorphine have been proven effective for the treatment of opioid dependence and can contribute to a decreased risk of human immunodeficiency virus (HIV) transmission. In addition, a buprenorphine/naloxone combination appears to have a decreased potential for abuse or diversion, compared with that associated with methadone. Largely because of these properties, recent legislation now affords an unprecedented opportunity for general physicians to offer opioid agonist treatment through their offices. This review focuses on the neurobiological basis of opioid dependence, the rationale for methadone and buprenorphine treatments, and issues in prescribing these medications to patients with HIV infection.

A Trial of Integrated Buprenorphine/Naloxone and HIV Clinical Care

BACKGROUND

Untreated opioid dependence adversely affects the care of human immunodeficiency virus (HIV)-positive patients. Buprenorphine, a partial opioid agonist, is available for maintenance treatment of opioid dependence in HIV specialty settings. We investigated the feasibility and efficacy of integrating buprenorphine, along with 2 levels of counseling, into HIV clinical care.

METHODS

HIV-positive, opioid-dependent patients were enrolled in a 12-week pilot study and randomized to receive daily buprenorphine/naloxone treatment along with either brief physician management or physician management combined with nurse-administered drug counseling and adherence management. Primary outcomes included treatment retention; illicit drug use, assessed by urine toxicology test and self-report; CD4 lymphocyte counts; and log(10) HIV type 1 (HIV-1) RNA levels.

RESULTS

Of the 16 patients who received at least 1 dose of buprenorphine, 13 (81%) completed 12 weeks of treatment. The proportion of opioid-positive weekly urine test results decreased from 100% at baseline to 32% (month 1), 20% (month 2), and 16% (month 3). Only 4 patients reported any opioid use (in the prior 7 days) during the 12-week study. CD4 lymphocyte counts remained stable over the course of the study. The mean log(10) HIV-1 RNA level (+/- standard deviation) declined significantly, from 3.66+/-1.06 log(10) HIV-1 RNA copies/mL at baseline to 3.0+/-0.57 log(10) HIV-1 RNA copies/mL at month 3 (P<.05). No significant differences based on counseling intervention were detected. All 13 patients who completed the study continued to receive treatment in an extension phase of at least 0-15 months' duration.

CONCLUSIONS

We conclude that it is feasible to integrate buprenorphine into HIV clinical care for the treatment of opioid dependence. Patients experienced good treatment retention and reductions in their opioid use. HIV biological markers remained stable or improved during buprenorphine/naloxone treatment.

Buprenorphine-containing treatments: place in the management of opioid addiction

Although the synthetic opioid buprenorphine has been available clinically for almost 30 years, its use has only recently become much more widespread for the treatment of opioid addiction. The pharmacodynamic and pharmacokinetic profiles of buprenorphine make it unique in the armamentarium of drugs for the treatment of opioid addiction. Buprenorphine has partial mu-opioid receptor agonist activity and is a kappa-opioid receptor antagonist; hence, it can substitute for other micro-opioid receptor agonists, yet is less apt to produce overdose reactions or dysphoria. On the other hand, buprenorphine can block the effects of opioids such as heroin (diamorphine) and morphine, and can even precipitate withdrawal in individuals physically dependent upon these drugs. Buprenorphine has significant sublingual bioavailability and a long half-life, making administration on a less than daily basis possible. Furthermore, its discontinuation is associated with only a mild withdrawal syndrome. Clinical trials have demonstrated that sublingual buprenorphine is effective in both maintenance therapy and detoxification of individuals addicted to opioids. The introduction of a sublingual formulation combining naloxone with buprenorphine further reduces the risk of diversion to illicit intravenous use. Because of its relative safety and lower risk of illegal diversion, buprenorphine has been made available in several countries for treating opioid addiction in the private office setting, greatly enhancing treatment options for this condition.

Effects associated with double-blind omission of buprenorphine/naloxone over a 98-h period

RATIONALE

Buprenorphine has a long duration of action that allows less than daily dosing for opioid dependence, but pharmacologic characterization of buprenorphine's duration of effects over multiple days is incomplete.

OBJECTIVES

This study assessed opioid blockade and spontaneous withdrawal effects of buprenorphine/naloxone (B/N) over a 98-h period.

