Office-based buprenorphine treatment for opioid-dependent patients

Treatment Experiences for Patients Receiving Buprenorphine/Naloxone for Opioid Use Disorder: A Qualitative Study of Patients' Perceptions and Attitudes

Background: Although buprenorphine/naloxone has been demonstrated to be an effective treatment for patients with opioid use disorder (OUD), treatment retention has been a challenge. This study extends what is presently a limited literature regarding patients' experiences with this medication and the implications for treatment retention. Methods: The study was conducted as a qualitative investigation of patients in treatment for OUD at the time of the study. Forty-three patients (27 men, 15 women, mean age 34.7) were recruited from three clinical settings, a community health center, an academically-based treatment site, and an independent substance abuse treatment facility. Most patients had returned to use in the past after attempts to become abstinent. Results: Patients generally reported positive experiences with this medication noting it helped to reduce opioid cravings quickly. As important considerations for treatment retention, patients emphasized a firm commitment to achieving abstinence when beginning treatment and a prescriber who is informed about and attentive to their emotional state. Diverging attitudes did exist regarding treatment duration as some patients were accepting of long-term treatment while others desired a relatively brief option. Among patients who had returned to use, potentially important issues emerged pertaining to the absence of patient outreach for missed medication appointments and inadequate discharge planning following stays at rehabilitation facilities. Conclusions: While results regarding the importance of patient motivation and strong patient-prescriber relationships have been noted in previous studies, other findings regarding opportunities to improve patient outreach and coordination of care have received relatively less attention and warrant further consideration.

Long-term patient outcomes following buprenorphine/naloxone treatment for opioid use disorder: a retrospective analysis in a commercially insured population

Background: While buprenorphine/naloxone (buprenorphine) has been demonstrated to be an effective medication for treating opioid use disorder (OUD), an important question exists about how long patients should remain in treatment.Objective: To examine the relationship between treatment duration and patient outcomes for individuals with OUD who have been prescribed buprenorphine.Methods: We conducted a retrospective, longitudinal study using the Massachusetts All Payer Claims Database, 2013 to 2017. The study comprised over 2,500 patients, approximately one-third of whom were female, who had been prescribed buprenorphine for OUD. The outcomes were hospitalizations and emergency room (ER) visits at 36 months following treatment initiation and 12 months following treatment discontinuation. Patients were classified into four groups based on treatment duration and medication adherence: poor adherence, duration <12 months; good adherence, duration <6 months; good adherence, duration 6 to 12 months, and good adherence, duration >12 months. We conducted analyses at the patient level of the relationship between duration and outcomes.Results: Better outcomes were observed for patients whose duration was greater than 12 months. Patients in the other groups had higher odds of hospitalization at 36 months following treatment initiation: poor adherence (2.71), <6 months (1.53), and 6 to 12 months (1.42). They also had higher odds of ER visits: poor adherence (1.69), <6 months (1.51), and 6 to 12 months (1.30). Similar results were observed following treatment discontinuation.Conclusions: OUD treatment with buprenorphine should be continued for at least 12 months to reduce hospitalizations and ED visits.

Effects of Buprenorphine Dose and Therapeutic Engagement on Illicit Opiate Use in Opioid Use Disorder Treatment Trials

The impact of agonist dose and of physician, staff and patient engagement on treatment have not been evaluated together in an analysis of treatment for opioid use disorder. Our hypotheses were that greater agonist dose and therapeutic engagement would be associated with reduced illicit opiate use in a time-dependent manner. Publicly-available treatment data from six buprenorphine efficacy and safety trials from the Federally-supported Clinical Trials Network were used to derive treatment variables. Three novel predictors were constructed to capture the time weighted effects of buprenorphine dosage (mg buprenorphine per day), dosing protocol (whether physician could adjust dose), and clinic visits (whether patient attended clinic). We used time-in-trial as a predictor to account for the therapeutic benefits of treatment persistence. The outcome was illicit opiate use defined by self-report or urinalysis. Trial participants (N = 3022 patients with opioid dependence, mean age 36 years, 33% female, 14% Black, 16% Hispanic) were analyzed using a generalized linear mixed model. Treatment variables dose, Odds Ratio (OR) = 0.63 (95% Confidence Interval (95%CI) 0.59−0.67), dosing protocol, OR = 0.70 (95%CI 0.65−0.76), time-in-trial, OR = 0.75 (95%CI 0.71−0.80) and clinic visits, OR = 0.81 (95%CI 0.76−0.87) were significant (p-values < 0.001) protective factors. Treatment implications support higher doses of buprenorphine and greater engagement of patients with providers and clinic staff.

