Interferons

Products

Interferons are sold exclusively as injectables, for example, in the form of prefilled syringes. They are stored in the refrigerator at 2 to 8°C. The body’s own cytokines were discovered in the 1950s.

Structure and properties

Interferons are proteins with a molecular weight between 15 to 21 kDa. They are now produced by biotechnological methods. Several types exist, including alpha-, beta-, and gamma-interferons:

  • IFN-α (leukocytes).
  • IFN-β (fibroblasts)
  • IFN-γ (lymphocytes)

Pegylated interferons are linked to a PEG chain and have a longer duration of action.

Effects

Interferons (ATC L03AB) have antiviral, antitumor (antiproliferative), antiangiogenic, and immunomodulatory properties. They are endogenous proteins produced by the immune system in response to, among other things, viral infection. Interferons bind to interferon receptors on the cell surface and, among other things, influence gene expression and activate antiviral enzymes. The half-life of non-pegylated agents is in the range of a few hours. Peginterferons, on the other hand, have a longer half-life, ranging from 40 to 80 hours, for example.

Indications

The following are indications for interferons. Not all representatives are approved for all indications: Diseases of the immune system:

  • Multiple sclerosis
  • Chronic granulomatosis

Cancers:

  • Chronic myeloid leukemia
  • Hairy cell leukemia
  • Cutaneous T-cell lymphoma
  • Kaposi’s sarcoma in patients with AIDS
  • Malignant melanoma
  • Renal cell carcinoma
  • Polycythaemia vera

Infectious diseases:

  • Chronic hepatitis B
  • Chronic hepatitis C
  • Condylomata acuminata (genital warts)

Dosage

According to the professional information. The drugs are usually injected subcutaneously. Paracetmol may be administered for symptomatic treatment of flu-like side effects.

Active Ingredients

  • Interferon alfa-2a (Roferon A)
  • Interferon alfa-2b (Intron A, out of commerce).
  • Peginterferon alfa-2a (Pegasys)
  • Peginterferon alfa-2b (PegIntron, out of commerce).
  • Interferon beta-1a (Avonex, Rebif)
  • Interferon beta-1b (Betaferon)
  • Peginterferon beta-1a (Plegridy)
  • Interferon gamma-1b (Imukin)
  • Ropeginterferon alfa-2b (Besremi)

Contraindications

Contraindications include:

  • Hypersensitivity
  • Psychiatric disorders, severe depression
  • Severe liver dysfunction
  • Renal dysfunction
  • Pregnancy, lactation (depending on the active substance).

Full precautions can be found in the drug label.

Interactions

Interferons may affect the activity of CYP450 isozymes.

Adverse effects

The most common possible adverse effects include (selection):

  • Reactions at the injection site
  • Flu-like symptoms: chills, fever, weakness, fatigue, muscle and joint pain, lack of appetite
  • Blood count disorders
  • Headaches, sleep disorders
  • Abdominal pain, weight loss
  • Skin rashes
  • Increased liver enzymes
  • Depression