Previous intravenous drug abusers with chronic hepatitis C who are under substitution therapy (buprenorphine, methadone) will be treated with PegIntron and Rebetol according to the approved European labeling. The study will assess the tolerability, safety and efficacy of the treatment with PegIntron plus Rebetol in this study population. The objective of the study is to collect data on the prevalence of the hepatitis C infections in drug-substituted patients. The study will also compare the feasibility of HCV (Hepatitis C Virus) treatment in patients receiving Subutex® vs other drug substitution pharmacotherapies.

Inclusion Criteria:

• Treatment-naïve participants or relapsers to interferon monotherapy

• Participants with chronic hepatitis C infection

• At least 18 years of age

• Must meet the following laboratory criteria:

  • Platelets >=100,000/mm^3
  • Neutrophil count >=1,500/mm^3
  • TSH (thyroid stimulating hormone) within normal limits
  • Hemoglobin >=12 g/dL (females); >=13 g/dL (males)

• Ex-intravenous drug abusers who are under stable substitution therapy

• Women of childbearing potential must practice adequate contraception and have a routine pregnancy test performed monthly during treatment and for 7 months post-treatment.

• Sexually-active participants must be practicing acceptable methods of contraception during the treatment and for 7 months post-treatment

Exclusion Criteria:

• Any contraindications specified in the SPC (Summary of Product Characteristics) and approved European labeling
• Hypersensitivity to the active substance or to any interferons or to any of the excipients
• Pregnant women
• Women who are breast-feeding
• Existence of or history of severe psychiatric condition, in particular severe depression, suicidal ideation or suicide attempt
• A history of severe pre-existing cardiac disease, including unstable or uncontrolled cardiac disease in the previous 6 months
• Severe debilitating medical conditions, including participants with chronic renal failure or creatinine clearance <50 mL/min
• Coinfection with HIV (Human Immunodeficiency Virus)
• Autoimmune hepatitis or history of autoimmune disease
• Severe hepatic dysfunction or decompensated cirrhosis of the liver
• Pre-existing thyroid disease unless it can be controlled with conventional therapy
• Epilepsy and/or compromised central nervous system function

Previous intravenous drug abusers with chronic hepatitis C receiving substitution therapy (buprenorphine, methadone or other) at approximately 100 sites in Germany.