Peginterferon alfa-2a are interferon proteins bound to polyethylene glycol (PEG) molecules resulting in higher and more prolonged serum interferon concentrations. It has antiviral, antiproliferative and immune-regulating activity. Interferons are activated when it interacts with cells through high affinity cell surface receptors. The effects of this activation include the induction of gene transcription, inhibition of cellular growth, alteration of cellular differentiation, interference with oncogene expression, alteration of cell surface antigen expression, increase in phagocytic activity of macrophages and augmentation of cytotoxicity of lymphocytes for target cells.

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

Chronic Hepatitis B: Peginterferon alfa-2a is indicated for the treatment of adult patients with HBeAg positive and HBeAg negative chronic hepatitis B who have compensated liver disease and evidence of viral replication and liver inflammation.

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= (400+0+600) mg, >75 kg= (600+0+600) mg.

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.

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

• Depression, suicide, relapse of drug abuse and bacterial infection
• Flu like symptoms: Fatigue, pyrexia,
• Gastrointestinal: Nausea/Vomiting, diarrhea, abdominal pain
• Metabolic and Nutritional: Anorexia
• Musculoskeletal: Myalgia, arthralgia
• Neurological: Headache, dizziness, insomnia
• Psychiatric reactions: Irritability, anxiety
• Injection site reaction, skin problems, hair loss
• Endocrine: Hypothyroidism

Overdose Effects

There are limited experiences of overdose. There were no serious reactions attributed to overdose. There is no specific antidote. Dialysis is not effective.

• Patients who have failed alpha interferon treatment with or without ribavirin
• Liver or other organ transplant recipients
• Hepatitis B patients coinfected with HCV or HIV
• Hepatitis C patients coinfected with HBV or coinfected with HIV with a CD4+ cell count < 100 cells/µL
• Caution should be exercised in initiating treatment in any patient with baseline risk of severe anemia

Use in Special Populations

Hepatic Impairment:

Chronic hepatitis C: Alanine transaminase (ALT) progressively rising above baseline: Decrease dose to 135 mcg/wk. If ALT continues to rise or is accompanied by increased bilirubin or hepatic decompensation, discontinue immediately.

Chronic hepatitis B: Alanine transaminase (ALT) >5 times the upper limits of normal: Monitor LFTs more frequently; consider 135 mcg/wk or temporarily discontinuing (may resume after ALT flare subsides). ALT >10 times the upper limits of normal: Consider discontinuing.

Dose modifications:

For moderate-to-severe adverse reactions: Initially, 135 mcg/wk or in some cases, 90 mcg/wk. Haematologic parameters: ANC <750/mm³: 135 mcg/wk; ANC <500/mm³: Discontinue therapy until >1000/mm³, then restart at 90 mcg/wk; monitor ANC. Platelet count: <50,000/mm³: 90 mcg/wk; <25,000/mm³: Discontinue therapy. Depression: Moderate: Decrease to 90-135 mcg once/wk; evaluate once wkly, if symptoms improve and remain stable for 4 wk, continue reduced dosing or return to normal dose; Severe: Discontinue treatment permanently. Administer in the abdomen or thigh.

Renal Impairment:

CrCl <50: Use caution; monitor for toxicity .

Pregnancy & Lactation

Pregnancy Category C: Peginterferon alfa-2a monotherapy. There are no adequate and well controlled trial on pregnant women & developing fetus due to teratogenic effects. Peginterferon alfa-2a is recommended for use in women of childbearing potential only when they are using effective contraception during therapy.

Pregnancy Category X. It is not known whether peginterferon or ribavirin or its components are excreted in human milk. Because of the potential for adverse reactions from the drugs in nursing infants, a decision must be made whether to discontinue nursing or discontinue peginterferon and ribavirin treatment.