Ribavirin is an antiviral medication.

Ribavirin must be used together with an interferon alfa product (such as Pegasys, PegIntron, Sylatron, 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 Pegasys, PegIntron, Sylatron, 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.

Ribavirin may decrease the number of red blood cells in your body. This is called anemia and it can be life-threatening in people who have heart disease or circulation problems. Your blood will need to be tested often. Your vision, liver function, and thyroid function may also need to be tested. Visit your doctor regularly.

Call your doctor at once if you have pale or yellowed skin, dark colored urine, fever, confusion, chest pain, weakness, or trouble breathing.

You should not take ribavirin if you are allergic to it, or if you have:

• severe liver disease (especially cirrhosis);

• autoimmune hepatitis;

• a hemoglobin disorder such as anemia, thalassemia (Mediterranean anemia), or sickle-cell anemia;

• if you are also taking didanosine (Videx); or

• if you are pregnant woman, or a man whose female sexual partner is pregnant.

To make sure you can safely take ribavirin, tell your doctor if you have any of these other conditions:

• kidney or liver disease (other than hepatitis C);

• hepatitis B infection;

• a blood cell disorder such as hemolytic anemia (a lack of red blood cells);

• human immunodeficiency virus (HIV or AIDS);

• diabetes;

• a pancreas disorder;

• sarcoidosis;

• breathing problems;

• a thyroid disorder;

• new or worsening eye problems (such as retinopathy);

• a history of heart disease, high blood pressure, or a heart attack;

• a history of depression or suicide attempt;

• a history of a liver, kidney, or other organ transplant; or

• if you have ever received treatment for hepatitis C that did not work well.

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. You will need frequent pregnancy tests to make sure you are not pregnant while taking ribavirin.

• 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. Your sexual partner will need frequent pregnancy tests to make sure she is not pregnant while you are 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.

Your name may need to be listed on a ribavirin pregnancy registry if you become pregnant while you or your male sexual partner are taking this medication or during the 6 months after treatment ends. This is to track the outcome of the pregnancy and to evaluate any effects of ribavirin on the baby.

It is not known whether ribavirin passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are taking ribavirin.

Ribavirin may affect growth in children.