Interferon alfa-2b

Generic Name: interferon alfa-2b ( IN ter FEAR on AL fa 2b)Brand Names: Intron A

What is interferon alfa-2b?

Interferon alfa-2b is made from human proteins. Interferons help the body fight viral infections.

Interferon alfa-2b is used to treat hairy cell leukemia, malignant melanoma, follicular lymphoma, Kaposi's sarcoma caused by AIDS, and certain types of genital warts. Interferon alfa-2b is also used to treat chronic hepatitis B or C.

Interferon alfa-2b is often used in combination with another drug called ribavirin (Rebetol). Some of the information in this medication guide applies to the use of both drugs in this combination.

Interferon alfa-2b may also be used for other purposes not listed in this medication guide.

What is the most important information I should know about interferon alfa-2b?

Interferon alfa-2b is often used in combination with another drug called ribavirin (Rebetol). Some of the information in this medication guide applies to the use of both drugs in this combination. Interferon alfa-2b may be harmful to an unborn baby, or may cause a miscarriage. Do not use interferon alfa-2b if you are pregnant, especially if you also take ribavirin (Rebetol). Use 2 forms of effective birth control while you are using this drug combination and for at least 6 months after your treatment ends.

If a man fathers a child while using interferon alfa-2b and ribavirin, the baby may have birth defects. Use a condom to prevent pregnancy during your treatment and for at least 6 months after you stop using this drug combination..

You should not use interferon alfa-2b if you are allergic to interferons, or if you have autoimmune hepatitis, or severe liver problems from causes other than hepatitis B or C.

You should not use the combination of interferon alfa-2b and ribavirin if you have an allergy to either drug, or if you have severe kidney disease, a blood cell disorder, if you are pregnant, or if you are a man and your female sex partner is pregnant.

What should I discuss with my healthcare provider before using interferon alfa-2b?

You should not use this medication if you are allergic to interferons, or if you have autoimmune hepatitis, or severe liver problems from causes other than hepatitis B or C.

You should not use the combination of interferon alfa-2b and ribavirin if you have:

  • severe kidney disease;

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

  • if you are allergic to interferons or ribavirin;

  • if you are pregnant; or

  • if you are a man and your female sex partner is pregnant.

If you have any of these other conditions, you may need a dose adjustment or special tests to safely use interferon alfa-2b:

  • diabetes;

  • cancer;

  • bone marrow suppression;

  • a bleeding disorder;

  • a thyroid disorder;

  • breathing problems;

  • a history of depression, mental illness, suicidal thoughts, or drug or alcohol addiction;

  • heart disease, a heart rhythm disorder, or history of a heart attack or blood clots;

  • an autoimmune disorder such as psoriasis, arthritis, or lupus;

  • colitis or other intestinal disorder; or

  • if you have recently received an organ transplant.

This medication may be harmful to an unborn baby, or may cause a miscarriage. Do not use interferon alfa-2b if you are pregnant, especially if you also take ribavirin (Rebetol). The combination of interferon alfa-2b and ribavirin can cause birth defects. Tell your doctor right away if you become pregnant during treatment. Use 2 forms of effective birth control while you are using this drug combination and for at least 6 months after your treatment ends.

If a man fathers a child while using interferon alfa-2b and ribavirin, the baby may have birth defects. Use a condom to prevent pregnancy during your treatment. Continue using condoms for at least 6 months after you stop using this drug combination..

It is not known whether interferon alfa-2b passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

The powder form of interferon alfa-2b contains albumin, but the solution (liquid) form does not. Albumin comes from human plasma (part of the blood) and may contain viruses and other infectious agents that can cause disease. Although donated human plasma is screened, tested, and treated to reduce the risk of it containing anything that could cause disease, there is still a small possibility it could transmit disease. Talk with your doctor about the risks and benefits of using this medication.

How should I use interferon alfa-2b?

Interferon alfa-2b is given as an injection into a muscle, under the skin, or directly into a genital wart. The medicine may also be given through a needle placed into a vein.

Your doctor, nurse, or other healthcare provider will give you this injection. You may be shown how to inject your medicine at home. Do not self-inject this medicine if you do not fully understand how to give the injection and properly dispose of used needles and syringes.

Use each disposable needle only one time. Throw away used needles in a puncture-proof container (ask your pharmacist where you can get one and how to dispose of it). Keep this container out of the reach of children and pets.

Do not shake the medication vial (bottle). Vigorous shaking can ruin the medicine. Do not draw your dose into a syringe or IV bag until you are ready to give yourself an injection.

Interferon alfa-2b powder medicine must be mixed with a liquid (diluent) before using it. If you are using the injections at home, be sure you understand how to properly mix and store the medication. Do not use the mixture if it is not clear or light yellow, or if it has any particles in it. Throw it away and mix another dose.