MATERIALS AND METHODS

Residential opioid-dependent volunteers (n = 8) were maintained, in randomized sequence, on each of three different daily sublingual B/N doses (8/2, 16/4, 32/8 mg). After 2 weeks on each maintenance dose, participants underwent challenge sessions on each weekday for 1 week. Challenges consisted of within-session, ascending dose administration of IM hydromorphone (H: 0, 6, and 12 mg). During that week, active B/N dose was given only on Monday; double-blind placebo was administered on the remaining weekdays. Thus, these sessions assessed the extent of both opioid blockade and spontaneous withdrawal at 2, 26, 50, 74, and 98 h after the last active B/N dose.

RESULTS

All three maintenance doses provided substantial but incomplete blockade against opioid agonist effects for 98 h. The extent of blockade diminished steadily but modestly over this time and did not differ as a function of B/N maintenance dose. In general, participants did not report marked spontaneous opioid withdrawal, although mild withdrawal effects were observed as time since the last active B/N dose increased. However, withdrawal did not differ as a function of B/N maintenance dose.

CONCLUSIONS

These findings suggest that B/N doses greater than 8/2 mg provide minimal incremental value in terms of opioid blockade and withdrawal suppression.

Males and females differ in response to opioid agonist medications

Few clinical trials include sex as a factor. This analysis explored within-sex differences in response to opioid agonist medications. Males and females randomly assigned to buprenorphine, LAAM, or methadone were compared on opioid use and retention in treatment. Females receiving buprenorphine had less objective drug use than females receiving methadone, while males receiving LAAM had less objective drug use than males receiving buprenorphine. Retention in treatment was longer for both sexes receiving methadone versus LAAM. Within-subject change results indicate that all three medications benefit both sexes. Clinical trials should be designed to examine the impact of sex on outcomes.

An injection depot formulation of buprenorphine: extended bio-delivery and effects

AIM

Buprenorphine is an effective medication for treatment of opioid dependence. An injectable depot formulation of buprenorphine has been developed using biodegradable polymer microcapsule technology. This formulation may offer effective treatment of opioid dependence and enhance treatment delivery while minimizing risks of patient non-adherence or illicit diversion of the medication. This report provides a characterization of the bio-delivery of this injectable depot in humans and of the relationship of drug blood levels to pharmacodynamic indices.

METHOD AND PARTICIPANTS

The data are from two studies in which 11 opioid-dependent volunteers each received a single depot injection containing 58 mg of buprenorphine, and include previously unreported detailed plasma concentration data over a 6-week time-course following depot administration and examination of their relationship to pharmacodynamic indices.

FINDINGS

Mean plasma buprenorphine increased gradually following depot administration, peaked at 2-3 days with a mean concentration of 1.25 ng/ml and then decreased gradually, approaching undetectable levels (< 0.10 ng/mL) by 6 weeks. There was substantial between-subject consistency in several aspects of buprenorphine bio-delivery, including time to first detectable blood level (4 hours), peak blood level (2 days) and undetectable blood level (6-6.5 weeks). In contrast, there was marked between-subject variability in the magnitude of peak buprenorphine concentrations, ranging from 0.17 to 3.47 ng/ml. Extent of opioid blockade was tested by weekly opioid challenges with 3 mg subcutaneous hydromorphone; subjective response and pupillary constriction were related inversely to both buprenorphine and norbuprenorphine plasma concentrations (r=0.84-0.95).

CONCLUSION

The data document that this depot formulation provides effective buprenorphine delivery for several weeks and that effects persist even at fairly low buprenorphine plasma concentrations. Suggestions are offered for further research needed to develop this formulation for clinical use as a detoxification and/or maintenance pharmacotherapy for opioid dependence.

Buprenorphine: Its Role in Preventing HIV Transmission and Improving the Care of HIV-Infected Patients with Opioid Dependence

In the United States, approximately 25% of the 40,000 new human immunodeficiency virus (HIV) infections each year are secondary to injection drug use. Worldwide, there are an estimated 12.6 million injection drug users, and 10% of HIV infections (420,000 infections in 2003) are associated with this practice. Buprenorphine is a new medication used to treat opioid dependence that shows promise for reducing the rate of HIV transmission and improving the care of opioid-dependent patients with HIV infection. Although buprenorphine faces fewer clinical and regulatory barriers than does methadone, the optimal strategy for integration of office-based treatment of opioid dependence and HIV disease is an area of ongoing research. This review addresses the introduction of buprenorphine, in terms of public health, policy, and clinical implications for HIV-infected patients and for HIV care providers.

