Interferon Beta-1A is a recombinant glycoprotein produced in Chinese Hamster Ovary (CHO) cells, identical in amino acid sequence to natural human interferon beta. It is a first-line disease-modifying therapy (DMT) for relapsing forms of multiple sclerosis (MS). It exerts immunomodulatory effects by reducing pro-inflammatory cytokines, inhibiting T-cell proliferation, and reducing the migration of inflammatory cells across the blood-brain barrier, thereby reducing the frequency of clinical exacerbations and slowing the accumulation of physical disability and MRI lesion activity.
Adult: 30 micrograms injected subcutaneously every 48 hours (alternate days). For the intramuscular formulation (different product): 30 micrograms injected intramuscularly once weekly.
Note: For SC use: Administer into thigh, abdomen, upper arm, or buttock. Rotate injection sites. Allow prefilled syringe/pen to reach room temperature (approx. 30 mins) before injection to reduce discomfort. Do not shake. Inspect for particulate matter. Use aseptic technique. Proper patient training on self-injection is mandatory. Premedication with analgesics/antipyretics (e.g., paracetamol) can mitigate flu-like symptoms.
Interferon Beta-1A binds to the type I interferon receptor (IFNAR) complex on the surface of human cells. This binding activates the JAK-STAT signaling pathway, leading to the transcription of interferon-stimulated genes (ISGs). The downstream effects are pleiotropic and result in immunomodulation rather than broad immunosuppression.
Pregnancy: Pregnancy Category C (US FDA). Animal studies show abortifacient effects. No adequate, well-controlled studies in pregnant women. Use only if potential benefit justifies potential fetal risk. Women of childbearing potential should use effective contraception. Consider discontinuing therapy prior to conception. Indian MS Society guidelines recommend discussing risks/benefits and considering discontinuation.
Driving: May cause fatigue, dizziness, and malaise. Patients should be cautioned about driving or operating machinery, especially during initial therapy or dose escalation.
| Myelosuppressive agents (e.g., Cladribine, Cyclophosphamide, Azathioprine) | Additive risk of severe leukopenia, thrombocytopenia, or pancytopenia. | Major |
| Hepatotoxic drugs (e.g., Methotrexate, Leflunomide, systemic Retinoids, high-dose Paracetamol, Antiepileptics like Valproate) | Increased risk of hepatotoxicity and elevated transaminases. | Major |
| Theophylline | Interferon beta may reduce the clearance of theophylline, increasing its plasma levels and risk of toxicity. | Moderate |
| Zidovudine (AZT) | Increased risk of hematologic toxicity (neutropenia). | Moderate |
| Live attenuated vaccines | Theoretical risk of enhanced vaccine replication and infection due to immunomodulation. Avoid concurrent use. | Major |