Peginterferon Alfa-2a

What it is and how it works

Peginterferon alfa-2a is recombinant interferon alfa-2a conjugated to a 40 kDa branched polyethylene glycol, which prolongs its half-life and allows weekly dosing. It binds type I interferon receptors and induces antiviral, antiproliferative and immunomodulatory gene expression.

Indications

Chronic hepatitis B (HBeAg-positive or -negative) in adults and children from 3 years; chronic hepatitis C, usually in combination with ribavirin or other antivirals (now largely superseded by interferon-free direct-acting antiviral regimens).

Dosage and administration (summary)

Subcutaneous injection: adults 180 micrograms once weekly, for 48 weeks in chronic hepatitis B; duration in hepatitis C depends on genotype and regimen; dose reduced for neutropenia, thrombocytopenia or other toxicity.

Contraindications

Autoimmune hepatitis, severe hepatic dysfunction or decompensated cirrhosis, history of severe pre-existing cardiac disease, severe psychiatric disorders, uncontrolled thyroid disease, neonates (benzyl alcohol), and combination with telbivudine; ribavirin combination is contraindicated in pregnancy.

Warnings and precautions

Severe depression, suicidal ideation and other neuropsychiatric effects may occur; monitor closely. Causes neutropenia, thrombocytopenia, thyroid dysfunction, autoimmune disorders, ophthalmological disorders and hepatic decompensation in cirrhosis; regular blood counts, liver and thyroid tests are required. Influenza-like symptoms are common.

Pregnancy

Use only if clearly needed; combination with ribavirin is contraindicated and requires strict contraception in both female patients and female partners of male patients.

Storage and supply

Store at 2–8 °C in a refrigerator; do not freeze; protect from light.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.