peginterferon alfa 2b (Rx)

Brand and Other Names:PEG Intron, PegIntron Redipen, more...Sylatron
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Dosing & Uses


Dosage Forms & Strengths

prefilled pen/vial (PegIntron Redipen, PEG Intron)

  • 50mcg
  • 80mcg
  • 120mcg
  • 150mcg

injectable powder with diluent (Sylatron)

  • 296mcg/vial
  • 444mcg/vial
  • 888mcg/vial

Chronic Hepatitis C

Patients who are initiating therapy for HCV infection or who experienced relapse after prior PEG/RBV therapy, by HCV genotype (AASLD and IAS guidelines, April 2014)

Peginterferon is not recommended as monotherapy for any patient group

Genotypes 1, 4, 5, or 6

  • Peginterferon alfa 2b + ribavirin + sofosbuvir (preferred regimen)
  • 1.5 mcg/kg/Week SC; not to exceed 150 mcg/week, PLUS
  • Ribavirin PO 1000-1200 mg/day (based on body weight) plus sofosbuvir 400 mg PO qDay
  • Treat for 12 weeks (treatment-naive or relapsed); for nonresponders, may extend treatment of PEG/RBV to 24 weeks
  • Reduce ribavirin dose if CrCl ≤50 mL/min

Alternative regimens

  • Genotype 1: Simeprevir 150 mg/day x 12 weeks + PEG/RBV x 24 weeks
  • Genotype 3: Sofosbuvir + PEG/RBV x 12 weeks
  • Genotype 4: Simeprevir 150 mg/day x 12 weeks + PEG/RBV x 24-48 weeks
  • Genotypes 5 and 6: PEG/RBV x 48 weeks

Melanoma (Sylatron)

Indicated for melanoma with microscopic or gross nodal involvement within 84 days of definitive surgical resection including complete lymphadenectomy

6 mcg/kg/week SC for 8 doses, THEN  

3 mcg/kg/week SC for up to 5 years

Renal Impairment

Dose reductions of 25% and 50% are recommended in patients with moderate and severe renal impairment, respectively, receiving alpha interferons for chronic hepatitis C

CrCl 30-50 mL/min: Reduce 25%

CrCl 10-29 mL/min (including HD): 50%

The effect of varying degrees of renal impairment on the pharmacokinetics of peginterferon alfa-2b at the recommended doses of 3 mcg/kg or 6 mcg/kg for patients with melanoma has not been studied

Hepatic Impairment

Peginterferon alfa-2b has not been studied in patients with melanoma who have hepatic impairment; in patients treated for viral hepatitis, peginterferon alfa-2b treatment is contraindicated in those with moderate or severe hepatic impairment (Child-Pugh scores >6)

Discontinue Sylatron if hepatic decompensation (Child-Pugh scores >6) occurs during treatment

Orphan Designations



Dosage Forms & Strengths

prefilled pen/vial (PegIntron Redipen, PEG Intron)

  • 50mcg
  • 80mcg
  • 120mcg
  • 150mcg

Chronic Hepatitis C

<3 years: Safety and efficacy not established

3-17 years: 60 mcg/m² SC qWeek (+ ribavirin 15 mg/kg/day PO divided q12hr); administer on same day each week



Interaction Checker

and peginterferon alfa 2b

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            Adverse Effects

            >10% (Hepatitis C Trials)

            Headache (56%)

            Fatigue (52%)

            Injection site inflammation/reaction (47%)

            Depression (16-29%)

            Anxiety/emotional lability/irritability (28%)

            Nausea (26%)

            Insomnia (23%)

            Alopecia (22%)

            Fever (22%)

            Anorexia (20%)

            Diarrhea (18%)

            Abdominal pain (15%)

            Dizziness (12%)

            Impaired concentration (5-12%)

            Pain (12%)

            Pruritus (12%)

            Dry skin (11%)

            Weight loss (11%)

            >10% (Melanoma Trials)

            Fatigue (94%)

            ALT or AST increased (77%)

            Pyrexia (75%)

            Headache (70%)

            Anorexia (69%)

            Myalgia (68%)

            Nausea (64%)

            Arthralgia (51%)

            Chills (63%)

            Injection site reactions (62%)

            Depression (59%)

            Dysgeusia (38%)

            Diarrhea (37%)

