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Interferon Alfa-2b (Injection)

Interferon Alfa-2b (in-ter-FEER-on AL-fa-2b)

Treats hepatitis B and C, lymphoma, malignant melanoma (skin cancer), genital warts, hairy cell leukemia, and Kaposi's sarcoma (in people with AIDS).

Brand Name(s):

Intron A

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You or your child should not receive this medicine if you have had an allergic reaction to interferon alfa-2b, or if you have a weakened immune system or serious liver problems that are getting worse (such as autoimmune hepatitis). Do not use this medicine together with ribavirin if you or your child have had an allergic reaction to ribavirin, if you are pregnant, if your female sexual partner is pregnant, or if you have a blood disorder (such as sickle cell anemia or thalassemia major) or severe kidney disease.

How to Use This Medicine:


  • Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given as a shot under your skin, into a muscle, or into a vein.
  • A nurse or other health provider will give you this medicine.
  • You may be taught how to give your medicine at home. Make sure you understand all instructions before giving yourself an injection. Do not use more medicine or use it more often than your doctor tells you to.
  • Use only the brand of medicine your doctor prescribed. Other brands may not work the same way.
  • This medicine comes in a vial (glass container) or prefilled syringe. You might not use all of the medicine in each vial or prefilled syringe. Use each vial or syringe only one time. Do not save an open vial or syringe. If the medicine in the vial or syringe has changed color, or if you see particles in it, do not use it.
  • The solution should be allowed to come to room temperature before using it.
  • You will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas.
  • Use a new needle and syringe each time you inject your medicine.
  • Drink extra fluids so you will urinate more often and help prevent kidney problems.
  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.

If a dose is missed:

  • You must use this medicine on a fixed schedule. Call your doctor or pharmacist if you miss a dose.

How to Store and Dispose of This Medicine:

  • If you store this medicine at home, keep it in the refrigerator. Do not freeze.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any leftover medicine, containers, and other supplies. You will also need to throw away old medicine after the expiration date has passed.
  • Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you are also using telbivudine (Tyzeka®), theophylline (Theo-Dur®), zidovudine (Retrovir®), or medicines that weaken the immune system (such as steroids, cancer medicines, or radiation).
  • Tell your doctor if you drink alcohol or if you are using any medicine that makes you sleepy, such as allergy medicine or narcotic pain medicine.
  • This medicine may interfere with vaccines. Ask your doctor before you get a flu shot or any other vaccines.

Warnings While Using This Medicine:

  • This medicine may cause birth defects if either partner is using it during conception or pregnancy. Tell your doctor right away if you or your partner becomes pregnant.
  • To make sure you are not pregnant, your doctor may ask you to have a pregnancy test before you start using this medicine together with ribavirin. You must have a negative pregnancy test before you will be allowed to use these medicines. You should test for pregnancy every month while you are using these medicines, and for 6 months after you stop.
  • Use two forms of birth control together to keep from getting pregnant while you are using this medicine together with ribavirin. Keep using the birth control even if the medicines are temporarily stopped. You must use two forms of birth control for at least 6 months after your treatment ends. This is very important for both men and women. Men who use this medicine together with ribavirin might need to use a condom with a spermicide, such as nonoxynol-9 as one form of birth control.
  • Make sure your doctor knows if you or your child are breastfeeding, have kidney disease, liver disease, heart or blood vessel disease, chest pains, heart rhythm problems (such as arrhythmias), low blood pressure, blood clots, or a history of a stroke or heart attack. Tell your doctor if you or your child have bleeding problems, bone marrow problems, brain disease (such as encephalopathy), bowel problem (such as colitis), diabetes, eye or vision problems, breathing problems or lung disease (such as COPD), seizures, thyroid problems, a weakened immune system, or an autoimmune disorder (such as lupus, psoriasis, rheumatoid arthritis, or sarcoidosis).
  • Make sure your doctor knows if you or your child have high triglycerides or fats in the blood, or a history of a head injury or an organ transplant. Tell your doctor if you or your child have a history of depression or mental illness, or if you have been addicted to drugs or alcohol.
  • This medicine may make you bleed, bruise, or get infections more easily. Take precautions to prevent illness and injury. Avoid people who are ill, and wash your hands often. Brush and floss your teeth gently, do not play rough sports, and be careful with sharp objects.
  • You or your child might have mood or behavior changes with this medicine, such as feeling sad or hopeless, or getting upset easily. You could feel nervous or hostile. Some people become violent and want to hurt themselves or others. You might have too much energy, or see or hear unusual things. Stop using this medicine and call your doctor right away if you or your child have any strange feelings, thoughts, or behaviors.
  • The powder form of this medicine contains albumin, which comes from human blood. Some human blood products have transmitted certain viruses to people who have received them. The risk of getting a virus from medicines made of human blood has been greatly reduced in recent years. This is the result of required testing of human donors for certain viruses, and testing during manufacture of these medicines. Although the risk is low, talk with your doctor if you have concerns.
  • Check with your doctor right away if you or your child have burning, numbness, tingling, or painful sensations in the arms, hands, legs, or feet. These could be symptoms of a condition called peripheral neuropathy.
  • This medicine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you or your child have a rash; itching; hoarseness; trouble breathing; trouble swallowing; or any swelling of your hands, face, or mouth while you are using this medicine.
  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
  • Check with your doctor if blurred vision, decreased vision, or any other change in vision occurs with this medicine. Your doctor may want you or your child to have your eyes checked by an ophthalmologist (eye doctor).
  • Stop using this medicine and check with your doctor right away if you or your child have pain or tenderness in the upper stomach; pale stools; dark urine; loss of appetite; nausea; unusual tiredness or weakness; or yellow eyes or skin. These could be symptoms of a serious liver problem.
  • This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.
  • Using this medicine together with ribavirin may cause teeth and gum problems. These medicines may cause a dry mouth, which can damage your teeth and gums if you take the medicines for a long time. To help prevent this, carefully brush your teeth or your child's teeth at least two times a day and have regular visits with your dentist.
  • Some patients who use this medicine with ribavirin have vomiting. If you or your child vomit during or after your treatment, rinse your mouth out with water. This may also help prevent damage to your teeth and gums.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Changes in vision or eye pain.
  • Chest pain, shortness of breath, or coughing up blood.
  • Dark-colored urine or pale stools.
  • Depressed mood or thoughts of hurting yourself or others.
  • Diarrhea that may contain blood.
  • Fast, slow, pounding, or uneven heartbeat.
  • Fever, chills, cough, sore throat, or stuffy or runny nose.
  • Lightheadedness, dizziness, or fainting.
  • Muscle pain, weakness, or cramps.
  • Nausea, vomiting, loss of appetite, or pain in the upper stomach.
  • Numbness, tingling, or a cold feeling in your hands or feet.
  • Red or black stools.
  • Severe stomach pain.
  • Unusual bleeding or bruising.
  • Unusual tiredness or weakness.
  • Yellowing of your skin or the whites of your eyes.

If you notice these less serious side effects, talk with your doctor:

  • Anxiety, nervousness, or trouble sleeping.
  • Hair loss.
  • Headache.
  • Mild nausea, diarrhea, or changes in taste.
  • Redness, swelling, or itching where the injection was given.
  • Skin rash or itching.
  • Sweating or dry mouth.

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Last Updated: 4/4/2014

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