Approaching treatment for hepatitis C virus infection in substance users.

Although injection drug users represent the majority of incident and prevalent cases of hepatitis C, most lack access to treatment because of concerns about adherence, treatment efficacy, and reinfection. On the basis of an increasing body of evidence suggesting that injection drug users can successfully undergo treatment for hepatitis C virus (HCV) infection, the 2002 National Institutes of Health Consensus Statement on Hepatitis C has recommended that substance users, even those with ongoing drug use, be considered for treatment for HCV infection on a case-by-case basis. However, the criteria on which these treatment decisions should be based are unclear: The duration of pretreatment drug abstinence, comorbid psychiatric illness, intercurrent drug use, and the potential for injected interferon to cause relapse of drug use may all influence results of treatment for HCV infection. This overview summarizes my group's current data about treatment for HCV infection in substance users and the effect of these potential barriers on outcomes of treatment.