This page shows what was measured, who it was measured in, and what that does not settle.
What Peginterferon alfa-2a does in the body
Long-standing hepatitis B or C, by stimulating the immune system.
When a cell notices a virus it releases interferon, a chemical shout that tells every cell nearby to switch on its defences. This drug is that shout, manufactured in bacteria and given by injection. It binds a receptor on the outside of your cells and turns on several hundred defensive genes, which between them make the cell a hostile place for a virus to copy itself. Because that receptor is on nearly every cell in the body, the defences switch on everywhere — which is why the treatment feels like a months-long case of influenza.
What happened in people
Weekly long-acting injections improved hepatitis cure or immune response compared with older treatments.
✓ Reviewed first-read answer
Where this came from
A person wrote this and a reviewer approved it against this exact record. It carries no effect size.
A reviewer approved this against this record. The reviewed-claim record carrying the exact population and effect size does not exist yet.
No source is stored against this line.
The limit that matters most
Studies measured virus and liver tests, not deaths, liver cancer or transplants.
Where it acts
The surface of essentially every nucleated cell in the body — which is why the side effects are systemic rather than hepatic
Kind of result
The kind of result is not recorded
Supervision
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
What the registries record it as
The substance registry classes this as protein.
FDA substance registry · Q46947FE7K · read 2026-08-29
Where each sentence above came from
No recorded sentence describes the change this makes in a way that stands on its own. The page opens with what it is taken for instead, and the recorded explanation follows below.
Shown as the opening line on this page.
The limit a reviewer approved as the one that matters most here.
The four opening statements run to 119 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Randomisation
Randomisation means chance decides who gets which treatment.
A picture of it, and where the picture fails
It is like a coin toss deciding the groups.
Where that stops being true. A coin toss is fair once. Fairness here comes from doing it for everyone.
What people get wrong. It is thought to make groups identical. It makes them similar on average, including on things nobody measured.
Allocation of participants to arms by a chance process, so that unmeasured factors are balanced in expectation.
Confidence interval
A confidence interval is the range the true answer is likely to sit in.
A picture of it, and where the picture fails
It is like a weather forecast giving a range rather than one number.
Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.
What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.
An interval estimate that would contain the true parameter in a stated proportion of repeated studies.
Receptor
A receptor is a part of a cell that a signal fits into.
A picture of it, and where the picture fails
A receptor is like a lock waiting for one key.
Where that stops being true. A lock either opens or does not. A receptor can be half-triggered, or worn out.
What people get wrong. Fitting a receptor is read as causing a benefit. It causes a step, and nothing more.
A protein that binds a specific ligand and converts that binding into a cellular response.
Pathway
A pathway is a chain of steps inside a cell, each one setting off the next.
A picture of it, and where the picture fails
A pathway is like a row of dominoes.
Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.
What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.
An ordered series of molecular interactions producing a defined cellular change.
What happened in people◇Read from sources, not yet reviewed
What was measured, goal by goal
One row for each goal a registered study measured something for. One column for each kind of thing that could be measured.
Registered studies list 40 outcome measures that RNAWiki could read. A registered study says what someone planned to measure. It does not say what they found. 0 of the matched studies tested this substance, and 0 posted a result.
There is no single score. A strong test result and a weak life result are different facts.
Goals down the side, kinds of measurement across the top. Each cell says what kind of thing was registered, not what was found.
Goal
Life outcome
What a body can do
How a person feels
A test result
A step in the body
Harms
How long
Who was studied
Mood
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
…Waiting for a reviewer1 registered symptom measure.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Which registered measures put each goal on this table
Mood
montgomery asberg depression scale a of 13 or higher
Sorted by fixed word lists, version v1. A name the rules do not recognise stays unsorted rather than moving to the nearest column.
What each mark on this table means
∅ Nothing in the sources checked
No registered study lists a life outcome for this goal.
… Waiting for a reviewer
1 registered symptom measure.
