Impact of adherence on the outcome of antiviral therapy for chronic hepatitis C.

Nearly 4 million people in the United States have evidence of hepatitis C infection (HCV), representing a significant cause of cirrhosis and liver cancer as well a major burden to our healthcare systems and society. Antiviral therapy can successfully eradicate HCV over the long term, potentially reducing the risk of progression and improving patients' quality of life. The currently preferred HCV treatment is a combination of pegylated interferon alfa and ribavirin, which can achieve an overall sustained viral eradication rate of 55%. The duration of this treatment is typically determined by HCV genotype and the patient's early virologic response to the antiviral regimen. Evidence has accumulated over the past few years to indicate that close adherence to the optimal antiviral regimen can enhance sustained virologic response. But optimal treatment outcomes require diligence and careful management of side effects related to combination therapy. Although reducing the dose of pegylated interferon alfa, ribavirin, or both can effectively treat side effects, suboptimal doses of this regimen, especially ribavirin, may negatively affect virologic response. An alternative strategy is to use growth factors to treat cytopenias. This strategy can obviate dose reductions while potentially improving patients' quality of life. Patient support seems especially important early after the initiation of antiviral therapy. Encouraging study findings involving the growth factors, epoetin alfa and darbepoetin alfa, suggest improved anemia and quality of life while maintaining the optimal ribavirin dose. Future work should be aimed at providing stronger evidence for the use of these "supportive products" during anti-HCV therapy. As we strive to develop better treatment options for our HCV patients, the importance of adhering to the treatment regimen continues to play a central role. Effective side effect management is crucial for the success of this treatment because adherence is negatively affected by side effects related to the antiviral regimen. By identifying and addressing the important side effects of combination therapy for HCV, adherence to treatment can be improved and optimal outcomes can be achieved.