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interferon alfa-2b

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

What is interferon alfa-2b?

Interferon alfa-2b is made from human proteins. Interferons help your body's immune system respond to bacteria, viruses, cancer, or other invading substances.

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 in adults, and to treat chronic hepatitis B in children who are at least 1 year old.

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

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

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

Do not use interferon alfa-2b together with ribavirin if you are pregnant, or if you are a man and your sexual partner is pregnant. Prevent pregnancy while using this medicine, and for at least 6 months after you stop using it.

Interferon alfa-2b can cause life-threatening infections, autoimmune disorders, serious mood or behavior problems, or a stroke.

Call your doctor at once if you have: unusual changes in mood or behavior, chest pain, trouble breathing, sudden numbness or weakness, or signs of infection (fever, chills, cough with mucus, or burning when you urinate).

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

You should not use interferon alfa-2b if you are allergic to it, 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;

  • an allergy to interferons or ribavirin;

  • if you are pregnant; or

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

To make sure interferon alfa-2b is safe for you, tell your doctor if you have:

  • cirrhosis or liver problems other than hepatitis;

  • a history of depression, mental illness, addiction to drugs or alcohol, or thoughts about hurting yourself or someone else;

  • heart disease, high blood pressure, or a history of heart attack, blood clot, or stroke;

  • a history of low blood cell counts;

  • asthma or other breathing disorder;

  • diabetes, or a thyroid disorder;

  • a weak immune system;

  • colitis or other intestinal disorder;

  • kidney disease; or

  • if you have recently received an organ transplant.

This medicine can harm an unborn baby or cause a miscarriage. Do not use interferon alfa-2b if you are pregnant, especially if you also take ribavirin (Rebetol). The combination of these medicines 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. You should not breast-feed while using this medicine.

Interferon alfa-2b with ribavirin can affect growth in children. Talk with your doctor if you think your child is not growing at a normal rate while using this medicine.

The powder form of interferon alfa-2b is made from human plasma (part of the blood) which may contain viruses and other infectious agents. Donated plasma is tested and treated to reduce the risk of it containing infectious agents, but there is still a small possibility it could transmit disease. Talk with your doctor about the risks and benefits of using this medication.

How is interferon alfa-2b given?

Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended. If your doctor changes your brand, strength, or type of interferon, your dosage needs may change. Do not change your doses or medication schedule without your doctor's advice.

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. You may be shown how to use the medicine at home. Do not give yourself this medicine if you do not understand how to use the injection and properly dispose of needles, IV tubing, and other items used.

The powder form of interferon alfa-2b 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 medicine. Do not shake the medication bottle. Do not use if the medicine has changed colors or has particles in it. Call your pharmacist for new medicine.

Use a disposable needle and syringe only once. Follow any state or local laws about throwing away used needles and syringes. Use a puncture-proof "sharps" disposal container (ask your pharmacist where to get one and how to throw it away). Keep this container out of the reach of children and pets.

Interferon alfa-2b can lower blood cells that help your body fight infections and help your blood to clot. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Your blood may need to be tested often. Your heart, lung, and liver function may also need to be checked.

Store this medicine in the refrigerator. Do not freeze. After mixing the powder with a diluent, store this mixture in the refrigerator and use it within 24 hours.

Each single-use vial (bottle) of this medicine is for one use only. Throw away after one use, even if there is still some medicine left in it after injecting your dose. Throw away any leftover medicine in a multi-dose vial 30 days after the first use.

What happens if I miss a dose?

Use the medicine as soon as you remember the missed dose, then go back to your regular schedule on the day your next dose is due. If several days pass after you miss a dose, call your doctor for instructions. Do not use extra medicine to make up a missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

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

Using this medicine will not prevent your disease from spreading. Follow your doctor's instructions about how to prevent passing the disease to another person.

Avoid drinking alcohol. It may increase your risk of liver damage.

