Pegasys (Peginterferon Alfa-2a) - Uses, Dose, Side effects, MOA, Contraindications

Pegasys (Peginterferon Alfa-2a) is prepared by recombinant DNA technology that is used to treat patients with chronic hepatitis B and chronic hepatitis C infections.

Peginterferon Alfa-2a Uses:

  • Chronic hepatitis B:

    • Treatment of adults with hepatitis B e antigen (HBeAg)-positive and HBeAg-negative chronic hepatitis B virus (HBV) infection with compensated liver disease and evidence of viral replication and liver inflammation.
    • Treatment of pediatric patients 3 years and older with HBeAg-positive chronic HBV infection who are non-cirrhotic and have evidence of viral replication and increased serum alanine aminotransferase.
  • Chronic hepatitis C:

    • Combination therapy: Treatment of adults with chronic hepatitis C (CHC) with compensated liver disease as part of a combination regiment with other hepatitis C virus (HCV) antiviral drugs.
    • Treatment of pediatric patients 5 years and older with CHC and compensated liver disease combined with ribavirin.
    • Note:
      • Current AASLD/IDSA guidelines do not recommend the use of interferon products.
      • Peginterferon and ribavirin, typically combined with a direct-acting antiviral, remain in use for certain genotypes, especially in resource-limited settings where newer interferon-free regimens are not available.
    • Monotherapy (for patients having contraindications or who are who cannot tolerate other HCV antiviral drugs):
      • Treatment (as a single agent) of chronic hepatitis C in patients with compensated liver disease in patients with contraindications or significant intolerance to other HCV antiviral drugs.
    • Note:
      • Current AASLD/IDSA guidelines do not recommend the use of interferon products. Peginterferon and ribavirin, typically combined with a direct-acting antiviral, remain in use for certain genotypes, particularly in resource-limited settings where newer interferon-free regimens are not available.
    • Limitations of use:
      • Peginterferon alfa-2a alone or combined with ribavirin without additional HCV antiviral drugs is not recommended for the treatment of patients with chronic HCV who didn't respond to ptior therapy with an interferon alfa.
      • Peginterferon alfa-2a is not recommended for treatment of patients with CHC with solid organ transplantation.

Read: Vosevi (Sofosbuvir, Velpatasvir, and Voxilaprevir) Tablets

Pegasys (Peginterferon Alfa-2a) Dose in Adults

Pegasys (Peginterferon Alfa-2a) Dose in the treatment of Chronic hepatitis C (monoinfection or coinfection with HIV):

  • SubQ: 180 mcg once weekly, duration of therapy variable with HCV genotype and concomitant HCV antivirals.

Note:

  • Current AASLD/IDSA guidelines do not recommend the use of interferon products. Peginterferon and ribavirin, typically combined with a direct-acting antiviral, remain in use for certain genotypes, particularly in resource-limited settings where newer interferon-free regimens are not available.

Pegasys (Peginterferon Alfa-2a) Dose in the treatment of Chronic hepatitis B:

  • SubQ: 180 mcg once weekly for 48 weeks
  • Missed dose:

    • If within 2 days of the usual day of administration, administer dose as soon as possible then restart previous schedule.

Pegasys (Peginterferon Alfa-2a) Dose in Childrens

Pegasys (Peginterferon Alfa-2a) Dose in the treatment of Chronic hepatitis B (CHB) infection (hepatitis B e antigen [HBeAg] positive):

  • Children ≥3 years and Adolescents:

    • SubQ: 104 mcg/m once weekly;
    • The maximum dose: 180 mcg/dose.
    • Duration of therapy: 48 weeks.
    • Note: Dosing presented is mathematically equivalent to weekly dosing presented in the manufacturer's labeling:
      • 180 mcg/1.73 m² x Body Surface Area (BSA);
      • adolescents who reach their 18th birthday during treatment should remain on the pediatric regimen.

Pegasys (Peginterferon Alfa-2a) Dose in the treatment of Chronic hepatitis C (CHC) infection:

Note: Although FDA approved in pediatric patients ≥5 years of age, AASLD/IDSA guidelines do not advise use of interferon products for the treatment of hepatitis C in children 3 to 11 years.