The Role of Behavioral Interventions in Buprenorphine Maintenance Treatment: A Review

(Reprinted with permission from Am J Psychiatry 2017;174:738-747).

Relationship between buprenorphine adherence and relapse, health care utilization and costs in privately and publicly insured patients with opioid use disorder

Background

Treatment for opioid use disorder is important because of the negative health, societal and economic consequences of illicit opioid use, but treatment adherence can be a challenge. This study assessed the association between buprenorphine medication-assisted treatment (MAT) adherence and relapse, health care utilization and costs.

Patients and methods

Patients with opioid use disorder who were newly initiating a buprenorphine MAT regimen were identified in the 2008-2014 MarketScan^® Commercial and Medicaid Databases and followed for 12 months after their earliest outpatient pharmacy claim for buprenorphine. Adherence was categorized using proportion of days covered (PDC) with buprenorphine, and patients with PDC≥0.80 were classified as adherent. Descriptive and adjusted analyses compared relapse prevalence, utilization and costs, all measured in the 12 months following buprenorphine MAT initiation, of adherent patients to patients in non-adherent PDC categories (PDC<0.20, 0.20≤PDC<0.40, 0.40≤PDC<0.60, 0.60≤PDC<0.80).

Results

Adherent patients were 37.1% of the Commercial sample (N=16,085) and 41.3% of the Medicaid sample (N=5,688). In both samples, non-adherent patients were significantly more likely than adherent patients to relapse and to have hospitalizations and emergency department visits. As a result, as buprenorphine MAT adherence increased, pharmacy costs increased, but medical costs decreased. Total costs (pharmacy plus medical costs) in the 12 months following buprenorphine MAT initiation decreased with adherence in Commercial patients ($28,525 for PDC<0.20 to $17,844 for PDC≥0.80). A slight decrease in total costs in the 12 months following buprenorphine MAT initiation was also observed in Medicaid patients ($21,292 for PDC<0.20 to $18,621 for PDC≥0.80). After adjustment, total costs of adherent patients in the Commercial sample ($17,519) were significantly lower compared with those of non-adherent patients (range $20,294-$24,431). In the Medicaid sample, adjusted total costs were not significantly different between adherence groups.

Conclusion

Buprenorphine MAT adherence in the 12 months following treatment was associated with reduced odds of relapse and reduced unadjusted medical costs. For Commercial patients who were adherent to treatment, the adjusted total costs were predicted to be 30% lower than those for patients with PDC<0.20.

The Role of Behavioral Interventions in Buprenorphine Maintenance Treatment: A Review

OBJECTIVE

Although counseling is a required part of office-based buprenorphine treatment of opioid use disorders, the nature of what constitutes appropriate counseling is unclear and controversial. The authors review the literature on the role, nature, and intensity of behavioral interventions in office-based buprenorphine treatment.

METHOD

The authors conducted a review of randomized controlled studies testing the efficacy of adding a behavioral intervention to buprenorphine maintenance treatment.

RESULTS

Four key studies showed no benefit from adding a behavioral intervention to buprenorphine plus medical management, and four studies indicated some benefit for specific behavioral interventions, primarily contingency management. The authors examined the findings from the negative trials in the context of six questions: 1) Is buprenorphine that effective? 2) Is medical management that effective? 3) Are behavioral interventions that ineffective in this population? 4) How has research design affected the results of studies of buprenorphine plus behavioral treatment? 5) What do we know about subgroups of patients who do and those who do not seem to benefit from behavioral interventions? 6) What should clinicians aim for in terms of treatment outcome in buprenorphine maintenance?

CONCLUSIONS

High-quality medical management may suffice for some patients, but there are few data regarding the types of individuals for whom medical management is sufficient. Physicians should consider a stepped-care model in which patients may begin with relatively nonintensive treatment, with increased intensity for patients who struggle early in treatment. Finally, with 6-month retention rates seldom exceeding 50% and poor outcomes following dropout, we must explore innovative strategies for enhancing retention in buprenorphine treatment.

