Peginterferon alfa-2a 180micrograms/0.5ml solution for injection pre-filled syringes
Requires a prescription from a doctor or prescriber
Peginterferon alfa-2a is a form of recombinant interferon used as part of combination therapy to treat chronic Hepatitis C, an infectious liver disease caused by infection with Hepatitis C Virus (HCV).
Genetic variations that may affect drug response
1 known genetic variation may influence how your body responds to Peginterferon alfa-2a 180micrograms/0.5ml solution for injection pre-filled syringes.Gene involved: IFNL3
These are known genetic variations. They don't mean the medicine won't work for you — speak to your doctor or a pharmacogenomics specialist for personalised advice. Source: DrugBank (CC BY-NC 4.0).
Safety information for pregnancy and breastfeeding
Pregnancy
Always consult your doctor or midwife before taking any medicine during pregnancy or while breastfeeding. Source: DrugBank (CC BY-NC 4.0).
Official documents, adverse reaction reporting, and safety monitoring
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Official medicine documents
Safety monitoring data
Yellow Card reports
The MHRA Yellow Card scheme collects reports of suspected side effects from healthcare professionals and patients. View the Drug Analysis Profile (iDAP) for real-world adverse reaction data.
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Report a side effect
Submit a Yellow Card report to the MHRA
Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
EudraVigilance
The European Medicines Agency (EMA) collects suspected adverse reaction reports from across the EU/EEA through the EudraVigilance system. Search for safety data on this medicine.
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Suspected adverse reactions reported for Peginterferon alfa-2a
About EudraVigilance
Learn about EU pharmacovigilance and safety monitoring
EudraVigilance data is published by the European Medicines Agency (EMA). A suspected adverse reaction is not necessarily caused by the medicine.
1 branded products available
MHRA licensed products
View all licensed products for Peginterferon alfa-2a on the MHRA register
Pegasys 180micrograms/0.5ml solution for injection pre-filled syringes
WHO defined daily dose (DDD)
26 microgram
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via the NHS dm+d supplementary BNF/ATC mapping files (NHSBSA). Contains public sector information licensed under the Open Government Licence v3.0.
Therapeutically similar medicines
Similarity is based on WHO Anatomical Therapeutic Chemical (ATC) classification and on a factual NHS dm+d therapeutic-grouping code prefix. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
NHS prescribing volume and spending trends
Guidelines from the National Institute for Health and Care Excellence
NICE clinical guidance(10)
Adefovir dipivoxil and peginterferon alfa-2a for the treatment of chronic hepatitis B (TA96)
Hepatitis B (chronic): diagnosis and management (CG165)
Peginterferon alfa and ribavirin for the treatment of chronic hepatitis C (TA200)
Interferon alfa (pegylated and non-pegylated) and ribavirin for the treatment of chronic hepatitis C (TA75)
Peginterferon alfa and ribavirin for treating chronic hepatitis C in children and young people (TA300)
Peginterferon alfa and ribavirin for the treatment of mild chronic hepatitis C (TA106)
Entecavir for the treatment of chronic hepatitis B (TA153)
Chlormethine gel for treating mycosis fungoides-type cutaneous T-cell lymphoma (TA720)
Sofosbuvir for treating chronic hepatitis C (TA330)
Bulevirtide for treating chronic hepatitis D (TA896)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
Pharmacy stock checkers
Search for this medicine at major UK pharmacy chains. These links open the retailer's own website — results depend on their current online catalogue.
Supply & safety information
Official UK regulator monitoring and safety alerts
Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. Shortage and safety information sourced from MHRA drug safety updates (gov.uk, Crown Copyright under OGL v3.0).
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
Browse tools
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. BNF code shown is the factual mapping value distributed by NHS Business Services Authority (NHSBSA) in the dm+d supplementary file under OGL v3.0; it is not affiliated with, nor licensed from, the publishers of the British National Formulary. ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Academic studies and reviews for this medicine's active substance
Showing the 50 most relevant studies.
Reviews & meta-analyses: 8 · Randomised trials: 10 · 2000–2026
Showing the 50 most relevant studies, sorted by most relevant.
Calogero Cammà, Danilo Di Bona, Filippo Schepis, et al.
Hepatology, 2004
- Polyethylene Glycols
- Interferon-alpha
- Interferon alpha-2
Heiner Wedemeyer, Cihan Yurdaydın, Svenja Hardtke, et al.
The Lancet Infectious Diseases, 2019
- Tenofovir
- Alanine Transaminase
- Antiviral Agents
Ira M. Jacobson, Gregory J. Dore, Graham R. Foster, et al.
The Lancet, 2014
- Simeprevir
- Antiviral Agents
- Genotype
Michael P. Manns, Patrick Marcellin, Fred Poordad, et al.
The Lancet, 2014
- Simeprevir
- Interferon alpha-2
- Antiviral Agents
E. Lawitz, J. Lalezari, T. Hassanein, et al.
The Lancet. Infectious diseases, 2013
- Sofosbuvir
- Antiviral Agents
- Genotype
Qin Ning, Meifang Han, Yongtao Sun, et al.