            Exfoliative rash (36%)

            Dizziness (35%)

            Alopecia (34%)

            Vomiting (26%)

            Olfactory nerve disorder (23%)

            Blood alkaline phosphatase increased (23%)

            Paraesthesia (21%)

            Weight loss (11%)

            1-10% (Hepatitis C Trials)

            Pharyngitis (10%)

            Transient increase in transaminases (10%)

            Malaise (8%)

            Dermatitis (7%)

            Sinusitis (7%)

            Vomiting (7%)

            Dyspepsia (6%)

            Flushing (6%)

            Hepatomegaly (6%)

            Rash (6%)

            Hypertonia (5%)

            Hypothyroidism (5%)

            Injection site pain (2%)

            Taste perversion



            1-10% (Melanoma Trials)

            GGT increased (8%)

            Proteinuria (7%)

            Anemia (6%)

            Dyspnea (6%)

            Cough (5%)

            <1% (Hepatitis C Trials)



            Autoimmune thrombocytopenia

            Blindess, thrombosis of retinal vein

            Aggressive behavior


            Homicidal thoughts, suicidal thoughts, suicide

            Frequency Not Defined

            As with all proteins, there is a potential for immunogenicity

            Postmarketing reports

            Pulmonary fibrosis

            Bacterial infection including sepsis

            Hepatitis B virus reactivation in HCV/HBV co-infected patients


            Aphthous stomatitis

            Tongue pigmentation



            Black Box Warnings

            Alfa interferons cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders

            The risk of serious depression, with suicidal ideation and completed suicides, and other serious neuropsychiatric disorders are increased with alpha interferons

            Discontinue drug if persistently severe or worsening signs or symptoms of the above conditions are present; disorders typically resolve after stopping therapy

            These disorders may not resolve after the drug is discontinued

            Monitored closely with periodic clinical and laboratory evaluations

            Combination therapy with ribavirin

            • Ribavirin may cause birth defects and/or fetal death
            • Extreme care must be taken to avoid pregnancy in women taking peginterferon alfa-2a and in female partners of men taking peginterferon alfa-2a
            • Ribavirin causes hemolytic anemia; associated anemia may result in worsening of cardiac disease
            • Because ribavirin is genotoxic and mutagenic, consider it a potential carcinogen



            Autoimmune hepatitis

            Decompensated liver disease (Child-Pugh >6 [class B and C])

            Contraindications for combination therapy with ribavirin:

            • Pregnant women and men whose female partners are pregnant
            • Hemoglobinopathies (e.g., thalassemia major, sickle-cell anemia)
            • Creatinine clearance less than 50 mL/min


            May cause/aggravate fatal or life threatening autoimmune, ischemic, and infectious disorders

            Life-threatening or fatal neuropsychiatric events, including suicide, suicidal and homicidal ideation, depression, relapse of drug addiction/overdose, and aggressive behavior sometimes directed towards others reported in patients with and without a previous psychiatric disorder during therapy and follow-up; psychoses, hallucinations, bipolar disorders, and mania have been observed in patients receiving this therapy and should be used with caution in patients with a history of psychiatric disorders; report any symptoms of depression or suicidal ideation to healthcare provider

            Monitor and evaluate patients for signs and symptoms of depression and other psychiatric symptoms every 3 weeks during first 8 weeks of treatment and every 6 months thereafter; monitor patients during treatment and for at least 6 months after last dose; permanently discontinue therapy for suicidal or homicidal ideation, aggressive behavior towards others, or other severe or persistent psychiatric symptoms (see Black Box Warnings)

            Caution with hypothyroidism, hyperthyroidism, hyperglycemia, and diabetes mellitus that cannot be effectively treated by medication

            Cardiac adverse reactions occurred in 4% of patients during clinical trials; permanently discontinue with new onset ventricular arrhythmia or cardiovascular decompensation

            Risk of visual impairment and retinal disorders; discontinue if ophthalmologic problems develop

            Dyspnea, pulmonary infiltrates, pneumonia, bronchiolitis obliterans, interstitial pneumonitis, pulmonary hypertension, and sarcoidosis, some resulting in respiratory failure or patient deaths, may be induced or aggravated by therapy; recurrence of respiratory failure has been observed with interferon rechallenge; monitor

