Prevention and treatment of hepatitis C in injection drug users

Evaluation of a hepatitis C education intervention with clients enrolled in methadone maintenance and needle/syringe programs in Malaysia

BACKGROUND

Approximately 40%-90% of people who inject drugs (PWID) in Malaysia have hepatitis C (HCV). PWID continue to be disproportionately affected by HCV due to their lack of knowledge, perceived risk and interest in HCV treatment. Education interventions may be an effective strategy for increasing HCV knowledge in PWID, and harm reduction services are uniquely positioned to implement and deploy such interventions.

METHODS

We recruited 176 clients from methadone maintenance treatment (MMT: N=110) and needle/syringe programs (NSP: N=66) between November 2015 and August 2016. After baseline knowledge assessments, clients participated in a standardized, 45-min HCV education program and completed post-intervention knowledge assessments to measure change in knowledge and treatment interest.

RESULTS

Participants were mostly male (96.3%), Malay (94.9%), and in their early 40s (mean=42.6years). Following the intervention, overall knowledge scores and treatment interest in MMT clients increased by 68% and 16%, respectively (p<0.001). In contrast, NSP clients showed no significant improvement in overall knowledge or treatment interest, and perceived greater treatment barriers. Multivariate linear regression to assess correlates of HCV knowledge post-intervention revealed that optimal dosage of MMT and having had an HIV test in the past year significantly increased HCV knowledge. Having received a hepatitis B vaccine, however, was not associated with increased HCV knowledge after participating in an education session.

CONCLUSION

Generally, HCV knowledge and screening is low among clients engaged in MMT and NSP services in Malaysia. Integrating a brief, but comprehensive HCV education session within harm reduction services may be a low-cost and effective strategy in improving overall HCV knowledge and risk behaviors in resource-limited settings. In order to be an effective public health approach, however, education interventions must be paired with strategies that improve social, economic and political outcomes for PWID. Doing so may reduce HCV disparities by increasing screening and treatment interest.

New Hopes for HIV and HCV Coinfection in 2004

An increase in liver-related causes of death in HIV-positive patients who are coinfected with the hepatitis C virus (HCV) has been acknowledged over the last few years, particularly since the mid 1990s, when the natural history of HIV infection started to improve with the use of highly active antiretroviral therapy (HAART). Chronic hepatitis C is very common among HIV-infected patients who were infected through intravenous drugs use or contaminated blood products (e.g., hemophiliacs). The bidirectional interferences between HIV and HCV modify the natural history of both infections. Moreover, interactions between anti-HIV and anti-HCV drugs are of concern, and a lower response to anti-HCV therapy limits its benefit in HIV-coinfected patients. Although a slower HCV RNA decay is seen in coinfected patients after standard therapy is initiated with pegylated interferon plus ribavirin, the stopping rule at week 12 that is recommended for HCV-monoinfected individuals seems to be equally valid in HIV-positive patients. This finding is of great value, because it allows treatment to be offered in the absence of contraindication (e.g., low CD4 count, alcohol abuse, etc.) but discontinued as early as 12 weeks when no chances of cure are predicted, which saves costs and deleterious side effects. HAART therapy seems to temper somehow the negative impact exerted by HIV infection over HCV-related liver fibrosis. Liver transplantation is currently the best option for HIV-infected patients with end-stage liver disease. However, the management of patients on the waiting list and after transplantation carries significant new challenges. New anti-HCV drugs are urgently needed and new strategies with the currently available drugs need to be assessed to reduce the negative impact of hepatitis C in HIV-coinfected individuals.

A comparison of risk factors for hepatitis C among young and older adult prisoners

Internationally, the prevalence of hepatitis C infection is higher among prisoners when compared to the general population, particularly among people who inject drugs. This study estimates the prevalence of, and compares the risk factors for, hepatitis C in young (< 25 years) and older (≥ 25 years) prisoners with a history of injection drug use. Participants were 677 sentenced prisoners in Queensland, Australia, with a lifetime history of injection drug use, recruited in the 6 weeks prior to release from custody. The prevalence of hepatitis C exposure was significantly lower in young prisoners than in older prisoners (20.7% vs. 29.4%, p = .03). Risk factors for hepatitis C varied between young and older prisoners. Young people who inject drugs and who have had shorter time at risk of hepatitis C exposure are an important target group for hepatitis C prevention efforts.

Hepatitis C virus infection epidemiology among people who inject drugs in Europe: a systematic review of data for scaling up treatment and prevention

BACKGROUND

People who inject drugs (PWID) are a key population affected by hepatitis C virus (HCV). Treatment options are improving and may enhance prevention; however access for PWID may be poor. The availability in the literature of information on seven main topic areas (incidence, chronicity, genotypes, HIV co-infection, diagnosis and treatment uptake, and burden of disease) to guide HCV treatment and prevention scale-up for PWID in the 27 countries of the European Union is systematically reviewed.

METHODS AND FINDINGS

We searched MEDLINE, EMBASE and Cochrane Library for publications between 1 January 2000 and 31 December 2012, with a search strategy of general keywords regarding viral hepatitis, substance abuse and geographic scope, as well as topic-specific keywords. Additional articles were found through structured email consultations with a large European expert network. Data availability was highly variable and important limitations existed in comparability and representativeness. Nine of 27 countries had data on HCV incidence among PWID, which was often high (2.7-66/100 person-years, median 13, Interquartile range (IQR) 8.7-28). Most common HCV genotypes were G1 and G3; however, G4 may be increasing, while the proportion of traditionally 'difficult to treat' genotypes (G1+G4) showed large variation (median 53, IQR 43-62). Twelve countries reported on HCV chronicity (median 72, IQR 64-81) and 22 on HIV prevalence in HCV-infected PWID (median 3.9%, IQR 0.2-28). Undiagnosed infection, assessed in five countries, was high (median 49%, IQR 38-64), while of those diagnosed, the proportion entering treatment was low (median 9.5%, IQR 3.5-15). Burden of disease, where assessed, was high and will rise in the next decade.

CONCLUSION

Key data on HCV epidemiology, care and disease burden among PWID in Europe are sparse but suggest many undiagnosed infections and poor treatment uptake. Stronger efforts are needed to improve data availability to guide an increase in HCV treatment among PWID.