This medicine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Interferon alfa-2b side effects

Get emergency medical help if you have signs of an allergic reaction: hives, skin rash with blistering and peeling; anxiety, chest pain, difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • vision changes;

  • severe stomach pain with bloody diarrhea;

  • pale skin, easy bruising or bleeding (nosebleeds, bleeding gums);

  • sudden chest pain or discomfort, wheezing, dry cough, feeling short of breath;

  • depression, irritability, confusion, thoughts about hurting yourself or others, or falling back into a previous pattern of drug addiction;

  • heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;

  • signs of a stroke--sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with balance;

  • new or worsened autoimmune disorders--skin problems, joint pain or swelling, cold feeling or pale appearance in your fingers or toes;

  • signs of infection--fever, chills, body aches, cough with yellow or pink mucus, pain or burning when you urinate;

  • liver problems--stomach pain or swelling, loss of appetite, severe drowsiness, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

  • pancreas problems--severe pain in your upper stomach spreading to your back, vomiting;

  • thyroid problems--weight changes, skin changes, feeling hot or cold all the time; or

  • high blood sugar--increased thirst or urination, hunger, fruity breath odor, tiredness, weight loss.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects may include:

  • flu-like symptoms, feeling tired;

  • nausea, loss of appetite, weight loss;

  • thinning hair; or

  • swelling, redness, or itching where an injection was given.

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.

See also: Side effects (in more detail)

Interferon alfa-2b dosing information

Usual Adult Dose for Hairy Cell Leukemia:

2 million international units/m2 IM or subcutaneously 3 times a week
Duration of therapy: Up to 6 months

Comments:
-This drug should be administered subcutaneously (and not IM) in patients with platelet counts below 50,000/mm3.
-Responding patients may benefit from continued treatment. A minimum effective dose has not yet been established.

Usual Adult Dose for Malignant Melanoma:

Induction phase: 20 million international units/m2/day IV (via 20-minute infusion), 5 consecutive days per week
Duration of therapy: 4 weeks

Maintenance phase: 10 million international units/m2 subcutaneously 3 times a week
Duration of therapy: 48 weeks

Comments: Differential WBC count and liver function tests should be monitored weekly during induction phase and monthly during maintenance phase of therapy.

Use: As adjuvant to surgical treatment in malignant melanoma patients free of disease but at high risk for systemic recurrence, within 56 days of surgery

Usual Adult Dose for Follicular Lymphoma:

5 million international units subcutaneously 3 times a week
Duration of therapy: Up to 18 months

Comments:
-This drug should be used in conjunction with anthracycline-containing chemotherapy regimen and after completion of the chemotherapy regimen.
-Doses of myelosuppressive drugs were reduced by 25% from a full-dose CHOP regimen (cyclophosphamide, doxorubicin, vincristine, prednisone), and cycle length increased by 33% (e.g., from 21 to 28 days) when alpha interferon was added to the regimen.
-Efficacy in patients with low-grade, low-tumor burden follicular non-Hodgkin's lymphoma has not been established.

Use: In conjunction with anthracycline-containing combination chemotherapy, for the initial treatment of clinically aggressive follicular non-Hodgkin's lymphoma

Usual Adult Dose for Condylomata Acuminata:

1 million international units injected into each lesion (up to 5 lesions in a single course) 3 times a week on alternate days
Duration of therapy: 3 weeks

Comments:
-An additional course may be administered at 12 to 16 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 (approximately 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 as this area is below the base of the lesion.
-This drug should not be injected too superficially since leakage may occur, infiltrating only the keratinized layer and not the dermal core.
-Should consider monitoring leukocytes and serum AST levels

Use: For intralesional treatment of selected patients with condylomata acuminata involving external surfaces of genital and perianal areas

Usual Adult Dose for Kaposi's Sarcoma:

30 million international units/m2 IM or subcutaneously 3 times a week
Duration of therapy: Until disease progression or maximal response achieved after 16 weeks of therapy

Comments:
-Dose reduction is often required.
-Greater likelihood of response to therapy in patients without systemic symptoms, with limited lymphadenopathy, and with relatively intact immune system (indicated by total CD4 count).

