SIDE EFFECTS: Nausea, diarrhea, stomach upset, headache, dizziness, blurred vision, trouble sleeping, flu-like symptoms (e.g., fever, chills, sore throat, muscle aches), cough, hair loss, low appetite, weight loss or gain, dry skin, and changes in taste/hearing may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tooth and gum problems may sometimes occur during ribavirin/interferon treatment. Dry mouth can worsen this side effect. Prevent dry mouth by drinking plenty of water or by using a saliva substitute. Brush your teeth well at least twice daily and see your dentist regularly. If you experience vomiting during treatment, rinse out your mouth afterwards to reduce tooth and gum problems.

Tell your doctor immediately if any of these unlikely but serious side effects occur: unusual tiredness/weakness, fast/pounding/irregular heartbeat, trouble breathing, mental/mood changes (e.g., severe depression, suicidal thoughts), muscle/joint pain, vision changes, easy bruising/bleeding, dark urine, yellowing of eyes/skin.

Seek immediate medical attention if any of these unlikely but very serious side effects occurs: chest pain, jaw/left arm pain, stomach/lower back pain, black/bloody stools.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the Rebetol (ribavirin) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before taking ribavirin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: other types of hepatitis (e.g., autoimmune hepatitis), blood disorders (e.g., sickle cell anemia, low hemoglobin, thalassemia), kidney disease.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: other liver problems, heart disease, high blood pressure, breathing problems, pancreas problems (e.g., pancreatitis), diabetes.

This drug may make you dizzy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Avoid alcoholic beverages.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, elderly people may be at greater risk for anemia while using this drug.

Children may be at greater risk for mental/mood changes, including severe depression or suicidal thoughts, while using this drug. Ribavirin/interferon treatment may also slow down a child's rate of growth. It is not known if this will affect final adult height. Monitor your child's height periodically during treatment.

Ribavirin must not be used during pregnancy. It is recommended that female patients or female partners of male patients take a pregnancy test before this medication is started, during treatment, and for 6 months after this drug is stopped. If you become pregnant or think you may be pregnant, inform your doctor immediately. See Warnings for additional information.

It is not known whether this drug passes into breast milk. Because of the potential risk to the infant, breast-feeding while using this medication is not recommended.