Confronting the emerging epidemic of HCV infection among young injection drug users

Hepatitis C virus infection is a significant public health problem in the United States and an important cause of morbidity and mortality. Recent reports document HCV infection increases among young injection drug users in several US regions, associated with America's prescription opioid abuse epidemic. Incident HCV infection increases among young injectors who have recently transitioned from oral opioid abuse present an important public health challenge requiring a comprehensive, community-based response. We summarize recommendations from a 2013 Office of HIV/AIDS and Infectious Disease Policy convening of experts in epidemiology, behavioral science, drug prevention and treatment, and other research; community service providers; and federal, state, and local government representatives. Their observations highlight gaps in our surveillance, program, and research portfolios and advocate a syndemic approach to this emerging public health problem.

Predictors of active injection drug use in a cohort of patients infected with hepatitis C virus

OBJECTIVES

We investigated potential risk factors for active injection drug use (IDU) in an inner-city cohort of patients infected with hepatitis C virus (HCV).

METHODS

We used log-binomial regression to identify factors independently associated with active IDU during the first 3 years of follow-up for the 289 participants who reported ever having injected drugs at baseline.

RESULTS

Overall, 142 (49.1%) of the 289 participants reported active IDU at some point during the follow-up period. In a multivariate model, being unemployed (prevalence ratio [PR] = 1.93; 95% confidence interval [CI] = 1.24, 3.03) and hazardous alcohol drinking (PR = 1.67; 95% CI = 1.34, 2.08) were associated with active IDU. Smoking was associated with IDU but this association was not statistically significant. Patients with all 3 of those factors were 3 times as likely to report IDU during follow-up as those with 0 or 1 factor (PR = 3.3; 95% CI = 2.2, 4.9). Neither HIV coinfection nor history of psychiatric disease was independently associated with active IDU.

CONCLUSIONS

Optimal treatment of persons with HCV infection will require attention to unemployment, alcohol use, and smoking in conjunction with IDU treatment and prevention.

Low incidence of reinfection with the hepatitis C virus following treatment in active drug users in Amsterdam

BACKGROUND

More than two-thirds of hepatitis C virus (HCV) infections are associated with injecting drug use. Despite the wide availability of standard treatment with pegylated interferon and ribavirin, active drug users (DU) have limited access to HCV treatment. Physicians may be reluctant to prescribe treatment because of the presumed high risk of reinfection. However, data on reinfection in treated DU remain scarce.

METHODS

Active DU with chronic HCV infection were treated in a multidisciplinary setting. After achieving a sustained virologic response, patients were tested at 6-12-monthly intervals for HCV RNA. To distinguish between relapse and reinfection, sequence and phylogenetic analyses were performed on the NS5B region of the HCV genome. The incidence of reinfection was calculated using person-time techniques.

RESULTS

From April 2005 to March 2010, 69 active DU treated for HCV had sufficient follow-up, median 2.5 years (interquartile range, 1.6-3.7). Sustained virologic response was achieved in 42 patients (61%). During follow-up, 41 patients remained HCV RNA-negative; of these, two patients died. During treatment, five out of 41 injected drugs, which increased to 11 out of 41 after the end of treatment. One case of reinfection was observed, followed by spontaneous clearance of the virus. The overall incidence was 0.76/100 person-years (95% confidence interval 0.04-3.73). For only those individuals reporting injecting drug use, the incidence was 3.42/100 person-years (95% confidence interval 0.17-16.90).

CONCLUSION

We report a low incidence of HCV reinfection following treatment in DU participating in a multidisciplinary programme. Active drug use, including injecting, should not preclude access to treatment for HCV.

Positive impact of hepatitis C virus (HCV) treatment on antiretroviral treatment adherence in human immunodeficiency virus-HCV coinfected patients: one more argument for expanded access to HCV treatment for injecting drug users

AIMS

Treatment for the hepatitis C virus (HCV) may be delayed significantly in human immunodeficiency virus (HIV)/HCV coinfected patients on antiretroviral treatment (ART) for fear that its burden could compromise ART adherence. However, the effect such treatment has on ART adherence in observational settings remains largely unknown. Longitudinal data were used to investigate the relationship between initiating HCV treatment and adherence to ART in HIV/HCV coinfected patients.

DESIGN

The French national prospective cohort of patients coinfected with HIV and HCV (ANRS-CO-13-HEPAVIH) is a multi-centre cohort.

SETTING

Seventeen out-patient hospital services delivering HIV and HCV care in France.

PARTICIPANTS

HIV/HCV coinfected patients on ART (n = 593 patients, 976 visits).

MEASUREMENTS

Self-administered questionnaires and medical records. A mixed logistic regression model based on generalized estimates equations (GEE) to identify factors associated with non-adherence to ART.

FINDINGS

Among the 593 patients, 36% were classified as non-adherent to ART at the enrolment visit and 12% started HCV treatment during follow-up. ART adherence was not associated statistically with HCV treatment initiation. The proportion of patients maintaining adherence or becoming adherent to ART for those starting HCV treatment was higher than in the rest of the sample (P = 0.07). After multiple adjustment for known correlates, such as poor housing conditions, binge drinking, recent drug use and depressive symptoms, patients who initiated HCV treatment were less likely to be non-adherent to ART [odds ratio (95% confidence interval) = 0.41 (0.24-0.71)].

CONCLUSIONS

Engaging human immunodeficiency virus/hepatitis C virus coinfected individuals in hepatitis C virus treatment is associated with high adherence to antiretroviral treatment. Physicians should prioritize hepatitis C virus treatment as part of a multi-disciplinary approach.

Low rates of hepatitis A and B vaccination in patients with chronic hepatitis C at an urban methadone maintenance program

Patients with chronic hepatitis C virus (HCV) are at increased risk for complications of liver disease if they become infected with the hepatitis A (HAV) or hepatitis B (HBV) viruses. The authors examined the rates of testing for HAV, HBV, and HCV, as well as rates of vaccination against HAV and HBV in patients with chronic HCV in a random sample (N = 207) of medical records of patients enrolled in a methadone maintenance program. Almost all patients reviewed were tested for HAV, HBV, and HCV. Of the 111 patients with chronic HCV, 53 (48.6%) and 68 (63%) lacked immunity to HAV and HBV, respectively. Of those lacking immunity, 29 (54.7%) and 2 (2.9%) were vaccinated for HAV and HBV, respectively. Despite high rates of testing for HAV, HBV, and HCV at a methadone maintenance program, approximately half of those with chronic HCV eligible for the HAV vaccine received it, and few of those eligible for HBV vaccine received it.

