Please consult your physician before taking any medication. Ribavirin is an antiviral medication. Ribavirin must be used together with an interferon alfa product (such as PegIntron or Intron A) to treat chronic hepatitis C. Ribavirin may also be used for purposes not listed in this medication guide. Ribavirin is not effective when used alone to treat hepatitis C. It must be used together with an interferon alfa product (such as Peg-Intron or Intron A) to treat chronic hepatitis C. You should not take ribavirin if you are allergic to it, or if you have severe liver disease, autoimmune hepatitis, a hemoglobin disorder (anemia, thalassemia, and others), if you are also taking didanosine (Videx), or if you are pregnant woman, or a man whose female sexual partner is pregnant. This medication can cause birth defects or death in an unborn baby. If you are a woman, do not take ribavirin if you are pregnant. If you are a man, do not take ribavirin if your female sexual partner is pregnant. An unborn baby could also be harmed if a man fathers the child while he is taking ribavirin. Use at least two effective forms of birth control while either sexual partner is taking ribavirin, and for at least 6 months after treatment ends. Tell your doctor right away if a pregnancy occurs while either the mother or the father is taking ribavirin.