Improving the oral bioavailability of buprenorphine: an in-vivo proof of concept

Objectives

The aim of this study was to improve the oral bioavailability of buprenorphine by inhibiting presystemic metabolism via the oral co-administration of ‘Generally Recognized as Safe’ compounds, thus providing an orally administered drug product with less variability and comparable or higher exposure compared with the sublingual route.

Methods

The present studies were performed in Sprague Dawley rats following either intravenous or oral administration of buprenorphine/naloxone and oral co-administration of ‘Generally Recognized as Safe’ compounds referred to as ‘adjuvants’. Plasma samples were collected up to 22 h postdosing followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis.

Key findings

The adjuvants increased Cmax (21 ± 16 ng/ml vs 75 ± 33 ng/ml; 3.6-fold) and AUC(0–22 h) (10.6 ± 8.11 μg min/ml vs 22.9 ± 11.7 μg min/ml; 2.2-fold) values of buprenorphine (control vs adjuvant-treated, respectively). The absolute oral bioavailability of buprenorphine doubled (from 1.24% to 2.68%) in the presence of the adjuvants.

Conclusions

One may suggest that the adjuvant treatment most likely inhibited the presystemic metabolic enzymes, thus decreasing the intestinal ‘first-pass effect’ on buprenorphine. Additional studies are now required to further explore the concept of inhibiting presystemic metabolism of buprenorphine by adjuvants to potentially increase the oral bioavailability of buprenorphine.

Acute Pain Management in Opioid Dependent Patients

Acute pain management remains a challenge in opioid dependent patients, and it has been recognised that these patients are commonly under-treated.Chronic opioid exposure leads to widespread adaptations both at cellular and synaptic level.Physical dependence is a neuropharmacological phenomenon as a result of neuroadaptation and neuroplasticity, in contrast to addiction that is both neuropharmacological and behavioural.While providing the patient's pre-existing opioid requirement, the acute pain episode should be managed using additional multimodal analgesia: non-opioid medications in combination with local anaesthetic techniques and as required, short-acting opioid titrated to effect.Patients on long term buprenorphine and methadone with acute pain episode should be continued with their maintenance therapy and an additional short-acting opioid analgesic titrated to achieve therapeutic effect.

Relationship between buprenorphine adherence and health service utilization and costs among opioid dependent patients

Buprenorphine-medication assisted therapy (B-MAT) is an effective treatment for opioid dependence, but may be considered cost-prohibitive based on ingredient cost alone. The purpose of this study was to use medical and pharmacy claims data to estimate the healthcare service utilization and costs associated with B-MAT adherence among a sample of opioid dependent members. Members were placed into two adherence groups based on 1-year medication possession ratio (≥ 0.80 vs. <0.80). The B-MAT adherent group incurred significantly higher pharmacy charges (adjusted means; $6,156 vs. $3,581), but lower outpatient ($9,288 vs. $14,570), inpatient ($10,982 vs. $26,470), ER ($1,891 vs. $4,439), and total healthcare charges ($28,458 vs. $49,051; p<0.01) compared to non-adherent members. Adherence effects were confirmed in general linear models. Though B-MAT adherence requires increased pharmacy utilization, adherent individuals were shown to use fewer expensive health care services, resulting in overall reduced healthcare expenditure compared to non-adherent patients.

Effects of HCV seropositive status on buprenorphine pharmacokinetics in opioid-dependent individuals

BACKGROUND AND OBJECTIVES

The purpose of this study was to examine the effect of hepatitis C virus (HCV) infection on buprenorphine pharmacokinetics in opioid-dependent, buprenorphine/naloxone-maintained adults.

METHODS

A retrospective analysis of buprenorphine pharmacokinetics in HCV seropositive and seronegative buprenorphine/naloxone-maintained individuals (N = 49) was undertaken.

RESULTS

Relative to HCV seronegative subjects, HCV seropositive subjects had higher buprenorphine exposure, as demonstrated by elevated buprenorphine AUC and Cmax values (p = .03 and .02, respectively) and corresponding elevations in the metabolites, buprenorphine-3-glucuronide AUC values (p = .03) and norbuprenorphine-3-glucuronide AUC and C24 values (p = .05 and .03, respectively).

DISCUSSION AND CONCLUSIONS

HCV infection was associated with higher plasma concentrations of buprenorphine and buprenorphine metabolites.

