Zepatier in Patients with Substance Use

Inclusion Criteria: * Adults (at least 18 years of age or older) * Chronic HCV (HCV antibody positive with detectable HCV-RNA) * HCV genotypes 1a, without the presence of baseline NS5A resistance (specifically, polymorphisms at amino acid positions 28, 30, 31, or 93), 1b, or 4 * HCV treatment-naïve or peginterferon/ribavirin-experienced * Managed by the UI Health Infectious Diseases Clinic or Liver Clinic * Recent or current substance use (per self-report or electronic medical record (EMR) data within 90 days of the screening visit, with or without positive baseline urine toxicology), inclusive of one or more of the following: Opiate substitution therapy; Prescription medication misuse (including: opiates, sedatives, tranquilizers, hypnotics, and psychostimulants); Illicit substances; Injection drug use; Alcohol Exclusion Criteria: * Incarcerated * Pregnant or breastfeeding * Decompensated liver disease (Child-Pugh B or C) * Albumin below 3 g/dL * Platelet count below 75,000 * Unwilling to commit to treatment and/or monitoring * Poor venous access inhibiting laboratory collection * Any condition considered by the investigators to be a contraindication to study participation * Hepatitis B virus (HBV) surface antigen (HBsAg) positive