Opioid detoxification using high doses of buprenorphine in 24 hours: a randomized, double blind, controlled clinical trial

In recent years, interest in shortening of opioid detoxification has increased with the rising demands to find more cost-effective approaches for treatment of opioid dependence. This study was designed to evaluate the efficacy of administration of high doses of buprenorphine during 24 h in the management of acute opioid withdrawal. A total of 40 treatment-seeking opioid dependents were admitted and randomly assigned to two groups in a double blind, parallel trial. Buprenorphine was administered intramuscularly. Twenty patients received 12 mg buprenorphine in 24 h and the remaining 20 patients treated with conventional doses of buprenorphine tapered down over 5 days. Variables that were assessed included retention in treatment, rates of successful detoxification, the Subjective Opiate Withdrawal Scale (OOWS) scores, the Objective Opiate Withdrawal Scale (SOWS) scores, intensity of craving, drug side effects, and levels of hepatic enzymes (ALT and AST). There was no significant difference between the two groups on most variables. The main difference was in the time that maximal withdrawal symptoms occurred, which in the experimental protocol group appeared early while in the conventional protocol group appeared later during the detoxification period. Moreover, the experimental protocol was not only tolerated well but also accompanied with significantly less elevation in the ALT levels compared to the conventional treatment. However, patients in this group used more indomethacin and trazodone for symptom palliation. This study suggests that administration of high doses of buprenorphine in 24 h may be a reasonable approach for shortening of opioid detoxification. However, a larger study to confirm our results is warranted.

Evaluation of an injection depot formulation of buprenorphine: placebo comparison

AIMS

Buprenorphine is a mu-opioid partial agonist that is marketed in a sublingual formulation as a treatment for opioid dependence. A microcapsule depot sustained-release formulation has been developed which may offer effective treatment of opioid dependence while also minimizing risks of illicit diversion or patient non-compliance. The present study examined the efficacy of depot buprenorphine in suppressing the opioid withdrawal syndrome and in attenuating the effects of exogenous opioid challenge.

DESIGN

A placebo-controlled, double-blind, randomized trial.

SETTING

A closed residential research facility.

PARTICIPANTS

A total of 15 opioid-dependent participants were enrolled into the 6-week study.

INTERVENTION

Fifteen participants were randomized to receive a single subcutaneous depot injection containing buprenorphine (58 mg) or placebo. Two participants, both of whom received placebo, terminated participation after depot administration. Thirteen participants (six buprenorphine, seven placebo) completed the 6-week study and were assessed throughout the study for signs and symptoms of opioid withdrawal and for response to weekly subcutaneous challenges with 3 mg hydromorphone.

MEASUREMENT

Subjective, physiological and observer-rated indices of opioid withdrawal and opioid agonist effects.

FINDINGS

Depot buprenorphine provided more effective relief from opioid withdrawal than placebo, as evidenced by significantly fewer buprenorphine participants requiring supplemental medications for withdrawal suppression after depot administration compared to participants receiving placebo. In the weekly hydromorphone challenge sessions, depot buprenorphine significantly reduced opioid response on measures of subjective effects and pupillary diameter.

CONCLUSIONS

Results from this double-blind, placebo-controlled study indicate that depot buprenorphine is effective in providing both withdrawal suppression and opioid blockade. Future studies examining additional doses and repeated dosing regimens with depot buprenorphine are warranted.

Practical considerations for the clinical use of buprenorphine

Buprenorphine is a new and attractive medication option for many opioid-addicted adults and their physicians. Before initiating buprenorphine treatment, providers must be aware of such critical factors as how the medication works, its efficacy and safety profile, how it is used in opioid withdrawal as well as maintenance treatment, and how patients can best be selected, educated about buprenorphine, and monitored throughout treatment. This article reviews these important issues as well as requirements for physician and staff training and needs for additional research on this unique medication.

Randomized trial of buprenorphine for treatment of concurrent opiate and cocaine dependence

BACKGROUND

Buprenorphine is a partial mu-opiate agonist and kappa-opiate antagonist with established efficacy in the treatment of opiate dependence. Its efficacy for cocaine dependence is uncertain. This study evaluated buprenorphine for the treatment of concomitant cocaine and opiate dependence.

