Mechanism of action
The drug's action begins at the cellular level and is realized through a complex cascade of intracellular reactions.
- Receptor binding: Interferon molecules interact with specific receptors located on the cell membrane.
- Intracellular cascade: Signal transmission inside the cell is triggered, leading to the induction of synthesis of various enzymes.
- Antiviral block: The key mechanism consists in the activation of a specific enzyme that inhibits (blocks) viral RNA translation. As a result, the virus loses its ability to replicate inside the infected cell.
- Cell cycle control: The drug affects cell proliferation, differentiation, and apoptosis processes.
Pharmacological effects
Interferons are characterized by the classical triad of effects:
- Antiviral: Direct suppression of viral replication by blocking the synthesis of their proteins.
- Immunomodulatory: Activation of immune effectors. The drug stimulates macrophages and increases lymphocyte cytotoxicity, helping the body independently destroy infected cells.
- Antiproliferative: Regulation of cell growth and suppression of excessive cell division.
Indications for use
Since Interferonum leucocyticum humanum siccum is a topical preparation, its systemic action is limited. The main indications include:
- Prevention and treatment of influenza.
- Therapy of other acute respiratory viral infections (ARVI).
Side effects
Despite topical administration, the use of interferon preparations (as a group) may cause a wide range of adverse reactions. Students must remember the main ones:
- Flu-like syndrome: The most frequent complication (fever, chills, myalgia).
- CNS: Dizziness, visual disturbances, confusion, depression, insomnia, tremor, paresthesia.
- Gastrointestinal tract: Nausea, loss of appetite.
- Hematopoiesis and kidneys: Transient leukopenia, proteinuria.
- Cardiovascular system: Symptoms of heart failure.
- Other reactions: Skin rash, itching, alopecia, epistaxis, temporary impotence.
Dosage form and rules of administration
The drug is available as a dry powder in 10 ml ampoules.
Important: Interferons have a protein structure, therefore they are inactive when taken orally (completely destroyed by enzymes in the gastrointestinal tract). They are administered strictly parenterally or topically.
Preparation and administration rules:
- First, the contents of the ampoule must be dissolved in 2 ml of boiled water.
- For the treatment and prevention of respiratory infections, the solution is instilled intranasally (into the nasal passages) at 5 drops.
- If ophthalmological use is required, the solution is instilled into the conjunctival sac at 2 drops.
Briefly: answers to topical questions
Which specific intracellular enzymes are induced by interferon to block viral RNA translation?
To block viral RNA translation, interferons induce the synthesis of specific protein kinases and RNA-degrading enzymes.
- Protein kinase R (serine/threonine-protein kinase R) — phosphorylates the translation initiation factor (eIF2), which causes enzyme inactivation and blockade of viral protein synthesis.
- 2'-5'-Oligoadenylate synthetase — activates endoribonucleases (RNase L dimer) that ensure the cleavage of viral and cellular messenger and ribosomal RNAs.
Interferon works like an INTERceptor — it intercepts cell control, blocking viral RNA translation and preventing the virus from assembling its copies.
Class and exam questions
Why is leukocyte interferon not prescribed in tablets?
Interferons are glycoproteins (proteins). When taken orally, they are completely destroyed by proteolytic enzymes of the gastrointestinal tract and lose their activity.
What is the principal difference between this drug and recombinant interferons?
Leukocyte interferon is a natural preparation obtained from real donor blood (leukocyte culture). Recombinant preparations (e.g., IFN-α-2b) are synthesized artificially using genetically engineered bacterial strains.
Which side effect is the hallmark of interferon preparations?
The most characteristic and frequent side effect for the entire group of interferons is flu-like syndrome.
What else to study on this topic
- Recombinant alpha-interferons (Roferon-A, Reaferon-EC) and their use in oncology
- Interferon inducers: mechanism of action and advantages over exogenous drugs
- The role of IFN-beta preparations in the therapy of multiple sclerosis
- Combined interferon preparations in ophthalmology (Oftalmoferon)
- Mechanisms of cellular apoptosis and proliferation under the action of cytokines
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