Reinfection with hepatitis C virus following sustained virological response in injection drug users

BACKGROUND AND AIM

Despite that 60-90% of injection drug users (IDUs) are infected with hepatitis C virus (HCV) infection, IDUs are often denied therapy based on concerns of reinfection following treatment. However, there are little data in this regard. We evaluated HCV re-infection following sustained virologic response (SVR) among HCV-infected IDUs having received HCV treatment in a multidisciplinary program.

METHODS

Following treatment, participants were encouraged to return at follow-up intervals of 1 year and illicit drug use histories were obtained. In those with SVR, HCV RNA testing by PCR was performed to determine if relapse or reinfection occurred.

RESULTS

Among 58 receiving HCV treatment between January 2002 and December 2006, 60% (35 of 58) achieved an SVR. Patients were followed for a median of 2.0 years following SVR (range, 0.4-5.0 years), with ongoing illicit and injection drug use reported in 54% (19 of 35) and 46% (16 of 35). Of the 35 with SVR, 28 remained HCV RNA negative during follow-up (80%), with four lost to follow-up and one dying of hepatocellular carcinoma and two cases of reinfection were observed (2 of 35). The rates of reinfection were 3.2 per 100 p-y (95% CI:0.4, 11.5) overall and 5.3 per 100 p-y (95% CI:0.6, 19.0) among those reporting injecting following SVR (n = 16). One of two participants with HCV re-infection spontaneously cleared virus following reinfection.

CONCLUSION

The rate of reinfection following treatment for HCV infection among current and former IDUs engaged in a multidisciplinary program is low.

A randomized clinical trial of methadone maintenance for prisoners: results at 12 months postrelease

This study examined the impact of prison-initiated methadone maintenance at 12 months postrelease. Males with pre-incarceration heroin dependence (N = 204) were randomly assigned to (a) Counseling Only: counseling in prison, with passive referral to treatment upon release; (b) Counseling + Transfer: counseling in prison with transfer to methadone maintenance treatment upon release; and (c) Counseling + Methadone: counseling and methadone maintenance in prison, continued in the community upon release. The mean number of days in community-based drug abuse treatment were, respectively, Counseling Only, 23.1; Counseling + Transfer, 91.3; and Counseling + Methadone, 166.0 (p < .01); all pairwise comparisons were statistically significant (all ps < .01). Counseling + Methadone participants were also significantly less likely than participants in each of the other two groups to be opioid-positive or cocaine-positive according to urine drug testing. These results support the effectiveness of prison-initiated methadone for males in the United States. Further study is required to confirm the findings for women.

Treat early or wait and monitor? A qualitative analysis of provider hepatitis C virus treatment decision-making in the context of HIV coinfection

Liver disease is a leading cause of death among patients with HIV coinfected with hepatitis C (HCV); yet, studies show that less than 10% receive HCV treatment, in part because of limited treatment response, high treatment toxicity, and psychosocial barriers to treatment readiness. Using a process model framework, we sought to explore the factors and processes by which providers make HCV treatment decisions for HIV-coinfected patients. We conducted 22 semistructured interviews with primary care providers and support staff at three HIV clinics in Los Angeles, California, in which rates of HCV treatment uptake varied from 10% to 38%. Providers agreed that stable HIV disease, favorable genotype, and significant signs of liver disease progression are all signs of need for treatment. However, two divergent treatment approaches emerged for genotype 1 and 4 patients with minimal disease, and in definitions of patient readiness. Providers with lower treatment rates preferred to delay treatment in hopes of better future treatment options, and were more conservative in requiring complete mental health screens and treatment and abstinence from substance use. Conversely, providers with higher treatment rates viewed all patients as needing treatment as soon as possible, and defined readiness more leniently, with some willing to treat even in the context of untreated depression and drug use, so long as ability to adhere well was demonstrated. Regardless of whether an aggressive or cautious approach to treatment is used, development of effective programs for promoting patient treatment readiness is critical to ensuring greater treatment uptake.

Predictors of treatment for hepatitis C virus (HCV) infection in drug users

Documented treatment rates for Hepatitis C virus (HCV) infection are low. Within this cohort of HCV-infected patients (N = 373), participants who were not actively injecting drugs or not co-infected with HIV were most likely to initiate HCV treatment. Persons of white race and HIV-infected participants with a CD4 count above 200 were also more likely to have initiated HCV treatment. We defined five factors as potentially modifiable, and found almost all (90%) of the cohort had at least one such factor. Participants with more than one of these factors were least likely to initiate treatment. The proportion of patients receiving treatment increased as their number of modifiable risk factors decreased (p < 0.01, for trend). Focused strategies to overcome these potentially modifiable factors may be indicated to increase HCV treatment in affected populations.

The HCV Synthesis Project: scope, methodology, and preliminary results

Background

The hepatitis C virus (HCV) is hyper-endemic in injecting drug users. There is also excess HCV among non-injection drug users who smoke, snort, or sniff heroin, cocaine, crack, or methamphetamine.

Methods

To summarize the research literature on HCV in drug users and identify gaps in knowledge, we conducted a synthesis of the relevant research carried out between 1989 and 2006. Using rigorous search methods, we identified and extracted data from published and unpublished reports of HCV among drug users. We designed a quality assurance system to ensure accuracy and consistency in all phases of the project. We also created a set of items to assess study design quality in each of the reports we included.

Results

We identified 629 reports containing HCV prevalence rates, incidence rates and/or genotype distribution among injecting or non-injecting drug user populations published between January 1989 and December 2006. The majority of reports were from Western Europe (41%), North America (26%), Asia (11%) and Australia/New Zealand (10%). We also identified reports from Eastern Europe, South America, the Middle East, and the Caribbean. The number of publications reporting HCV rates in drug users increased dramatically between 1989 and 2006 to 27–52 reports per year after 1998.

