Hepatic safety and lack of antiretroviral interactions with buprenorphine/naloxone in HIV-infected opioid-dependent patients

Drug-drug interactions and clinical considerations with co-administration of antiretrovirals and psychotropic drugs

Psychotropic medications are frequently co-prescribed with antiretroviral therapy (ART), owing to a high prevalence of psychiatric illness within the population living with HIV, as well as a 7-fold increased risk of HIV infection among patients with psychiatric illness. While ART has been notoriously associated with a multitude of pharmacokinetic drug interactions involving the cytochrome P450 enzyme system, the magnitude and clinical impact of these interactions with psychotropics may range from negligible effects on plasma concentrations to life-threatening torsades de pointes or respiratory depression. This comprehensive review summarizes the currently available information regarding drug-drug interactions between antiretrovirals and pharmacologic agents utilized in the treatment of psychiatric disorders-antidepressants, stimulants, antipsychotics, anxiolytics, mood stabilizers, and treatments for opioid use disorder and alcohol use disorder-and provides recommendations for their management. Additionally, overlapping toxicities between antiretrovirals and the psychotropic classes are highlighted. Knowledge of the interaction and adverse effect potential of specific antiretrovirals and psychotropics will allow clinicians to make informed prescribing decisions to better promote the health and wellness of this high-risk population.

Physicians' Decision-making When Implementing Buprenorphine With New Patients: Conjoint Analyses of Data From a Cohort of Current Prescribers

OBJECTIVES

Few studies have considered how providers make decisions to prescribe buprenorphine to new patients with opioid use disorder. This study examined the relative importance of patients' clinical, financial, and social characteristics on physicians' decision-making related to willingness to prescribe buprenorphine to new patients and the number of weeks of medication that they are willing to initially prescribe after induction.

METHODS

A national sample of 1174 current prescribers was surveyed. Respondents rated willingness to prescribe on a 0 to 10 scale and indicated the number of weeks of medication (ranging from none to >4 weeks) for 20 hypothetical patients. Conjoint analysis estimated relative importance scores and part-worth utilities for these 2 outcome ratings.

RESULTS

The mean rating for willingness to prescribe was 5.52 (SD 2.47), indicating a moderate willingness to implement buprenorphine treatment. The mean prescription length was 2.06 (SD 1.34), which corresponds to 1 week of medication. For both ratings, the largest importance scores were for other risky substance use, method of payment, and spousal involvement in treatment. Illicit benzodiazepine use, having Medicaid insurance to pay for the office visit, and having an opioid-using spouse were negatively associated with these outcome ratings, whereas a history of no risky alcohol or benzodiazepine use, cash payment, and having an abstinent spouse were positively associated with both ratings.

CONCLUSIONS

Reticence to prescribe to individuals using an illicit benzodiazepine and individuals with a drug-using spouse aligns with practice guidelines. However, reluctance to prescribe to patients with Medicaid may hamper efforts to expand access to treatment.

Primary Care-Based Models for the Treatment of Opioid Use Disorder: A Scoping Review

Greater integration of medication-assisted treatment (MAT) for opioid use disorder (OUD) in U.S. primary care settings would expand access to treatment for this condition. Models for integrating MAT into primary care vary in structure. This article summarizes findings of a technical report for the Agency for Healthcare Research and Quality describing MAT models of care for OUD, based on a literature review and interviews with key informants in the field. The report describes 12 representative models of care for integrating MAT into primary care settings that could be considered for adaptation across diverse health care settings. Common components of existing care models include pharmacotherapy with buprenorphine or naltrexone, provider and community education, coordination and integration of OUD treatment with other medical and psychological needs, and psychosocial services and interventions. Models vary in how each component is implemented. Decisions about adopting MAT models of care should be individualized to address the unique milieu of each implementation setting.

Hepatic Safety of Buprenorphine in HIV-Infected and Uninfected Patients With Opioid Use Disorder: The Role of HCV-Infection

INTRODUCTION

Individuals with HIV and hepatitis C (HCV) infection, alcohol use disorder, or who are prescribed potentially hepatotoxic medications may be at increased risk for buprenorphine (BUP) associated hepatotoxicity.

MATERIALS AND METHODS

We examined a cohort of HIV-infected and uninfected patients receiving an initial BUP prescription between 2003 and 2012. We compared changes in alanine and aspartate aminotransferases (ALT and AST) and total bilirubin (TB) stratified by HIV status. We identified cases of liver enzyme elevation (LEE), TB elevation (TBE), and conducted chart review to assess for cases of drug induced liver injury (DILI) and death. We examined associations between age, sex, race, HIV-infection, HCV-infection, alcohol use disorder, and prescription of other potentially heptatotoxic medications with the composite endpoint of LEE, TBE, and DILI.

