AIM:To assess the acceptance,safety and efficacy of care and treatment for chronic hepatitis C(CHC)in drug addicts.METHODS:We designed a multidisciplinary,phase IV prospective cohort study.All illicit drug users(IDUs)visited a Territorial Addiction Service(SerT)in the District of Brescia,and hepatitis C antibody(HCVAb)testing positive were offered as part of a standardised hepatologic visit in our Gastroenterology Unit.Patients with confirmed CHC and without medical contraindications were administered peginterferon alfa-2b 1.5μg/kg per week plus ribavirin(800-1400 mg/d)for 16-48wk.All IDUs were unselected because of ongoing addiction and read and signed an informed consent form.Virologic responses at weeks 4 and 12 of therapy,at the end of treatment and 24 wk after the end of treatment were the main measures of efficacy.Adherence was estimated according to the 80/80/80 criteria.RESULTS:From November 2007 to December 2009,162 HCVAb+IDUs were identified.Sixty-seven patients(41%of the initial cohort)completed the diagnostic procedure,and CHC was diagnosed in 54(33%of the total).Forty-nine patients were offered therapy,and 39agreed(80%of acceptance rate).The prevalent HCV genotype was type 1,and the HCV RNA baseline level was over 5.6 log/mL in 61%of cases.Five patients dropped out,two because of severe adverse events(SAEs)and three without medical need.Twenty-three and 14 patients achieved end of treatment responses(ETRs;59%)and sustained virologic responses(SVRs;36%),respectively.Thirty-one patients were fully compliant with the study protocol(80%adherence).The prevalence of host and viral characteristics negatively affecting the treatment response was high:age over40 years(54%),male gender(85%),overweight body type(36%),previous unsuccessful antiviral therapy(21%),HCV genotype and viral load(60%and 62%,respectively),earlier contact with HBV(40%)and steatosis and fibrosis(44%and 17%,respectively).In a univariate analysis,alcohol intake was associated with a non-response(P=0.0018,95%CI:0.0058-0.4565).CONCLUSION:Drug addicts with CHC can be successfully treated in a multidisciplinary setting using standard antiviral combination therapy,despite several"difficult to reach,manage and treat"characteristics.