Conclusion

The data collection and quality assurance phases of the HCV Synthesis Project have been completed. Recommendations for future research on HCV in drug users have come out of our data collection phase. Future research reports can enhance their contributions to our understanding of HCV etiology by clearly defining their drug user participants with respect to type of drug and route of administration. Further, the use of standard reporting methods for risk factors would enable data to be combined across a larger set of studies; this is especially important for HCV seroconversion studies which suffer from small sample sizes and low power to examine risk factors.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of PEGIFN and RBV is the most effective therapy for patients with chronic hepatitis C. Although more than half of all patients are able to achieve SVR, a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. An approach in the management of these patients is to identify factors that could have led to the NR or relapse and that could be corrected before or during a second course of therapy. Because fibrosis progression occurs slowly over decades for many patients with chronic hepatitis C, avoiding alcohol or other factors that could lead to fibrosis progression may be sufficient for the vast majority of patients. Other options that could be considered in patients who have more advanced disease include retreating with one of several new antiviral agents; retreating with higher doses of IFN or PEGIFN and RBV; or using IFN, PEGIFN, or RBV monotherapy long-term as maintenance therapy. The safety and efficacy of these approaches is being evaluated in numerous clinical trials.

Exploring drug users' attitudes and decisions regarding hepatitis C (HCV) treatment in the U.S

Individuals with a history of injecting drugs are at the highest risk of becoming infected with the hepatitis C virus (HCV), with studies of patients in methadone maintenance treatment programmes (MMTPs) reporting that 60-90 percent of intravenous drug users (IDUs) have the virus. Fortunately, HCV therapy has been shown to be effective in 42-82 percent of all patients with chronic HCV infection, including IDUs. While the decision to start HCV therapy requires significant consideration, little research exists that explores the attitudes of drug users toward HCV therapy. Therefore, this paper examines how drug users perceive the treatment, as well as the processes by which HCV-positive individuals examined the advantages and disadvantages of starting the HCV medications. Interviews were conducted with 164 patients from 14 drug treatment programmes throughout the United States, and both uninfected and HCV-positive drug users described a pipeline of communication among their peers that conveys largely negative messages about the medications that are available to treat HCV. Although many of the HCV-positive individuals said that these messages heightened their anxiety about the side effects and difficulties of treatment, some patients said that their peers helped them to consider, initiate HCV treatment or both. Gaining a better understanding of drug users' perceptions of HCV treatment is important, because so many of them, particularly IDUs, are already infected with HCV and may benefit from support in addressing their HCV treatment needs. In addition, currently uninfected drug users will likely remain at high risk for contracting HCV and may need to make decisions about whether or not to start the HCV medical regimen in the future.

A randomized clinical trial of methadone maintenance for prisoners: results at 1-month post-release

BACKGROUND

Despite its effectiveness, methadone maintenance is rarely provided in American correctional facilities. This study is the first randomized clinical trial in the US to examine the effectiveness of methadone maintenance treatment provided to prisoners with pre-incarceration heroin addiction.

METHODS

A three-group randomized controlled trial was conducted between September 2003 and June 2005. Two hundred eleven Baltimore pre-release inmates who were heroin dependent during the year prior to incarceration were enrolled in this study. Participants were randomly assigned to the following: counseling only: counseling in prison, with passive referral to treatment upon release (n=70); counseling+transfer: counseling in prison with transfer to methadone maintenance treatment upon release (n=70); and counseling+methadone: methadone maintenance and counseling in prison, continued in a community-based methadone maintenance program upon release (n=71).

RESULTS

Two hundred participants were located for follow-up interviews and included in the current analysis. The percentages of participants in each condition that entered community-based treatment were, respectively, counseling only 7.8%, counseling+transfer 50.0%, and counseling+methadone 68.6%, p<.05. All pairwise comparisons were statistically significant (all ps<.05). The percentage of participants in each condition that tested positive for opioids at 1-month post-release were, respectively, counseling only 62.9%, counseling+transfer 41.0%, and counseling+methadone 27.6%, p<.05, with the counseling only group significantly more likely to test positive than the counseling+methadone group.

CONCLUSIONS

Methadone maintenance initiated prior to or immediately after release from prison appears to have beneficial short-term impact on community treatment entry and heroin use. This intervention may be able to fill an urgent treatment need for prisoners with heroin addiction histories.

Controversies in and challenges to our understanding of hepatitis C

Discovered in 1989, the hepatitis C virus (HCV) continues to cause significant morbidity and mortality world-wide despite a huge research commitment to defining and understanding the virus and the disease it causes. This paper discusses a number of areas where progress in the management of the HCV have not kept pace with the scientific understanding of the HCV. It is suggested that in the fields of HCV prevention and providing access to treatment, practice falls short of what could be achieved. The role of alcohol in the pathogenesis of HCV liver injury is discussed. Discrimination against those with HCV infection and particularly those in prison settings fails to match good clinical practice. The complicated processes of sharing information between specialty groups is also discussed in an attempt to optimise knowledge dissemination in this field.

Treatment of hepatitis C virus infection

Acute and chronic hepatitis C virus (HCV) infection remains a serious health problem worldwide, however, there has been advancement in the treatment of HCV infection due to standard treatment using pegylated interferon and ribavirin. The literature indicates that therapy for HCV is becoming more individualized. In addition to considering genotype and viral RNA levels before treatment, achievement of an early virologic response (EVR) and a rapid virologic response (RVR) is now possible during therapy. Moreover, problem patients, such as non-responders, relapsers, HIV or HBV co-infected patients, patients with liver cirrhosis, and pre- or post-liver transplantation patients are an increasing fraction of the patients requiring treatment. This article reviews the literature regarding standard treatments and problem patients with acute and chronic HCV infection. It also includes discussion on contraindications and side effects of treatment with interferon and ribavirin, as well as new drug development.

[Expert recommendations for the diagnosis and treatment of chronic hepatitis C infection in the prison setting]

The prevalence of HCV infection in Spanish prisons is very high (38.5%). The characteristics of the infected patients, particularly the high rate of HIV coinfection, makes it very likely that the morbidity and mortality produced by serious liver disease secondary to this infection will increase considerably in the coming years. A group of Spanish experts with experience in patients who are inmates has been invited to establish a series of recommendations for the diagnosis and treatment of chronic hepatitis C infection in Spanish prisons.