METHODS

Two hundred outpatients currently dependent on both cocaine and opiates were randomly assigned to double-blind groups receiving a sublingual solution of buprenorphine (2, 8, or 16 mg daily, or 16 mg on alternate days, or placebo), plus weekly individual drug abuse counseling, for 13 weeks. The chief outcome measures were urine concentrations of opiate and cocaine metabolites (quantitative) and proportion of urine samples positive for opiates or cocaine (qualitative). Group differences were assessed by use of mixed regression modeling.

RESULTS

The target dose of buprenorphine was achieved in 179 subjects. Subjects receiving 8 or 16 mg buprenorphine daily showed statistically significant decreases in urine morphine levels (P =.0135 for 8 mg and P <.001 for 16 mg) or benzoylecgonine concentrations (P =.0277 for 8 mg and P =.006 for 16 mg) during the maintenance phase of the study. For the 16-mg group, mean benzoylecgonine concentrations fell from 3715 ng/mL during baseline to 186 ng/mL during the withdrawal phase; mean morphine concentrations fell from 3311 ng/mL during baseline to 263 ng/mL during withdrawal. For the 8-mg group, mean benzoylecgonine concentrations fell from 6761 ng/mL during baseline to 676 ng/mL during withdrawal; mean morphine concentrations fell from 3890 ng/mL during baseline to 661 ng/mL during withdrawal. Qualitative urinalysis showed a similar pattern of results. Subjects receiving the highest dose showed concomitant decreases in both urine morphine and benzoylecgonine concentrations. There were no significant group differences in treatment retention or adverse events.

CONCLUSIONS

A sublingual buprenorphine solution at 16 mg daily is well tolerated and effective in reducing concomitant opiate and cocaine use. The therapeutic effect on cocaine use appears independent of that on opiate use.

Open-label trial of an injection depot formulation of buprenorphine in opioid detoxification

Buprenorphine, a partial mu-opioid agonist, has been shown effective for treatment of opioid dependence but also has some abuse potential. A novel formulation of buprenorphine, using a polymer microcapsule depot sustained-release technology, has been developed which may offer effective treatment of opioid dependence while also minimizing risks of patient noncompliance and illicit diversion. This open-label, first-in-human study evaluated the safety and pharmacokinetics of a single-dose buprenorphine depot in physically dependent opioid abusers. The present study also examined the efficacy of depot buprenorphine in suppressing symptoms of opioid withdrawal, attenuating the effects of exogenous opioid challenge, and providing clinical detoxification. Five opioid-dependent volunteers each received a single subcutaneous depot injection containing 58 mg of buprenorphine and were assessed for at least four weeks for signs and symptoms of opioid withdrawal, first residentially and then as outpatients. Depot buprenorphine appeared to provide effective relief from opioid withdrawal, with no participant requiring additional medication for withdrawal relief following depot administration. The depot was safe and well-tolerated, with no significant side effects, signs of intoxication, or respiratory depression. In the opioid challenge sessions, depot buprenorphine appeared to produce substantial opioid blockade that persisted for 6 weeks post-depot administration. Results from the present study suggest that depot buprenorphine offers significant promise for enhancing the delivery of effective opioid agonist treatment while minimizing risk for abuse of the medication.

Buprenorphine maintenance versus placebo or methadone maintenance for opioid dependence

BACKGROUND

Buprenorphine has recently been reported to be an alternative to methadone and LAAM for maintenance treatment of opioid dependent individuals, differing results are reported concerning its relative effectiveness indicating the need for an integrative review.

OBJECTIVES

To evaluate the effects of buprenorphine maintenance against placebo and methadone maintenance in retaining patients in treatment and in suppressing illicit drug use.

SEARCH STRATEGY

We searched the following databases up to 2001, inclusive: Cochrane Drugs and Alcohol Review Group Register, the Cochrane Controlled Trials Register, MEDLINE, EMBASE, Current Contents, Psychlit, CORK [www. state.vt.su/adap/cork], Alcohol and Drug Council of Australia (ADCA) [www.adca.org.au], Australian Drug Foundation (ADF -VIC) [www.adf.org.au], Centre for Education and Information on Drugs and Alcohol (CEIDA) [www.ceida.net.au], Australian Bibliographic Network (ABN), and Library of Congress databases, available NIDA monographs and the College on Problems of Drug Dependence Inc. proceedings, the reference lists of all identified studies and published reviews and authors of identified RCT's were asked about any other published or unpublished relevant RCT.

