Background and aim: There are few studies investigating the treatment of hepatitis C virus (HCV) infection in current and former drug users. With this in mind, we sought to evaluate the antiviral efficacy of interferon alpha-2b (IFN alpha-2b) or pegylated-interferon alpha-2b (PEG-IFN alpha-2b) and ribavirin (RBV) in injection drug users (IDU) enrolled in a directly observed therapy (DOT) program, as measured by sustained virologic response (SVR).
Methods: Viremic HCV-infected IDU, with alanine aminotransferase (ALT) >1.5x upper limit of normal (ULN) were offered 24-48 week (based on HCV genotype) therapy with RBV (800-1200 mg/day, based on weight) along with IFN alpha-2b (3 million IU thrice weekly) replaced by PEG-IFN alpha-2b (1.5 ìg/kg once weekly) as it became available. All injections were directly observed. The primary endpoint was SVR.
Results: Overall, 40 patients (33 males) received IFN alpha-2b (12) or PEG-IFN alpha-2b (28), 55% with HCV genotypes 2 or 3. Only 14 discontinued therapy, 5 due to toxicity, 6 due to illicit drug use and 3 did not achieve an early virologic response. In an intent-to-treat analysis, the overall SVR was 55% (22/40), 64% (14/22) in subjects with genotypes 2/3. There was no significant difference in response rates among those with >6 (50%) or <or=6 months (64%) drug abstinence (P = 0.51) or among those with (53%) and without (57%) intercurrent drug use (P = 0.99); however, frequent users (n = 9) had a decreased SVR (22%) when compared with occasional users (n = 10, 80%, P = 0.12).
Conclusion: Treatment of HCV in current and former IDU within a multidisciplinary DOT program can be successfully undertaken, resulting in SVR similar to those in randomized controlled trials.