Pegasys Dosage

Generic name: peginterferon alfa-2a
Dosage form: injection

The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

Dosage Overview

Administer PEGASYS by subcutaneous injection once weekly in the abdomen or thigh for the treatment of:

For treatment of CHC, use PEGASYS in combination with other HCV antiviral drugs. For information about the recommended dosage and administration and the safe and effective use of these other HCV antiviral drugs, refer to their prescribing information. PEGASYS monotherapy is only indicated in the treatment of CHC if there are contraindications to or significant intolerance to other HCV antiviral drugs.

For dosage modifications in patients with CHC or CHB:

  • Due to neutropenia, thrombocytopenia, ALT elevation, and depression [see Dosage and Administration (2.5)].
  • In patients with severe renal impairment (creatinine clearance less than 30 mL/minute) and in patients with creatinine clearance between 30 and 50 mL/minute [see Dosage and Administration (2.5)].

For important administration instructions for all the PEGASYS injection presentations (i.e., vial, prefilled syringe, autoinjector) see Dosage and Administration (2.6).

Adult Patients with Chronic Hepatitis C

Dosage in Adults with CHC without HIV Coinfection

Table 1 displays the recommended dosage and duration of PEGASYS and other HCV antiviral drugs in adults with CHC (without HIV coinfection) based on HCV genotype.

For treatment of HCV genotype 1 with PEGASYS in combination with ribavirin or alone, discontinuation of treatment is recommended if at least a 2 log10 reduction from baseline in HCV RNA has not been demonstrated by 12 weeks of therapy or if undetectable HCV RNA has not been achieved after 24 weeks of therapy [see Clinical Studies (14)]. Refer to the prescribing information for specific HCV antiviral drugs used in combination with PEGASYS for information on stopping therapy based on treatment response.

Immediately discontinue PEGASYS for hepatic decompensation (Child-Pugh score greater than 6 [class B and C]).

Table 1 Recommended Adult Dosage for PEGASYS for CHC Infection*
Hepatitis C Virus Genotype PEGASYS Dosage PEGASYS Duration
*
If PEGASYS is used in combination with other antiviral drugs for CHC, refer to the prescribing information of the other HCV antiviral drugs for the recommended dosage of the other HCV antiviral drugs and duration of the entire treatment regimen.
If PEGASYS and ribavirin are used without other HCV antiviral drugs the recommended duration of therapy is 48 weeks.
If PEGASYS and ribavirin are used without other HCV antiviral drugs the recommended duration of therapy is 24 weeks.
Genotypes 1, 4 180 mcg subcutaneous injection in thigh or abdomen once weekly Refer to the prescribing information of HCV antiviral drugs
Genotypes 2, 3    
Genotypes 5, 6 There is insufficient data for dosage recommendations

If PEGASYS monotherapy is used for treatment of CHC, the recommended PEGASYS dosage is 180 mcg via subcutaneous injection in thigh or abdomen once weekly for 48 weeks.

Dosage in Adults with CHC with HIV Coinfection

The recommended PEGASYS dosage in adults with CHC and HIV coinfection is 180 mcg subcutaneously once weekly in the thigh or abdomen. If PEGASYS is used in combination with other antiviral drugs, refer to the prescribing information of the other HCV antiviral drugs for the recommended dosage of the other HCV antiviral drugs and duration of the entire treatment regimen (including PEGASYS). If PEGASYS and ribavirin are used without other HCV antiviral drugs, the recommended duration of therapy is 48 weeks (regardless of HCV genotype).

Pediatric Patients with CHC

PEGASYS is administered as 180 mcg/1.73 m2 × BSA subcutaneously once weekly, to a maximum dose of 180 mcg, and should be given in combination with ribavirin. The recommended treatment duration for pediatric patients with HCV genotype 2 or 3 is 24 weeks and for other HCV genotypes is 48 weeks. Patients who initiate treatment prior to their 18th birthday should maintain the recommended pediatric dosage (not the adult dosage) through the completion of therapy. Refer to the prescribing information of ribavirin for the recommended dosage and duration.

