Pronunciation:

rye-ba-VYE-rin, in-ter-FEER-on AL-fa-2b

Dosage Forms:

• Tablet
• Solution
• Capsule

Uses of This Medicine:

Ribavirin and interferon alfa-2b combination is used to treat a viral liver infection known as hepatitis C infection. Ribavirin is taken by mouth and interferon alfa-2b is administered beneath the skin (subcutaneously). Ribavirin is used to treat virus infections. Interferons are substances naturally produced by cells in the body to help fight infections and tumors. Interferon alfa-2b is a synthetic (man-made) version of these substances. Interferon alfa-2b is used to treat a variety of tumors and viruses including the hepatitis C virus.

Ribavirin is available for oral administration. Interferon alfa-2b is available only as an injectable form.

This medicine was available only with your doctor's prescription.

Effective November 2004, Rebetron® was discontinued by the manufacturer.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children

Studies on this combination medicine have been done only in adult patients and there is no specific information comparing use of ribavirin and recombinant interferon alfa-2b combination in children younger than 18 years of age with use in other age group.

Older adults

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of ribavirin and interferon alfa-2b combination medicine in the elderly with use in other age group.

Pregnancy

	Pregnancy Category	Explanation
All Trimesters	X	Studies in animals or pregnant women have demonstrated positive evidence of fetal abnormalities. This drug should not be used in women who are or may become pregnant because the risk clearly outweighs any possible benefit.

Breast-feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Didanosine

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Abacavir
• Azathioprine
• Lamivudine
• Stavudine
• Zalcitabine
• Zidovudine

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Interferon Alfa-2b
• Ribavirin

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Anemia, severe or
• Autoimmune hepatitis or
• Bleeding disorders May worsen with ribavirin and/or recombinant interferon alfa-2b.

• Diabetes (increased sugar in blood) May increase the risk of developing eye problems.

• Heart disease May worsen with ribavirin and/or recombinant interferon alfa-2b.

• Hepatitis B or human immunodeficiency virus infection or
• Hepatitis C which has worsened or
• Hepatitis C which did not get better when treated with interferon alone Safety and effectiveness in these conditions are unknown.

• High blood pressure May increase the risk of developing eye problems.

• Kidney problems May worsen with ribavirin and/or recombinant interferon alfa-2b.

• Liver or other organ transplant Safety and effectiveness in these conditions are unknown.

• Lung problems May worsen with ribavirin and/or recombinant interferon alfa-2b.

• Mental problems (or history of) May result in depression, aggressive, violent, and suicidal behavior.

• Problem with immune system or
• Psoriasis (inflammatory skin problem) or
• Thyroid problem May worsen with ribavirin and/or recombinant interferon alfa-2b.

• Virus infections, other Use of ribavirin alone is not recommended.

Proper Use of This Medicine:

If you are injecting interferon alfa-2b yourself, use it exactly as directed by your doctor. Do not use more or less of it, and do not use it more often than your doctor ordered. The exact amount of medicine you need has been carefully worked out. Using too much will increase the risk of side effects, while using too little may not improve your condition.

Interferon alfa-2b often cause unusual tiredness. This effect is less likely to cause problems if you inject this medicine at bedtime. Also, your doctor may want you to drink extra fluids, especially during the early phase of treatment.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed dose

Call your doctor or pharmacist for instructions.

Storage

Store in the refrigerator. Do not freeze.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions While Using This Medicine:

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

This medicine may cause some people to become unusually tired or dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or if you are not alert.

This medicine may make you feel very sad, depressed, or very angry. Call your doctor if you feel you cannot cope or you feel like you want to hurt yourself or someone else.

Interferon alfa-2b commonly causes a flu-like reaction, with aching muscles, fever and chills, and headache. To prevent problems from your temperature going too high, your doctor may ask you to take medicine for pain and fever such as acetaminophen (e.g., Anacin 3, Tylenol) before each dose of interferon alfa-2b. You may also need to take it after a dose to bring your temperature down. Follow your doctor's instructions carefully about taking your temperature, and how much and when to take the medicine such as acetaminophen.

Women of childbearing potential should use two reliable forms of effective contraception.

Alpha interferon can lower the number of white blood cells in your blood temporarily, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If you can, avoid being close to people with infections. Check with your doctor immediatelyif you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or have painful or difficult urination.
• Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in urine or stools; or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

More common

Chest pain

mood changes

trouble breathing

unusual tiredness or weakness

Rare

Thoughts of suicide, attempts at suicide, changes in behavior

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Dizziness

fatigue

fever

headache

impaired concentration

impaired taste

influenza-like symptoms such as unusual tiredness or weakness

irritability

large swing in moods

loss of appetite

muscle or joint pain

nausea, vomiting, or upset stomach

nervousness

red, itchy skin

redness and warm feeling at the site of injection

shaking

stuffy nose

temporary thinning of hair

trouble sleeping

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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