  • Children ≥5 years and Adolescents:

    • SubQ: 104 mcg/m once weekly;
    • The maximum dose: 180 mcg/dose; combined with ribavirin;
    • Note: Dosing presented is mathematically equivalent to weekly dosing presented in the manufacturer's labeling:
      • 180 mcg/1.73 m x BSA; adolescents who reach their 18th birthday during treatment should remain on the pediatric regimen.
  • Duration of therapy (based on genotype):

    • HCV genotype 1, 4, 5, 6: 48 weeks
    • HCV genotype 2, 3: 24 weeks

Note:

  • Pharmacokinetic simulation and modeling have developed a simplified weight-band dosing for BSA ranges (see the following) to provide similar exposure to the 104 mcg/m² (180 mcg/1.73 m²) weekly regimen; direct patient experience is not available.
    • BSA 0.71 to 0.74 m²: 65 mcg/dose
    • BSA 0.75 to 1.08 m²: 90 mcg/dose
    • BSA 1.09 to 1.51 m²: 135 mcg/dose
    • BSA >1.51 m²: 180 mcg/dose

Pegasys (Peginterferon Alfa-2a) Dosing adjustment for toxicity:

Note: Pediatric dosing adjustments shown below correspond to the following doses in manufacturer's labeling:

  • 78 mcg/m² = 135 mcg/1.73 m²;
  • 52 mcg/m² = 90 mcg/1.73 m²; and
  • 26 mcg/m² = 45 mcg/1.73 m².
  • Depression:

    • CHB, CHC: Children ≥3 years and Adolescents:
      • Mild depression:
        • No dosage adjustment needed; evaluate once weekly.If depression remains stable, continue weekly visits.
        • If improves, restart normal visit schedule. If  worsens after 2 months, consider psychiatric consultation; discontinue therapy or decrease dose to 78 mcg/m² once weekly or a further dose reduction to 52 mcg/m² once weekly.
      • Moderate depression:
        • Decrease dose to 78 mcg/m² once a week  or further reduce dose  to 52 mcg/m² once every week.
        • Follow up at least every other week.
        • After 2 months, if symptoms improve and remain stable for 4 weeks, restart normal visit schedule; may continue reduced dosing or return to normal dose.
        • If depression remains stable, consider psychiatric evaluation and continue reduced dosing.
        • If symptoms worsen, obtain immediate psychiatric consultation and discontinue therapy permanently.
      • Severe depression:
        • Discontinue interferon treatment permanently.
        • Consult psychiatry immediately.
  • Hematologic toxicity:

Note: For CHC, management dependent upon weeks of therapy

    • Neutropenia:

    • ANC 750 to 999/mm³:
      • CHB:
        • Children ≥3 years and Adolescents:
          • No dosage modification.
      • CHC:
        • Children ≥5 years and Adolescents:
          • Week 1 to 2: Decrease dose to 78 mcg/m² once weekly
          • Weeks 3 to 48: No modification
    • ANC 500 to 749/mm³:
      • CHB:
        • Children ≥3 years and Adolescents:
          • Decrease dose to 78 mcg/m² once weekly
      • CHC:
        • Children ≥5 years and Adolescents:
          • Week 1 to 2: Hold dose until ANC >750/mm³ then resume therapy at 78 mcg/m once weekly. Assess WBC 3 times weekly to verify ANC >750/mm³.
          • Weeks 3 to 48: Decrease dose to 78 mcg/m once weekly
    • ANC 250 to 499/mm³:
      • CHB:
        • Children ≥3 years and Adolescents:
          • Hold dose until ANC ≥1,000/mm³, then resume dose at 52 mcg/m² once weekly
      • CHC:
        • Children ≥5 years and Adolescents:
          • Week 1 to 2: Hold dose until ANC >750/mm³ then resume dose at 52 mcg/m² once weekly
          • Weeks 3 to 48: Hold dose until ANC >750/mm³ then resume dose at 78 mcg/m² once weekly
    • ANC <250/mm³ or febrile neutropenia:
        • CHB, CHC:
          • Children ≥3 years and Adolescents:
            • Discontinue treatment.
        • Thrombocytopenia:
          • Platelet count 25,000 to <50,000/mm³:
            • CHB, CHC: Children ≥3 years and Adolescents: Decrease dose to 52 mcg/m once weekly.
          • Platelet count <25,000/mm³:
            • CHB, CHC: Children ≥3 years and Adolescents: Discontinue treatment.

