peginterferon beta-1a: clinical use

Prescribing considerations

• Initiate under a clinician experienced in managing multiple sclerosis.
• Use caution with previous depression, seizure disorders, significant cardiac disease, severe renal impairment or severe hepatic impairment.
• Review aseptic self-injection technique and site rotation.
• Record product name and batch number for biological traceability.

Contraindications and cautions

• Hypersensitivity to natural or recombinant interferon beta, peginterferon or any excipient.
• Current severe depression and/or suicidal ideation.

Monitoring

• Obtain blood counts, platelet count and blood chemistry including liver tests before treatment and regularly after initiation, then periodically.
• Check thyroid function in people with previous thyroid dysfunction, or when clinically indicated.
• Monitor mood, suicidal ideation, cardiac deterioration, oedema, proteinuria and renal function.
• Assess persistent or severe injection-site reactions and skin breakdown or drainage.

Clinical pharmacology

A recombinant interferon beta-1a protein conjugated to linear polyethylene glycol. It activates type I interferon receptors and produces immunomodulatory gene responses; pegylation reduces clearance and prolongs circulating half-life.

Formulation and product differences

• Single-use pre-filled pens and syringes are available for subcutaneous administration; the intramuscular presentation is a single-use pre-filled syringe.
• Subcutaneous devices have an attached needle; the intramuscular syringe has a separate needle.
• The routes were bioequivalent in a pharmacokinetic study, but switching between routes has not been directly studied.