Recruitment and follow-up of injecting drug users in the setting of early hepatitis C treatment: insights from the ATAHC study

Despite current injecting drug users (IDUs) being the major risk group for new hepatitis C virus (HCV) infections in most countries, they constitute a small minority of study populations in almost all studies of acute HCV infection treatment. The Australian Trial in Acute Hepatitis C (ATAHC) is examining natural history and treatment efficacy among predominantly IDU-acquired acute HCV. Recruitment is through an Australian network of primary and tertiary care sites. Eligible participants are offered treatment with pegylated-interferon alpha-2a (PEG-IFN) for 24 weeks, with both treated and untreated participants followed for up to three years. Quantitative and qualitative data on injecting behaviour is collected on study participants. Participants are regularly reviewed by a multidisciplinary team that includes the treating clinician, HCV clinic nurse, outreach worker and when necessary are referred to a drug and alcohol worker, social worker, psychiatrist or other appropriate services. A contact log records all interactions between participants and the study team. In September 2006, 121 subjects had been screened, 107 were enrolled and 75 had chosen to commence a 24-week course of PEG-IFN (HIV/HCV coinfected participants are treated with PEG-IFN/ribavirin combination therapy). Eighty per cent of ATAHC participants reported IDU within the previous six months. Recruitment is planned to continue through mid-2007. Through a series of case reports, this paper describes factors that are potential barriers to recruitment, follow-up, and treatment of IDUs in the context of acute HCV infection. PEG-IFN adherence and toxicity, current substance use or mental health issues are not presenting as the only barriers to HCV treatment. Financial and transport difficulties, isolation and social support, and legal issues have been prominent and had the potential to impact on clinic attendance and treatment success. Our work suggests that by using a multidisciplinary approach, potential barriers to recruitment and follow-up of current IDUs to HCV treatment can be effectively addressed, and this highly marginalised population can be successfully engaged and treated.

Recomendaciones de expertos sobre el diagnóstico y tratamiento de la hepatitis C crónica en el medio penitenciario

The prevalence of HCV infection in Spanish prisons is very high (38.5%). The characteristics of the infected patients, particularly the high rate of HIV coinfection, makes it very likely that the morbidity and mortality produced by serious liver disease secondary to this infection will increase considerably in the coming years. A group of Spanish experts with experience in patients who are inmates has been invited to establish a series of recommendations for the diagnosis and treatment of chronic hepatitis C infection in Spanish prisons.

Overcoming barriers to prevention, care, and treatment of hepatitis C in illicit drug users

Injection drug use accounts for most of the incident infections with hepatitis C virus (HCV) in the United States and other developed countries. HCV infection is a complex and challenging medical condition in injection drug users (IDUs). Elements of care for hepatitis C in illicit drug users include prevention counseling and education; screening for transmission risk behavior; testing for HCV and human immunodeficiency virus infection; vaccination against hepatitis A and B viruses; evaluation for comorbidities; coordination of substance-abuse treatment services, psychiatric care, and social support; evaluation of liver disease; and interferon-based treatment for HCV infection. Caring for patients who use illicit drugs presents challenges to the health-care team that require patience, experience, and an understanding of the dynamics of substance use and addiction. Nonetheless, programs are successfully integrating hepatitis C care for IDUs into health-care settings, including primary care, methadone treatment and other substance-abuse treatment programs, infectious disease clinics, and clinics in correctional facilities.

Guidelines for the treatment of hepatitis C virus infection in injection drug users: status quo in the European Union countries

Treatment guidelines are considered to be an important tool in steering patients to medical treatment. This study was conducted to analyze guidelines for the treatment of hepatitis C virus (HCV) infection in injection drug users (IDUs) in the European Union (EU) countries as a component of treatment access. National and international databases, expert contacts, professional societies, and health administrations were approached to acquire guidelines. According to their quality standard, guidelines were divided into expert opinions, semiofficial guidelines, official guidelines, and consensus processes. Recommendations for the treatment of HCV infection in IDUs vary substantially, from lack of recommendations and outright treatment disapproval to recommendations for treatment under specified circumstances. Recent guidelines that apply qualified process procedures that include literature research tend to be more permissive. Qualified guideline processes in each EU country and subsequently renewed pan-European guidelines are needed.

Knowledge and attitudes about treatment for hepatitis C virus infection and barriers to treatment among current injection drug users in Australia

Despite recent improvements in outcomes of treatment for infection with hepatitis C virus (HCV), very few current injection drug users (IDUs) have access to treatment programs. We examined the natural history of and treatment knowledge about HCV infection and barriers and willingness to seek treatment for HCV infection. A convenience sample of current IDUs (n=100) with self-reported HCV-positive status drawn from a primary health facility and methadone clinic in inner Sydney completed an interviewer-administered questionnaire. Participants had a reasonable knowledge of the natural history of HCV infection but poorer knowledge of treatment for HCV infection. Most believed that being a current IDU was an exclusion criterion for treatment. Despite this, 70%-80% of IDUs reported that they would consider treatment under current scenarios in Australia: requirement for liver biopsy, subcutaneous injections, common adverse effects, and 40% efficacy. Study participants at the methadone clinic had higher levels of consideration of treatment. These findings support the development of specific education programs regarding treatment for HCV infection for current IDUs.

Barriers to treatment of hepatitis C in HIV/HCV-coinfected adults with alcohol problems

BACKGROUND

Alcohol use and human immune deficiency virus (HIV) infection are both associated with accelerated progression of hepatitis C virus (HCV) disease and reduced response rates to interferon therapy. In this study, we assessed the prevalence of barriers to interferon treatment in a population of HIV/HCV-coinfected patients with current or past alcohol problems and the extent to which they received treatment to address the barriers.

METHODS

This is a cross-sectional, descriptive analysis of baseline data from a prospective study assessing the impact of HCV and alcohol use on HIV disease progression. Using consensus guidelines, subjects were categorized as having absolute, relative, or no contraindications to interferon therapy for HCV. Absolute contraindications to treatment included heavy alcohol use, decompensated liver disease, CD4 cell count <100 cells/microL, recent needle sharing, and suicidal ideation. Relative contraindications included moderate alcohol use, recent injection drug use, depressive symptoms, and CD4 cell count from 100 to 199 cells/microL.

RESULTS

Of 401 HIV-infected subjects, 200 were HCV RNA-positive. Fifty-three percent had an absolute contraindication to interferon therapy, 35% a relative but no absolute contraindication, and only 12% had no contraindication. Of those with an absolute contraindication, 61% reported heavy drinking and the majority (88%) had multiple contraindications. These contraindications were present despite the fact that over 50% were in receipt of substance abuse and mental health treatment.

CONCLUSIONS

Continued alcohol and drug use as well as depressive symptoms are the major barriers to interferon therapy in HCV/HIV-coinfected subjects and these barriers persist despite high treatment rates for these problems. Therefore, more intensive treatments of alcohol, drug, and mental health issues are needed to improve HCV treatment eligibility in HCV/HIV-coinfected persons.

