Methadone Maintenance as HIV Risk Reduction With Street-Recruited Injecting Drug Users:

Opioid and neuroHIV Comorbidity - Current and Future Perspectives

With the current national opioid crisis, it is critical to examine the mechanisms underlying pathophysiologic interactions between human immunodeficiency virus (HIV) and opioids in the central nervous system (CNS). Recent advances in experimental models, methodology, and our understanding of disease processes at the molecular and cellular levels reveal opioid-HIV interactions with increasing clarity. However, despite the substantial new insight, the unique impact of opioids on the severity, progression, and prognosis of neuroHIV and HIV-associated neurocognitive disorders (HAND) are not fully understood. In this review, we explore, in detail, what is currently known about mechanisms underlying opioid interactions with HIV, with emphasis on individual HIV-1-expressed gene products at the molecular, cellular and systems levels. Furthermore, we review preclinical and clinical studies with a focus on key considerations when addressing questions of whether opioid-HIV interactive pathogenesis results in unique structural or functional deficits not seen with either disease alone. These considerations include, understanding the combined consequences of HIV-1 genetic variants, host variants, and μ-opioid receptor (MOR) and HIV chemokine co-receptor interactions on the comorbidity. Lastly, we present topics that need to be considered in the future to better understand the unique contributions of opioids to the pathophysiology of neuroHIV.

Graphical Abstract

Preventing blood-borne virus infection in people who inject drugs in the UK: systematic review, stakeholder interviews, psychosocial intervention development and feasibility randomised controlled trial

BACKGROUND

Opioid substitution therapy and needle exchanges have reduced blood-borne viruses (BBVs) among people who inject drugs (PWID). Some PWID continue to share injecting equipment.

OBJECTIVES

To develop an evidence-based psychosocial intervention to reduce BBV risk behaviours and increase transmission knowledge among PWID, and conduct a feasibility trial among PWID comparing the intervention with a control.

DESIGN

A pragmatic, two-armed randomised controlled, open feasibility trial. Service users were Steering Group members and co-developed the intervention. Peer educators co-delivered the intervention in London.

SETTING

NHS or third-sector drug treatment or needle exchanges in Glasgow, London, Wrexham and York, recruiting January and February 2016.

PARTICIPANTS

Current PWID, aged ≥ 18 years.

INTERVENTIONS

A remote, web-based computer randomisation system allocated participants to a three-session, manualised, psychosocial, gender-specific group intervention delivered by trained facilitators and BBV transmission information booklet plus treatment as usual (TAU) (intervention), or information booklet plus TAU (control).

MAIN OUTCOME MEASURES

Recruitment, retention and follow-up rates measured feasibility. Feedback questionnaires, focus groups with participants who attended at least one intervention session and facilitators assessed the intervention's acceptability.

RESULTS

A systematic review of what works to reduce BBV risk behaviours among PWID; in-depth interviews with PWID; and stakeholder and expert consultation informed the intervention. Sessions covered improving injecting technique and good vein care; planning for risky situations; and understanding BBV transmission. Fifty-six per cent (99/176) of eligible PWID were randomised: 52 to the intervention group and 47 to the control group. Only 24% (8/34) of male and 11% (2/18) of female participants attended all three intervention sessions. Overall, 50% (17/34) of men and 33% (6/18) of women randomised to the intervention group and 47% (14/30) of men and 53% (9/17) of women randomised to the control group were followed up 1 month post intervention. Variations were reported by location. The intervention was acceptable to both participants and facilitators. At 1 month post intervention, no increase in injecting in 'risky' sites (e.g. groin, neck) was reported by participants who attended at least one session. PWID who attended at least one session showed a trend towards greater reduction in injecting risk behaviours, a greater increase in withdrawal planning and were more confident about finding a vein. A mean cost of £58.17 per participant was calculated for those attending one session, £148.54 for those attending two sessions and £270.67 for those attending all three sessions, compared with £0.86 in the control group. Treatment costs across the centres vary as a result of the different levels of attendance, as total session costs are divided by attendees to obtain a cost per attendee. The economic analysis suggests that a cost-effectiveness study would be feasible given the response rates and completeness of data. However, we have identified aspects where the service use questionnaire could be abbreviated given the low numbers reported in several care domains. No adverse events were reported.