— Not recorded
Harms were not a registered measure for this goal.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
Sustained virologic response after 48 weeks of treatment in previously untreated genotype 1 hepatitis C
✓ The study showed what it set out to show
Who was studied
IDEAL (NCT00081770)
How many people
3070
Study design
Phase 3, randomised, three-arm, head-to-head against peginterferon alfa-2b
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
40.9% with peginterferon alfa-2a against 39.8% with standard-dose peginterferon alfa-2b; difference -1.1% (95% CI -5.3 to 3.0), P=0.57
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Relapse after end of treatment was 31.5% on alfa-2a against 23.5% on standard-dose alfa-2b — a real difference in durability that cancels out in the headline response rate.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Subcutaneous injection, once weekly, from a prefilled syringe or autoinjector
Interval reported. 95% CI -5
Written into the record, not signed off as a reviewed claim.
32% with peginterferon monotherapy and 27% with peginterferon plus lamivudine against 19% with lamivudine alone; P<0.001 and P=0.02
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Serious adverse events in 4% and 6% of interferon arms against 2% on lamivudine. 87% of the population was Asian and most were infected with HBV genotype B or C, which limits how far the result generalises to genotype A or D populations.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Subcutaneous injection, once weekly, from a prefilled syringe or autoinjector
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
59% and 43% with peginterferon monotherapy against 44% and 29% with lamivudine; P=0.004 and P=0.007. Sustained HBV DNA below 400 copies/mL 19% against 7%, P<0.001
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Adding lamivudine to peginterferon did not improve post-therapy response rates. Pyrexia, fatigue, myalgia and headache were markedly more frequent on interferon-containing arms.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Subcutaneous injection, once weekly, from a prefilled syringe or autoinjector
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
RNAWiki holds 3 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What happened in people◇Read from sources, not yet reviewed
How close this is to real life
The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.
■Living longer, or avoiding a major eventEvidence recorded. Death, a heart attack, a stroke, a hospital stay.4 registered measures of this kind. No reviewed result.
□What a body can do day to dayNo evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
□Measured performanceNo evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
■Symptoms and quality of lifeEvidence recorded. Pain, tiredness, mood, sleep, as the person rated it.1 registered measure of this kind.
□A number that stands in for healthNo evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.No registered study measures this.
■A step measured inside a personEvidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
■AnimalsEvidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse. A result in animals says what to test next. It does not say what happens in people.
□Cells in a dishNo evidence recorded. Cells or chemistry on a bench, far from a whole body.No cell or bench record is stored.
□A guess from softwareNo evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.
Higher on these steps means closer to something a person would feel. It does not mean better done.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Peginterferon alfa-2a
What a person takes: Subcutaneous injection, once weekly, from a prefilled syringe or autoinjector.
The measurement behind this step
Given weekly rather than three times weekly because the attached 40 kDa branched polyethylene glycol chain slows renal clearance. Treatment is for a defined course — typically 48 weeks — rather than indefinitely, which is the feature that distinguishes it from the oral hepatitis B drugs.
Getting in
One injection a week, under the skin
A polymer chain attached to the protein slows how fast the body clears it, turning a three-times-weekly injection into a weekly one.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Recombinant interferon alfa-2a of about 20 kDa, produced in Escherichia coli, joined through a stable amide bond at a single lysine to a branched bis-monomethoxy polyethylene glycol chain of about 40 kDa, giving a conjugate of roughly 60 kDa. Given subcutaneously at 180 micrograms once weekly.
Unlike every other hepatitis drug, this one has no viral target. It binds a receptor on the outside of your own cells.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Binds the type I interferon receptor, an IFNAR1/IFNAR2 heterodimer expressed on essentially every nucleated cell. The label describes it as an inducer of the innate antiviral immune response rather than as an antiviral.
A signal runs to the nucleus and switches on hundreds of genes
Binding the receptor sends a chemical relay into the cell nucleus, which turns on several hundred defensive genes at once.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Receptor engagement activates JAK1 and TYK2, which phosphorylate STAT1 and STAT2; with IRF9 these form ISGF3, which binds interferon-stimulated response elements and induces several hundred interferon-stimulated genes including MxA, OAS and PKR.
The cell becomes an inhospitable place to copy a virus
The induced genes degrade viral RNA, shut down protein production and mark infected cells for the immune system. No single one of them is the mechanism.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
The induced proteins act by several routes at once: OAS activates RNase L to degrade viral RNA, PKR phosphorylates eIF2-alpha to arrest translation, MxA interferes with viral nucleocapsids, and MHC class I upregulation improves presentation of infected cells. The antiviral effect is the sum, which is why no resistance mutation defeats it the way one defeats a direct-acting antiviral.