Treatment of hepatitis C virus infection in intravenous drug users

BACKGROUND

Hepatitis C virus (HCV) infection is common among intravenous drug users, and because of the long latent period, HCV liver disease is set to increase.

OBJECTIVES

We sought to examine practice guidelines regarding treatment of HCV in drug users and to review the evidence for current practices.

METHODS

A structured search of the Pubmed database, websites of the National Institute for Clinical Excellence and national and international expert groups and opinion of independent experts in the field.

RESULTS AND CONCLUSIONS

All those infected with HCV need to be assessed to ascertain whether they have active ongoing viral replication and the extent of liver damage. HCV-infected individuals should be educated about the modes of transmission and means of reducing the risk of infecting others. They should also be advised to avoid cofactors (especially alcohol) that accelerate the progression of liver disease. Specific treatment with antivirals can cause viral clearance and prevent the progression of liver disease. Therapy is effective in those on opiate-replacement treatments and also in motivated individuals who continue to use intravenous drugs. The decision whether to treat drug users should be made jointly by specialists in the management of viral hepatitis and addiction on a case-by-case basis. Current combination drug regimens are expensive but are claimed to be cost-effective, and are certainly much less costly than managing end-stage liver disease. In addition to satisfactory sustained viral response rates, other benefits such as a beneficial effect on drug habit, self-esteem and rehabilitation have been reported. Encouraging suitable drug users to take-up and comply with treatment seems to be more easily achieved in supportive drug dependency unit settings (rather than the more formal surroundings of a hospital clinic).

[HIV and HCV coinfection]

Chronic hepatitis due to hepatitis C virus (HCV) infection is now one of the leading causes of morbidity and mortality among HIV-infected individuals. Coinfected patients present an accelerated course toward cirrhosis and an enhanced risk of liver toxicity associated with the use of antiretroviral agents. Treatment of chronic hepatitis C in HIV1 patients is less efficacious than in HCV-monoinfected individuals and requires particular expertise.

Orphan nuclear receptors: therapeutic opportunities in skeletal muscle

Nuclear hormone receptors (NRs) are ligand-dependent transcription factors that bind DNA and translate physiological signals into gene regulation. The therapeutic utility of NRs is underscored by the diversity of drugs created to manage dysfunctional hormone signaling in the context of reproductive biology, inflammation, dermatology, cancer, and metabolic disease. For example, drugs that target nuclear receptors generate over $10 billion in annual sales. Almost two decades ago, gene products were identified that belonged to the NR superfamily on the basis of DNA and protein sequence identity. However, the endogenous and synthetic small molecules that modulate their action were not known, and they were denoted orphan NRs. Many of the remaining orphan NRs are highly enriched in energy-demanding major mass tissues, including skeletal muscle, brown and white adipose, brain, liver, and kidney. This review focuses on recently adopted and orphan NR function in skeletal muscle, a tissue that accounts for approximately 35% of the total body mass and energy expenditure, and is a major site of fatty acid and glucose utilization. Moreover, this lean tissue is involved in cholesterol efflux and secretes that control energy expenditure and adiposity. Consequently, muscle has a significant role in insulin sensitivity, the blood lipid profile, and energy balance. Accordingly, skeletal muscle plays a considerable role in the progression of dyslipidemia, diabetes, and obesity. These are risk factors for cardiovascular disease, which is the the foremost cause of global mortality (>16.7 million deaths in 2003). Therefore, it is not surprising that orphan NRs and skeletal muscle are emerging as therapeutic candidates in the battle against dyslipidemia, diabetes, obesity, and cardiovascular disease.

Using latent class analysis to identify patterns of hepatitis C service provision in drug-free treatment programs in the U.S

Hepatitis C virus (HCV) infection is a global health problem, and in many countries (including the U.S.), illicit drug users constitute the group at greatest risk for contracting and transmitting HCV. Drug treatment programs are therefore unique sites of opportunity for providing medical care and support for many HCV infected individuals. This paper determines subtypes of a large sample of U.S. drug-free treatment programs (N=333) according to services they provide to patients with HCV infection, and examines the organizational and aggregate patient characteristics of programs in these subtypes. A latent class analysis identified four subtypes of HCV service provision: a "Most Comprehensive Services" class (13% of the sample), a "Comprehensive Off-Site Medical Services" class (54%), a "Medical Monitoring Services" class (8%) and a "Minimal Services" class (25%). "Comprehensive" services class programs were less likely to be outpatient and private for profit than those in the other two classes. It is of concern that so many programs belong to the "Minimal Services" class, especially because some of these programs serve many injection drug users. "Minimal Services" class programs in the U.S. need to innovate services so that their HCV infected patients can get the medical and support care they need. Similar analyses in other countries can inform their policy makers about the capacity of their drug treatment programs to provide support to their HCV infected patients.

High prevalence of alcohol use among hepatitis C virus antibody positive injection drug users in three US cities

Injection drug users (IDUs) acquire the majority of new hepatitis C virus (HCV) infections and frequently use alcohol. Alcohol abuse accelerates liver disease among HCV-infected persons, can reduce the effectiveness of treatment for HCV infection and may be a contraindication for HCV treatment. HCV seropositive, HIV-negative IDUs aged 18-35 years in Baltimore, New York City and Seattle who were enrolled in a behavioral risk-reduction intervention trial underwent computerized self-interviews to assess baseline alcohol use and dependence and medical history. We measured problem alcohol use using the 10-item Alcohol Use Disorders Identification Test (AUDIT) scale. Of 598 participants, 84% responded "false" to: "it is safe for a person with HCV to drink alcohol". Problem drinking, defined as score > or =8 on AUDIT, was identified in 37%. Correlates of scoring > or =8 on AUDIT included homelessness, male gender, primarily injecting speedballs, having injected with used needles, prior alcohol treatment and depression. Although most HCV seropositive IDUs in our sample appear informed about their increased risk of liver disease from alcohol, two-fifths screened positive for problem alcohol use. These findings underscore the importance of referring HCV-positive persons to effective alcohol treatment programs to reduce future liver damage and improve eligibility for and effectiveness of treatment of HCV.