Adults with Chronic Hepatitis B (CHB)

The recommended PEGASYS dosage in adults with CHB is 180 mcg subcutaneously once weekly in the thigh or abdomen for 48 weeks.

Dosage Modifications

Dosage Modifications Due to Adverse Reactions, Neutropenia or Thrombocytopenia in Adults

Table 2 displays the recommended PEGASYS dosage modifications due to adverse reactions, or due to neutropenia, or thrombocytopenia in adults. Following improvement of the adverse reaction, neutropenia or thrombocytopenia, consider re-escalation of the dosage back to the previous dosage [see Warnings and Precautions (5) and Adverse Reactions (6)].

Table 2 Recommended PEGASYS Dosage Modifications Due to Adverse Reactions, Neutropenia or Thrombocytopenia in Adults
Laboratory Values Recommended PEGASYS Dosage
ANC = absolute neutrophil count
Neutropenia
ANC < 750 cells/mm3 Reduce to 135 mcg subcutaneously once weekly
ANC < 500 cells/mm3 Discontinue treatment until ANC values return to more than 1000 cells/mm3. Reinstitute at 90 mcg subcutaneously once weekly and monitor ANC.
Thrombocytopenia
Platelet < 50,000 cells/mm3 Reduce to 90 mcg subcutaneously once weekly
Platelet < 25,000 cells/mm3 Discontinue treatment

Dosage Modifications 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 immediately discontinued. In CHC patients with progressive ALT increases above baseline values, the dosage of PEGASYS should be reduced to 135 mcg and more frequent monitoring of liver function should be performed. After PEGASYS dosage reduction or withholding, therapy can be resumed after ALT flares subside.

In chronic hepatitis B patients with elevations in ALT (greater than 5 × ULN), more frequent monitoring of liver function should be performed and consideration should be given to either reducing the dosage of PEGASYS to 135 mcg or temporarily discontinuing treatment. After PEGASYS dosage reduction or withholding, therapy can be resumed after ALT flares subside.

In adult patients with persistent, severe (ALT greater than 10 times above the upper limit of normal) hepatitis B flares, consideration should be given to discontinuation of treatment.

Dosage Modifications Due to Depression

Table 3 displays the recommended PEGASYS dosage modifications in adults and pediatric patients who develop interferon-related depression or whose underlying depression worsens. Table 3 also includes recommended frequency of psychiatric visits.

Table 3 Recommended PEGASYS Dosage Modifications and Psychiatric Visits Due to Depression in Adult & Pediatric Patients
Depression Severity Initial Management
(4-8 weeks)
Depression Status After 8 Weeks
Dose Modification Visit schedule Depression Severity Remains Stable Depression Severity Improves Depression Severity Worsens
Mild No change Evaluate once weekly by visit and/or phone Continue weekly visit schedule Resume normal visit schedule Consider psychiatric consultation. Discontinue PEGASYS or reduce dosage to 135 mcg (135 mcg/1.73 m2 × BSA for pediatric patients) or 90 mcg once weekly (90 mcg/1.73 m2 × BSA for pediatric patients)
Moderate Decrease PEGASYS dosage to 135 mcg (135 mcg/1.73 m2 × BSA for pediatric patients) or 90 mcg (90 mcg/1.73 m2 × BSA for pediatric patients) once weekly Evaluate once weekly (office visit at least every other week) Consider psychiatric consultation. Continue reduced dosing If symptoms improve and are stable for 4 weeks, may resume normal visit schedule. Continue reduced dosage or return to normal dosage Obtain immediate psychiatric consultation.
Discontinue PEGASYS permanently.
Severe Discontinue PEGASYS permanently Obtain immediate psychiatric consultation Psychiatric therapy necessary

Dosage Modifications Due to Adverse Reactions or Laboratory Abnormalities in Pediatric Patients

Table 4 displays the recommended PEGASYS dosage modifications due to adverse reactions, neutropenia, thrombocytopenia, or elevated liver enzymes in pediatric patients with CHC.