SCIENTIFIC SIGNIFICANCE AND FUTURE DIRECTIONS

Findings suggest the potential for opioid toxicity among HCV-infected patients treated with buprenorphine/naloxone, and possible hepatotoxic effects related to increased buprenorphine exposure. HCV-infected patients receiving buprenorphine may need lower doses to maintain therapeutic plasma concentrations.

Participant characteristics and buprenorphine dose

BACKGROUND

Clinical parameters for determining buprenorphine dose have not been adequately examined in treatment outcome research.

OBJECTIVES

This study is a secondary analysis of data collected in a recently completed comparison of buprenorphine taper schedules conducted as part of the National Institute on Drug Abuse's Clinical Trials Network to assess whether participant baseline characteristics are associated with buprenorphine dose.

METHODS

After 3 weeks of flexible dosing, 516 participants were categorized by dose provided in the final dosing week (9.3% received a final week dose of 8 mg buprenorphine, 27.3% received 16 mg, and 63.4% received 24 mg).

RESULTS

Findings show that final week dose groups differed in baseline demographic and drug use characteristics including education, heroin use, route of drug administration, withdrawal symptoms, and craving. These groups also differed in opioid use during the four dosing weeks, with the lowest use in the 8 mg group and highest use in the 24 mg group (p < .0001). Additional analyses address withdrawal symptoms and craving.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Final week dose groups differed in demographic and drug use characteristics, and the group receiving the largest final week dose had the highest rate of continued opioid use. These findings may contribute to the development of clinical guidelines regarding buprenorphine dose in the treatment of opioid dependence; however, further investigations that include random assignment to dose by baseline characteristics are needed.

Rifampin, but not rifabutin, may produce opiate withdrawal in buprenorphine-maintained patients

BACKGROUND

This series of studies examines the pharmacokinetic/pharmacodynamic interactions between buprenorphine, an opioid partial agonist increasingly used in treatment of opioid dependence, and rifampin, a medication used as a first line treatment for tuberculosis; or rifabutin, an alternative antituberculosis medication.

METHODS

Opioid-dependent individuals on stable doses of buprenorphine/naloxone underwent two, 24-h blood sampling studies: (1) for buprenorphine pharmacokinetics and (2) following 15 days of rifampin 600 mg daily or rifabutin 300 mg daily for buprenorphine and rifampin or rifabutin pharmacokinetics.

RESULTS

Rifampin administration produced significant reduction in plasma buprenorphine concentrations (70% reduction in mean area under the curve (AUC); p=<0.001) and onset of opiate withdrawal symptoms in 50% of participants (p=0.02). While rifabutin administration to buprenorphine-maintained subjects resulted in a significant decrease in buprenorphine plasma concentrations (35% decrease in AUC; p<0.001) no opiate withdrawal was seen. Compared with historical control data, buprenorphine had no significant effect on rifampin pharmacokinetics, but was associated with 22% lower rifabutin mean AUC (p=0.009), although rifabutin and its active metabolite concentrations remained in the therapeutic range.

CONCLUSIONS

Rifampin is a more potent inducer of buprenorphine metabolism than rifabutin with pharmacokinetic and pharmacodynamic adverse consequences. Those patients requiring rifampin treatment for tuberculosis and receiving buprenorphine therapy are likely to require an increase in buprenorphine dose to prevent withdrawal symptoms. Rifabutin administration was associated with decreases in buprenorphine plasma concentrations, but no clinically significant adverse events were observed.

Gender differences in pharmacokinetics of maintenance dosed buprenorphine

AIMS

Gender differences are known to occur in the pharmacokinetics of many drugs. Mechanisms may include differences in body composition, body weight, cardiac output, hormonal status, and use of different co-medications. Recently subtle gender-dependent differences in cytochrome P450 (CYP) 3A-dependent metabolism have been demonstrated. Buprenorphine N-dealkylation to norbuprenorphine is primarily performed by CYP3A. We therefore asked whether gender-dependent differences occur in the pharmacokinetics of buprenorphine.

METHODS

A retrospective examination was made of control (buprenorphine/naloxone-only) sessions from a number of drug interaction studies between buprenorphine and antiretroviral drugs. Twenty males and eleven females were identified who had a negative cocaine urine test prior to participation in the control session and were all on the same maintenance dose (16/4 mg) of sublingual buprenorphine/naloxone. Pharmacokinetic data from their control sessions (buprenorphine/naloxone only) were sorted by gender and compared using the two-sample t-test.