The impact of barriers to hepatitis C virus treatment in recovering heroin users maintained on methadone

Although most cases of hepatitis C virus (HCV) infection are associated with injection drug use, there are few data regarding the impact of putative barriers such as psychiatric disease and intercurrent drug use on HCV treatment outcomes. To define the impact of characteristics often cited as reasons for withholding HCV treatment, we studied HCV treatment in a real world sample of 76 recovering heroin users maintained on methadone. Overall, 21 (28%) had a sustained virological response and 18 (24%) discontinued treatment early. Although there was a modest decrement in response rates in patients reporting a preexisting psychiatric history (p = .01), neither intercurrent drug use nor short duration of pretreatment drug abstinence led to significant reductions in virological outcomes (p = .09 and p = .18, respectively.) We conclude that injection drug users can be safely and effectively treated for HCV despite multiple barriers to treatment when they are treated in a setting that can address their special needs.

Acceptabilité d’un traitement du virus de l’hépatite C chez des utilisateurs de drogues injectables au Canada

BACKGROUND

The majority of prevalent and incident hepatitis C (HCV) infections in Canada are related to injection drug use (IDU), thus positioning injection drug users (IDUs) as a critical population to be targeted for HCV treatment. Little research has been undertaken in order to discover the willingness of IDUs to receive HCV treatment, however.

METHODS

The study sample was part of the Opican (illicit OPIoid use in CANada) cohort study of illicit opioid and other drug users in five Canadian cities.

RESULTS

Data were collected from a sub-sample of 50 HCV-positive IDUs in Toronto. Four fifths of participants indicated general willingness to participate in HCV treatment. Two conditional treatment questions led to significant decreases in treatment willingness (potential treatment side effects and requirement of addiction treatment).

CONCLUSION

The majority of IDUs in this sample indicated willingness to participate in HCV treatment, yet the particular needs and situations of this marginalized population have to be considered and addressed for responsive HCV treatment delivery.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of peginterferon and ribavirin is the most effective therapy for patients with chronic hepatitis C virus (HCV) infection. Although more than half of all patients are able to achieve a sustained virologic response (SVR), a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. The management of these patients creates a formidable challenge. This article outlines various strategies for patients who have failed to achieve SVR and discusses the merits of different approaches to management.

Treatment for Hepatitis C Virus Infection among Current Injection Drug Users in Australia

An estimated 210,000 people were living with hepatitis C virus (HCV) infection in Australia at the end of 2001, and the number of people developing cirrhosis was projected to increase 4-fold by 2020. Eighty percent of prevalent and 90% of incident HCV infections are related to injection drug use. Current injection drug use was an exclusion criterion for access to government-funded treatment for HCV infection until May 2001. Despite the removal of this barrier to treatment access for current injection drug users (IDUs), the number of IDUs receiving treatment remains extremely low. Treatment outcomes among IDUs with chronic HCV infection treated at 2 public hospital-based hepatitis clinics are presented. These data demonstrate that IDUs who continue to inject infrequently during treatment for HCV infection can achieve a sustained virological response. Further studies are under way to examine outcomes of treatment for HCV among clients undergoing treatment for drug dependency who have chronic HCV infection and among current IDUs with acute and newly acquired HCV infection.

Delivering Care to Injection Drug Users Coinfected with HIV and Hepatitis C Virus

Injection drug use has fueled the epidemic of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection in the United States. Nevertheless, drug dependence is among the main reasons that coinfected persons are not being treated for HCV infection. This report describes the development and progress of an HIV clinic program (funded by the Ryan White Comprehensive AIDS Resources Emergency Act) to deliver care for HCV infection to HIV-seropositive injection drug users. To optimize safety and adherence, pegylated interferon is directly administered to patients in the context of integrated addiction, psychiatric, and HIV and HCV therapy. Ribavirin is packed weekly in pill boxes for patients to take at home. Thus far, adherence to weekly visits for treatment with interferon has been 99%. No one has had to stop treatment for HCV infection because of ongoing drug use, addiction relapse or exacerbation, or psychiatric complications. Presented here is a work in progress, rather than a finished research project or definitive model of care.

Therapies for HIV and viral hepatitis coinfection

The natural history of chronic viral hepatitis is altered by HIV coinfection. Liver fibrosis rates and clinical features of liver disease develop more rapidly. Although HIV-hepatitis C virus coinfected subjects may progress more rapidly to AIDS, this is probably explained by comorbid illness, substance abuse and socioeconomic circumstances. Safe and virologically active treatment of HIV-hepatitis B virus coinfection can be concurrently achieved by the use of highly active antiretroviral therapy regimens containing lamivudine and/or tenofovir. In most cases, highly active antiretroviral therapy represents the most beneficial initial pharmaceutical intervention for HIV-hepatitisC virus coinfection. HepatitisC virus antiviral therapy should, in most cases, be reserved for those achieving HIV RNA suppression and immune restoration from highly active antiretroviral therapy or with nadir CD4 T-lymphocytes above 350 cells/microl.

Transforming growth factor-β1 gene polymorphisms are associated with progression of liver fibrosis in Caucasians with chronic hepatitis C infection

AIM: Considerable attention is focused on polymorphisms in the gene encoding transforming growth factor-β1 (TGF-β1), a multifunctional cytokine that is in turn a potent growth inhibitor involved in wound healing and differentiation. In humans, it promotes the pathogenesis of organ fibrosis, atherosclerosis, cancer, autoimmune and inflammatory diseases, keloid disease, and hypertrophic scarring. For this reason, much emphasis has been placed on studies elucidating the impact of TGF-β1 and its gene variations for the susceptibility and pathogenesis of these diseases. Unfortunately, some studies have serious limitations.

METHODS: We have recently described a high-throughput method for investigation the Arg25Pro polymorphism of human TGF-β1 gene and showed that the frequency of the Pro25 allele is significantly associated with hepatic fibrogenesis. In this report, we describe two novel LightCycler (LC) techniques that facilitate the examination of the two other known alterations in the coding region of TGF-β1. We investigated whether these polymorphisms contribute to hepatitis-induced progression of fibrogenesis in Chinese and Caucasians.

RESULTS: In the Chinese ancestry, the gene polymorphisms at codons 25 and 263 were not found and the genetic variant at codon 10 is unlikely to confer susceptibility to hepatic fibrosis. Contrarily, in Caucasians TGF-β1 allelic variations are more frequent and the presence of prolines either in codon 25 or 10 is associated with the interindividual variability in developing more severe fibrosis during chronic hepatitis C infection.

CONCLUSION: In summary, these results confirm the hypothesis that TGF-β1 polymorphisms are associated with fibrosis progression in Caucasians chronically infected with hepatitis C.