Pegasys (Peginterferon Alfa-2a) Pregnancy Category: C

  • Alfa interferon can be found in normal amniotic fluid, but it is not endogenous.
  • Placenta perfusion studies show that exogenous interferon does not cross the placenta.
  • Peginterferon alfa is not recommended during pregnancy according to the Health and Human Services (HHS), Perinatal HIV Guidelines.
  • This is because it has antigrowth and proliferative properties.
  • Studies on animal reproduction have shown abortifacient results.
  • Hepatitis C treatment is not recommended for pregnant women or to lower the chance of mother-to child transmission.
  • To reduce the risk of HCV transmission, HCV-infected women with childbearing potential may want to postpone pregnancy until treatment is completed.
  • Before administering to females of reproductive-age, verify pregnancy status.
  • Animal studies also showed disruptions in the menstrual cycle. Therefore, the manufacturer recommends that pregnant females use reliable contraception.
  • Peginterferon alfa-2a and ribavirin are contraindicated for pregnant females or males who have female partners who are pregnant.
  • Combination therapy with Ribavirin can cause birth defects or death in unborn children.
  • You should follow all warnings regarding ribavirin use during pregnancy and contraception.

Use of peginterferon during breastfeeding

  • Interferon alfa can be added to breast milk endogenously.
  • Interferon alfa-2b administration did not affect breast milk samples taken from a lactating mom before and after administration.
  • The spread of the hepatitis C viruses is not associated with breastfeeding.
  • However, it is advised to discontinue breastfeeding if nipples crack or bleed (milk should be expressed and discarded).
  • HIV co-infection means that breastfeeding is not advised.

Pegasys (Peginterferon Alfa-2a) Dose in Kidney Disease:

  • CrCl ≥30 mL/minute:
    • No dosage adjustment needed.
  • CrCl <30 mL/minute:
    • 135 mcg once weekly; monitor for toxicity
  • End-stage renal disease (ESRD) requiring hemodialysis:
    • 135 mcg once weekly; monitor for toxicity.
    • If severe adverse reactions or laboratory abnormalities develop, decrease dose to 90 mcg once weekly until adverse reactions improve; if intolerance persists after dosage adjustment, stop.

Pegasys (Peginterferon Alfa-2a) Dose in Liver disease:

  • Hepatic impairment prior to initiation:
    • Contraindicated in autoimmune hepatitis, hepatic decompensation (Child-Pugh >6 [class B and C]) in cirrhotic patients prior to treatment, and hepatic decompensation with Child-Pugh ≥6 in cirrhotic HCV patients coinfected with HIV before treatment.
  • Hepatic impairment during treatment:

Note: Immediately stop therapy if hepatic decompensation (Child-Pugh ≥6 [class B and C]) is observed.

  • HCV:
    • ALT progressively rising above baseline:
      • Decrease dose to 135 mcg once weekly and monitor LFTs more frequently.
      • If ALT continues to rise despite dose reduction or ALT increase is accompanied by increased bilirubin or hepatic decompensation, stop therapy immediately.
      • Therapy may resume after ALT flare subsides.
  • HBV:

    • ALT >5 x ULN:
      • Consider decreasing the dose to 135 mcg once weekly or temporarily discontinuing and monitor LFTs more frequently.
      • If ALT continues to rise despite dose reduction or ALT increase is accompanied by increased bilirubin or hepatic decompensation, stop therapy immediately.
      • Therapy may be started after the ALT flare resolves.
    • ALT >10 x ULN:
      • Consider stopping.