CONCLUSIONS

As only 19% of participants attended all three intervention sessions and 47% were followed up 1 month post intervention, a future definitive randomised controlled trial of the intervention is not feasible. Exposure to information on improving injecting techniques did not encourage riskier injecting practices or injecting frequency, and benefits were reported among attendees. The intervention has the potential to positively influence BBV prevention. Harm reduction services should ensure that the intervention content is routinely delivered to PWID to improve vein care and prevent BBVs.

FUTURE WORK

The intervention did not meet the complex needs of some PWID, more tailoring may be needed to reach PWID who are more frequent injectors, who are homeless and female.

LIMITATIONS

Intervention delivery proved more feasible in London than other locations. Non-attendance at the York trial site substantially influenced the results.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN66453696 and PROSPERO 014:CRD42014012969.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 72. See the NIHR Journals Library website for further project information.

Drug Treatment Needs of Hispanic Drug Users in Long Beach, California

The objective of this study is to investigate differences between Hispanic and non-Hispanic drug users in Long Beach, CA, with respect to drug use, HIV risk behaviors, and drug treatment experience and to explore the dissimilarities between Hispanic drug users who identify their family origin as Mexican American compared to those who identify their family origin as Mexican. We recruited 1,728 drug users into an HIV risk reduction intervention; of these, 404 were Hispanic. The Risk Behavior Assessment (RBA) was used to collect information on demographics, drug and sex risk behaviors, and drug treatment experience. Hispanic drug users are significantly more likely to inject drugs than non-Hispanic drug users and were found to have a higher mean number of injections in the last 30 days. Hispanic drug users were more likely to have taken part in drug treatment programs, specifically methadone detoxification and maintenance programs. Self-identified Mexican drug users were less likely to have ever attended a drug treatment program than were Mexican-American drug users. Greater availability of drug treatment programs for monolingual and bilingual Hispanic injectors is needed.

Predictors of Positive Outcomes for Out-of-Treatment Opiate Injectors Recruited into Methadone Maintenance through Street Outreach

This study was conducted to assess behavior change in the areas of drug use, productivity, criminal activity, and HIV risk among street-recruited injection drug users who entered methadone maintenance treatment. In addition, the study examined a number of variables that could account for these changes, including demographics, intervention effects, and treatment-related measures. A total of 168 participants were interviewed at baseline, received outreach interventions, entered methadone maintenance treatment, and were reinterviewed 5–9 months later. Significant (p<.001) improvements were seen in the areas of drug use, productivity, criminality, and HIV risk behaviors. The only variables significantly associated with behavior change were related to drug treatment. In particular, being in treatment at the time of the follow-up assessment had the strongest relationship to positive outcomes, including length of treatment. Having no prior treatment experience was associated with fewer injections at follow-up. These findings emphasize the importance of retaining clients, given the likelihood that positive change is likely to be evidenced while they remain in treatment

Potential cost-effectiveness of supervised injection facilities in Toronto and Ottawa, Canada

BACKGROUND AND AIMS

Supervised injection facilities (legally sanctioned spaces for supervised consumption of illicitly obtained drugs) are controversial public health interventions. We determined the optimal number of facilities in two Canadian cities using health economic methods.

DESIGN

Dynamic compartmental model of HIV and hepatitis C transmission through sexual contact and sharing of drug use equipment.

SETTING

Toronto and Ottawa, Canada.

PARTICIPANTS

Simulated population of each city.

INTERVENTIONS

Zero to five supervised injection facilities.

MEASUREMENTS

Direct health-care costs and quality-adjusted life-years (QALYs) over 20 years, discounted at 5% per year; incremental cost-effectiveness ratios.

FINDINGS

In Toronto, one facility cost $4.1 million and resulted in a gain of 385 QALYs over 20 years, for an incremental cost-effectiveness ratio (ICER) of $10,763 per QALY [95% credible interval (95CrI): cost-saving to $278,311]. Establishing one facility in Ottawa had an ICER of $6127 per QALY (95CrI: cost-saving to $179,272). At a $50,000 per QALY threshold, three facilities would be cost-effective in Toronto and two in Ottawa. The probability that establishing three, four, or five facilities in Toronto was cost-effective was 17, 21, and 41%, respectively. Establishing one, two, or three facilities in Ottawa was cost-effective with 13, 35, and 41% probability, respectively. Establishing no facility was unlikely to be the most cost-effective option (14% in Toronto and 10% in Ottawa). In both cities, results were robust if the reduction in needle-sharing among clients of the facilities was at least 50% and fixed operating costs were less than $2.0 million.