RESULTS

Of 666 patients prescribed BUP, 36% were HIV-infected, 98% were male, 60% had RNA-confirmed HCV infection, 50% had a recent diagnosis of alcohol use disorder, and 64% were prescribed other potentially hepatotoxic medications. No clinically significant changes were observed in median ALT, AST and TB and these changes did not differ between HIV-infected and uninfected patients. Compared with uninfected patients, HIV-infected (OR 7.3, 95% CI 2.1-26.1, p=0.002), HCV-infected (OR 4.9 95% CI 1.6-15.2, p=0.007) or HIV/HCV co-infected patients (OR 6.9, 95%CI 2.1-22.2, p=0.001) were more likely to have the composite endpoint of LEE, TB elevation or DILI, in analyses that excluded 60 patients with evidence of pre-existing liver injury. 31 patients had LEE, 14/187 HIV-infected and 17/340 uninfected (p=0.25); 11 had TBE, including 9/186 HIV-infected and 2/329 uninfected (p=0.002); 8 experienced DILI, 4/202 HIV-infected and 4/204 uninfected (p=0.45). There were no significant associations with alcohol use disorder or prescription of other potentially hepatotoxic medications after adjustment for HIV/HCV status.

CONCLUSIONS

Liver enzymes and TB are rarely elevated in HIV-infected and uninfected patients receiving BUP. Risk of hepatotoxicity was greater in individuals infected with HIV, HCV, or HIV/HCV co-infection, who may benefit from increased monitoring.

Substance use in older HIV-infected patients

PURPOSE OF REVIEW

Substance use may persist throughout the life course and has a substantial impact on health outcomes globally. As HIV-infected individuals are disproportionately impacted by substance use and living longer, it is critical that providers and researchers alike understand the impact of substance use on older, HIV-infected patients and potential treatment options. To this end, we conducted a review of the literature focusing on the most commonly used substances to outline the epidemiology, health consequences, treatment options and latest research relevant to older, HIV-infected patients.

RECENT FINDINGS

Substance use impacts older, HIV-infected patients with regards to HIV-related and non-HIV-related outcomes. Counseling strategies are available for marijuana and stimulant use disorders. Brief counseling is useful alongside medications for alcohol, tobacco and opioid use disorders. Many medications for alcohol, tobacco and opioid use disorders are safe in the setting of antiretroviral therapy. Unfortunately, few interventions targeting substance use in older, HIV-infected patients have been developed and evaluated.

SUMMARY

As older, HIV-infected patients continue to experience substance use and its related health consequences, there will be a growing need for the development of safe and effective interventions, which address the complex needs of this population.

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

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

Buprenorphine-naloxone treatment in opioid dependence and risk of liver enzyme elevation: results from a 12-month observational study

BACKGROUND

Some case series mention possible liver toxicity in opioid-dependent patients under buprenorphine treatment.

METHODS

This 12-month prospective observational follow-up study in opioid-dependent patients under buprenorphine-naloxone treatment assessed outcome and safety issues. At baseline, 337 eligible datasets were available; 181 patients completed the 12-month study. Liver enzymes were tested at baseline and after 12, 24, and 52 weeks' treatment.

RESULTS

One to two percent of patients showed mostly discrete elevations of liver enzymes, but no patient met the criteria for drug-induced liver injury. No serious liver-related adverse events occurred, but two non-serious cases of liver enzyme increase were recorded. No patient dropped out of treatment for liver-related disorders.

CONCLUSION

This study is in line with some recent studies and provides further evidence that buprenorphine-naloxone is relatively safe with respect to liver injury.

Hepatotoxicity in a 52-week randomized trial of short-term versus long-term treatment with buprenorphine/naloxone in HIV-negative injection opioid users in China and Thailand

BACKGROUND

Buprenorphine/naloxone (BUP/NX), an effective treatment for opioid dependence, has been implicated in hepatic toxicity. However, as persons taking BUP/NX have multiple hepatic risk factors, comparative data are needed to quantify the risk of hepatoxicity with BUP/NX.

METHODS

We compared rates of alanine aminotransferase (ALT) elevation≥grade 3 (ALT≥5.1 times the upper limit of normal) and graded bilirubin elevations in HIV-negative opioid injectors randomized to long-term (52 weeks) or short-term (18 days) medication assisted treatment (LT-MAT and ST-MAT, respectively) with BUP/NX in a multisite trial conducted in China and Thailand. ALT and bilirubin were measured at baseline, 12, 26, 40 and 52 weeks, times temporally remote from BUP/NX exposure in the ST-MAT participants.

