What is the structure/class of interferon?
Cytokine glycoproteins (Type I: IFN-α/β; Type II: IFN-γ). Produced by fibroblasts, leukocytes, and T cells. [expanded for LO1]
How is interferon administered and absorbed?
Administered subcutaneously or intramuscularly; poor oral absorption due to peptide degradation. [expanded for LO1]
What is the biological half-life and bioavailability of interferon?
Half-life: IFN-α ~3–8 h, pegylated forms 40–60 h; bioavailability ~80% after SC injection. [expanded for LO1]
How is interferon metabolised and excreted?
Degraded by proteolysis in kidneys and liver; metabolites excreted renally. [expanded for LO1]
What is the mechanism of action of interferon?
Binds cell-surface receptors → activates JAK-STAT pathway → transcription of antiviral, antiproliferative, and immunomodulatory genes; enhances MHC expression and macrophage activity.
What are the clinical indications for interferon in dermatology?
CTCL (mycosis fungoides, Sézary syndrome), Kaposi sarcoma, viral warts, melanoma, haemangiomas.
What are the contraindications for interferon?
Hypersensitivity; decompensated liver disease; autoimmune disease; severe depression or psychosis; pregnancy/lactation (Category D).
What are the common adverse effects of interferon?
Flu-like symptoms (fever, chills, myalgia, fatigue); malaise; headache.
What are the serious adverse effects of interferon?
Depression, psychosis, cytopenias, hepatotoxicity, thyroid dysfunction, autoimmune disease flare, cardiotoxicity. [expanded for LO1]
What are important drug interactions for interferon?
Additive myelosuppression with other cytotoxic drugs; increased risk of hepatotoxicity with other hepatotoxic agents; potentiates neurotoxicity with CNS depressants. [expanded for LO1]
What is the dosing of interferon in dermatology?
IFN-α 3–10 million IU SC 3×/week (CTCL, melanoma, Kaposi); adjust by response and tolerance. [expanded for LO1]
What baseline investigations are required before interferon therapy?
FBC, LFT, TFT, UEC, pregnancy test if relevant, screening for autoimmune disease or psychiatric history. [expanded for LO1]
How should patients on interferon be monitored?
Monitor FBC, LFT, TFT every 3 months; assess mood and psychiatric status regularly. [expanded for LO1]
What are clinical pearls for interferon use?
Counsel regarding flu-like syndrome and depression risk; premedicate with paracetamol; avoid in severe autoimmune disease. Compared with methotrexate or azathioprine, interferon is immunomodulatory (not cytotoxic) with greater mood disturbance risk. [expanded for LO1]