The single-dose vial of interferon alfa-2b is for one use only. Throw the vial away after measuring your dose, even if there is still some medicine in it. Do not save it for later use. Not all brands, forms, and strengths of interferon alfa-2b are used to treat the same medical conditions. Always check your refills to make sure you have received the correct brand and type of medicine prescribed by your doctor. Ask the pharmacist if you have any questions about the medicine you receive at the pharmacy.

To be sure this medication is not causing harmful effects, your blood will need to be tested on a regular basis. Do not miss any scheduled appointments.

Store interferon alfa-2b in the refrigerator and do not allow it to freeze. After mixing the powder medicine with a diluent, you may store the mixture in the refrigerator but you must use it within 24 hours.

To reduce or prevent certain side effects, your doctor may recommend you take acetaminophen (Tylenol) at the time of your interferon alfa-2b injection. Follow your doctor's instructions about the correct dose.

What happens if I miss a dose?

Use the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine. Symptoms of an interferon alfa-2b overdose are not known.

What should I avoid while using interferon alfa-2b?

If you are being treated for hepatitis or genital warts, avoid having unprotected sex or sharing needles, razors, or toothbrushes. Taking this medication will not prevent you from passing hepatitis or genital warts to other people. Talk with your doctor about safe methods of preventing transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person. Avoid drinking alcohol if you are also taking acetaminophen (Tylenol) while using interferon alfa-2b.

Interferon alfa-2b side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using interferon alfa-2b and call your doctor at once if you have a serious side effect such as:
  • severe depression, aggressive behavior, or thoughts of hurting yourself or others;

  • fast, slow, or uneven heart rate, feeling like you might pass out;

  • fever, chills, body aches, flu symptoms, pale skin, easy bruising or bleeding, unusual weakness;

  • vision or hearing problems;

  • urinating less than usual or not at all;

  • severe stomach pain, jaundice (yellowing of the skin or eyes);

  • cough with yellow or green mucus, feeling short of breath;

  • chest pain, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling;

  • sudden numbness or weakness, headache, confusion, or problems with speech or balance; or

  • a severe blistering, peeling, and red skin rash.

Less serious side effects may include:

  • dizziness, spinning sensation;

  • muscle pain, tired feeling;

  • nausea, vomiting, diarrhea, loss of appetite;

  • dry mouth, dry cough, sore throat, hair loss;

  • mild itching or skin rash; or

  • burning, bleeding, pain, itching, or skin changes where the medicine was injected.

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.

Interferon alfa-2b Dosing Information

Usual Adult Dose for Hairy Cell Leukemia:

2 million intl units/m2 IM or subcutaneously three times a week for up to six months. Higher doses are not recommended. Responding patients may benefit from continued treatment. A minimum effective dose has not yet been established.

Usual Adult Dose for Malignant Melanoma:

Induction Treatment:20 million intl units/m2 by IV infusion for five consecutive days per week for 4 weeksMaintenance Treatment:10 million intl units/m2 subcutaneously three times per week for 48 weeks

Usual Adult Dose for Follicular Lymphoma:

5 million intl units subcutaneously three times a week for up to 18 months in conjunction with an anthracycline-containing chemotherapy regimen. The dosing regimen should be modified for evidence of serious toxicity. The following dose modification guidelines for hematologic toxicity were used in the clinical trial: The chemotherapy regimen was delayed if either the neutrophil count was less than 1500/mm3 or the platelet count was less than 75,000/mm3. Administration was temporarily interrupted for a neutrophil count less than 1000/mm3 or a platelet count less than 50,000/mm3, or reduced by 50% to 2.5 million intl units times a week for a neutrophil count greater than 1000/mm3 but less than 1500/mm3. Reinstitution of the initial dose of 5 million intl units times a week was tolerated after resolution of hematologic toxicity (greater than or equal to 1500/mm3). (In published reports, the doses of myelosuppressive drugs were reduced by 25% from those utilized in a full-dose CHOP regimen, and cycle length increased by 33% (e.g., from 21 to 28 days) when an alfa interferon was added to the regimen.)

Usual Adult Dose for Condylomata Acuminata:

1 million units injected into each lesion three times per week on alternate days, for three weeks. The injection should be administered intralesionally using a tuberculin or similar syringe and a 25 to 30 gauge needle. The needle should be directed at the center of the base of the wart and at an angle almost parallel to the plane of the skin (approximating that in the commonly used PPD test). This will deliver the interferon to the dermal core of the lesion, infiltrating the lesion and causing a small wheal. Care should be taken not to go beneath the lesion too deeply; subcutaneous injection should be avoided, since this area is below the base of the lesion. Do not inject too superficially since this will result in possible leakage, infiltrating only the keratinized layer, and not the dermal core. As many as five lesions can be treated at one time. To reduce side effects, injections may be administered in the evening, when possible. Additionally, acetaminophen may be administered at the time of injection to alleviate some of the potential side effects. The maximum response usually occurs four to eight weeks after initiation of the first treatment course. If results are not satisfactory twelve to sixteen weeks after the initial treatment course has concluded, then a second course of treatment using the above dosage schedule may be instituted providing that clinical symptoms and signs, or changes in laboratory parameters (liver function tests, WBC, and platelets) do not preclude such a course of action. Patients with six to ten condylomata may receive a second (sequential) course of treatment at the above dosage schedule to treat up to five additional condylomata per course of treatment. Patients with greater than ten condylomata may receive additional sequences depending on how large a number of condylomata are present.

