Intron A
Classifications: immunomodulator; interferon; antineoplastic;
Therapeutic: immunomodulator
; interferon; antineoplastic
Prototype: Interferon alfa-2a
Pregnancy Category: C


5 million IU, 10 million IU, 18 million IU, 25 million IU, 50 million IU vials


Interferon (IFN) alfa-2b, one of 4 types of alpha interferons, is a highly purified protein and natural product of human leukocytes within 4–6 h after viral stimulation. Produced by recombinant DNA technology (rIFN-A). Antiviral action: Reprograms virus-infected cells to inhibit various stages of virus replication. Antitumor action: Suppresses cell proliferation. Immunomodulating action: Enhances phagocytic activity of macrophages and augments specific cytotoxicity of lymphocytes for target cells. The immune system and the interferon system of defense are complementary.

Therapeutic Effect

Has a broad spectrum of antiviral, cytotoxic, and immunomodulating activity (i.e., favorably adjusts immune system to better combat foreign invasion of antigens, cancers, and viruses).


Hairy cell leukemia in splenectomized and non-splenectomized patients ≥18 y, chronic hepatitis B or C, malignant melanoma, condylomata acuminata, AIDS-related Kaposi's sarcoma.

Unlabeled Uses

Multiple sclerosis, condylomata acuminata.


Hypersensitivity to interferon alfa-2b or to any components of the product; colitis; pancreatitis; neonates, pregnancy (category C), lactation.

Cautious Use

Severe, preexisting cardiac, renal, or hepatic disease; pulmonary disease (e.g., COPD); diabetes mellitus patients prone to ketoacidosis; coagulation disorders; severe myelosuppression; recent MI; previous dysrhythmias.

Route & Dosage

Hairy Cell Leukemia
Adult: IM/SC 2 million U/m2 3 times/wk

Kaposi's Sarcoma
Adult: IM/SC 30 million U/m2 3 times/wk

Condylomata Acuminata
Adult: IM/SC 1 million U/m2 3 times/wk

Chronic Hepatitis B or C
Adult: SC 3 million U 3 times/wk x 18–24 mo

Malignant Melanoma
Adult: IV 20 million IU/m2 daily for 5 d per wk x 4 wk; maintenance dose is 10 million IU/m2 given SC weekly x 48 wk

Renal Impairment
Not removed by dialysis.


Note: Interferon alfa-2b should be administered under the guidance of a qualified physician.

  • Reconstitution: The final concentration with the amount of required diluent is determined by the condition being treated (see manufacturer's directions). Inject diluent (bacteriostatic water for injection) into interferon alfa-2b vial; gently agitate solution before withdrawing dose with a sterile syringe.
  • Make sure reconstituted solution is clear and colorless to light yellow and free of particulate material; discard if there are particles or solution is discolored.
  • Store vials and reconstituted solutions at 2°–8° C (36°–46° F); remains stable for 1 mo. Discard any remaining drug in reconstituted vials.

PREPARE: IV Infusion: Prepare immediately before use. Select the appropriate number of vials (i.e., 10, 18, or 50 million IU) of recombinant powder for injection and add to each the 1 mL of supplied diluent. Swirl gently to dissolve but do not shake. Further dilute by adding the required dose to 100 mL of NS. The final concentration should be <10 million IU/100 mL.  

ADMINISTER: IV Infusion: Infuse over 20 min.  

INCOMPATIBILITIES Solution/additive: Dextrose-containing solutions.

Adverse Effects (≥1%)

Body as a Whole: Flu-like syndrome (fever, chills) associated with myalgia and arthralgia, leg cramps. CNS: Depression, nervousness, anxiety, confusion, dizziness, fatigue, somnolence, insomnia, altered mental states, ataxia, tremor, paresthesias, headache. CV: Hypertension, dyspnea, hot flushes. Special Senses: Epistaxis, pharyngitis, sneezing; abnormal vision. GI: Taste alteration, anorexia, weight loss, nausea, vomiting, stomatitis, diarrhea, flatulence. Hematologic: Mild thrombocytopenia, transient granulocytopenia, anemia, neutropenia, leukemia. Skin: Mild pruritus, mild alopecia, rash, dry skin, herpetic eruptions, nonherpetic cold sores, urticaria.


Drug: May increase theophylline levels; additive myelosuppression with antineoplastics, zidovudine may increase hematologic toxicity, increase doxorubicin toxicity, increase neurotoxicity with vinblastine. Use with ribavirin increases risk of hemolytic anemia; do not use in combination with ribavirin if Clcr <50 mL/min.


Peak: 6–8 h. Metabolism: In kidneys. Half-Life: 6–7 h.

Nursing Implications


Assessment & Drug Effects

  • Assess hydration status; patient should be well hydrated, especially during initial stage of treatment and if vomiting or diarrhea occurs.
  • Lab tests: Closely monitor CBC with differential and platelet counts.
  • Monitor for ecchymoses, petechiae, and bruising.
  • Assess for flu-like symptoms, which may be relieved by acetaminophen (if prescribed).
  • Monitor level of GI distress and ability to consume fluids and food.
  • Monitor mental status and alertness; implement safety precautions if needed.

Patient & Family Education

  • Learn techniques for reconstitution and administration of drug.
  • Do NOT change brands of interferon without first consulting the physician.
  • Note: If flu-like symptoms develop, take acetaminophen as advised by physician and take interferon at bedtime.
  • Note: Fertile, nonpregnant women need to use effective contraception.
  • Use caution with hazardous activities until response to drug is known.
  • Learn about adverse effects and notify physician about those that cause significant discomfort.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2023 Last Updated On: 01/27/2023 (0)
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