RESULTS

Among1036 subjects with at least one laboratory follow-up measurement, 76 (7%) participants experienced ALT elevation≥grade 3. In an intent-to-treat analysis, the risk of ALT events was similar in participants randomized to LT-MAT compared with ST-MAT (adjusted hazard ratio 1.25, 95% confidence interval 0.79 to 1.98). This finding was supported by an as-treated analysis, in which actual exposure to BUP/NX was considered. Hepatitis C seroconversion during follow-up was strongly associated with ALT events. Bilirubin elevations≥grade 2 occurred in 2% of subjects, with no significant difference between arms.

CONCLUSIONS

Over 52-week follow-up, the risk of hepatotoxicity was similar in opioid injectors receiving brief and prolonged treatment with BUP/NX. These data suggest that most hepatotoxic events observed during treatment with BUP/NX are due to other factors.

A review of pharmacological interactions between HIV or hepatitis C virus medications and opioid agonist therapy: implications and management for clinical practice

Global access to opioid agonist therapy and HIV/hepatitis C virus (HCV) treatment is expanding but when used concurrently, problematic pharmacokinetic and pharmacodynamic interactions may occur. Articles published from 1966 to 2012 in Medline were reviewed using the following keywords: HIV, AIDS, HIV therapy, HCV, HCV therapy, antiretroviral therapy, highly active antiretroviral therapy, drug interactions, methadone and buprenorphine. In addition, a review of abstracts from national and international meetings and conference proceedings was conducted; selected reports were reviewed as well. The metabolism of both opioid and antiretroviral therapies, description of their known interactions and clinical implications and management of these interactions were reviewed. Important pharmacokinetic and pharmacodynamic drug interactions affecting either methadone or HIV medications have been demonstrated within each class of antiretroviral agents. Drug interactions between methadone, buprenorphine and HIV medications are known and may have important clinical consequences. Clinicians must be alert to these interactions and have a basic knowledge regarding their management.

Representation of women and pregnant women in HIV research: a limited systematic review

BACKGROUND

HIV-related outcomes may be affected by biological sex and by pregnancy. Including women in general and pregnant women in particular in HIV-related research is important for generalizability of findings.

OBJECTIVE

To characterize representation of pregnant and non-pregnant women in HIV-related research conducted in general populations.

DATA SOURCES

All HIV-related articles published in fifteen journals from January to March of 2011. We selected the top five journals by 2010 impact factor, in internal medicine, infectious diseases, and HIV/AIDS.

STUDY ELIGIBILITY CRITERIA

HIV-related studies reporting original research on questions applicable to both men and women of reproductive age were considered; studies were excluded if they did not include individual-level patient data.

STUDY APPRAISAL AND SYNTHESIS METHODS

Articles were doubly reviewed and abstracted; discrepancies were resolved through consensus. We recorded proportion of female study participants, whether pregnant women were included or excluded, and other key factors.

RESULTS

In total, 2014 articles were published during this period. After screening, 259 articles were included as original HIV-related research reporting individual-level data; of these, 226 were determined to be articles relevant to both men and women of reproductive age. In these articles, women were adequately represented within geographic region. The vast majority of published articles, 183/226 (81%), did not mention pregnancy (or related issues); still fewer included pregnant women (n=33), reported numbers of pregnant women (n=19), or analyzed using pregnancy status (n=9).

LIMITATIONS

Data were missing for some key variables, including pregnancy. The time period over which published works were evaluated was relatively short.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

The under-reporting and inattention to pregnancy in the HIV literature may reduce policy-makers' ability to set evidence-based policy around HIV/AIDS care for pregnant women and women of child-bearing age.

Buprenorphine for human immunodeficiency virus/hepatitis C virus-coinfected patients: does it serve as a bridge to hepatitis C virus therapy?

OBJECTIVES

Buprenorphine is associated with enhanced human immunodeficiency virus (HIV) treatment outcomes including increased antiretroviral therapy initiation rates, adherence, and CD4 cell counts among HIV-infected opioid-dependent individuals. Buprenorphine facilitates hepatitis C virus (HCV) treatment in opioid-dependent patients with HCV monoinfection. Less is known about buprenorphine's role in HIV/HCV coinfection.

METHODS

We conducted a retrospective chart review to evaluate HCV care for HIV-infected buprenorphine patients in the first 4 years of buprenorphine's integration into a Rhode Island HIV clinic.