SELECTION CRITERIA

Randomised clinical trials of buprenorphine maintenance compared with either placebo or methadone maintenance for opioid dependence.

DATA COLLECTION AND ANALYSIS

Reviewers evaluated the papers separately and independently, rating methodological quality of concealment of allocation; data were extracted independently for meta-analysis and double-entered.

MAIN RESULTS

Thirteen studies met the inclusion criteria, all were randomised clinical trials, all but one were double-blind. The method of concealment of allocation was not clearly described in 11 of the studies, otherwise methodological quality was good. Buprenorphine given in flexible doses appeared statistically significantly less effective than methadone in retaining patient in treatment (RR= 0.82; 95% CI: 0.69-0.96). Low dose buprenorphine is not superior to low dose methadone. High dose buprenorphine does not retain more patients than low dose methadone, but may suppress heroin use better. There was no advantage for high dose buprenorphine over high dose methadone in retention (RR=0.79; 95% CI:0.62-1.01), and high dose buprenorphine was inferior in suppression of heroin use. Buprenorphine was statistically significantly superior to placebo medication in retention of patients in treatment at low doses (RR=1.24; 95% CI: 1.06-1.45), high doses (RR=1.21; 95% CI: 1.02-1.44), and very high doses (RR=1.52; 95% CI: 1.23-1.88). However, only high and very high dose buprenorphine suppressed heroin use significantly above placebo.

REVIEWERS' CONCLUSIONS

Buprenorphine is an effective intervention for use in the maintenance treatment of heroin dependence, but it is not more effective than methadone at adequate dosages.

1-year retention and social function after buprenorphine-assisted relapse prevention treatment for heroin dependence in Sweden: a randomised, placebo-controlled trial

BACKGROUND

The partial opiate-receptor agonist buprenorphine has been suggested for treatment of heroin dependence, but there are few long-term and placebo-controlled studies of its effectiveness. We aimed to assess the 1-year efficacy of buprenorphine in combination with intensive psychosocial therapy for treatment of heroin dependence.

METHODS

40 individuals aged older than 20 years, who met DSM-IV criteria for opiate dependence for at least 1 year, but did not fulfil Swedish legal criteria for methadone maintenance treatment were randomly allocated either to daily buprenorphine (fixed dose 16 mg sublingually for 12 months; supervised daily administration for a least 6 months, possible take-home doses thereafter) or a tapered 6 day regimen of buprenorphine, thereafter followed by placebo. All patients participated in cognitive-behavioural group therapy to prevent relapse, received weekly individual counselling sessions, and submitted thrice weekly supervised urine samples for analysis to detect illicit drug use. Our primary endpoint was 1-year retention in treatment and analysis was by intention to treat.

FINDINGS

1-year retention in treatment was 75% and 0% in the buprenorphine and placebo groups, respectively (p=0.0001; risk ratio 58.7 [95% CI 7.4-467.4]). Urine screens were about 75% negative for illicit opiates, central stimulants, cannabinoids, and benzodiazepines in the patients remaining in treatment.

INTERPRETATION

The combination of buprenorphine and intensive psychosocial treatment is safe and highly efficacious, and should be added to the treatment options available for individuals who are dependent on heroin.

A placebo-controlled study of high dose buprenorphine in opiate dependents waiting for medication-assisted rehabilitation in Oslo, Norway

AIMS

To evaluate whether buprenorphine. even without additional control and psychosocial treatment and support, alleviates the problems faced by patients waiting for medication assisted rehabilitation (MAR).

DESIGN

A randomized, double-blind, 12-week study of Subutex versus placebo without additional support as an interim therapy.

PARTICIPANTS

One hundred and six patients, 70 males and 36 females, waiting for MAR in Oslo. The average age was 38 years with an average history of heroin use of 20 years. Fifty-five patients were assigned to buprenorphine and 51 to a placebo.

INTERVENTION

Subutex or placebo sublingual tablets were given under supervision in a daily dose of 16 mg with the exception of a double dose on Saturday and no dose on Sunday.

MEASUREMENT

Retention, compliance, self-reported drug-abuse, wellbeing and mental health.

