Peginterferon alfa-2a alone or in combination with Ribavirin is indicated for the treatment of chronic hepatitis C (CHC) infection in adults who have compensated liver disease and have not been previously treated with interferon alpha.

Peginterferon alfa-2a is also indicated for the treatment of chronic hepatitis B (CHB) infection in adults, both HBeAg positive and HBeAg negative, who have compensated liver disease, with evidence of viral replication and liver inflammation.

Peginterferon alfa-2a is a covalent conjugate of recombinant interferon alfa-2a with a single branched bismonomethoxy polyethylene glycol (PEG) chain. The Peginterferon alfa-2a portion is attached at a single site to the interferon alfa moiety via a stable amide bond to lysine. Peginterferon alfa-2a has an approximate molecular weight of 60,000 daltons. Interferon alfa-2a is produced using recombinant DNA technology, where a cloned human leukocyte interferon gene is inserted into and expressed in Escherichia coli.

Chronic hepatitis C: The recommended dose of Peg interferon is 180 mcg once weekly for 48 weeks by subcutaneous administration on abdomen

or thigh Chronic hepatitis B: The recommended dose of Peg interferon is 180 mcg once weekly for 48 weeks by subcutaneous administration on abdomen or thigh

Hepatitis C Genotype 1 & 4:

• Pegylated Interferon alfa-2a Monotherapy: 180 mcg once weekly for 48 weeks
• Pegylated Interferon alfa-2a dual therapy: 180 mcg once weekly for 48 weeks; Celbarin: 75 kg= (600+0+600) mg.

Hepatitis C Genotype 2 & 3:

• Hepatitis C Genotype 2 & 3: Pegylated Interferon alfa-2a Monotherapy: 180 mcg once weekly for 48 weeks
• Pegylated Interferon alfa-2a dual therapy: 180 mcg once weekly for 24 weeks; Celbarin: (400+0+400) mg.

Pediatric Use: The safety and effectiveness of Pegferon®, alone or in combination with Ribavirin in patients below the age of 5 years have not been established.

• Drugs metabolized by CYP1A2: Monitor for increased serum levels of theophylline and adjust the dose as needed.
• Methadone: Watch for signs of methadone toxicity.
• Nucleoside analogues: Closely monitor for toxicities, and reduce the dose or discontinue Peginterferon alfa-2a, Ribavirin, or both if adverse effects worsen.
• Zidovudine: Monitor for worsening neutropenia and/or anemia when used with Peginterferon alfa and Ribavirin.
• Azathioprine: Use with caution due to potential additive toxic effects.

Peginterferon alfa-2a is contraindicated in patients with:

• Hypersensitivity to any component of the product
• Autoimmune hepatitis
• Hepatic decompensation in cirrhotic patients before or during treatment
• Hepatic decompensation with Child-Pugh score ≥6 in cirrhotic CHC patients co-infected with HIV before or during treatment
• Neonates or infants

Peginterferon alfa-2a may cause:

• Depression, suicidal thoughts, relapse of drug abuse, and bacterial infections
• Flu-like symptoms including fatigue and fever
• Gastrointestinal effects such as nausea, vomiting, diarrhea, and abdominal pain
• Metabolic and nutritional issues like loss of appetite (anorexia)
• Musculoskeletal problems including muscle pain (myalgia) and joint pain (arthralgia)
• Neurological effects such as headache, dizziness, and insomnia
• Psychiatric reactions including irritability and anxiety
• Injection site reactions, skin problems, and hair loss
• Endocrine effects such as hypothyroidism

Pregnancy Category C: Peginterferon alfa-2a monotherapy has not been adequately studied for teratogenic effects. There are no well-controlled studies in pregnant women. It should be used in women of childbearing potential only if effective contraception is used during therapy.

Pregnancy Category X: Combination therapy with Ribavirin is contraindicated. Ribavirin has significant teratogenic and embryocidal effects in all animal species studied. This therapy must not be used in pregnant women or in male patients whose partners are pregnant.

Nursing Mothers: The effect of peginterferon alfa-2a or Ribavirin in breast milk on nursing infants is unknown. Due to potential adverse reactions in infants, a decision should be made whether to stop breastfeeding or discontinue therapy.

Peginterferon alfa-2a should be used with caution in the following patients:

• Patients who have failed previous alpha interferon treatment, with or without Ribavirin
• Liver or other organ transplant recipients
• Hepatitis B patients co-infected with HCV or HIV
• Hepatitis C patients co-infected with HBV or HIV with a CD4+ cell count below 100 cells/µL
• Any patient with a baseline risk of severe anemia should be carefully assessed before initiating treatment

There is limited experience with Peginterferon alfa-2a overdose. No serious reactions have been clearly attributed to overdose. There is no specific antidote, and dialysis is not effective in removing the drug.

Hepatic viral infections (Hepatitis C)

Peginterferon alfa-2a should be stored in a refrigerator at 2–8°C, do not freeze or shake, and protect from light.