Common Side Effects of Pegasys (Peginterferon Alfa-2a):

  • Central Nervous System:

    • Fatigue
    • Headache
    • Rigors
    • Insomnia
    • Anxiety
    • Irritability
    • Nervousness
    • Depression
    • Dizziness
    • Pain
  • Dermatologic:

    • Alopecia
    • Pruritus
  • Endocrine & Metabolic:

    • Growth Suppression
      • Weight
      • Height
  • Gastrointestinal:

    • Nausea
    • Vomiting
    • Anorexia
    • Abdominal Pain
    • Diarrhea
  • Hematologic & Oncologic:

    • Neutropenia
  • Hepatic:

    • Increased Serum ALT
  • Local:

    • Injection Site Reaction
  • Neuromuscular & Skeletal:

    • Weakness
    • Myalgia
    • Arthralgia
  • Respiratory:

    • Cough
    • Flu-Like Symptoms
  • Miscellaneous:

    • Fever

Less Common Side Effects Of Pegasys (Peginterferon Alfa-2a):

  • Central Nervous System:

    • Lack Of Concentration
    • Memory Impairment
    • Mood Changes
  • Dermatologic:

    • Skin Rash
    • Dermatitis
    • Diaphoresis
    • Xeroderma
    • Eczema
  • Endocrine & Metabolic:

    • Weight Loss
    • Hypothyroidism
    • Hyperthyroidism
  • Gastrointestinal:

    • Decreased Appetite
    • Xerostomia
  • Hematologic & Oncology:

    • Thrombocytopenia
    • Lymphocytopenia
    • Anemia
  • Hepatic:

    • Increased Serum AST
    • Liver Decompensation
  • Infection:

    • Bacterial Infection
  • Neuromuscular & Skeletal:

    • Back Pain
  • Ophthalmic:

    • Blurred Vision
  • Respiratory:

    • Epistaxis
    • Upper Respiratory Tract Infection
    • Nasopharyngitis
    • Dyspnea

Contraindications to Pegasys (Peginterferon Alfa-2a):

  • Hypersensitivity reactions (eg. urticaria and angioedema), to peginterferonalfa-2a, other Alfa interferons or any component of formulation
  • autoimmune hepatitis;
  • Hepatic decompensation in patients with cirrhotics (Child–Pugh score >6, classes B and C before treatment);
  • Hepatic decompensation after Child-Pugh score>=6 in cirrhotic CHC co-infected with HIV prior to treatment
  • Neonatals and infants (due the benzyl alcohol component).
  • Pregnancy is not a good time to combine peginterferon alfa-2a with ribavirin.
  • Men whose female partners become pregnant are considered to be married;
  • Patients with hemoglobinopathies (ie. thalassemia major or sickle cell disease)
  • Coadministration with didanosine

There is not much evidence of cross-reactivity between allergenic interferons. Cross-sensitivity is possible due to similarities in chemical structure or pharmacologic effects.

Canadian labeling: Additional contraindications not in US labeling

  • Hypersensitivity to E.coli-derived products
  • Histories of autoimmune diseases;
  • severe psychiatric disorder, or history of severe mental disorder
  • Thyroid disorder uncontrolled
  • Breastfeeding

Warnings and precautions

  • Suppression of bone marrow

    • Causes bone marrow suppression and possibly severe cytopenias. Alfa interferons can (rarely) cause anemia.
    • These effects may be exacerbated by Ribavirin.
    • Use caution when combined with ribavirin.
    • If ANC is 500/mm3 and platelet count 25,000/mm3, stop therapy.
    • HIV coinfected patients may experience more severe neutropenia or thrombocytopenia than patients who are monoinfected.
    • Before starting treatment, obtain CBC and continue to monitor during therapy.
  • CNS depression:

    • CNS depression can lead to mental or physical impairments. Patients should be cautious about driving or operating machinery that requires mental alertness.
  • Dermatologic effects

    • Use of ribavirin therapy, whether or not with it, has been associated with serious cutaneous reactions.
  • Gastrointestinal effects:

    • Interferon alfa has been used to treat gastrointestinal hemorhage, ulcerative, and hemorhagic/ischemic collitis. These conditions can be life-threatening and severe. Stop using interferon immediately if colitis symptoms (eg, fever, bloody diarrhea, or abdominal pain) occur.
    • Generally, colitis resolves in 1 to 3 days after discontinuing treatment.
  • Hepatic effects

    • Pegasys and cirrhotic chronic liver disease patients have reported hepatic decompensation, death and even death due to the use of alpha-interferons. Patients infected with HIV who are receiving antiretroviral treatment have also shown increased risk.
    • Monitor your hepatic function carefully during treatment; stop immediately if you notice decompensation (Child–Pugh score 6 in monoinfected patients, and (Child–Pugh score =6, class A and C in HIV-infected patients).
    • Advise patients not to drink alcohol. It can increase liver damage.
  • Hypersensitivity reactions

    • Acute hypersensitivity reactions severe (eg, angioedema and bronchoconstriction, anaphylaxis, etc.) have been reported. It is important to discontinue treatment immediately.
  • Neuropsychiatric disorders [US Boxed Warning]

    • You may be at risk of developing life-threatening neuropsychiatric disorder. Monitor closely and stop any treatment if you notice persistently severe or worsening symptoms.
    • These effects are usually reversible if the medication is stopped. However, not all cases are like this.
    • Negative effects of neuropsychiatric disorders include depression, suicidal thoughts, suicide attempt and homicidal ideastion. They can also occur in patients who have had a history of psychiatric disorders.
    • Avoid severe psychiatric disorders and patients who have had a history depressive episodes.
  • Ophthalmic effects

    • A decrease in vision, or loss, or retinopathy (including macular edema and optic neuritis), retinal hemorhages, retinal detached (serious), cotton wool spots and retinal artery/vein thrombosis) may occur or get worse during treatment.
    • All patients should have a visual examination before they are allowed to use the device.
    • Patients with preexisting conditions (eg, diabetes or hypertensive retinalopathy) should also have regular exams during therapy.
    • If you experience new or worsening ophthalmologic conditions, discontinue use.
  • Pancreatitis

    • Alfa interferon therapy and ribavirin therapy have been used to treat pancreatitis.
    • Stop treatment for suspected pancreatitis.
  • Effects on the pulmonary system:

    • This condition may cause or aggravate dyspnea.
    • Pay attention.
    • Do not ignore pulmonary infiltrates and evidence of impaired pulmonary function.
    • Patients with pulmonary dysfunction and a history of pulmonary diseases should be cautious.
  • Autoimmune disease: [US-Boxed Warning]

    • Patients with autoimmune diseases may be at risk.
    • These effects are usually reversible if the medication is stopped. However, not all cases are like this.
    • Interferon therapy is recommended for patients with autoimmune conditions.
  • Cardiovascular disease

    • Patients with previous cardiovascular disease should be treated with caution. Hypertension, supraventricular arrhythmias and chest pain have all been reported.
    • Patients who have a history of unstable or significant cardiac disease should not be treated with ribavirin.
  • Diabetes:

    • Patients with diabetes mellitus should be cautious; hyper/hypoglycemia is a possibility; adjustments may be needed in anti-diabetic medication; discontinue if you are unable to manage your diabetes with medication.
  • Hepatitis B:

    • Flares, which are transient and possibly severe increases in serum ALT, may be experienced by hepatitis B sufferers during or after treatment. It is recommended to have more frequent monitoring and to reduce the dose.
    • If ALT elevation persists despite dose reduction, or if hepatic decompensation or increased bilirubin occurs, discontinue use immediately
  • Infectious disorders: [US Boxed Warning]:

    • Patients with persistently severe or worsening symptoms/signs may be at risk of developing infectious diseases.
    • These effects are usually reversible after discontinuation in most cases. However, not all cases.
    • Treatment has been recommended for serious and fatal infections, including viral and bacterial.
    • Flu-like symptoms such as fever and interferon therapy are common. It is important to rule out other infections or causes of persistent or high fever.
  • Ischemic disorders: [US Boxed Warning]:

    • Patients with persistent or worsening ischemia should be monitored closely.
    • These effects are usually reversible if the medication is stopped. However, not all cases are like this.
    • It has been reported in stroke patients who have not had stroke risk factors.
  • Renal impairment

    • Patients with impaired renal function (CrCl 30mL/minute) should be cautious.
    • Dosage adjustment is recommended. Monitor for signs and symptoms of toxic effects (dosage adjustment necessary if there are any).
  • Seizure disorders:

    • The clinical practice guidelines for chronic hepatitis B treatment do not recommend its use to patients suffering from uncontrolled seizures.
  • Thyroid disorders:

    • Patients with thyroid diseases (hyper- and hypothyroidisms) or exacerbations should be cautious. If you are unable to manage your thyroid condition with medication, discontinue use.

Pegylated interferon (peginterferon) alfa-2a: Drug Interaction

Risk Factor C (Monitor therapy)

Chloramphenicol (Ophthalmic)

May enhance the adverse/toxic effect of Myelosuppressive Agents.

CloZAPine

Myelosuppressive Agents may enhance the adverse/toxic effect of CloZAPine. Specifically, the risk for neutropenia may be increased.

CloZAPine

CYP1A2 Inhibitors (Weak) may increase the serum concentration of CloZAPine. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs.

Mesalamine

May enhance the myelosuppressive effect of Myelosuppressive Agents.

Methadone

Interferons (Alfa) may increase the serum concentration of Methadone.

Pegloticase

May diminish the therapeutic effect of PEGylated Drug Products.

Pegvaliase

PEGylated Drug Products may enhance the adverse/toxic effect of Pegvaliase. Specifically, the risk of anaphylaxis or hypersensitivity reactions may be increased.

Promazine

May enhance the myelosuppressive effect of Myelosuppressive Agents.

Ribavirin (Oral Inhalation)

Interferons (Alfa) may enhance the adverse/toxic effect of Ribavirin (Oral Inhalation). Hemolytic anemia has been observed.

Ribavirin (Systemic)

Interferons (Alfa) may enhance the adverse/toxic effect of Ribavirin (Systemic). Hemolytic anemia has been observed.

Theophylline Derivatives

Interferons may decrease the metabolism of Theophylline Derivatives. Exceptions: Dyphylline.

Zidovudine

Interferons may enhance the adverse/toxic effect of Zidovudine. Interferons may decrease the metabolism of Zidovudine.

Risk Factor D (Consider therapy modification)

Aldesleukin

Interferons (Alfa) may enhance the adverse/toxic effect of Aldesleukin. In particular, risks of myocardial and renal toxicity may be increased by this combination.

Deferiprone

Myelosuppressive Agents may enhance the neutropenic effect of Deferiprone. Management: Avoid the concomitant use of deferiprone and myelosuppressive agents whenever possible. If this combination cannot be avoided, monitor the absolute neutrophil count more closely.

TiZANidine

CYP1A2 Inhibitors (Weak) may increase the serum concentration of TiZANidine. Management: Avoid these combinations when possible. If combined use is necessary, initiate tizanidine at an adult dose of 2 mg and increase in 2 to 4 mg increments based on patient response. Monitor for increased effects of tizanidine, including adverse reactions.

Risk Factor X (Avoid combination)

BCG (Intravesical)

Myelosuppressive Agents may diminish the therapeutic effect of BCG (Intravesical).

Cladribine

May enhance the myelosuppressive effect of Myelosuppressive Agents.

Dipyrone

May enhance the adverse/toxic effect of Myelosuppressive Agents. Specifically, the risk for agranulocytosis and pancytopenia may be increased

Telbivudine

Peginterferon Alfa-2a may enhance the adverse/toxic effect of Telbivudine. Specifically, the risk for peripheral neuropathy may be increased.

Monitoring parameters:

Manufacturer’s labeling: Clinical studies tested as follows:

  • Pediatric patients:
    • Hematologic and biochemical assessments were made at weeks 1, 3, 5, and 8, and then every 4 weeks onwards;
    • TSH measured every 12 weeks
  • Adults:
    • CBC (including hemoglobin, WBC, and platelets) and chemistries (including liver function tests and uric acid) measured at weeks 1, 2, 4, 6, and 8, and then every 4-6 weeks (more frequently if abnormal).
    • TSH measured every 3 months.