FINDINGS

The average number of days of participation was significantly higher in the buprenorphine group, 42 (median: 29) compared to 14 (median: 11) for the placebo group (P < 0.001). The retention of patients after 12 weeks was 16 patients in the buprenorphine group and one patient in the placebo group. The buprenorphine group had a larger decrease in reported opioid use (p < 0.001) and in reported use of other drugs, tablets and alcohol abuse (p < 0.01). The group also showed a stronger increase in wellbeing (p < 0.01) and life satisfaction (p < 0.05). None of the participants died.

CONCLUSION

The patients waiting for MAR benefited significantly from the buprenorphine as an interim therapy according to retention, self-reported use of drugs and wellbeing. However, the patients had difficulties in remaining in treatment over time without psychosocial support.

Characterization of the pharmacokinetics of buprenorphine and norbuprenorphine in rats after intravenous bolus administration of buprenorphine

The purpose of this project was to characterize the dose-dependent pharmacokinetics of buprenorphine (BN) and norbuprenorphine (NBN), the primary metabolite, after intravenous administration of different doses of BN to rats. Adult male Sprague-Dawley rats were divided into six groups and received a single intravenous bolus dose of 0.1, 0.3, 1, 3, 10 or 30 mg/kg of BN. A separate study was performed where BN and NBN were simultaneously administered intravenously (1 mg/kg+1 mg/kg). Plasma samples were obtained by centrifugation of the blood and analyzed for BN and NBN using a sensitive and selective gas chromatographic-mass spectrometric (GC-MS) bio-analytical method. Noncompartmental and compartmental methods were used to perform pharmacokinetic data analysis. BN declined triexponentially with a dose-dependent increase in its volume of distribution, V(ss) (8.37-18.2 l/kg) and clearance CL (2.70-6.10 l/h per kg). The pharmacokinetics of NBN were linear and biexponential. Coadministration of BN and NBN resulted in a significant increase in the volume of distribution and clearance of BN. The present results suggest that the nonlinear disposition in the clearance and volume of distribution of BN can be attributed, in part, to the increasing concentration of the metabolite.

Retention rate and illicit opioid use during methadone maintenance interventions: a meta-analysis

The efficacy of methadone maintenance in opioid addiction was assessed in terms of programme retention rate and reduction of illicit opioid use by means of a meta-analysis of randomised, controlled and double blind clinical trials. The results were compared with interventions using buprenorphine and levo-acetylmethadol (LAAM). Trials were identified from the PubMed database from 1966 to December 1999 using the major medical subject headings 'methadone' and 'randomised controlled trial'. Data for a total of 1944 opioid-dependent patients from 13 studies were analysed. Sixty-four percent of patients received methadone, administered either as fixed or adjusted doses. Thus, 890 patients received > or = 50 mg/day (high dose group) and 392 were given < 50 mg/day (low dose group). Of 662 controls, 131 received placebo, 350 buprenorphine (265 at doses > or = 8 mg/day and 85 at doses < 8 mg/day) and 181 LAAM. High doses of methadone were more effective than low doses in the reduction of illicit opioid use (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.26--2.36). High doses of methadone were significantly more effective than low doses of buprenorphine (< 8 mg/day) for retention rates and illicit opioid use, but similar to high doses of buprenorphine (> or = 8 mg/day) for both parameters. Patients treated with LAAM had more risk of failure of retention than those receiving high doses of methadone (OR 1.92, 95% CI 1.32--2.78). It is proposed that in agonist-maintenance programmes, oral methadone at doses of 50 mg/day or higher is the drug of choice for opioid dependence.

Limits to buprenorphine dosing: a comparison between quintuple and sextuple the maintenance dose every 5 days

The relative efficacy of quintuple and sextuple buprenorphine dosing in abating withdrawal symptoms for 120 h was compared in opioid-dependent outpatients. Fourteen subjects received buprenorphine in a double-blind, placebo-controlled, cross-over design. Daily sublingual maintenance doses were 4 mg/70 kg (n=4) and 8 mg/70 kg (n=10). After a stabilization period of daily maintenance administration, subjects received quintuple (5x daily maintenance dose) and sextuple (6x daily maintenance dose) doses every 120 h. Measures of opioid agonist and withdrawal effects were assessed daily. Subjective ratings of withdrawal were significantly greater than baseline ratings beyond 96-h post dosing under both regimens. There was no evidence, however, that those subjective ratings of withdrawal differed between the two regimens. Thus, these data suggest that sextuple buprenorphine dosing, administered every 5 days, does not abate opioid-withdrawal beyond 96 hours.

