Interferon Alfa, Human Recombinant
Interferon alfa is a **cytokine** used primarily to alleviate the clinical effects of certain viral diseases and as an immunomodulator. * **In Cats**: It is used via subcutaneous (SC) or oral/buccal administration to treat virus-induced diseases such as Feline Immunodeficiency Virus (FIV), Feline Leukemia Virus (FeLV), and Feline Herpesvirus-1 (FHV-1). * **In Dogs**: It is used as an adjunctive treatment for viral or immunosuppression-related conditions (e.g., papillomas, pododermatitis, digital keratomas) and has been evaluated for certain neoplastic diseases like hemangiosarcoma. > **Clinical Pearl**: Because this is a *human* recombinant protein, cats given parenteral human interferon-alfa may develop significant neutralizing antibodies after 3-7 weeks of treatment, resulting in a loss of efficacy. Feline interferon-omega is often preferred in modern practice when available. Low-dose oral administration is thought to act via local oropharyngeal immunomodulation rather than systemic absorption.
Mecanismo: Interferon alfa exhibits **antiviral, antiproliferative, and immunomodulating effects**. * **Mechanism**: It binds to specific cell-surface receptors → activates the **JAK-STAT signaling pathway** → induces transcription of interferon-stimulated genes (ISGs). * **Antiviral Activity**: The ISGs produce proteins (e.g., 2',5'-oligoadenylate synthetase, protein kinase R) that inhibit the synthesis of viral RNA, DNA, and cellular proteins, effectively degrading viral RNA and halting viral replication. * **Immunomodulation**: Enhances macrophage phagocytic activity and augments specific cytotoxicity of lymphocytes for target cells.
Dosificación por especie
- FeLV infection (Low dose) · 30 Units/cat · PO · daily · 7 days on, 7 days off
- FeLV infection (High dose) · 10,000-1,000,000 Units/kg · SC · once daily
- FIV infection · 30 Units/cat · PO · daily · 7 days on, 7 days off
- Chronic FHV-1 infections (Systemic) · 30 Units/cat · PO · daily · 7 days on, 7 days off; repeat cycle
- Chronic FHV-1 infections (Ophthalmic) · 1 drop of 25-50 Units/mL of saline in affected eye(s) · Topical · q4-6h
- Acute life-threatening FHV-1 infections in kittens · 10,000 Units/kg · SC · daily · up to 3 weeks
- Cutaneous T-cell lymphoma and severe cases of oral/cutaneous papillomas · 1.5-2 million Units/m2 · SC · 3 times weekly
- Immunostimulant for adjunctive treatment of dermatologic conditions (e.g., pododermatitis, papillomas, digital keratomas) · 1000 Units · PO · once daily · Given as 1000 Unit/mL solution
Las dosis son una referencia clínica para veterinarios colegiados. Confirme siempre con la ficha técnica vigente y el paciente individual.
Vías de administración
Contraindicaciones
- Feline Infectious Peritonitis (FIP) - low dose oral therapy is contraindicated
- Preexisting autoimmune disease
- Severe cardiac disease
- Severe pulmonary disease
- 'Brittle' diabetes
- CNS disorders
- Known hypersensitivity to the drug
Efectos adversos
- Malaise
- Fever
- Allergic reactions
- Myelotoxicity (anemia, leukopenia, thrombocytopenia)
- Myalgia
- Neutralizing antibody formation (in cats, leading to loss of efficacy)
- Hepatotoxicity (reported in humans)
- Neurotoxicity (reported in humans)
- Flu-like syndrome (reported in humans)
Interacciones farmacológicas
- Acyclovir · Additive or synergistic antiviral effects may occur.
- Zidovudine (AZT) · Additive or synergistic antiviral effects may occur.
- Vidarabine · Increased toxicities may occur without synergistic antiviral effects.
Monitorización
- Clinical efficacy and symptom resolution
- Complete Blood Count (CBC) if used parenterally (monitor for myelotoxicity)
- Body temperature (monitor for fever)
Sobredosis
No specific information is available regarding acute toxicity or overdosage. Dosages should be determined and calculated carefully.
La referencia de fármacos de VetSheet está destinada a veterinarios colegiados como apoyo a la decisión clínica, no sustituye el juicio profesional ni la ficha técnica vigente del fabricante.