Interferon alfa-2b is a recombinant, non-glycosylated protein belonging to the type I interferon family. It is a highly purified, single-chain polypeptide containing 165 amino acids, produced by recombinant DNA technology using genetically engineered Escherichia coli. It possesses potent immunomodulatory, antiproliferative, and antiviral properties. In the Indian context, it is a critical therapeutic agent for several viral and neoplastic conditions, though its use has evolved with the advent of newer targeted therapies.
Adult: Varies widely by indication. **Chronic Hepatitis B:** 5-10 Million IU SC/IM thrice weekly for 16-24 weeks. **Chronic Hepatitis C (monotherapy):** 3 Million IU SC/IM thrice weekly for 48-52 weeks. **Hairy Cell Leukemia:** 2 Million IU/m² SC/IM thrice weekly for up to 6 months. **Follicular Lymphoma:** 5 Million IU SC thrice weekly for up to 18 months as maintenance. **Malignant Melanoma:** 20 Million IU/m² IV for 5 days/week for 4 weeks induction, then 10 Million IU/m² SC thrice weekly for 48 weeks maintenance.
Note: For SC/IM use only. Reconstitute the lyophilized powder with provided sterile water for injection. Gently swirl, do not shake vigorously. Use immediately after reconstitution. Rotate injection sites (thigh, abdomen, upper arm). Administer in the evening to mitigate flu-like symptoms. Pre-medication with acetaminophen/paracetamol is common.
Interferon alfa-2b exerts its effects by binding to specific cell surface receptors (IFNAR1 and IFNAR2), leading to the activation of the JAK-STAT signaling pathway. This results in the transcription of interferon-stimulated genes (ISGs), which mediate its antiviral, antiproliferative, and immunomodulatory actions.
Pregnancy: Category C (US FDA). Animal studies show abortifacient effects. No adequate human studies. Use only if potential benefit justifies potential fetal risk. Effective contraception is required during treatment and for several months after in both male and female patients.
Driving: May cause fatigue, dizziness, and somnolence. Patients should be cautioned about operating machinery or driving until they know how the drug affects them.
| Theophylline | Interferon alfa-2b inhibits cytochrome P450 1A2, increasing theophylline levels and risk of toxicity. | Major |
| Zidovudine (AZT) | Increased risk of myelosuppression (neutropenia, anemia). | Major |
| Ribavirin | Additive hemolytic anemia risk. Used therapeutically in combination for HCV but requires close hematological monitoring. | Major |
| Other Myelosuppressive Agents (e.g., chemotherapeutics, clozapine) | Increased risk of severe bone marrow suppression. | Major |
| Live Attenuated Vaccines | Theoretical risk of enhanced vaccine replication and infection. Avoid vaccination during therapy. | Moderate |
| CNS Depressants (e.g., alprazolam, opioids) | Potential additive sedative and neuropsychiatric effects. | Moderate |