Buprenorphine and naloxone for heroin dependence

The pharmacology of buprenorphine is unique because of its partial agonist profile at the mu-opioid receptor (ie, high affinity, low intrinsic activity and slow dissociation). This unique profile results in greater safety, less physical dependence, and greater flexibility in dose scheduling. Buprenorphine has been investigated in combination with the opioid antagonist, naloxone, with the goal of decreasing abuse, misuse, and diversion. When combined with naloxone in a sublingual tablet, buprenorphine has been shown to be effective 1) in retaining patients in treatment, 2) in reducing opioid use and craving, and 3) when dosed less-than-daily. The pharmacologic effects of buprenorphine are not altered by the addition of naloxone when administered to the population in an appropriate combination ratio. However, if taken intravenously by individuals dependent on short- or long-acting opioids a precipitated withdrawal syndrome is observed, which should reduce its abuse potential. This review discusses the rationale for development and evidence supporting the use of a buprenorphine/naloxone combination product. The buprenorphine/naloxone combination product should be considered for use in primary care office-based settings as a safe and effective treatment that is likely to increase the availability of agonist treatment for opioid dependence.

A comparison of levomethadyl acetate, buprenorphine, and methadone for opioid dependence

BACKGROUND

Opioid dependence is a chronic, relapsing disorder with important public health implications.

METHODS

In a 17-week randomized study of 220 patients, we compared levomethadyl acetate (75 to 115 mg), buprenorphine (16 to 32 mg), and high-dose (60 to 100 mg) and low-dose (20 mg) methadone as treatments for opioid dependence. Levomethadyl acetate and buprenorphine were administered three times a week. Methadone was administered daily. Doses were individualized except in the group assigned to low-dose methadone. Patients with poor responses to treatment were switched to methadone.

RESULTS

There were 55 patients in each group; 51 percent completed the trial. The mean (+/-SE) number of days that a patient remained in the study was significantly higher for those receiving levomethadyl acetate (89+/-6), buprenorphine (96+/-4), and high-dose methadone (105+/-4) than for those receiving low-dose methadone (70+/-4, P<0.001). Continued participation was also significantly more frequent among patients receiving high-dose methadone than among those receiving levomethadyl acetate (P=0.02). The percentage of patients with 12 or more consecutive opioid-negative urine specimens was 36 percent in the levomethadyl acetate group, 26 percent in the buprenorphine group, 28 percent in the high-dose methadone group, and 8 percent in the low-dose methadone group (P=0.005). At the time of their last report, patients reported on a scale of 0 to 100 that their drug problem had a mean severity of 35 with levomethadyl acetate, 34 with buprenorphine, 38 with high-dose methadone, and 53 with low-dose methadone (P=0.002).

CONCLUSIONS

As compared with low-dose methadone, levomethadyl acetate, buprenorphine, and high-dose methadone substantially reduce the use of illicit opioids.

Improving the quality of substance dependency treatment with pharmacotherapy

This article provides an overview of current pharmacological treatments for alcohol, opioid, cocaine, and nicotine use disorders. Guidelines for a "patient-treatment" matching framework to physicians working with various "substance-abusing" patients are presented, as well as recommendations regarding when to initiate and discontinue pharmacotherapy. Standard and newer pharmacological treatments for substance dependence are reviewed, as well as therapies that may be especially useful when treating the patient with comorbid substance dependency and psychiatric disorders. To maximize the therapeutic benefits of substance dependency treatment, patients should be individually assessed and provided adjunctive medications as clinically indicated. Specific areas for future laboratory and/or clinical research are recommended.

Pharmacologic treatment of heroin-dependent patients

Patients with heroin dependence frequently present to internists and other physicians for heroin-related medical, psychiatric, and behavioral health problems and often seek help with reducing their heroin use. Thus, physicians should be familiar with the identification and diagnosis of heroin dependence in their patients and be able to initiate treatment of heroin dependence both directly and by referral. Recent research has provided much information concerning effective pharmacologically based treatment approaches for managing opioid withdrawal and helping patients to remain abstinent Methadone maintenance and newer approaches using L-alpha acetylmethadol and buprenorphine seem to be particularly effective in promoting relapse prevention. Although these treatments are currently provided in special drug treatment settings, recent and ongoing research indicates that the physician's office may be an effective alternative site for these treatments.

