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Generic name: ribavirin (oral) [ RYE-ba-VYE-rin ]
Drug classes: Inhaled anti-infectives, Purine nucleosides

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jun 14, 2021.

What is Ribasphere?

Ribasphere is an antiviral medication

Ribasphere capsules are used with either interferon alfa-2b (Intron A) or peginterferon alfa-2b (Pegasys, PegIntron, Sylatron) to treat chronic hepatitis C infection in people 3 years and older with liver disease.

It is not known if Ribasphere use for longer than 1 year is safe and will work.

It is not known if Ribasphere use in children younger than 3 years old is safe or if it will work.


You should not use Ribasphere if you have autoimmune hepatitis, severe kidney disease, or a hemoglobin blood cell disorder.

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

Ribasphere is not effective when used alone. It must be used together with an interferon alfa product. You should not take this medicine with didanosine.

Ribavirin can cause birth defects or death in an unborn baby. Do not use this medicine if you are pregnant, or if you are a man and your sexual partner is pregnant. Use 2 forms of birth control to prevent pregnancy while either sexual partner is taking this medicine, 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 Ribasphere.

In rare cases, ribavirin can cause fatal heart problems. Get emergency medical attention if you have chest pain.

Before taking this medicine

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

  • a hemoglobin blood cell disorder such as sickle-cell anemia or thalassemia;

  • autoimmune hepatitis;

  • moderate to severe kidney disease;

  • if you are also taking didanosine; or

  • if you are pregnant, or if you are a man whose sex partner is pregnant.

When you take Ribasphere in combination with other medications: There may be other reasons you should not take the combination treatment. Tell your doctor about all your medical conditions.

To make sure this medicine is safe for you, tell your doctor if you have ever had:

  • a blood cell disorder such as anemia (low red blood cells);

  • heart problems, high blood pressure, or heart attack;

  • breathing problems;

  • vision problems (you may need an eye exam before taking Ribasphere);

  • diabetes;

  • human immunodeficiency virus (HIV or AIDS) or a weak immune system;

  • depression, mental illness, thoughts of hurting yourself or others;

  • a thyroid disorder;

  • kidney disease;

  • an organ transplant;

  • liver problems other than hepatitis C; or

  • treatment for hepatitis C that did not work well.

Both men and women taking Ribasphere should use effective birth control to prevent pregnancy. Ribavirin can cause birth defects, miscarriage, or death to an unborn baby if the mother or father is using this medicine.

  • If you are a woman, do not take ribavirin if you are pregnant. You will need to have a negative pregnancy test before taking ribavirin. You will also need pregnancy tests during treatment and for 6 months after your last dose.

  • If you are a man, do not take ribavirin if your sex partner is pregnant.

  • Both men and women should keep using effective birth control for at least 6 months after the last dose of ribavirin.

  • Tell your doctor right away if a pregnancy occurs while either the mother or the father is taking Ribasphere. Your name may be listed on a pregnancy registry to track the effects of ribavirin on the baby.

It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk.

Ribasphere is not approved for use by anyone younger than 3 years old.

How should I take Ribasphere?

Ribasphere is not effective when used alone and must be used in combination with other medications to treat hepatitis C.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take Ribasphere with food.

Swallow the capsule whole and do not crush, chew, break, or open it. Tell your doctor if you have trouble swallowing the capsule.

Drink extra fluids while you are taking Ribasphere to keep from getting dehydrated.

Ribasphere can cause dry mouth, which could lead to tooth decay or gum disease. If you vomit while taking this medicine, rinse your mouth out with water to prevent damage to your teeth or gums. Be sure to have regular dental exams while you are taking this medication.

You will need frequent medical tests.

Store Ribasphere capsules at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the missed dose on the same day you remember it. Skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Get your prescription refilled before you run out of medicine completely.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

Avoid drinking alcohol. It can make your liver problems worse.

Using this medicine will not prevent you from passing hepatitis to other people. Follow your doctor's instructions about how to prevent passing the disease to another person.

Ribasphere side effects

Get emergency medical help if you have signs of an allergic reaction to Ribasphere: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Ribavirin can cause anemia. In rare cases, this can lead to fatal heart problems. Get emergency medical attention if you have chest pain.

Call your doctor at once if you have:

  • problems with your vision;

  • severe pain in your upper stomach spreading to your back, nausea, vomiting, diarrhea;

  • new or worsening cough, fever, stabbing chest pain, wheezing, feeling short of breath;

  • severe depression, thoughts about suicide, or thoughts about hurting someone else;

  • signs of serious anemia - pale or yellowed skin, dark colored urine, confusion or weakness; or

  • other signs of low blood cell counts - fever, chills, flu-like symptoms, swollen gums, mouth sores, skin sores, easy bruising, unusual bleeding, feeling light-headed.

Ribavirin can affect growth in children. Tell your doctor if your child is not growing at a normal rate while using this medicine.

Common Ribasphere side effects may include:

  • nausea, vomiting, loss of appetite;

  • fever, chills or shaking;

  • low blood cell counts, anemia;

  • feeling weak or tired;

  • headache, muscle pain; or

  • mood changes, feeling anxious or irritable.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Ribasphere?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with ribavirin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Ribasphere only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.