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Interferon Alfa-2a
Pronunciation: IN-ter-FEER-ahn AL-fuh-2a
Class: Immunomodulator
Trade Names
Roferon-A
- 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)
Pharmacology
Interferon alfa-2a has antiproliferative and immunomodulatory activities. Its elimination half-life is 3.7 to 8.5 h after IV infusion.
Pharmacokinetics
Absorption
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.
Distribution
The Vd ss is 0.223 to 0.748 L/kg.
Metabolism
Totally filtered through the glomeruli and undergoes rapid proteolytic degradation during tubular reabsorption. The hepatic metabolism has a minor pathway.
Elimination
The t ½ is 3.7 to 8.5 h. The mean Cl is 2.79 mL/min/kg.
Indications and Usage
AdultHairy cell leukemia, AIDS-related Kaposi sarcoma, chronic myelogenous leukemia.
ChildrenChronic myelogenous leukemia.
Unlabeled Uses
AdultsBladder tumors, mycosis fungoides, essential thrombocythemia, non-Hodgkin lymphoma, ovarian and cervical cancer, renal cell carcinoma, melanoma.
ChildrenHemangiomas of infancy, pulmonary hemangiomatosis.
Contraindications
Standard considerations.
Dosage and Administration
Hairy Cell LeukemiaAdults
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 SarcomaAdults
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 LeukemiaAdults
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.
ChildrenIM 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 HemangiomatosisChildren
Subcutaneous 1 to 3 million units/m 2 /day once daily.
Drug Interactions
AldesleukinThere is an increased risk of renal failure when using aldesleukin with interferon alfa-2a.
MelphalanCoadministration of melphalan and interferon alfa-2a may decrease serum levels of melphalan.
Theophylline and possibly barbituratesAlfa-interferon may inhibit hepatic metabolism of theophylline and possibly barbiturates, leading to increased serum concentrations of theophylline or barbiturates.
VidarabineAlfa-interferon may potentiate neurotoxicity when administered with vidarabine.
Zidovudine, acyclovirThere 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.
Adverse Reactions
Cardiovascular
Edema; hypotension.
CNS
Perioral tingling; dizziness; depression and suicidal ideation; paresthesia; sleep disturbances; confusion; hallucination; seizures; encephalopathy; gait disturbance; ataxia; tremor.
Dermatologic
Rash; transient alopecia or thinning of the hair; excessive sweating or night sweats.
Endocrine
Hypothyroidism; hyperthyroidism.
GI
Moderate potential for nausea and vomiting; dysgeusia; diarrhea; dry mouth; gingivitis; anorexia; weight loss; elevated LFTs.
Hematologic
Neutropenia; thrombocytopenia.
Hypersensitivity
Antinuclear antibodies; anaphylaxis; neutralizing antibody formation.
Musculoskeletal
Severe lower extremities myalgias in chronic myelogenous leukemia patients.
Renal
Proteinuria; acute renal failure; nephrotic syndrome.
Respiratory
Dyspnea; cough; pharyngitis; sinusitis; drying of the oropharynx.
Special Senses
Visual disturbance; ocular pain.
Miscellaneous
Flu-like syndrome.
Precautions
WarningsNeuropsychiatric, autoimmune, ischemic, and infectious disordersInterferons 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. |
Pregnancy
Category C .
Lactation
Discontinue breast-feeding or discontinue the drug.
Hypersensitivity
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.
Anemia
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
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
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.
Patient Information
- 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.
Further information
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