In a minority the immune system takes over and keeps control
When it works, the benefit lasts after the injections stop — which is why hepatitis B treatment with interferon has an end date and tablet treatment does not.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
HBeAg seroconversion in 32% at 24 weeks after a 48-week course against 19% on lamivudine; sustained HBV DNA below 400 copies/mL in 19% of HBeAg-negative patients against 7%; HBsAg loss in a low single-digit percentage against none on lamivudine. In hepatitis C genotype 1, sustained virologic response 40.9%.
Because the receptor is on nearly every cell, the same signal that fights the virus in the liver produces fever, exhaustion, low blood counts, thyroid disease and depression throughout the body.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Boxed warning for fatal or life-threatening neuropsychiatric, autoimmune, ischemic and infectious disorders. Serious adverse events occurred in 4% to 6% of interferon recipients against 2% on lamivudine in the hepatitis B trials, and in 8.6% to 11.7% across arms of the 3,070-patient IDEAL trial.
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 6 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
montgomery asberg depression scale a of 13 or higher
Measured
Things only a test, a scale or a device shows.
No registered study measured anything of this kind.
Meaningful
Things that change how a life goes, not only a number.
death from any cause
progression free survival
complete remission
partial remission
A registered study says what someone planned to measure. It does not say what they found. A number moving is not the same as a life going better. The two are shown apart here.
Felt, but not shown to help. A person notices a change. No study showed it leads anywhere good.
Measured, but not felt. A number moves. The person notices nothing. Both can be true.
Measured, but not shown to matter. A number moves in the good direction. Nobody showed that lives went better.
Matters, but takes years. The result that counts may take longer than anyone would keep watching.
Names that fit none of the three (35)
ascites
hepatic encephalopathy
sustained virologic response
virological response
sustained virologic response rate
sustained virological response
early virological response
complete response or partial response
sustained viral response
experiencing an adverse event
undetectable hcv rna level
who experienced at least 1 adverse event
who experienced an adverse event
who experienced a serious adverse event
who discontinued study treatment due to an adverse event
early virologic response
hcv rna
incidence and severity of adverse events
experiencing adverse events
experiencing serious adverse events
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
In hepatitis B, a selected minority of patients suited to a finite course. In hepatitis C, now very few. It is contraindicated in decompensated cirrhosis, in autoimmune hepatitis, and in neonates and infants.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What the label states about particular groups
On pediatric, the label states: “The safety and efficacy of PEGASYS in pediatric patients with CHC below the age of 5 years have not been established.”
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-30
On older people, the label states: “Clinical studies of PEGASYS alone or in combination with ribavirin did not include sufficient numbers of subjects aged 65 or over to determine whether they respond differently from younger subjects.”
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-30
On people who are pregnant, the label states: “Exposure Registry – Use with ribavirin A ribavirin Pregnancy Registry has been established to monitor maternal and fetal outcomes of pregnancies of female patients and female partners of male patients exposed to ribavirin during pregnancy or who become pregnant within 6 months following cessation of treatment with ribavirin.”
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-30
On people who are breastfeeding, the label states: “There is no information regarding the presence of peginterferon alfa-2a in human milk, the effects on the breastfed infant, or the effects on milk production.”
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-30
On people with reduced liver function, the label states: “CHC patients with cirrhosis may be at risk of hepatic decompensation and death when treated with alpha interferons, including PEGASYS.”
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-30
On people with reduced kidney function, the label states: “Renal function should be evaluated in all patients prior to initiation of PEGASYS by estimating the patient's creatinine clearance.”
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-30
Where the result stopped carrying
Boxed warning for fatal or life-threatening neuropsychiatric, autoimmune, ischemic and infectious disorders — four categories in one warning
Sixty per cent of genotype 1 hepatitis C patients were not cured after 48 weeks of weekly injections
Adding lamivudine to peginterferon did not improve post-therapy response in either hepatitis B trial
Contraindicated in decompensated cirrhosis and in autoimmune hepatitis, excluding the patients with the most advanced liver disease
Interferon-induced thyroid dysfunction is frequently permanent after the drug is stopped
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied for a different goal
The studies measured something else entirely.