CONCLUSIONS

Using a $50,000 per quality-adjusted life-years threshold for cost-effectiveness, it is likely to be cost-effective to establish at least three legally sanctioned spaces for supervised injection of illicitly obtained drugs in Toronto, Canada and two in Ottawa, Canada.

Heroin dependence and bloodborne virus transmission behaviors for HIV infection among newly incarcerated injection drug users in Taiwan

The purpose of the study was to determine heroin dependence and risky behaviors associated with human immunodeficiency virus (HIV) infection among newly incarcerated injection drug users (IDUs). Three self-administrated questionnaires were collected among 450 newly incarcerated male heroin users during 2005-2007. Inmates were categorized as heroin-dependent if they met three or more of the six ICD-10 criteria. Heroin-dependent inmates had higher scores of bloodborne virus transmission risk than non-dependent IDUs (12.8 ± 16.0 vs. 7.2 ± 11.5, p < 0.001). Multiple logistic regression analysis indicated that heroin dependence was a significant moderator of the association between risky injection behaviors and HIV infection. It is crucial to integrate substance treatment with behavioral interventions into harm reduction programs to prevent bloodborne virus transmission among IDUs.

Methadone Maintenance Therapy in Liver Transplantation

Cirrhosis due to chronic infection with hepatitis C virus remains by far the most common reason for liver transplantation in North America. Currently, parenteral use of street drugs is the most common means of acquiring hepatitis C. Methadone maintenance therapy is an accepted form of treatment for chronic opiate (eg, heroin) addiction and, not surprisingly, a significant proportion of methadone-treated patients have chronic hepatitis C. The feasibility of liver transplant candidacy in hepatitis patients who require methadone maintenance therapy is controversial, and some transplant centers require patients to withdraw from such therapy in order for the transplant process to move forward. Thus stable patients with end-stage cirrhosis who are receiving methadone maintenance are left in a most difficult situation: discontinue methadone and accept the side effects of withdrawal with the risk of recidivism to use of street opiates, an absolute contraindication for transplantation, or continue methadone therapy and risk exclusion from the transplant process. The issue of methadone replacement therapy in end-stage cirrhosis and the posttransplant literature on the subject are explored in this paper.

The effect of methadone maintenance on positive outcomes for opiate injection drug users

This study examined outcome variables for 160 opiate injection drug users (IDUs) who entered methadone maintenance between baseline and 6-month follow-up. Outcome variables of interest included drug use, productivity, and HIV risk behaviors. Participants were recruited through street outreach in Denver, CO, from 2000 through 2004 using targeted sampling. The sample was primarily men, White (48%), averaged 39 years of age, and had been injecting drugs for an average of nearly 20 years. Significant improvements were found in univariate tests. Logistic regression revealed that spending more time in treatment was a significant predictor of positive outcomes on drug use and HIV risk behaviors. The results underscore the importance of retaining IDUs in methadone maintenance to maximize their treatment success. Results from this study show that time in treatment can affect many aspects of the participant's life in a positive way, including reduction of HIV risk.

Ethnic differences in HIV risk behaviors among methadone-maintained women receiving contingency management for cocaine use disorders

OBJECTIVE

To identify ethnic differences in HIV risk behaviors among cocaine using women receiving methadone maintenance for opioid dependence, and to evaluate the efficacy of contingency management (CM) for cocaine use disorders in reducing HIV risk behaviors.

METHODS

African American (N=47), Hispanic (N=47), and White women (N=29) were randomized to standard methadone treatment or standard methadone treatment plus a CM intervention. They completed the HIV Risk Behavior Scale (HRBS) indicating frequency of drug use and sexual behaviors across the lifetime, in the month before baseline, and in the 3 months following clinical trial participation. Ethnic group differences and the effect of CM on change in HIV risk behaviors between baseline and follow-up were evaluated.