RESULTS

Sixty-one patients initiated buprenorphine. All had HCV antibody testing; 57 (93%) were antibody-positive. All antibody-positive patients underwent HCV RNA testing; 48 (84%) were RNA-positive. Of these, 15 (31%) were not referred to HCV care. Among chronically infected patients, 3 received HCV treatment after buprenorphine; all had cirrhosis and none achieved viral eradication. At buprenorphine induction, most patients had inadequately controlled HIV infection, with detectable HIV RNA (59%) or CD4 cell count less than or equal to 350/μL (38%).

CONCLUSIONS

Buprenorphine has shown limited success to date as a bridge to HCV treatment within an HIV clinic. Buprenorphine's stabilization of opioid dependence and HIV disease may permit the use of HCV therapy over time.

Effect of buprenorphine dose on treatment outcome

The goal of this meta-analysis is to provide evidence based information about proper dosing for buprenorphine maintenance treatment to improve treatment outcome. To be selected for the review and inclusion in the meta-analysis, articles had to be randomized, controlled, or double-blind clinical trials, with buprenorphine as the study drug; the length of buprenorphine maintenance treatment had to be 3 weeks or longer; doses of buprenorphine had to be clearly stated; outcome measures had to include retention rates in buprenorphine treatment; outcome measures had to include illicit opioid use based on analytical determination of drugs of abuse in urine samples as outcome variables; and outcome measures had to include illicit cocaine use based on analytical determination of drugs of abuse in urine samples as outcome variables. Twenty-nine articles were excluded because they did not meet the inclusion criteria. The authors present the results of 21 articles that met inclusion criteria. The higher buprenorphine dose (16-32 mg per day) predicted better retention in treatment compared with the lower dose (less than 16 mg per day) (P = .009, R(2) adjusted = 0.40), and the positive urine drug screens for opiates predicted dropping out of treatment (P = .019, R(2) Adjusted = 0.40). Retention in treatment predicted less illicit opioid use (P = .033, R(2) Adjusted = 0.36), and the positive urine drug screens for cocaine predicted more illicit opioid use (P = .021, R(2) Adjusted = 0.36). Strong evidence exists based on 21 randomized clinical trials that the higher buprenorphine dose may improve retention in buprenorphine maintenance treatment.

Current and potential pharmacological treatment options for maintenance therapy in opioid-dependent individuals

Opioid dependence, manifesting as addiction to heroin and pharmaceutical opioids is increasing. Internationally, there are an estimated 15.6 million illicit opioid users. The global economic burden of opioid dependence is profound both in terms of HIV and hepatitis C virus transmission, direct healthcare costs, and indirectly through criminal activity, absenteeism and lost productivity. Opioid agonist medications, such as methadone and buprenorphine, that stabilize neuronal systems and provide narcotic blockade are the most effective treatments. Prolonged provision of these medications, defined as maintenance treatment, typically produces improved outcomes when compared with short-duration tapers and withdrawal. The benefits of opioid agonist maintenance include decreased illicit drug use, improved retention in treatment, decreased HIV risk behaviours and decreased criminal behaviour. While regulations vary by country, these medications are becoming increasingly available internationally, especially in regions experiencing rapid transmission of HIV due to injection drug use. In this review, we describe the rationale for maintenance treatment of opioid dependence, discuss emerging uses of opioid antagonists such as naltrexone and sustained-release formulations of naltrexone and buprenorphine, and provide a description of the experimental therapies.

A multi-level analysis of counselor attitudes toward the use of buprenorphine in substance abuse treatment

Despite evidence that buprenorphine is effective and safe and offers greater access as compared with methadone, implementation for treatment of opiate dependence continues to be weak. Research indicates that legal and regulatory factors, state policies, and organizational and provider variables affect adoption of buprenorphine. This study uses hierarchical linear modeling to examine National Treatment Center Study data to identify counselor characteristics (attitudes, training, and beliefs) and organizational factors (accreditation, caseload, access to buprenorphine, and other evidence-based practices) that influence implementation of buprenorphine for treatment of opiate dependence. Analyses showed that provider training about buprenorphine, higher prevalence of opiate-dependent clients, and less treatment program emphasis on a 12-step model predicted greater counselor acceptance and perceived effectiveness of buprenorphine. Results also indicate that program use of buprenorphine for any treatment purpose (detoxification, maintenance, and/or pain management) and time (calendar year in data collection) was associated with increased diffusion of knowledge about buprenorphine among counselors and with more favorable counselor attitudes toward buprenorphine.