Management of hepatitis C virus in special populations: patient and treatment considerations

The most common chronic blood-borne infection in the United States is caused by hepatitis C virus. An estimated 3.9 million people (1.8%) in the United States have been infected with the hepatitis C virus, excluding certain subpopulations who are at high risk for hepatitis C virus infection. Among these subpopulations are an estimated 255,000 (15%) of prison inmates and 175,000 (22%) of homeless people. Prevalence of hepatitis C virus infection is also high among veterans (6.6% overall and even higher among homeless veterans). The single most important risk factor for hepatitis C virus infection is injection drug use; up to 90% of illicit injection drug users are infected with hepatitis C virus. This review describes the prevalence of hepatitis C virus in special populations and discusses the treatment options for patients with severe disease, transplant recipients, and patients at high risk for infection. Close monitoring and management of therapeutic side effects are required to assist these patients in adhering to therapy.

Peginterferon alfa-2a does not alter the pharmacokinetics of methadone in patients with chronic hepatitis C undergoing methadone maintenance therapy

OBJECTIVE

Our objective was to quantify the pharmacokinetics of methadone and the pharmacokinetics and pharmacodynamics of peginterferon alfa-2a (40 kd) in patients with chronic hepatitis C undergoing methadone maintenance therapy.

METHODS

Adults with chronic hepatitis C who had been receiving a consistent methadone maintenance regimen for at least 3 months were eligible for this open-label, multicenter, nonrandomized drug interaction study. All patients received 180 microg subcutaneous peginterferon alfa-2a once weekly for 4 weeks and continued their methadone regimen. Serial blood samples were collected at baseline and immediately before and for up to 168 hours after study drug administration for the purposes of quantifying methadone and peginterferon alfa-2a serum concentrations, measuring serum 2',5'-oligoadenylate synthetase activity, and determining hepatitis C virus ribonucleic acid levels.

RESULTS

Twenty-four patients were enrolled. Methadone exposure, as measured by maximum serum concentration (C(max)) and area under the concentration-time curve (AUC) normalized to a 100-mg/d dose, after 4 doses of peginterferon alfa-2a increased by 10% to 15% when compared with baseline. The week 4/baseline ratio of the mean C(max) was 1.11 (90% confidence interval [CI], 1.02-1.22), and for AUC from time 0 to 24 hours, the week 4/baseline ratio was 1.15 (90% CI, 1.08-1.23). The mean accumulation ratios (week 4/first dose) for C(max) and AUC from time 0 to 168 hours of peginterferon alfa-2a were 2.1 and 2.3, respectively.

CONCLUSIONS

Peginterferon alfa-2a does not appreciably alter the pharmacokinetics of methadone.

Integrating hepatitis C services into existing HIV services: the experiences of a sample of U.S. drug treatment units

Hepatitis C virus (HCV) is the most prevalent blood-borne infectious disease in the United States, especially among drug users, and coinfection with HIV is common. Because drug users are often medically underserved, drug treatment units are important sites of opportunity for providing services for these infectious diseases. Given the commonalities in the routes of transmission of HIV and HCV, and the fact that many drug treatment units have established an infrastructure to provide HIV services, some have suggested integrating HCV services into those already established for HIV. Using data collected in a telephone survey with 89 drug treatment units throughout the United States, this paper examines the extent to which drug treatment units have expanded their HIV services to include those for HCV, and the extent to which this expansion was facilitated by having HIV services in place. Overall, a greater proportion of methadone maintenance than drug-free treatment units provided services for HIV and HCV. The majority of units in both modalities that provided HIV- and HCV-related services expanded their HIV service delivery to include similar HCV services, and one third expanded all of their HIV services. A large number of these units, however, indicated that having an HIV service infrastructure did not facilitate this expansion, often because the units wanted to emphasize differences in the two viral infections. Policy makers and individual treatment units need to develop strategies that capitalize on existing infrastructures while maintaining the distinction between HIV and HCV primary and secondary prevention efforts.

The impact of injecting drug use status on hepatitis C-related referral and treatment

More than 160,000 people are living with chronic hepatitis C virus (HCV) infection in Australia, however, rates of medical treatment are low. The aim of this study is to examine uptake and predictors of HCV-related health care services among a community-based sample of people with HCV. A self-administered questionnaire was completed by a largely non-clinical sample of 362 women and 308 men with HCV living in the state of Victoria. Analyses were performed according to injecting drug use (IDU) status: no history of injecting (non-IDUs), previous history of injecting (past-IDUs) and current (within the last 12 months) history of injecting (current IDUs). Bivariate and multivariate predictors of referral to a specialist liver clinic were also assessed. Fifty-one percent of participants were current IDUs, 33% past-IDUs and 16% non-IDUs. Fifty-two percent of women and 37% of men reported ever being referred to a specialist liver clinic and 18% of women and 20% of men reported previous HCV antiviral therapy. Although there were many factors related to an increased likelihood of referral (e.g. being female, longer time since diagnosis, longer consultation time at diagnosis, experiencing HCV-related symptoms), multivariate analysis revealed that not being a current IDU and seeing a GP specifically for HCV were the most important independent predictors of referral. For those who had been referred to a liver clinic, a history of IDU was associated with a lower chance of receiving antiviral therapy. IDU status is associated with both referral and treatment. The extension of HCV treatment services to involve GPs and drug and alcohol practitioners should be explored as models to improve access to antiviral therapy.

Medical illness and comorbidities in drug users: implications for addiction pharmacotherapy treatment

Providing effective medical care to those with substance use disorders can be a challenge to clinicians. In this article, we briefly summarize issues that occur frequently in the medical treatment of substance users. The focus of this article is twofold. The first is to briefly summarize common co-occurring medical illnesses in those manifesting substance use disorders with an emphasis on issues related to providing effective treatment for these diseases in this population. Using specific examples of frequently occurring comorbid medical illness in substance users, including infectious diseases (hepatitis C and HIV disease), sexually transmitted diseases, and pregnancy as examples, the complexities of medical care for this population is demonstrated. Second, this article addresses some of the difficulties encountered in pharmacotherapy aimed specifically at treatment of substance use disorders. For example, difficulties in managing concomitant opiate therapy in those requiring medications for medical illness that may have strong and adverse interactions with opiates are addressed. Adverse events reported for some substance use disorder pharmacotherapies are also highlighted. We conclude with a brief review of models of care that have been effective in addressing the needs of this challenging population that can provide additional means for enhancing the clinical care of substance users.