Ribavirin has been studied for over 20 years as a potential therapy against a number of RNA and DNA viruses. It is well known that Ribavirin in combination with Interferon is a key antiviral component in the treatment of Hepatitis C virus infection. In this book, the authors discuss the biochemistry, clinical applications and potential side effects of Ribavirin. Topics include optimising Ribavirin use for the treatment of Hepatitis C; Ribavirin and its great potential in infectious diseases; the antiviral actions of Ribavirin; a novel prediction method for the responsiveness of Hepatitis C patients to drug treatment; and Ribavirin's intolerable cough during HCV combination therapy which can be overcome by replacement with Nitazoxanide.