Pronunciation: IN-ter-FEER-ahn AL-fuh-2a
- Solution for injection 6 million units/mL, 0.5 mL single-use prefilled syringes (3 million units/syringe)
- Solution for injection 12 million units/mL, 0.5 mL single-use prefilled syringes (6 million units/syringe)
- Solution for injection 18 million units/mL, 0.5 mL single-use prefilled syringes (9 million units/syringe)
Interferon alfa-2a has antiproliferative and immunomodulatory activities. Its elimination half-life is 3.7 to 8.5 h after IV infusion.
The mean T max is 3.8 h (IM) and 7.3 h (subcutaneous). The mean C max is 2,020 pg/mL for IM and 1,730 pg/mL for subcutaneous. The apparent bioavailability is more than 80% for IM.
The Vd ss is 0.223 to 0.748 L/kg.
Totally filtered through the glomeruli and undergoes rapid proteolytic degradation during tubular reabsorption. The hepatic metabolism has a minor pathway.
The t ½ is 3.7 to 8.5 h. The mean Cl is 2.79 mL/min/kg.
Indications and UsageAdult
Hairy cell leukemia, AIDS-related Kaposi sarcoma, chronic myelogenous leukemia.Children
Chronic myelogenous leukemia.
Bladder tumors, mycosis fungoides, essential thrombocythemia, non-Hodgkin lymphoma, ovarian and cervical cancer, renal cell carcinoma, melanoma.Children
Hemangiomas of infancy, pulmonary hemangiomatosis.
Dosage and AdministrationHairy Cell Leukemia
IM or Subcutaneous Induction : 3 million units/day, for 16 to 24 wk; Maintenance : 3 million units IM or Subcutaneous 3 times/wk. Treat patients for about 6 mo before determining whether to continue therapy.AIDS-Related Kaposi Sarcoma
IM or Subcutaneous Induction : 36 million units/day, for 10 to 12 wk. Alternative induction : 3 million units for 3 days, then 9 million units for 3 days, then 18 million units for 3 days, then 36 million units daily for a total of 10 to 12 wk. Maintenance : 36 million units IM or Subcutaneous 3 times/wk. Continue therapy until no evidence of tumor exists or rapid disease progression, severe opportunistic infection, or adverse reactions require discontinuation.Chronic Myelogenous Leukemia
IM or Subcutaneous 9 million units/day. Alternative regimen : 3 million units/day for 3 days, then 6 million units/day for 3 days, then 9 million units/day for the duration of therapy. Treat patients for several months before determining whether to continue therapy.Children
IM 2.5 to 5 million units/m 2 /day. Treat patients for several months before determining whether to continue therapy; some patients may require therapy for up to 18 mo.Hemangiomas of Infancy, Pulmonary Hemangiomatosis
Subcutaneous 1 to 3 million units/m 2 /day once daily.
There is an increased risk of renal failure when using aldesleukin with interferon alfa-2a.Melphalan
Coadministration of melphalan and interferon alfa-2a may decrease serum levels of melphalan.Theophylline and possibly barbiturates
Alfa-interferon may inhibit hepatic metabolism of theophylline and possibly barbiturates, leading to increased serum concentrations of theophylline or barbiturates.Vidarabine
Alfa-interferon may potentiate neurotoxicity when administered with vidarabine.Zidovudine, acyclovir
There are synergestic antiviral effects with alfa-interferon and zidovudine and acyclovir.
Laboratory Test Interactions
Leukopenia, neutropenia, thrombocytopenia, decreased hemoglobulin, severe anemia, severe cytopenias, AST, alkaline phosphatase, LDH, proteinuria, uric acid.
Perioral tingling; dizziness; depression and suicidal ideation; paresthesia; sleep disturbances; confusion; hallucination; seizures; encephalopathy; gait disturbance; ataxia; tremor.
Rash; transient alopecia or thinning of the hair; excessive sweating or night sweats.
Moderate potential for nausea and vomiting; dysgeusia; diarrhea; dry mouth; gingivitis; anorexia; weight loss; elevated LFTs.
Antinuclear antibodies; anaphylaxis; neutralizing antibody formation.
Severe lower extremities myalgias in chronic myelogenous leukemia patients.
Proteinuria; acute renal failure; nephrotic syndrome.
Dyspnea; cough; pharyngitis; sinusitis; drying of the oropharynx.
Visual disturbance; ocular pain.
WarningsNeuropsychiatric, autoimmune, ischemic, and infectious disorders
Interferons may cause or aggravate fatal or life-threatening disorders of this nature. Persistent severe or worsening signs or symptoms may necessitate discontinuation of therapy. Closely monitor patients with periodic clinical and laboratory evaluations.
Category C .
Discontinue breast-feeding or discontinue the drug.
Avoid use in patients with hypersensitivity to mouse immunoglobulin.
Special Risk Patients
Administer with caution in patients with severe renal or hepatic disease, cardiac disease, seizure disorders, or compromised CNS function.
Leukopenia and thrombocytopenia may occur.
Depression and suicidal behavior
Depression and suicidal behavior including suicidal ideation, suicidal attempts, and suicides reported in association with alfa-interferon treatment.
Dosage reduction by 50% or withholding therapy may be needed when severe adverse reactions occur.
Leukopenia and elevation of hepatic enzymes
Leukopenia and elevation of hepatic enzymes occurred frequently.
Neutralizing antibodies can develop during alfa-interferon therapy and may contribute to therapeutic failure in some patients. In some studies, development of neutralizing antibodies was more common with interferon alfa-2a than with interferon alfa-2b.
- Warn patients not to change brands of interferon; changes in dosage may be necessary.
- Well hydrate patients, especially during initial treatment.
Copyright © 2009 Wolters Kluwer Health.
More Interferon Alfa-2a resources
- interferon alfa-2a Concise Consumer Information (Cerner Multum)
- interferon alfa-2a Subcutaneous Advanced Consumer (Micromedex) - Includes Dosage Information
- interferon alfa-2a solution MedFacts Consumer Leaflet (Wolters Kluwer)
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