RESULTS

Females had significantly higher area under the plasma concentration curve (AUC) and maximum plasma concentrations for buprenorphine, norbuprenorphine and norbuprenorphine-3-glucuronide. AUCs relative to dose per body weight and surface area were significantly higher for only norbuprenorphine. AUCs relative to lean body mass were, however, not significantly different.

CONCLUSIONS

Gender-related differences exist in the pharmacokinetics of buprenorphine; differences in body composition appear to have a major impact; differences in CYPA-dependent metabolism may also contribute.

Drug interactions associated with methadone, buprenorphine, cocaine, and HIV medications: implications for pregnant women

Pregnancy in substance-abusing women with HIV/AIDS presents a complex clinical challenge. Opioid-dependent women need treatment with opioid therapy during pregnancy to protect the health of mother and developing fetus. However, opioid therapies, methadone and buprenorphine, may have drug interactions with some HIV medications that can have adverse effects leading to suboptimal clinical outcomes. Further, many opioid-dependent individuals have problems with other forms of substance abuse, for example, cocaine abuse, that could also contribute to poor clinical outcomes in a pregnant woman. Physiological changes, including increased plasma volume and increased hepatic and renal blood flow, occur in the pregnant woman as the pregnancy progresses and may alter medication needs with the potential to exacerbate drug interactions, although there is sparse literature on this issue. Knowledge of possible drug interactions between opioids, other abused substances such as cocaine, HIV therapeutics, and other frequently required medications such as antibiotics and anticonvulsants is important to assuring the best possible outcomes in the pregnant woman with opioid dependence and HIV/AIDS.

Interactions between buprenorphine and antiretrovirals: nucleos(t)ide reverse transcriptase inhibitors (NRTI) didanosine, lamivudine, and tenofovir

To improve outcomes among injection drug users with HIV and/or chronic hepatitis B, it is important to identify drug interactions between antiretroviral and opiate therapies. We report the results of a study designed to examine the interaction between buprenorphine and the nucleos(t)ide reverse transcriptase inhibitors (NRTI) didanosine (ddI), lamivudine (3TC), and tenofovir (TDF). Opioid-dependent, buprenorphine/naloxone-maintained, HIV-negative volunteers (n = 27) participated in two 24-hour sessions to determine (1) pharmacokinetics of buprenorphine alone and (2) pharmacokinetics of both buprenorphine and either ddI, 3TC, or TDF. Among buprenorphine/naloxone-maintained study participants, no significant changes in buprenorphine pharmacokinetics were observed following ddI, 3TC, or TDF administration. Buprenorphine had no significant effect on NRTI concentrations. Concomitant use of buprenorphine with ddI, 3TC, or TDF results in neither a significant pharmacokinetic nor pharmacodynamic interaction.

Lack of clinically significant drug interactions between nevirapine and buprenorphine

This study was conducted to determine whether drug interactions of clinical importance occur between buprenorphine, an opioid partial agonist medication used in treatment of opioid dependence, and the nonnucleoside reverse transcriptase inhibitor (NNRTI) nevirapine. Opioid-dependent, buprenorphine/naloxone-maintained, HIV-negative volunteers (n = 7) participated in 24-hour sessions to determine the pharmacokinetics of buprenorphine alone and of buprenorphine and nevirapine following administration of 200 mg nevirapine daily for 15 days. Opiate withdrawal symptoms, cognitive effects, and adverse events were determined prior to and following nevirapine administration. Modest decreases were observed for AUC for buprenorphine and its metabolites. There was a trend for more rapid clearance of both buprenorphine (p = .08) and buprenorphine-3-glucuronide (p = .08). While no single effect reached statistical significance, the joint probability that the consistent declines in all measures of exposure were due to chance was extremely low, indicating that nevirapine significantly reduces overall exposure to buprenorphine and buprenorphine metabolites. Clinically significant consequences of the interaction were not observed. Buprenorphine did not alter nevirapine pharmacokinetics. Dose adjustments of either buprenorphine or nevirapine are not likely to be necessary when these drugs are coadministered for the treatment of opiate dependence and HIV disease.