Journal of Hepatology, 2014
- Hepatitis B virus
- Antiviral Agents
- DNA, Viral
Elgadi A, Wagealla M, Noorallah T, et al.
2026
- Polycythemia Vera
- Polyethylene Glycols
- Interferon-alpha
Paul Walden, Noemi Hummel, Agnieszka Kopiec, et al.
Journal of Comparative Effectiveness Research, 2025
Aim: Polycythemia vera (PV), a rare, chronic myeloproliferative neoplasm, that negatively impacts patient outcomes, and optimal therapy remains unclear due to a lack of head-to-head trials. A targeted literature review and feasibility assessment for an indirect comparison of ropeginterferon alfa-2b-njft versus peginterferon alfa-2a or ruxolitinib, using standard of care comprising hydroxyurea (HU) as a common comparator was conducted. Materials & methods: A targeted literature review evaluated clinical comparative evidence for PV treatments published between January 2014 and May 2024 in PubMed and relevant conference abstracts. End points of interest included complete hematologic response, molecular response, allele burden, event-free survival and safety. The feasibility of a network metaanalysis (NMA) was evaluated based on homogeneity of patient populations, treatment regimens and end point definitions. Results: Of 193 PubMed records and 460 conference abstracts screened, 40 records were included, representing evidence from 11 randomized controlled trials and 10 observational studies. Among these, 20 studies formed connected evidence networks for the end points of interest. Substantial heterogeneity across studies precluded a robust NMA: patient populations varied (newly diagnosed, highrisk, low-risk, HU-refractory or -intolerant), complete hematologic response definitions differed (e.g., requirement for absence of disease-related symptoms), molecular response thresholds were inconsistent, follow-up durations varied and definitions of standard of care ranged from almost exclusive use of HU to mixed regimens. Conclusion: An NMA for PV treatments was not feasible due to significant clinical and methodological heterogeneity across studies, including differences in patient characteristics, treatments, outcome definitions and follow-up times. These findings highlight the importance of standardized clinical trial designs and outcome definitions to enable robust comparative evidence generation for rare conditions like PV.
Abstract licence: CC BY-NC-ND
Pavlovic V, Yang L, Chan HL, et al.
2019
- Hepatitis B virus
- Hepatitis B, Chronic
- Polyethylene Glycols
Zhengyan Wang, Ling Sun, Yuwan Wu, et al.
Clinics and research in hepatology and gastroenterology, 2016
- Hepatitis B, Chronic
- Polyethylene Glycols
- Interferon-alpha
Sources: aggregated from Europe PMC (EMBL-EBI), OpenAlex, Crossref, PubMed and other open scholarly databases. Retracted articles are excluded. Study information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
None known
Half-life
84-353 hours
Mechanism
Peginterferon alfa-2a is derived from recombinant human interferon's alfa-2a moeity [FDA Label].
Food interactions
1 warning
Human targets
3 targets
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
72-96 hours
Half-life
84-353 hours
Clearance
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
In a joint recommendation published in 2016, the American Association for the Study of Liver Diseases (AASLD) and the Infectious Diseases Society of America (IDSA) no longer recommend Peginterferon alfa-2a for the treatment of Hepatitis C [A19593]. Peginterferon alfa-2a was used alongside DB00811 with the intent to cure, or achieve a sustained virologic response (SVR), after 48 weeks of therapy. SVR and eradication of HCV infection is associated with significant long-term health benefits including reduced liver-related damage, improved quality of life, reduced incidence of Hepatocellular Carcinoma, and reduced all-cause mortality [A19626].
Peginterferon alfa-2a is available as a fixed dose injector (tradename Pegasys) used for the treatment of chronic Hepatitis C. Approved in 2002 by the FDA, Pegasys is indicated for the treatment of HCV with DB00811 or other antiviral drugs [FDA Label]. When combined together, Peginterferon alfa-2a and DB00811 have been shown to achieve a SVR between 36% for genotype 1 and 59% for genotypes 2-6 after 48 weeks of treatment.
Peginterferon alfa-2a is also indicated as a monotherapy for adult patients with HBeAg positive and HBeAg negative chronic hepatitis B infection who have compensated liver disease and evidence of viral replication and liver inflammation [FDA Label].
Known interactions with other medications. Always consult a healthcare professional.
Showing 50 of 746 interactions
Peginterferon alfa-2a causes or aggravates hypothyroidism and hyperthyroidism. Hyperglycemia, hypoglycemia, and diabetes mellitus have been observed to develop in patients treated with Peginterferon alfa-2a. Peginterferon alfa-2a may decrease or produce loss of vision, retinopathy including macular edema, retinal artery or vein thrombosis, retinal hemorrhages and cotton wool spots, optic neuritis, papilledema and serous retinal detachment.
Peginterferon mayy be related to increased ischemic and hemorrhagic cerebrovascular events. Patients with cirrhosis on Peginterferon alfa-2a are at risk of hepatic decompensation. Dyspnea, pulmonary infiltrates, pneumonia, bronchiolitis obliterans, interstitial pneumonitis, pulmonary hypertension and sarcoidosis may be induced or aggravated by Peginterferon alfa-2a.
