Abstract: The present invention provides methods using erythropoietin to improve the tolerance of anti-viral and anti-tumor chemotherapeutic regimens containing interferon. The invention also described improved methods to treat chronic HCV by adjusting the dose of ribavirin to tailor the active dose of the drug while supporting the hemoglobin levels in the patient with EPO. The present invention also provides anti-viral dosing regimens, particularly for chronic HCV comprising administration of an interferon containing anti-viral medicament, EPO, and a compound that reduces the amount of active tumor necrosis factor in the subject.