Usual Adult Dose for Kaposi's Sarcoma:

For use in the treatment of AIDS-Related Kaposi's Sarcoma:30 million intl units/m2 subcutaneously or IM three times a weekThe dosage regimen should be maintained unless the disease progresses rapidly or severe intolerance is manifested. When patients initiate therapy at 30 million intl units/m2 three times a week, the average dose tolerated at the end of twelve weeks of therapy is 110 million intl units/week and 75 million intl units/week at the end of 24 weeks of therapy. When disease stabilization or a response to treatment occurs, treatment should continue until there is no further evidence of tumor or until discontinuation is required by evidence of a severe opportunistic infection or adverse effect.

Usual Adult Dose for Chronic Hepatitis C:

3 million intl units subcutaneously or IM three times a weekIn patients tolerating therapy with normalization of ALT at sixteen weeks of treatment, therapy should be extended to eighteen to twenty four months (72 to 96 weeks) at 3 million intl units three times a week to improve the sustained response rate. Patients who do not normalize their ALTs after sixteen weeks of therapy rarely achieve a sustained response with extension of treatment. Consideration should be given to discontinuing these patients from therapy.

Usual Adult Dose for Chronic Hepatitis B:

30 to 35 million intl units per week subcutaneously or IM, either as 5 million intl units daily or as 10 million intl units three times a week for 16 weeks.For patients with decreases in white blood cell, granulocyte, or platelet counts, the following guidelines for dose modification should be followed: For a decrease in white blood cell count to less than 1.5(9)/L, a decrease in granulocyte count to less than .75(9)/L, or a decrease in platelet count to 50(9)/L, the dose should be reduced by 50%.For a decrease in white blood cell count to less than 1(9)/L, a decrease in granulocyte count to less than .5(9)/L, or a decrease in platelet count to 25(9)/L, the dose should be permanently discontinued.Therapy was resumed at up to 100% of the initial dose when white blood cell, granulocyte, and/or platelet counts returned to normal or baseline values. At the discretion of the physician, the patient may self-administer the medication.

Usual Adult Dose for Conjunctival Mucosa-Associated Lymphoid Tissue Lymphoma:

Case Report - Conjunctival MALT Lymphoma1 million intl units intralesional injection three times a week for a total of 12 doses.

Usual Pediatric Dose for Chronic Hepatitis B:

3 million intl units/m2 subcutaneously three times a week for the first week of therapy followed by dose escalation to 6 million intl units/m2 three times a week (maximum of 10 million intl units three times a week) for a total therapy duration of 16 to 24 weeks.For patients with decreases in white blood cell, granulocyte, or platelet counts, the following guidelines for dose modification exists: For a decrease in white blood cell count to less than 1.5(9)/L, a decrease in granulocyte count to less than .75(9)/L, or a decrease in platelet count to 50(9)/L, the dose should be reduced by 50%.For a decrease in white blood cell count to less than 1(9)/L, a decrease in granulocyte count to less than .5(9)/L, or a decrease in platelet count to 25(9)/L, the dose should be permanently discontinued.Therapy was resumed at up to 100% of the initial dose when white blood cell, granulocyte, and/or platelet counts returned to normal or baseline values.

Usual Pediatric Dose for Angioblastoma:

Case Reports - Giant Cell Angioblastoma Greater than 4 months: 3 million intl units/m2 subcutaneously daily

Usual Pediatric Dose for Idiopathic (Immune) Thrombocytopenic Purpura:

Study (n=14)Greater than 4 years old: 3 million intl units/m2 three times a week subcutaneously for 4 weeks. In patients with no increase or partial increase in platelets (less than 150 x 10(9)/L) continue therapy for another 8 weeks.

What other drugs will affect interferon alfa-2b?

Tell your doctor about all other medications you use, especially:

  • zidovudine (Retrovir);

  • theophylline (Elixophyllin, Respbid, Slo-Bid, Theobid, Theo-Dur, Theochron, Theolair, and others); or

  • medicines used to prevent organ transplant rejection, such as sirolimus (Rapamune) or tacrolimus (Prograf).

This list is not complete and there may be other drugs that can interact with interferon alfa-2b. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Where can I get more information?

  • Your pharmacist can provide more information about interferon alfa-2b.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with other, and use this medication only for the indication prescribed.
  • Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2006 Cerner Multum, Inc. Version: 8.01. Revision Date: 10/26/2009 3:12:13 PM.
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