In addition, the following baseline values were used as entrance criteria in adults:

  • Platelet count ≥90,000/mm³ (as low as 75,000/mm³ in patients with cirrhosis or 70,000/mm³ in patients with CHC coinfected with HIV)
  • ANC ≥1,500/mm³
  • Serum creatinine <1.5 times ULN
  • TSH and T4 within normal limits or adequately controlled
  • CD4 cell count ≥200 cells/mm³ or CD4 cell count ≥100 cells/mm³ but <200 cells/mm³ and HIV-1 RNA <5,000 copies/mL in CHC patients coinfected with HIV.
  • Hemoglobin ≥12 g/dL for women and ≥13 g/dL for men in CHC monoinfected patients
  • Hemoglobin ≥11 g/dL for women and ≥12 g/dL for men in CHC patients coinfected with HIV
  • Serum HCV RNA levels (pretreatment, 12- and 24 weeks after therapy initiation, 24 weeks after completion of therapy).
  • Note:
    • Discontinuation of therapy may be considered after 12 weeks in patients with HCV (genotype 1) who fail to attain an early virologic response (EVR) (defined as ≥ 2-log decrease in HCV RNA compared to pretreatment) or after 24 weeks with detectable HCV RNA.
    • Treat patients with HCV (genotypes 2,3) for 24 weeks (if tolerated) and then assess HCV RNA levels.

Before treatment, pregnancy screening should occur for women of childbearing age who are receiving treatment or who have male partners who are on treatment. Combined with ribavirin, pregnancy tests should continue monthly up to 6 months following discontinuation of therapy. Assess for depression and other psychiatric symptoms before and during therapy; baseline eye examination and periodically in patients with baseline disorders; baseline echocardiogram in patients with cardiac disease. In children, growth velocity and weight should be observed during and periodically after combination therapy is stopped.

Alternate recommendations: Chronic Hepatitis B: During therapy:

  • CBC (monthly to every 3 months);
  • TSH (every 3 months);
  • monitor for autoimmune, ischemic, neuropsychiatric, and infectious complications.

How to administer Pegasys (Peginterferon Alfa-2a)?

SubQ: Administer in the abdomen or thigh. Rotate injection site. The administration should be done on the same day and at around the same time each week.

Mechanism of action of Pegasys (Peginterferon Alfa-2a):

  • Alpha interferons, a group of proteins produced by nucleated cells, have antiviral and antiproliferative properties as well as immune-regulating activities.
  • There are 16 types of alpha interferons. Interferons are able to interact with cells through high-affinity cell surface receptors.
  • Multiple effects can be observed after activation including induction gene transcription. 
  • Interferons can inhibit cell growth, alter the state cellular differentiation, interfere oncogene gene expression, alter cell membrane antigen expression, enhance phagocytic activity, augment cytotoxicity and lymphocytes for target tissues.

Half-life elimination:

  • Terminal: 50-160 Hours; extended with renal dysfunction

Time to peak, serum:

  • 72 to 96 hours

International Brand Names of Peginterferon Alfa-2a:

  • Pegasys
  • Pegasys ProClick
  • Optipeg-A
  • Pegasys
  • Pegasys PFS
  • Pegferon
  • Pegin

Peginterferon Alfa-2a Brand Names in Pakistan:

Peginterferon Alfa-2a Injection 180 mcg in Pakistan

PEG FEROZSONS LABORATOIES LTD.

 

Peginterferon Alfa-2a Injection 180 mcg/ml in Pakistan

UNIPEG GETZ PHARMA PAKISTAN (PVT) LTD.

 

Peginterferon Alfa-2a Injection 180 mcg/0.5ml in Pakistan

PEG-INF FEROZSONS LABORATOIES LTD.
PEGASYS ROCHE PAKISTAN LTD.
ROPEGRA ROCHE PAKISTAN LTD.
TAGET HILTON PHARMA (PVT) LIMITED

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