Serious and severe infections (bacterial, viral, or fungal) have been reported during treatment with Peginterferon alfa-2a. Ulcerative and hemorrhagic/ischemic colitis have been observed within 12 weeks of starting Peginterferon alfa-2a treatment. Pancreatitis and peripheral nephropathy have also been reported.
Peginterferon alfa-2a is associated with growth inhibition in pediatric patients. Use of Peginterferon alfa-2a while pregant may result in delopmental abnormalities or death of the fetus.
How the body processes this drug — absorption, distribution, metabolism, and elimination
Proteins and enzymes this drug interacts with in the body
PMID:10049744 PMID:10556041 PMID:21854986 PMID:26424569 PMID:28165510 PMID:32972995 PMID:7665574 PMID:7759950 PMID:8181059 PMID:8798579 PMID:8969169
Type I interferon binding activates the JAK-STAT signaling cascade, resulting in transcriptional activation or repression of interferon-regulated genes that encode the effectors of the interferon response .
PMID:10049744 PMID:17517919 PMID:21854986 PMID:26424569 PMID:28165510 PMID:32972995 PMID:7665574 PMID:7759950 PMID:8181059 PMID:8798579 PMID:8969169
Mechanistically, type I interferon-binding brings the IFNAR1 and IFNAR2 subunits into close proximity with one another, driving their associated Janus kinases (JAKs) (TYK2 bound to IFNAR1 and JAK1 bound to IFNAR2) to cross-phosphorylate one another .
PMID:10556041 PMID:11682488 PMID:12105218 PMID:21854986 PMID:32972995
The activated kinases phosphorylate specific tyrosine residues on the intracellular domains of IFNAR1 and IFNAR2, forming docking sites for the STAT transcription factors (STAT1, STAT2 and STAT) .
PMID:11682488 PMID:12105218 PMID:21854986 PMID:32972995
STAT proteins are then phosphorylated by the JAKs, promoting their translocation into the nucleus to regulate expression of interferon-regulated genes PMID:12105218 PMID:28165510 PMID:9121453
PMID:10049744 PMID:14532120 PMID:15337770 PMID:2153461 PMID:21854986 PMID:24075985 PMID:31270247 PMID:33252644 PMID:35442418 PMID:7813427
Type I interferon binding activates the JAK-STAT signaling cascade, resulting in transcriptional activation or repression of interferon-regulated genes that encode the effectors of the interferon response .
PMID:10049744 PMID:21854986 PMID:7665574
Mechanistically, type I interferon-binding brings the IFNAR1 and IFNAR2 subunits into close proximity with one another, driving their associated Janus kinases (JAKs) (TYK2 bound to IFNAR1 and JAK1 bound to IFNAR2) to cross-phosphorylate one another .
PMID:21854986 PMID:32972995 PMID:7665574 PMID:7813427
The activated kinases phosphorylate specific tyrosine residues on the intracellular domains of IFNAR1 and IFNAR2, forming docking sites for the STAT transcription factors .
PMID:21854986 PMID:32972995 PMID:7526154 PMID:7665574 PMID:7813427
STAT proteins are then phosphorylated by the JAKs, promoting their translocation into the nucleus to regulate expression of interferon-regulated genes .
PMID:19561067 PMID:21854986 PMID:32972995 PMID:7665574 PMID:7813427 PMID:9121453
Can also act independently of IFNAR2: form an active IFNB1 receptor by itself and activate a signaling cascade that does not involve activation of the JAK-STAT pathway (By similarity)
Enzymes involved in drug metabolism — important for understanding drug interactions
ATC L03AB11
ATC L03AB61
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
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Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Peginterferon alfa-2a
Additional database identifiers
Drugs Product Database (DPD)
13246
HUGO Gene Nomenclature Committee (HGNC)
HGNC:5433
GenAtlas
IFNAR2
GeneCards
IFNAR2
GenBank Gene Database
L42243
GenBank Protein Database
995300
UniProt Accession
INAR2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:5432
GenAtlas
IFNAR1
GeneCards
IFNAR1
GenBank Gene Database
J03171
GenBank Protein Database
306914
Guide to Pharmacology
1723
UniProt Accession
INAR1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:5423
GenAtlas
IFNA2
GeneCards
IFNA2
GenBank Gene Database
M29883
UniProt Accession
IFNA2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2596
GenAtlas
CYP1A2
GeneCards
CYP1A2
GenBank Gene Database
Z00036
Guide to Pharmacology
1319
UniProt Accession
CP1A2_HUMAN
DrugBank citations
If you use DrugBank data in your research, please cite the following publications:
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Structured knowledge from the free knowledge base
ATC classifications (Wikidata)
Linked open data from Wikidata (Q420056), a free and open knowledge base operated by the Wikimedia Foundation. Data is available under the Creative Commons CC0 1.0 Public Domain Dedication.