Effect of cocaine use on buprenorphine pharmacokinetics in humans

The effect of chronic cocaine use on buprenorphine pharmacokinetics was investigated to identify drug interactions and potential toxicities. In a retrospective analysis, pharmacokinetics were compared for 16 studies completed on subjects who were regular cocaine users and 74 studies on subjects who used cocaine only occasionally or not at all. All participants were stably maintained on buprenorphine/naloxone 16/4 mg daily. Participants who used cocaine regularly had lower buprenorphine exposure (AUC 34% lower; C(max) 27% lower and C(24) 37% lower; p <or= .001 for all comparisons). Regular cocaine users were younger (p = .0007), and used more heroin (p = .004) and cocaine (p < .0001). Regular cocaine use may result in lower buprenorphine plasma concentrations with potential for adverse clinical outcomes.

Methadone, buprenorphine, and street drug interactions with antiretroviral medications

While street drugs appear unlikely to alter the metabolism of antiretroviral (ARV) medications, several ARVs may induce or inhibit metabolism of various street drugs. However, research on these interactions is limited. Case reports have documented life-threatening overdoses of ecstasy and gamma-hydroxybutyrate after starting ritonavir, an ARV that inhibits several metabolic enzymes. For opioid addiction, methadone or buprenorphine are the treatments of choice. Because a number of ARVs decrease or increase methadone levels, patients should be monitored for methadone withdrawal or toxicity when they start or stop ARVs. Most ARVs do not cause buprenorphine withdrawal or toxicity, even if they alter buprenorphine levels, with rare exceptions to date including atazanavir/ritonavir associated with significant increases in buprenorphine and adverse events related to sedation and mental status changes in some cases. There are newer medications yet to be studied with methadone or buprenorphine. Further, there are many frequently used medications in treatment of complications of HIV disease that have not been studied. There is need for continuing research to define these drug interactions and their clinical significance.

From research to the real world: buprenorphine in the decade of the Clinical Trials Network

The National Institute on Drug Abuse (NIDA) established the National Drug Abuse Treatment Clinical Trials Network (CTN) in 1999 to bring researchers and treatment providers together to develop a clinically relevant research agenda. Initial CTN efforts addressed the use of buprenorphine, a mu-opioid partial agonist, as treatment for opioid dependence. Strong evidence of buprenorphine's therapeutic efficacy was demonstrated in clinical trials involving several thousand opioid-dependent participants, and in 2002, the Food and Drug Administration approved buprenorphine for the treatment of opioid dependence. With the advent of a sublingual tablet containing both buprenorphine and naloxone to mitigate abuse and diversion (Suboxone), buprenorphine appeared poised to be the first-line treatment for opioid addiction. Notwithstanding its many attributes, certain implementation barriers remained to be addressed in CTN studies, and these efforts have brought a body of knowledge on buprenorphine to frontline clinicians. The purpose of this article is to review CTN-based buprenorphine research and related efforts to overcome challenges to the implementation of buprenorphine therapy in mainstream practice. Furthermore, this article explores current issues and future challenges that may require additional CTN efforts.

Drug interactions of clinical importance among the opioids, methadone and buprenorphine, and other frequently prescribed medications: a review

Drug interactions are a leading cause of morbidity and mortality. Methadone and buprenorphine are frequently prescribed for the treatment of opioid addiction. Patients needing treatment with these medications often have co-occurring medical and mental illnesses that require medication treatment. The abuse of illicit substances is also common in opioid-addicted individuals. These clinical realities place patients being treated with methadone and buprenorphine at risk for potentially toxic drug interactions. A substantial literature has accumulated on drug interactions between either methadone or buprenorphine with other medications when ingested concomitantly by humans. This review summarizes current literature in this area.

Integrating buprenorphine treatment into office-based practice: a qualitative study

BACKGROUND

Despite the availability and demonstrated effectiveness of office-based buprenorphine maintenance treatment (BMT), the systematic examination of physicians' attitudes towards this new medical practice has been largely neglected.

OBJECTIVE

To identify facilitators and barriers to the potential or actual implementation of BMT by office-based medical providers.

DESIGN

Qualitative study using individual and group semi-structured interviews.

PARTICIPANTS

Twenty-three practicing office-based physicians in New England.

APPROACH

Interviews were audiotaped, transcribed, and entered into a qualitative software program. The transcripts were thematically coded using the constant comparative method by a multidisciplinary team.