            Ischemic and hemorrhagic cerebrovascular events observed

            Development or exacerbation of autoimmune disorders (e.g., thyroiditis, thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, rheumatoid arthritis, interstitial nephritis, systemic lupus erythematosus, and psoriasis) observed; use with caution in patients with autoimmune disorders

            Pancreatitis and ulcerative or hemorrhagic/iscemic colitis may occur

            Severe decreases in neutrophil or platelet counts reported

            May cause birth defects and fetal death: use extreme care to avoid pregnancy in female patients and female partners of male patients

            When administered in combination with ibavirin causes hemolytic anemia; associated anemia may result in worsening of cardiac disease

            Hepatitis C (CHC) patients with cirrhosis may be at risk of hepatic decompensation and death when treated with alpha interferons, including peginterferon alpha 2b; cirrhotic CHC patients co-infected with HIV receiving highly active antiretroviral therapy (HAART) and alpha interferons with or without ribavirin appear to be at increased risk for development of hepatic decompensation compared to patients not receiving HAART; monitor clinical status and hepatic function during treatment and discontinue immediately if decompensation (Child-Pugh score greater than 6) observed

            Monitor closely patients with impaired renal function, for signs and symptoms of interferon toxicity, including increases in serum creatinine; adjust dose or discontinue therapy accordingly

            Serious, acute hypersensitivity reactions and cutaneous eruptions reported

            Dental/periodontal disorders reported with combination therapy

            Hypertriglyceridemia may result in pancreatitis (e.g., triglycerides greater than 1000 mg/dL)

            Weight loss and growth inhibition reported during combination therapy in pediatric patients

            Long-term growth inhibition (height) reported in some patients

            Peripheral neuropathy observed when used in combination with telbivudine


            Pregnancy & Lactation


            Available human data on use in pregnant women are insufficient to identify a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes

            Verify pregnancy status in females of reproductive potential prior to initiating treatment

            Drug may be used in combination with ribavirin; if administered with ribavirin, the information for ribavirin regarding pregnancy testing, contraception, and infertility also applies to this combination regimen; refer to ribavirin prescribing information for additional information


            • Treatment may cause embryo-fetal harm when administered to a pregnant woman; advise female patients of reproductive potential to use effective contraception during treatment and for at least 10 days after final dose


            • Based on animal fertility studies conducted in female cynomolgus monkeys, drug may impair human fertility; effects have been shown to be reversible

            Animal data

            • Based on findings from animal studies, treatment can cause embryo-fetal harm when administered to a pregnant woman; administration of nonpegylated interferon alfa-2b was abortifacient in rhesus monkeys at doses approximately 13 times higher than recommended dose of 6 mcg/kg/week; premature infant death was also observed


            There are no data on presence of peginterferon alfa-2b in human or animal milk, or on its effects on the breastfed infant, or milk production; nonpegylated interferon alfa 2-b is present in human milk at low levels; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for treatment and any potential adverse effects from treatment on breastfed infant or from underlying maternal condition

            Therapy may be used in combination with ribavirin; if drug is administered with ribavirin, breastfeeding is not recommended because of potential for serious adverse reactions from ribavirin in the breastfed infant

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.



            Mechanism of Action

            Immunomodulatory cytokine that enhances phagocytic activity of macrophages and cytotoxic activity of lymphocytes for target cells


            Half-life: 4.6 hr

            Peak plasma time: 15-44 hr


            Conjugation with polyethylene glycol slows metabolism


            Half-life: 40 hr

            Excretion: Urine (30%)


            A genetic variant near the gene encoding interferon-lambda-3 (IL28B rs12979860, a C to T change) is a strong predictor of response to peginterferon and ribavirin

            Sustained virologic response rates tended to be lower with the C/T and T/T genotypes compared to those with the C/C genotype, particularly among previously untreated subjects receiving 48 weeks of peginterferon and ribavirin



            SC Preparation (Sylatron)

            Reconstitute with 0.7 mL sterile water for injection

            Do not withdraw more than 0.5 mL of reconstituted solution from vial

            Resulting concentration following reconstitution

            • 296 mg/vial = 40 mcg/0.1 mL
            • 444 mg/vial = 60 mcg/0.1 mL
            • 888 mg/vial = 120 mcg/0.1 mL

            SC Administration

            Once weekly dosing: Administer on same day each week

            Rotate injection site





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            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.