RESULTS

White women reported significantly higher lifetime rates of risky drug use and sexual behaviors on the HRBS than African American women; neither group differed significantly from Hispanic women. No ethnic group differences in HIV risk behaviors were identified in the month prior to baseline. At follow-up, African American women reported fewer high-risk drug use behaviors than White or Hispanic women, and Hispanic women reported more high-risk sexual behaviors than White or African American women. CM was associated with reduction in high-risk drug use behaviors regardless of ethnicity, but did not affect high-risk sexual behaviors.

CONCLUSIONS

White women receiving methadone maintenance engage in more lifetime HIV risk behaviors than African American women. CM for cocaine use reduces risky drug use behaviors, but certain ethnic groups may benefit from additional targeted HIV prevention efforts.

Hepatitis C and human immunodeficiency virus risk behaviors in polydrug users on methadone maintenance

We examined the impact of methadone maintenance treatment (MMT) on risk behaviors for transmission of blood-borne diseases in polydrug users who had tested positive or negative for hepatitis C virus (HCV). At intake, HCV-positive participants (n=362) engaged in more human immunodeficiency virus (HIV) risk behaviors (as measured by the HIV Risk-Taking Behavior Scale) than HCV-negative participants (n=297; p< .001). This difference was specific to injection-related behaviors and decreased significantly within the first few weeks of MMT (p< .0001). Where needles continued to be used, HCV-positive participants became more likely over time to engage in safer injecting practices. Furthermore, HCV-positive participants became more likely to use condoms than HCV-negative participants. These findings demonstrate that both drug- and sex-related risk behaviors decrease during MMT and emphasize the benefits of methadone programs for public health and HIV/HCV prevention.

Factors associated with methadone maintenance treatment retention among street-recruited injection drug users

This study examined factors associated with methadone maintenance retention, defined as remaining in treatment for a minimum of 90 days, among street recruited injection drug users (IDUs). Targeted sampling methods were used to establish recruitment quotas in Denver census tracks. A total of 577 IDUs were randomly assigned to either a risk reduction intervention, focusing on safer injection and sex behaviors, or motivational interviewing, addressing more sweeping lifestyle changes including drug treatment. All subjects who wanted treatment were provided transportation, rapid intake and a waiver of the intake fee. In addition, 50% were randomly assigned a coupon for 90 days of free treatment. Overall, 33% entered treatment and of these, 60% remained for at least 90 days. Factors associated with retention included higher methadone dose, free treatment, greater contacts with the clinic and counselor rating of patient cooperation. Although desire for treatment, or motivation, was associated in univariate analyses with greater retention, there were no differences observed between the motivational interviewing and risk reduction interventions.

Impact of Methadone Program Philosophy Changes on Early Treatment Outcomes

This paper describes the consequences of changing from methadone maintenance treatment focussed primarily on elimination of all illicit drug use and social reintegration to patient-centred care. Counselling (formerly mandatory) became optional, patients were retained in treatment despite continued illicit drug use, the ceiling on methadone doses was removed, patient input became a part of methadone prescribing and the number of patients in treatment more than doubled. Across three cohorts (before, during and after the program was redesigned) the mean daily dose of methadone increased (50.4 mg +/- 2.5, 72.6 mg +/- 2.4, 92.2 mg +/- 4.0, respectively). The number of physician visits increased linearly with cohort while the number of therapist visits was unchanged overall. Two-year treatment retention was not significantly different (73%, 69% and 67%, respectively). In all three cohorts there was a significant reduction in opioid and benzodiazepine use but not cocaine use over the first six months of treatment.

Adherence to methadone is associated with a lower level of HIV-related risk behaviors in drug users

There have been limited studies on the potential role of methadone treatment in HIV prevention in Asia. Over an 8-week period, we assessed the profiles of drug-taking and HIV risk behaviors, and tried to identify their relationships with methadone adherence in 690 clients who attended Hong Kong's methadone treatment program. In the preceding month, 71% of respondents reported using drugs and two-thirds of those respondents who had injected drugs at some time in their lives injected then. Infrequent clients who attended methadone clinics <2 times in the previous week were twice more likely to have injected drugs in the last month and six times more likely to have >5 injections in the last week than frequent clinic attendees. Also, clients taking <60 mg methadone daily were twice more likely to have >5 injections in the last week than those taking > or = 60 mg methadone. The findings called for further studies on harm reduction programs for HIV prevention among drug users in Asian countries.