Peginterferon Alfa-2A Dosage

Medically reviewed by Drugs.com. Last updated on Jul 4, 2023.

Usual Adult Dose for Chronic Hepatitis C

PATIENTS WITHOUT HIV COINFECTION:
Combination Therapy:

• HCV genotypes 1, 2, 3, 4: 180 mcg subcutaneously once a week
• HCV genotypes 5, 6: Insufficient data for dosing recommendations

Duration of therapy when used with other HCV antiviral drugs:

• HCV genotypes 1, 2, 3, 4: The manufacturer product information of the other HCV antiviral drugs should be consulted.

Duration of therapy when used with ribavirin without other HCV antiviral drugs:

• HCV genotypes 1, 4: 48 weeks
• HCV genotypes 2, 3: 24 weeks

Monotherapy: 180 mcg subcutaneously once a week for 48 weeks

Discontinuation of Therapy for HCV Genotype 1 (when used with ribavirin or alone):

• Therapy should be discontinued if there is not at least a 2 log10 reduction from baseline in HCV RNA by 12 weeks of therapy or if HCV RNA remains detectable after 24 weeks of therapy.
• The manufacturer product information for specific coadministered HCV antiviral drugs should be consulted for information on discontinuation based on treatment response.

PATIENTS WITH HIV COINFECTION:
Combination Therapy: 180 mcg subcutaneously once a week

Duration of therapy:

• When used with other HCV antiviral drugs: The manufacturer product information of the other HCV antiviral drugs should be consulted.
• When used with ribavirin without other HCV antiviral drugs: 48 weeks, regardless of HCV genotype

COMMENTS:

• The manufacturer product information for coadministered HCV antiviral drugs should be consulted.
• This drug should not be used alone or in combination with ribavirin without additional HCV antiviral drugs for treatment of chronic hepatitis C (CHC) patients who failed prior interferon alfa therapy.
• This drug is not recommended for treatment of CHC patients who have had solid organ transplantation.
• Therapy should be discontinued at once if hepatic decompensation occurs.

USE: For the treatment of CHC patients (with or without HIV coinfection) with compensated liver disease

• As part of a combination regimen with other HCV antiviral drugs
• As monotherapy if contraindications or significant intolerance to other HCV antiviral drugs

Usual Adult Dose for Chronic Hepatitis B

180 mcg subcutaneously once a week for 48 weeks

Use: For the treatment of patients with HBeAG-positive and HBeAG-negative chronic hepatitis B who have compensated liver disease and evidence of viral replication and liver inflammation

Usual Pediatric Dose for Chronic Hepatitis C

5 years or older: 180 mcg/1.73 m2 x BSA subcutaneously once a week
Maximum dose: 180 mcg

Duration of therapy:

• HCV genotypes 2, 3: 24 weeks
• Other HCV genotypes: 48 weeks

Comments:

• For use with ribavirin
• The manufacturer product information for ribavirin should be consulted.
• Patients who start therapy before their 18th birthday should remain on the recommended pediatric dose until therapy is finished.

Use: In combination with ribavirin, for the treatment of CHC patients with compensated liver disease

Renal Dose Adjustments

Adults:
CrCl less than 30 mL/min: 135 mcg subcutaneously once a week

Comments:

• Signs/symptoms of interferon toxicity should be closely monitored.
• If severe side effects or laboratory abnormalities develop, the dose may be reduced to 90 mcg subcutaneously once a week until the side effects abate. If intolerance persists after dose adjustment, this drug should be discontinued.
• The manufacturer product information for coadministered HCV antiviral drugs should be consulted.

Pediatrics: Data not available

Liver Dose Adjustments

Hepatic decompensation (Child-Pugh B or C [score greater than 6]) in cirrhotic patients: Contraindicated
Hepatic decompensation with Child-Pugh score at least 6 in cirrhotic CHC patients coinfected with HIV: Contraindicated

Dose Modification Due To ALT Elevation in Adults:
If ALT increases are progressive despite dose reduction or accompanied by increased bilirubin or evidence of hepatic decompensation, therapy should be discontinued immediately.

Chronic hepatitis B:

• In patients with ALT elevations (greater than 5 times the upper limit of normal [5 x ULN]), liver function should be monitored more often and either reducing the dose to 135 mcg or temporarily discontinuing therapy should be considered; after dose reduction or withholding, therapy can be resumed after ALT flares subside.
• In patients with persistent, severe (ALT greater than 10 x ULN) hepatitis B flares, therapy discontinuation should be considered.

Chronic hepatitis C:

• In patients with progressive ALT increases above baseline values, the dose should be reduced to 135 mcg and liver function should be monitored more often; after dose reduction or withholding, therapy can be resumed after ALT flares subside.

Dose Modification Due To ALT Elevation in Pediatrics:

• Persistent or increasing ALT elevations 5 to less than 10 x ULN: Dose should be reduced to 135 mcg/1.73 m2 x BSA; weekly monitoring recommended, with further dose reduction if needed, until stable or ALT level decreases.
• Persistent ALT values at least 10 x ULN: Therapy should be discontinued.

Dose Adjustments

ADULTS:
After the side effect, neutropenia, or thrombocytopenia improves, reescalation of the dose back to the previous dose may be considered.

Dose Modification Due To Neutropenia:

• Absolute neutrophil count (ANC) less than 750 cells/mm3: Dose should be reduced to 135 mcg subcutaneously once a week.
• ANC less than 500 cells/mm3: Therapy should be suspended until ANC values return to more than 1000 cells/mm3. Therapy should be restarted at 90 mcg subcutaneously once a week and ANC should be monitored.

