Peginterferon Alfa-2b

Indications

Peginterferon Alfa-2b is used for: Chronic hepatitis C

Adult Dose

Subcutaneous Chronic Hepatitis C Patients who are initiating therapy for HCV infection or who experienced relapse after prior PEG/RBV therapy, by HCV genotype 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 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 Elderly: Dosage reduction may be necessary. 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)

Child Dose

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

Renal Dose

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%

Administration

Contra Indications

Autoimmune hepatitis; decompensated liver disease; in combination with ribavirin in pregnant women.

Precautions

Neuropsychiatric disorders, discontinue treatment with worsening or persistently severe signs/symptoms; chronically immunosuppressed and myelosuppresion; pulmonary disease; autoimmune disease; cardiovascular disease; DM; infectious disorders; ischaemic disorders; renal impairment; thyroid disorders; failed other alfa interferon therapy, received organ transplants, coinfected with HIV or hepatitis B, or received treatment for >1 yr. Elderly. Safety and efficacy not been established in children. Do not change brands of interferon without the concurrence of healthcare provider (product variability). Hazardous agent, handle and dispose appropriately. May affect ability to drive or operate machinery. Lactation: Unknown if excreted in human milk; decide whether to discontinue drug or breastfeeding

Pregnancy-Lactation

Pregnancy 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 Contraception 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 Infertility 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 Lactation 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

Interactions

Increased risk of haemolytic anemia, birth defects and/or foetal mortality, genotoxicity, mutagenicity, and may possibly be carcinogenic with ribavirin; decreases metabolism of theophylline; enhances adverse/toxic effects of zidovudine, decreases metabolism of zidovudine. Avoid ethanol in hepatitis C virus patients.

Adverse Effects

Side effects of Peginterferon Alfa-2b : >10% 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%) 1-10% 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, Neutropenia, Thrombocytopenia <1% (Hepatitis C Trials) Colitis, Pancreatitis, Autoimmune thrombocytopenia, Blindess, thrombosis of retinal vein, Aggressive behavior, Depression, Homicidal thoughts, suicidal thoughts, suicide

Mechanism of Action

Peginterferon alfa-2b are interferon proteins bound to polyethylene glycol (PEG) molecules resulting in higher and more prolonged serum interferon concentrations. It has a straight chain PEG; and requires reconstitution prior to use. 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.