Thrice-weekly versus daily buprenorphine maintenance

BACKGROUND

Buprenorphine is a promising alternative to methadone or levo-acetyl alpha methadol for opioid agonist maintenance treatment, and thrice-weekly dosing would facilitate its use for this purpose.

METHODS

After a 3-day induction, opioid-dependent patients (n = 92) were randomly assigned to daily clinic attendance and 12-weeks maintenance treatment with sublingual buprenorphine administered double blind either daily (n = 45; 16 mg/70 kg) or thrice weekly (n = 47; 34 mg/70 kg on Fridays and Sundays and 44 mg/70 kg on Tuesdays). Outcome measures include retention, results of 3x/week urine toxicology tests, and weekly self-reported illicit drug use.

RESULTS

There were no significant differences at baseline in important social, demographic, and drug-use features. Retention was 71% in the daily and 77% in the 3x/week conditions. The proportion of opioid-positive urine tests decreased significantly from baseline in both groups and averaged 57% (daily) and 58% in 3x/week. There were no significant differences between groups in self-reported number of bags of heroin used for any day of the week, including Thursdays (48-72 hours following the last buprenorphine dose for subjects in the 3x/week condition), or in medication compliance (92%, 91%) and counseling attendance (82%, 82%).

CONCLUSIONS

At an equivalent weekly dose of 112 mg/70 kg, thrice-weekly and daily sublingual buprenorphine appear comparable in efficacy with regard to retention and reductions in illicit opioid and other drug use. These findings support the potential for utilizing thrice-weekly buprenorphine dosing in novel settings.

Disulfiram versus placebo for cocaine dependence in buprenorphine-maintained subjects: a preliminary trial

BACKGROUND

We examined the effects of disulfiram versus placebo on cocaine dependence in buprenorphine-maintained subjects.

METHODS

Opioid and cocaine dependent subjects (n = 20) were induced onto buprenorphine maintenance, then randomized to disulfiram (250 mg q.d. ; n = 11) or placebo (n = 9) treatment for 12 weeks.

RESULTS

Groups were comparable at baseline on demographic measures and on baseline measures of drug-use severity. Fifteen subjects completed the study, including 8 subjects randomized to disulfiram (72.7%) and 7 subjects randomized to placebo (77.8%). The total number of weeks abstinent from cocaine was significantly greater on disulfiram versus placebo (mean +/- SD: 7.8 +/- 2.6 vs. 3.3 +/- 0.5, p <.05) and the number of days to achieving 3 weeks (24.6 +/- 15.1 vs. 57.8 +/- 7.7, p <.01) of continuous cocaine abstinence was significantly lower in disulfiram compared with placebo. The number of cocaine-negative urine tests during the trial were also higher on disulfiram (14.7) than on placebo (8.6); furthermore, subjects in the disulfiram group achieved consistently higher rates of cocaine-negative urine tests in each 3-week interval and the increase over time was faster in the disulfiram compared with placebo.

CONCLUSIONS

This preliminary study suggests the potential efficacy of disulfiram versus placebo for treatment of cocaine dependence in buprenorphine-maintained patients.

A controlled trial of daily versus thrice-weekly buprenorphine administration for the treatment of opioid dependence

This study was aimed at determining whether thrice-weekly administration of buprenorphine is as effective as daily administration for treating opioid dependence. A total of 60 treatment-seeking opioid addicts were randomly assigned to take buprenorphine tablets sublingually either every day (8 mg) or thrice-weekly (16 mg on Mondays and Wednesdays and 24 mg on Fridays) over the course of a 12-week, double-blind, parallel trial. The buprenorphine dosing schedule had no significant effect on treatment retention. The rates of opioid-positive urine tests were significantly higher among those subjects who were given buprenorphine thrice weekly (58.5%) than among those who took it daily (46.6%). An analysis of the completers did not detect a significant effect of buprenorphine dosing schedule. The results obtained in our clinical trials indicate the advisability of daily doses of buprenorphine, at least at the beginning of a maintenance programme.