While ribavirin has been used extensively for the treatment of viral hepatitis C and its safety profile has been well defined, it has never been used in patients with AML. This study will establish the efficacy and safety of ribavirin in M4/M5 AML patients. In addition, this study will also include correlative studies to determine the effect of ribavirin on eIF4E activity and eIF4E related pathways in M4/M5 AML patients.