RESULTS

Eighty percent of the physicians were white; 55% were women. The mean number of years since graduating medical school was 14 (SD = 10). The primary areas of clinical specialization were internal medicine (50%), infectious disease (20%), and addiction medicine (15%). Physicians identified physician, patient, and logistical factors that would either facilitate or serve as a barrier to their integration of BMT into clinical practice. Physician facilitators included promoting continuity of patient care, positive perceptions of BMT, and viewing BMT as a positive alternative to methadone maintenance. Physician barriers included competing activities, lack of interest, and lack of expertise in addiction treatment. Physicians' perceptions of patient-related barriers included concerns about confidentiality and cost, and low motivation for treatment. Perceived logistical barriers included lack of remuneration for BMT, limited ancillary support for physicians, not enough time, and a perceived low prevalence of opioid dependence in physicians' practices.

CONCLUSIONS

Addressing physicians' perceptions of facilitators and barriers to BMT is crucial to supporting the further expansion of BMT into primary care and office-based practices.

Buprenorphine tapering schedule and illicit opioid use

AIMS

To compare the effects of a short or long taper schedule after buprenorphine stabilization on participant outcomes as measured by opioid-free urine tests at the end of each taper period.

DESIGN

This multi-site study sponsored by Clinical Trials Network (CTN, a branch of the US National Institute on Drug Abuse) was conducted from 2003 to 2005 to compare two taper conditions (7 days and 28 days). Data were collected at weekly clinic visits to the end of the taper periods, and at 1-month and 3-month post-taper follow-up visits.

SETTING

Eleven out-patient treatment programs in 10 US cities.

INTERVENTION

Non-blinded dosing with Suboxone during the 1-month stabilization phase included 3 weeks of flexible dosing as determined appropriate by the study physicians. A fixed dose was required for the final week before beginning the taper phase.

MEASUREMENTS

The percentage of participants in each taper group providing urine samples free of illicit opioids at the end of the taper and at follow-up.

FINDINGS

At the end of the taper, 44% of the 7-day taper group (n = 255) provided opioid-free urine specimens compared to 30% of the 28-day taper group (n = 261; P = 0.0007). There were no differences at the 1-month and 3-month follow-ups (7-day = 18% and 12%; 28-day = 18% and 13%, 1 month and 3 months, respectively).

CONCLUSION

For individuals terminating buprenorphine pharmacotherapy for opioid dependence, there appears to be no advantage in prolonging the duration of taper.

Addiction to prescription opioids: characteristics of the emerging epidemic and treatment with buprenorphine

Dependence on and abuse of prescription opioid drugs is now a major health problem, with initiation of prescription opioid abuse exceeding cocaine in young people. Coincident with the emergence of abuse and dependence on prescription opioids, there has been an increased emphasis on the treatment of pain. Pain is now the "5th vital sign" and physicians face disciplinary action for failure to adequately relieve pain. Thus, physicians are whipsawed between the imperative to treat pain with opioids and the fear of producing addiction in some patients. In this article, the authors characterize the emerging epidemic of prescription opioid abuse, discuss the utility of buprenorphine in the treatment of addiction to prescription opioids, and present illustrative case histories of successful treatment with buprenorphine.

Interaction between buprenorphine and atazanavir or atazanavir/ritonavir

Opioid addiction and HIV disease frequently co-occur. Adverse drug interactions have been reported between methadone and some HIV medications, but less is known about interactions between buprenorphine, an opioid partial agonist used to treat opioid dependence, and HIV therapeutics. This study examined drug interactions between buprenorphine and the protease inhibitors atazanavir and atazanavir/ritonavir. Opioid-dependent, buprenorphine/naloxone-maintained, HIV-negative volunteers (n=10 per protease inhibitor) participated in two 24-h sessions to determine pharmacokinetics of (1) buprenorphine and (2) buprenorphine and atazanavir (400mg daily) or atazanavir/ritonavir (300/100mg daily) following administration for 5 days. Objective opiate withdrawal scale scores and mini-mental state examination were determined prior to and following antiretroviral administration to examine pharmacodynamic effects. Pharmacokinetics of atazanavir and atazanavir/ritonavir were compared in subjects and matched, healthy controls (n=10 per protease inhibitor) to determine effects of buprenorphine. With atazanavir and atazanavir/ritonavir, respectively concentrations of buprenorphine (p<0.001, p<0.001), norbuprenorphine (p=0.026, p=0.006), buprenorphine glucuronide (p=0.002, p<0.001), and norbuprenorphine glucuronide (NS, p=0.037) increased. Buprenorphine treatment did not significantly alter atazanavir or ritonavir concentrations. Three buprenorphine/naloxone-maintained participants reported increased sedation with atazanavir/ritonavir. Atazanavir or atazanavir/ritonavir may increase buprenorphine and buprenorphine metabolite concentrations and might require a decreased buprenorphine dose.