On this record: Some registered studies measured things that match no goal on this page.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Given by a clinician
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Subcutaneous injection, once weekly, from a prefilled syringe or autoinjector
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Suppression classes recorded: S6.
No source is stored against this line.
What is in the pack
Given weekly rather than three times weekly because the attached 40 kDa branched polyethylene glycol chain slows renal clearance. Treatment is for a defined course — typically 48 weeks — rather than indefinitely, which is the feature that distinguishes it from the oral hepatitis B drugs.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇Read from sources, not yet reviewed
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
·Worth asking a clinician aboutWritten into the record from the studies named on this page
Boxed warning that alpha interferons may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic and infectious disorders, with instruction to monitor closely and withdraw therapy on persistently severe or worsening signs. Contraindicated in autoimmune hepatitis and in decompensated cirrhosis, and in neonates and infants because the injection contains benzyl alcohol. Common reactions are systemic rather than hepatic: fever, fatigue, myalgia, headache, neutropenia, thrombocytopenia, depression and thyroid dysfunction. Serious adverse events occurred in 4% to 6% of interferon arms in the hepatitis B trials against 2% on lamivudine, and in 8.6% to 11.7% across the arms of IDEAL.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
These are reports people sent to a regulator. They do not show the medicine caused the reaction.
Nobody counted how many people took the medicine and reported nothing.
The same event can be reported more than once, and many reports are incomplete.
News coverage, lawsuits and new warnings change how often people report.
A count is not a rate and not a risk.
Peginterferon alfa-2a appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 16684 reaction mentions were counted. One report can name several reactions.
The recorded terms (10)
anaemia — 3638 reaction mentions
fatigue — 2280 reaction mentions
rash — 1878 reaction mentions
white blood cell count decreased — 1720 reaction mentions
pyrexia — 1299 reaction mentions
platelet count decreased — 1223 reaction mentions
depression — 1181 reaction mentions
haemoglobin decreased — 1171 reaction mentions
asthenia — 1161 reaction mentions
pruritus — 1133 reaction mentions
open-targets-adr · recorded 2026-06-24 · a recorded source, not a stored snapshot
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Subcutaneous injection, once weekly, from a prefilled syringe or autoinjector
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
Treatment is for a defined course — typically 48 weeks — rather than indefinitely, which is the feature that distinguishes it from the oral hepatitis B drugs.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on which forms are sold and how they compare.
No source is stored against this line.
What is recorded as being sold
2 products list this as an active ingredient in the United States drug directory. 2 of them contain it and nothing else.
FDA National Drug Code directory · 82154-0449 · read 2026-08-29
They are sold as injection, solution, taken subcutaneous.
FDA National Drug Code directory · 82154-0449 · read 2026-08-29
The regulator's established pharmacologic class for it is interferon alpha [epc] and interferon-alpha [cs].
FDA National Drug Code directory · 82154-0449 · read 2026-08-29
1 published label names it as an active ingredient. 1 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-29
Pegasys is subcutaneous at 3 DOSAGE FORMS AND STRENGTHS PEGASYS is a colorless to slightly yellowish solution available as: Injection: 180 mcg/mL in a single-dose vial Injection: 180 mcg/0.5 mL in a single-dose prefilled syringe Injection: 180 mc…, recorded as fda label in effect 2026-07-07 in the United States.
US prescribing information · d9290e5b-6d40-2318-e053-2995a90a9916 · read 2026-08-30
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
Self-experiment planning is not offered for a prescription or clinician-supervised medicine. The questions below are for a clinician or pharmacist.
Questions worth asking
Which of the trials of Peginterferon alfa-2a studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
Claims that go past the evidence
Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.
✗Goes past the evidence
That seroconversion or sustained virologic response on interferon translates into fewer cancers, transplants or deaths — no registrational trial measured any of those
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the two pegylated interferons differ clinically; 3,070 patients found a 1.1-point difference with a confidence interval spanning zero
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That combining interferon with a nucleoside analogue should help, an intuition both hepatitis B trials tested and neither supported
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the hepatitis B results generalise across viral genotypes; 87% of the HBeAg-positive population was Asian and mostly infected with HBV genotype B or C
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Peginterferon alfa-2a are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
Pegylation itself was worth 12 percentage points in hepatitis C
In plain words
In a 1,121-patient trial, attaching a polymer chain to interferon so it lasted a week instead of a day raised the cure rate from 44% to 56% when both groups also took ribavirin.
