Treatment of Hepatitis C in Drug Users

  Treatment of Hepatitis C in Drug Users

Decisions about the treatment of hepatitis C in patients who use illicit drugs, as in other patients, should be made by the patients together with their physicians based on individualized risk-benefit assessments.Risk-benefit considerations for drug users include those that apply to all patients with hepatitis C, including the limited likelihood of achieving a sustained virological response, particularly in patients with genotype 1 infection, African-American ethnicity, or both; the substantial side effects; and, if the disease is not advanced, the option of delaying therapy while better regimens are developed. Moreover, although the likelihood of achieving a sustained virological response has been well studied in various patient groups, little is known about the likelihood that patients will develop clinical endpoints— cirrhosis, liver cancer, end-stage liver disease, or death—and even less is known about how much or even whether treatment will reduce those risks. Before embarking on therapy, therefore, patients should understand that although one can estimate the likelihood that treatment will clear HCV infection (or achieve a histological benefit), it is not known whether treatment will reduce their chances of becoming sick or dying from hepatitis C. Patients should have access to treatment, but they should make their own decisions, with the aid of a balanced portrayal of the known risks and benefits. For patients with advanced hepatic fibrosis, in whom clinical progression is more imminent, treatment may be more compelling, although data are still needed on the effects of treatment on clinical endpoints such as decompensated cirrhosis and mortality in such patients. Liver biopsy examination can assist in making treatment decisions by identifying patients with advanced fibrosis, in addition to providing information to all patients about their disease status and prognosis.

For patients in stable, long-term recovery, including those receiving methadone maintenance therapy, there is no reason to withhold hepatitis C treatment because of a past history of illicit drug use. For active drug users, adherence, psychologic side effects, and the possibility of reinfection may present challenges to effective treatment. Each of these issues requires attention, but none warrants categorically excluding all active or recent drug users from therapy. Rather, these issues should be considered in each individual patient on a case-by-case basis. Patients who believe they can adhere to therapy can be allowed to try. Much less is lost by treating a patient who does not adhere to therapy than by letting a patient progress to cirrhosis or death without a trial of treatment because of a prior assumption that the patient would not adhere to the regimen.

Adherence. 

There is abundant evidence from diseases other than hepatitis C that drug users can adhere to medical treatments. When compared with nonusers in conventional clinical settings, drug users often, although not always, have lower levels of adherence. But rates of adherence among drug users range from 30% to nearly 100%, a range that is similar to that in patients being treated for hypertension, diabetes, or asthma. Moreover, when programs are designed specifically for drug users by groups with experience working with substance abuse, adherence rates often exceed 80%. In addition, numerous studies have shown that most physicians are not able to predict patient adherence accurately. Thus, although there are many effective strategies for improving patient adherence, attempting to screen out patients who are predicted to have poor adherence is not effective. The extensive and rapidly growing literature on adherence has been summarized in the latest revision of the treatment guidelines for human immunodeficiency virus (HIV) infection. These guidelines recommend that readiness for treatment be assessed before therapy in all patients and that no patient be excluded automatically from treatment.

Adherence by Injection Drug Users to MedicalTreatments

Tolerance and Effectiveness. 

Few data are available on results of hepatitis C treatment in active injection drug users who are not receiving treatment for drug use. Several recent studies, however, have shown the safety and effectiveness of hepatitis C treatment in patients receiving drug use treatment, even when they were not completely abstinent from illicit drug use. In a study of 50 heroin injectors entering opiate detoxification in Munich, Germany, 34 patients were treated with interferon alfa monotherapy and 16 were treated with combination therapy of interferon and ribavirin for 24 to 48 weeks, depending on HCV genotype. The overall sustained virological response rate was 36% , a rate comparable to that in other populations treated for hepatitis C, even though 80% of patients relapsed to drug use during the study. This response rate exceeded the 10% to 20% response rate for interferon alfa monotherapy that was recommended in the 1997 Consensus Development Conference and was similar to rates of response achieved with combination therapy in nonuser populations. In this study, all patients were managed by physicians who specialized in hepatology and in addiction medicine. Patients who relapsed to drug use were offered methadone maintenance therapy but were allowed to continue treatment for HCV even if they continued to inject illicit drugs. Sizeable proportions of patients had a sustained virological response, regardless of whether they relapsed to drug use or received methadone maintenance therapy ; indeed, sustained response rates were not significantly associated with either relapse to drug use or receipt of methadone maintenance therapy. The strongest predictor of virological response was adherence to their weekly clinic appointments. Of those who kept at least two thirds of appointments, 45% had a sustained virological response, compared with only 8% of those who did not. This study showed that drug users receiving treatment for substance use can be treated successfully for hepatitis C, despite ongoing drug use. The study also showed the importance of combining expertise in hepatology and substance use and maintaining strong relationships with patients that can continue even when patients relapse to drug use.