Description: Interferon alfa-2a has antiviral, antitumour and immunomodulatory activity that inhibits replication of a wide range of RNA and DNA viruses. Interferon alfa-2a suppresses antibody formation through an effect on B-lymphocytes and inhibits onset of delayed hypersensitivity.

This medication is used to treat various cancers (e.g., leukemia, melanoma, AIDS-related Kaposi’s sarcoma) and virus infections (e.g., chronic hepatitis B, chronic hepatitis C, condylomata acuminata). It is thought to work by affecting cell function/growth and the body’s natural defenses (immune system) in many ways. Adding more interferon may help your body fight off cancer or virus infections.

How to use interferon alfa-2a subcutaneous

Read the Medication Guide available from your pharmacist before you start using this drug and each time you get a refill. Learn all preparation and usage instructions given by the manufacturer. If you have any questions, consult your doctor or pharmacist.

This medication is given by injection into a muscle or under the skin as directed by your doctor. Rotate the injection site each time you inject this medication to prevent soreness. It may also be given by injection into a vein or directly into a lesion, usually by a health care professional.

If you are giving this medication to yourself at home, learn all preparation and usage instructions from your health care professional. Do not shake the medication container (vial or syringe). Doing so may decrease the effectiveness of the drug. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely. Never reuse single-use syringes or needles. It is okay to reuse the multidose pen. It is best used in the evening before bedtime to reduce side effects.

Drink plenty of fluids while using this medication unless otherwise directed by your doctor.

Dosage is based on your medical condition and response to therapy. Do not change the dose or how often you use this medication without your doctor’s approval. Use this medication regularly to get the most benefit from it. To help you remember, use it at the same time each evening that you have a scheduled dose.

Different brands of interferon alfa can result in different amounts of medication in the blood. This medication comes in different forms (a powder in a vial, a solution in a vial, and a multidose pen). The way you inject this medication depends on the form you are using. Follow your doctor’s directions carefully. Do not switch brands without your doctor’s permission.

This medication can infrequently cause or worsen serious (rarely fatal) medical conditions, including:

  • mental/mood conditions (e.g., depression)
  • circulation problems
  • infections
  • immune system problems (autoimmune conditions such as lupus or rheumatoid arthritis)

This medication may be combined with ribavirin to treat chronic hepatitis C but Ribavirin may cause harm to an unborn baby or death.

Tell your doctor or pharmacist promptly if any of these effects persist or worsen:

  • Injection site reactions (pain/swelling/redness)
  • Headache
  • Tiredness
  • Diarrhea
  • upset stomach
  • loss of appetite
  • back pain
  • dizziness
  • dry mouth
  • taste changes
  • nausea
  • vomiting

Flu-like symptoms such as fever, chills, and muscle aches may occur, especially when you first start this medication. These last about 1 day after the injection and improve or go away after a few weeks of continued use.

Tooth and gum problems may sometimes occur during treatment.

Temporary hair loss may occur. Normal hair growth should return after treatment has ended.

Tell your doctor right away if you have any serious side effects, including:

feeling too hot or cold (more than others around you)

  • fast/irregular heartbeat
  • increased thirst/urination
  • menstrual changes (absent/delayed/irregular periods)
  • numbness/tingling of hands/feet, swelling (especially of face/hands/feet)
  • trouble sleeping, trouble walking
  • vision changes (such as blurred vision, partial loss of vision)
  • easy bleeding/bruising
  • persistent nausea/vomiting
  • signs of infection (e.g., fever, persistent sore throat)
  • stomach/abdominal pain
  • dark urine
  • black/tarry stools
  • yellowing eyes/skin

Get medical help right away if any of these very serious side effects occur:

  • chest pain
  • seizures
  • weakness on one side of the body
  • slurred speech

This drug may cause you to develop serious mental/mood changes that may get worse during treatment or after your last dose.

A very serious allergic reaction to this drug is rare.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.


  • Allergic reaction to this medication
  • Patients with medical history of:
    • blood cell disorders (e.g., anemia, neutropenia, thrombocytopenia)
    • blood clots, cancer
    • diabetes
    • eye problems
    • heart disease (e.g., angina, irregular heartbeat)
    • high blood pressure
    • HIV infection
    • immune system diseases (e.g., lupus, psoriasis, rheumatoid arthritis)
    • intestinal disease (e.g., colitis)
    • kidney disease
    • liver disease (e.g., autoimmune hepatitis, decompensated liver disease)
    • lung diseases (e.g., chronic obstructive pulmonary disease-COPD, asthma, pneumonia)
    • mental/mood disorders (e.g., anxiety, depression)
    • high blood triglyceride levels
    • pancreatitis
    • seizure disorder
    • thyroid disease
    • use/abuse of drugs/alcohol
  • This drug may make you dizzy
  • Do not have immunizations/vaccinations without the consent of your doctor
  • Avoid contact with people who have recently received oral polio vaccine or flu vaccine inhaled through the nose
  • Tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products) before having surgery.
  • Children may be more sensitive to the side effects of this drug, especially mental/mood changes (such as severe depression, thoughts/attempts of suicide)
  • Interferon and ribavirin may also slow down a child’s rate of growth
  • elderly may be more sensitive to the effects of the drug, especially dizziness, mental/mood changes, and effects on the heart
  • Interferon alfa is not recommended for use during pregnancy
  • Interferon alfa, when used in combination with ribavirin, must not be used during pregnancy
  • Consult your doctor before breast-feeding

Consult your doctor regarding the precautions mentioned above.



Some products that may interact with this drug include:

  • barbiturates (e.g., phenobarbital)
  • colchicine
  • drugs that may affect your immune system (e.g., cancer chemotherapy, aldesleukin, cyclosporine)
  • hydroxyurea
  • stavudine
  • telbivudine
  • theophyllines (e.g., aminophylline, theophylline)
  • zidovudine


If overdose is suspected, contact a poison control center or emergency room immediately. Symptoms of overdose may include: chest pain, persistent nausea/vomiting, stomach/abdominal pain, dark urine.


Do not share this medication with others.

Laboratory and/or medical tests (such as blood counts, thyroid tests, kidney/liver function, triglyceride levels, eye exams) should be performed before you start treatment, periodically to monitor your progress, or to check for side effects. Depending on your medical history, other tests (such as EKG) may be needed. Consult your doctor for more details.

Do not change brands of interferon without checking with your doctor or pharmacist. Other interferons may not have the same effects on your disease.

Missed Dose

For the best possible benefit, it is important to receive each scheduled dose of this medication as directed. If you miss a dose, contact your doctor or pharmacist immediately to establish a new dosing schedule. Do not double the dose to catch up.


Store in the refrigerator between 36-46 degrees F (2-8 degrees C) away from light and moisture. Do not freeze. Keep all medications away from children and pets. Consult the product instructions or your pharmacist for more storage details once this medication is mixed.

The multi-dose pen may be used for up to 4 weeks after the first injection. Do not leave this medication outside of the refrigerator for more than 48 hours. After 4 weeks of use, discard the pen, even if it still contains unused solution.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.



Available Brands

Reliferon [ Reliance ] Roferon-A [ Roche ]

Also marketed as

Enduferon [ Heber ] Intron A [ Schering-Plough ]
Shaferon [ Beijing Kawin Technology ] Shanferon [ Shantha Biotechnics ]

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