Table 4 Recommended PEGASYS Dosage Modifications for Neutropenia, Thrombocytopenia, and Elevated ALT in Pediatric Patients
 
Laboratory Abnormality
Recommended PEGASYS Dosage Modification
Neutropenia ANC 750-999 cells/mm3 Week 1-2: immediate modification to 135 mcg/1.73 m2 × BSA

Week 3-48: no modification.
ANC 500-749 cells/mm3 Week 1-2:
  • Delay or hold dosage until >750 cells/mm3 then resume dosage at 135 mcg/1.73 m2 × BSA
  • Assess weekly × 3 to verify ANC >750 cells/mm3;

Week 3-48:immediate modification to 135 mcg/1.73 m2 × BSA.

 
ANC 250-499 cells/mm3 Week 1-2: Delay or hold dosage until
>750 cells/mm3 then resume dose at 90 mcg/1.73 m2 × BSA;
Week 3-48: Delay or hold dosage until >750 cells/mm3 then resume dosage at 135 mcg/1.73 m2 × BSA.
 
ANC <250 cells/mm3 (or febrile neutropenia): Discontinue treatment.  
Thrombocytopenia Platelet <50,000 cells/mm3 Reduce dosage to 90 mcg/1.73 m2 × BSA.
Increased alanine transaminase (ALT) For persistent or increasing elevations ≥5 but <10 × ULN,
  • Modify dosage to 135 mcg/1.73 m2 × BSA.
  • Monitor weekly, reduce dosage further if necessary, until stable or ALT level decreases.
For persistent ALT values ≥10 × ULN Discontinue treatment.  

Dosage Modifications in Adults and Pediatric Patients with Renal Impairment

Prior to administering PEGASYS, evaluate renal function. Table 5 displays the recommended dosage modifications in adults with creatinine clearance less than 30 mL/minute, including patients with end-stage renal disease requiring hemodialysis [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3)]. Because there are no data in pediatric patients with renal impairment, dosage recommendations in pediatric patients are not provided. Refer to the respective prescribing information of other HCV antiviral drugs regarding use in patients with renal impairment.

Table 5 PEGASYS Dosage Modification for Adults with Renal Impairment
Creatinine Clearance Recommended PEGASYS Dosage
*
If severe adverse reactions or laboratory abnormalities develop, PEGASYS dose can be reduced to 90 mcg once weekly until adverse reactions abate. If intolerance persists after dosage adjustment, PEGASYS should be discontinued.
30 to 50 mL/minute 180 mcg once weekly
Less than 30 mL/minute including patients on hemodialysis 135 mcg once weekly
Less than 30 mL/minute including patients on hemodialysis* 135 mcg once weekly

Preparation and Administration

After proper training in subcutaneous injection, a patient may subcutaneously self-inject with PEGASYS if a healthcare provider determines that it is appropriate [see Instructions for Use]. Visually inspect PEGASYS for particulate matter and discoloration before administration (do not use if particulate matter is visible or product is discolored).

Table 6 displays the recommended volume of PEGASYS to be administered for the single-dose vial, prefilled syringe, and autoinjector presentations for the different dosages recommendations (i.e., 180, 135, or 90 mcg once weekly). Discard the unused portion of PEGASYS in single-use vials or prefilled syringes in excess of the labeled volume.

Table 6 Use of the Vial, Prefilled Syringe, and Autoinjector for Different PEGASYS Dosages
Recommended PEGASYS Dosage PEGASYS Presentations
  180 mcg/mL in a vial 180 mcg/0.5 mL in a prefilled syringe 180 mcg/0.5 mL in an autoinjector 135 mcg/0.5 mL in an autoinjector
180 mcg Use entire 1 mL Use entire 0.5 mL May use Do not use
135 mcg Use 0.75 mL Use 0.375 mL Do not use May use
90 mcg Use 0.5 mL Use 0.35 mL Do not use Do not use
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