Dose Modification Due To Thrombocytopenia:

• Platelet count less than 50,000 cells/mm3: Dose should be reduced to 90 mcg subcutaneously once a week.
• Platelet count less than 25,000 cells/mm3: Therapy should be discontinued.

Dose Modification Due To Depression:

• Mild: No adjustment recommended.
• Moderate: Initial management (4 to 8 weeks) includes reducing dose to 135 mcg subcutaneously once a week; dose reduction to 90 mcg subcutaneously once a week may be required in some cases. Patient should be evaluated once weekly (office visit at least every other week). If symptoms improve and are stable for 4 weeks, recommendations are to continue reduced dosing or return to normal dose.
• Severe: This drug should be permanently discontinued. Psychiatric therapy may be necessary.

PEDIATRICS:
Dose Modification Due To Neutropenia:
ANC 750 to 999 cells/mm3:

• Week 1 to 2: Dose should be reduced to 135 mcg/1.73 m2 x BSA at once.
• Week 3 to 48: No modification.

ANC 500 to 749 cells/mm3:

• Week 1 to 2: Dose should be delayed or held until greater than 750 cells/mm3, then dose should be resumed at 135 mcg/1.73 m2 x BSA. Weekly assessment is recommended for 3 weeks to verify ANC greater than 750 cells/mm3.
• Week 3 to 48: Dose should be reduced to 135 mcg/1.73 m2 x BSA at once.

ANC 250 to 499 cells/mm3:

• Week 1 to 2: Dose should be delayed or held until greater than 750 cells/mm3, then dose should be resumed at 90 mcg/1.73 m2 x BSA.
• Week 3 to 48: Dose should be delayed or held until greater than 750 cells/mm3, then dose should be resumed at 135 mcg/1.73 m2 x BSA.

ANC less than 250 cells/mm3 (or febrile neutropenia): Therapy should be discontinued.

Dose Modification Due To Thrombocytopenia:

• Platelet count less than 50,000 cells/mm3: Dose should be reduced to 90 mcg/1.73 m2 x BSA.

Dose Modification Due To Depression:

• Mild: No adjustment recommended.
• Moderate: Initial management (4 to 8 weeks) includes reducing dose to 135 mcg/1.73 m2 x BSA subcutaneously once a week; dose reduction to 90 mcg/1.73 m2 x BSA subcutaneously once a week may be required in some cases. Patient should be evaluated once weekly (office visit at least every other week). If symptoms improve and are stable for 4 weeks, recommendations are to continue reduced dosing or return to normal dose.
• Severe: This drug should be permanently discontinued. Psychiatric therapy may be necessary.

Precautions

US BOXED WARNING:

• RISK OF SERIOUS DISORDERS: Alpha interferons may cause/aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Close monitoring with periodic clinical and laboratory evaluations are recommended. Therapy should be withdrawn in patients with persistently severe or worsening signs/symptoms of these disorders. In most (but not all) cases, these disorders resolve after therapy is stopped.

Safety and efficacy have not been established in patients younger than 5 years; this drug is contraindicated in neonates and infants because it contains benzyl alcohol.

Consult WARNINGS section for additional precautions.

Dialysis

Adults:
CrCl less than 30 mL/min, including patients on hemodialysis: 135 mcg subcutaneously once a week

Comments:

• Signs/symptoms of interferon toxicity should be closely monitored.
• If severe side effects or laboratory abnormalities develop, the dose may be reduced to 90 mcg subcutaneously once a week until the side effects abate. If intolerance persists after dose adjustment, this drug should be discontinued.
• The manufacturer product information for coadministered HCV antiviral drugs should be consulted.

Pediatrics: Data not available

Other Comments

Administration advice:

• Administer dose on the same day of each week and at the same time.
• Administer the subcutaneous injection in the abdomen or thigh (different location each time).
• Consult the manufacturer product information regarding missed doses.

Storage requirements:

• Store in refrigerator at 2C to 8C (36F to 46F)
• Do not leave out of the refrigerator for more than 24 hours.
• Do not freeze or shake.
• Protect from light.

Preparation techniques:

• The manufacturer product information should be consulted.

General:

• For combination therapy: The manufacturer product information for coadministered HCV antiviral drugs should be consulted.

Monitoring:

• Cardiovascular: ECG for patients with preexisting cardiac disease (before combination therapy)
• General: Standard biochemical laboratory tests (before therapy, at 4 weeks, and periodically during therapy); HCV RNA (periodically during therapy); signs/symptoms of interferon toxicity or other serious side effects
• Hematologic: Standard hematological laboratory tests (before therapy, at 2 and 4 weeks, and periodically during therapy); CBC (before and routinely during therapy)
• Hepatic: Clinical status and hepatic function (during therapy; more often if ALT flares)
• Ocular: Eye examination in all patients (at baseline); ophthalmologic exams in patients with preexisting ophthalmologic disorders (periodically during therapy)
• Psychiatric: Signs/symptoms of depression and other psychiatric symptoms
• Renal: Renal function in all patients by estimating CrCl (before therapy); CrCl in patients with renal dysfunction

Patient advice:

• Keep well hydrated, especially during initial stages of therapy.
• Consult healthcare provider if full dose is not received (e.g., leakage around injection site).

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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