If you are taking INTRON A in combination with REBETOL®, you should also read the Medication Guide for REBETOL (ribavirin, USP) for more information about side effects and how to take REBETOL. REBETOL capsules should be taken twice a day with food. Taking REBETOL with food helps your body take up more of the medicine. Taking REBETOL at the same time of day every day will help keep the amount of medicine in your body at a steady level. This can help your healthcare provider decide how your treatment is working and how to change the number of REBETOL capsules you take if you have side effects. If you miss a dose of REBETOL, take the missed dose as soon as possible during the same day. If an entire day has passed, check with your healthcare provider about what to do. Do not double your next dose.

You must see your healthcare provider on a regular basis for blood tests so your healthcare provider can check how the treatment is working for you and to check for side effects.

Tell your healthcare provider if you are taking or planning to take other prescription or nonprescription medicines, including vitamin and mineral supplements and herbal medicines.

What should I avoid while taking INTRON® A?

Avoid becoming pregnant while taking INTRON A. INTRON A alone and INTRON A taken in combination with REBETOL® may harm your unborn child or cause you to lose your baby (miscarry). If you or your partner becomes pregnant during treatment or during the 6 months after treatment with INTRON A/REBETOL combination therapy, immediately report the pregnancy to your healthcare provider. Your healthcare provider will make decisions about your treatment. Your healthcare provider should call 1-800-593-2214. Your healthcare provider will be asked to give follow-up information about the pregnancy.
Do not breast-feed your baby while taking INTRON A.
Avoid taking telbivudine (Tyzeka), a drug used to treat hepatitis B. People who take INTRON A or other alpha interferon products with telbivudine (Tyzeka) can have nerve problems such as continuing numbness, tingling, or burning sensation in the arms or legs, or problems walking.
What are the possible side effects of INTRON® A?

INTRON A may cause serious side effects including:

See "What is the most important information I should know about INTRON A?"
Other body organ problems. Certain symptoms like severe pain in the middle of your body, nausea, and vomiting may mean that your liver or pancreas is being damaged. A few patients have inflammation of the kidney. If you have severe stomach or back pains or a fever, you should call your healthcare provider right away.
Thyroid problems. Some patients develop changes in the function of their thyroid. Symptoms of thyroid changes include the inability to concentrate, feeling cold or hot all the time, a change in your weight and changes to your skin.
New or worsening autoimmune disease. Some patients taking INTRON A develop autoimmune diseases (a condition where the body's immune cells attack other cells or organs in the body), including rheumatoid arthritis, systemic lupus erythematosus, sarcoidosis, and psoriasis. In some patients who already have an autoimmune disease, the disease may worsen while on INTRON A.
Nerve problems. People who take INTRON A or other alpha interferon products with telbivudine (Tyzeka) can have nerve problems such as continuing numbness, tingling, or burning sensation in the arms or legs (peripheral neuropath