Use: For the treatment of selected patients with AIDS-related Kaposi's sarcoma

Usual Adult Dose for Chronic Hepatitis C:

3 million international units IM or subcutaneously 3 times a week

Duration of Therapy:
Combination therapy with ribavirin:
-Interferon alpha-naive patients: 24 to 48 weeks
-Retreatment in patients relapsing after nonpegylated interferon monotherapy: 24 weeks

Monotherapy: 72 to 96 weeks

Comments:
-In patients tolerating therapy with ALT normalization at 16 weeks of treatment, monotherapy should be extended to 18 to 24 months to improve sustained response rate.
-Patients whose ALTs have not normalized or high levels of HCV-RNA persist after 16 weeks of monotherapy rarely achieve sustained response with extended treatment; should consider discontinuing therapy in such patients
-When used with ribavirin, patients with renal dysfunction and/or those older than 50 years should be carefully monitored for anemia.
-The manufacturer product information for ribavirin capsules/oral solution should be consulted.
-Duration of combination therapy should be individualized for interferon alpha-naive patients depending on baseline disease characteristics, response to therapy, and tolerability of regimen.
-Virologic response should be assessed after 24 weeks of combination therapy; discontinuation of combination therapy should be considered in any interferon alpha-naive patient whose HCV-RNA levels remain detectable after 24 weeks of therapy.
-Studies established that this drug can have clinically meaningful effects on this disease, shown by serum ALT normalization and reduced liver necrosis and degeneration.
-Liver biopsy is recommended to establish diagnosis of chronic hepatitis; patients should be tested for antibody to HCV.
-Confirmation that the patient has compensated liver disease is recommended before starting this drug.
-The following should be considered before therapy (patient entrance criteria for compensated liver disease in clinical studies): No history of hepatic encephalopathy, variceal bleeding, ascites, or other clinical signs of decompensation; bilirubin up to 2 mg/dL; albumin stable and within normal limits; prothrombin time prolonged less than 3 seconds; WBC at least 3000/mm3; platelets at least 70,000/mm3; serum creatinine normal/near normal
-Before starting therapy, CBC and platelet counts should be evaluated to establish baselines (for monitoring potential toxicity); these tests should be repeated at 1 and 2 weeks after starting therapy, and monthly thereafter.
-Serum ALT should be measured about every 3 months (to assess response to therapy).
-Thyroid-stimulating hormone (TSH) should be within normal limits when starting therapy; TSH testing should be repeated at 3 and 6 months.

Uses: For the treatment of chronic hepatitis C in patients with compensated liver disease who have history of blood or blood-product exposure and/or are HCV antibody positive; in combination with ribavirin, for the treatment of chronic hepatitis C in patients with compensated liver disease previously untreated with alpha interferon therapy and in patients who relapsed after alpha interferon therapy

Usual Adult Dose for Chronic Hepatitis B:

30 million to 35 million international units per week IM or subcutaneously, either as 5 million international units once a day or as 10 million international units 3 times a week
Duration of therapy: 16 weeks

Comments:
-Therapy may be appropriate for patients who have been serum HBsAg positive for at least 6 months and have proof of HBV replication (serum HBeAg positive) with elevated serum ALT; studies in such patients showed virologic remission (loss of serum HBeAg) and normalization of serum aminotransferases with this drug; therapy lead to loss of serum HBsAg in some responding patients.
-Liver biopsy is recommended before starting therapy to confirm presence of chronic hepatitis and the extent of liver damage.
-Confirmation that the patient has compensated liver disease is recommended.
-The following should be considered before therapy (patient entrance criteria for compensated liver disease in clinical studies): No history of hepatic encephalopathy, variceal bleeding, ascites, or other clinical signs of decompensation; bilirubin normal; albumin stable and within normal limits; prothrombin time prolonged less than 3 seconds; WBC at least 4000/mm3; platelets at least 100,000/mm3
-Before starting therapy, CBC and platelet counts should be evaluated to establish baselines (for monitoring potential toxicity).
-CBC, platelet counts, liver function tests including serum ALT, albumin, and bilirubin should be assessed at treatment weeks 1, 2, 4, 8, 12, and 16.
-Transient increase in ALT (at least 2 times baseline value) can occur during therapy; therapy should generally continue unless signs/symptoms of liver failure; clinical symptomatology and liver function tests including ALT, prothrombin time, alkaline phosphatase, albumin, and bilirubin should be monitored about every 2 weeks during ALT flare.
-HBeAg, HBsAg, and ALT should be measured at the end of therapy and 3 and 6 months post-therapy.