Interactions between buprenorphine and antiretrovirals. I. The nonnucleoside reverse-transcriptase inhibitors efavirenz and delavirdine

This study examined drug interactions between buprenorphine, an opioid partial agonist medication used in the treatment of opioid dependence, and the nonnucleoside reverse-transcriptase inhibitors (NNRTIs) efavirenz (EFV) and delavirdine (DLV). Opioid-dependent, buprenorphine/naloxone-maintained, human immunodeficiency virus (HIV)-negative volunteers (n=10 per NNRTI) participated in 24-h sessions to determine pharmacokinetics of buprenorphine and of buprenorphine with either EFV or DLV after administration of standard doses of either antiretroviral for 15 or 7 days, respectively. Opiate withdrawal symptoms, cognitive effects, and adverse events were determined before and after antiretroviral administration in opioid-dependent participants. The pharmacokinetics of NNRTIs in healthy control participants were used to determine the effect of buprenorphine on NNRTIs. EFV decreased the buprenorphine area under the concentration-time curve (P<.001). DLV increased buprenorphine concentrations (P<.001). Clinically significant consequences of these interactions were not observed. Buprenorphine did not alter antiretroviral pharmacokinetics. Adjustments of doses of either buprenorphine or EFV or DLV are not likely to be necessary when these drugs are administered for the treatment of opiate dependence and HIV disease.

Interactions between buprenorphine and antiretrovirals. II. The protease inhibitors nelfinavir, lopinavir/ritonavir, and ritonavir

We examined drug interactions between buprenorphine, an opioid partial agonist available by prescription for treatment of opioid dependence, and the protease inhibitors (PIs) nelfinavir (NFV), ritonavir (RTV), and lopinavir/ritonavir (LPV/R). Opioid-dependent, buprenorphine/naloxone-maintained, human immunodeficiency virus (HIV)-negative volunteers (n=10 per PI) participated in 24-h pharmacokinetic studies, before and after administration of each PI. Symptoms of opiate withdrawal and excess were determined before and after PI administration. PI pharmacokinetics were determined and compared between opiate-dependent participants and healthy control participants (n=15 per PI). Administration of RTV, but not of NFV or LPV/R, resulted in a significant increase in the buprenorphine area under the concentration-time curve (AUC). Symptoms of opiate excess, however, were not observed. Buprenorphine had no significant effects on PI AUC. Adjustments of doses of either buprenorphine or NFV, LPV/R, or RTV are not likely to be necessary when these drugs are administered for the treatment of opioid dependence and HIV disease.

Buprenorphine assay and plasma concentration monitoring in HIV-infected substance users

The availability of buprenorphine (BUP) provides an alternative approach to the treatment of opioid addiction with methadone, an agent that has many drug-drug interactions when combined with antiretroviral therapy (ART). However, due to limited long-term pharmacokinetic studies in HIV-infected patients, the clinical use of BUP, a CYP450-3A4 substrate, will require that studies be conducted to examine safety, tolerability and pharmacokinetics when these drugs are taken for chronic treatment. One clinical approach could include plasma concentration monitoring to avoid under- or overdosing BUP secondary to drug interactions with ART. The measurement of BUP and its active metabolite, norbuprenorphine (NBUP) facilitates the addition of BUP to ART in an attempt to avoid drug toxicity as described in a recent report by Bruce et al. Therefore, our objective was to validate a BUP assay and integrate its application into an ongoing antiretroviral (ARV) plasma concentration monitoring program. A chromatographic method for monitoring BUP and its active metabolite, NBUP was investigated. An assay was developed that would facilitate BUP and ARV measurement from a single 3 mL blood sample (0.75 mL plasma required) in conjunction with a previously validated multiple ARV HPLC method. The method measures BUP and NBUP over the range from 0.25 to 50 ng/mL with mass spectrometry detection. Inter- and intra-assay variation was <or=11%, across the concentration range. The method quantitates BUP and NBUP plasma concentrations within the range of expected values from current BUP dosing guidelines. Use of this combined BUP and ARV plasma concentration monitoring approach for a representative patient receiving BUP, atazanavir and efavirenz demonstrated its clinical application.

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.