Use: For the treatment of chronic hepatitis B in patients with compensated liver disease

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

Case Report - Conjunctival MALT Lymphoma
1 million international units via intralesional injection 3 times a week for 12 doses (total)

Usual Pediatric Dose for Chronic Hepatitis C:

3 years or older:
25 to 61 kg: 3 million international units/m2 subcutaneously 3 times a week
Greater than 61 kg: 3 million international units subcutaneously 3 times a week

Duration of therapy:
-Genotype 1: 48 weeks
-Genotypes 2 and 3: 24 weeks

Comments:
-For use in combination with ribavirin (capsules or oral solution)
-The manufacturer product information for ribavirin capsules/oral solution should be consulted.
-Virologic response should be assessed after 24 weeks of therapy.
-Discontinuation of therapy should be considered in any patient whose HCV-RNA levels remain detectable after 24 weeks of therapy.

Use: In combination with ribavirin, for the treatment of chronic hepatitis C in patients with compensated liver disease previously untreated with alpha interferon therapy

Usual Pediatric Dose for Chronic Hepatitis B:

1 year or older:
First week: 3 million international units/m2 subcutaneously 3 times a week
Subsequent weeks: Dose escalation to 6 million international units/m2 subcutaneously 3 times a week
Maximum dose: 10 million international units 3 times a week
Duration of therapy: 16 to 24 weeks (total)

Comments:
-Therapy may be appropriate for patients who have been serum HBsAg positive for at least 6 months and have proof of HBV replication (serum HBeAg positive) with elevated serum ALT; studies in such patients showed virologic remission (loss of serum HBeAg) and normalization of serum aminotransferases with this drug; therapy lead to loss of serum HBsAg in some responding patients.
-Liver biopsy is recommended before starting therapy to confirm presence of chronic hepatitis and the extent of liver damage.
-Confirmation that the patient has compensated liver disease is recommended.
-The following should be considered before therapy (patient entrance criteria for compensated liver disease in clinical studies): No history of hepatic encephalopathy, variceal bleeding, ascites, or other clinical signs of decompensation; bilirubin normal; albumin stable and within normal limits; prothrombin time prolonged up to 2 seconds; WBC at least 4000/mm3; platelets at least 150,000/mm3
-Before starting therapy, CBC and platelet counts should be evaluated to establish baselines (for monitoring potential toxicity).
-CBC, platelet counts, liver function tests including serum ALT, albumin, and bilirubin should be assessed at treatment weeks 1, 2, 4, 8, 12, and 16.
-Transient increase in ALT (at least 2 times baseline value) can occur during therapy; therapy should generally continue unless signs/symptoms of liver failure; clinical symptomatology and liver function tests including ALT, prothrombin time, alkaline phosphatase, albumin, and bilirubin should be monitored about every 2 weeks during ALT flare.
-HBeAg, HBsAg, and ALT should be measured at the end of therapy and 3 and 6 months post-therapy.

Use: For the treatment of chronic hepatitis B in patients with compensated liver disease

Usual Pediatric Dose for Angioblastoma:

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

Usual Pediatric Dose for Idiopathic (Immune) Thrombocytopenic Purpura:

Study (n=14)
Greater than 4 years old: 3 million international units/m2 subcutaneously 3 times a week for 4 weeks

Comments: In patients with no increase or partial increase in platelets (less than 150 x 10[9]/L), therapy should continue for another 8 weeks.

What other drugs will affect interferon alfa-2b?

Tell your doctor about all your current medicines and any you start or stop using, especially:

  • telbivudine;

  • theophylline; or

  • zidovudine.

This list is not complete. Other drugs may interact with interferon alfa-2b, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Where can I get more information?

  • Your doctor or 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 others, and use this medication only for the indication prescribed.
  • Disclaimer: 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 1996-2012 Cerner Multum, Inc. Version: 9.02. Revision Date: 2015-12-06, 10:27:00 AM.

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