What was measured
Sustained virologic response, pegylated against conventional interferon on identical ribavirin
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Fried and colleagues randomised 1,121 patients to peginterferon alfa-2a with ribavirin, peginterferon alfa-2a with placebo, or conventional interferon alfa-2b with ribavirin, all for 48 weeks. Sustained virologic response was 56% with peginterferon plus ribavirin against 44% with conventional interferon plus ribavirin, P<0.001, and 29% with peginterferon plus placebo. In genotype 1 the figures were 46%, 36% and 21%. Influenza-like symptoms and depression were less frequent in the peginterferon groups than in the conventional interferon group, so the improvement was not bought with worse tolerability.
Written into the record, not signed off as a reviewed claim
In hepatitis B it beat lamivudine on the endpoint that lets treatment stop
In plain words
Across 814 patients, a 48-week course of injections produced the immune change that allows treatment to end in 32%, against 19% on a daily tablet. Sixteen patients cleared surface antigen; none on the tablet did.
What was measured
HBeAg seroconversion 24 weeks after a finite 48-week course
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Lau and colleagues randomised 814 HBeAg-positive patients, 87% Asian, to peginterferon alfa-2a 180 micrograms weekly plus oral placebo, peginterferon plus lamivudine, or lamivudine alone, for 48 weeks with 24 weeks of follow-up. HBeAg seroconversion 24 weeks after treatment was 32% with peginterferon monotherapy and 27% with the combination, against 19% with lamivudine (P<0.001 and P=0.02). HBV DNA below 100,000 copies/mL was 32% and 34% against 22%. Sixteen patients receiving peginterferon had HBsAg seroconversion against 0 on lamivudine alone (P=0.001). Serious adverse events occurred in 4%, 6% and 2% respectively. Two lamivudine patients had irreversible liver failure after stopping treatment, one transplanted and one died.
Written into the record, not signed off as a reviewed claim
Adding lamivudine to it did nothing, and that negative result held twice
In plain words
Two large hepatitis B trials tested the obvious idea of giving the injection and the tablet together. In both, the combination was no better after treatment stopped than the injection alone.
What was measured
Post-treatment response with peginterferon alone against peginterferon plus lamivudine
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
In the HBeAg-negative trial, 177 patients received peginterferon alfa-2a plus placebo, 179 peginterferon plus lamivudine and 181 lamivudine alone, for 48 weeks with 24 weeks of follow-up. ALT normalisation was 59% and 60% against 44% (P=0.004 and P=0.003) and HBV DNA below 20,000 copies/mL was 43% and 44% against 29% (P=0.007 and P=0.003). Sustained suppression below 400 copies/mL was 19%, 20% and 7%. HBsAg loss occurred in 12 patients in the peginterferon groups against 0 on lamivudine alone. The authors state directly that the addition of lamivudine to peginterferon alfa-2a did not improve post-therapy response rates. The HBeAg-positive trial found the same, with the combination arm numerically below monotherapy on seroconversion, 27% against 32%.
Written into the record, not signed off as a reviewed claim
In 2009 the reason some people never responded turned out to be a common gene variant
In plain words
For twenty years, why interferon worked in some people and not others was explained by dose, adherence, viral load and liver damage. A genome-wide scan found a single common variant near one gene that roughly doubled the chance of cure — and it explained about half of the long-observed difference in response rates between patients of African and European ancestry.
What was measured
Approximately twofold change in sustained virologic response by IL28B genotype; roughly half the ancestry gap explained
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Ge and colleagues reported that a polymorphism near IL28B, encoding interferon-lambda-3, was associated with an approximately twofold change in treatment response in patients of European ancestry (P = 1.06 x 10^-25) and in African-Americans (P = 2.06 x 10^-3). Because the favourable genotype is substantially more frequent in European than African populations, the variant explained roughly half of the difference in response rates between the two groups. This reframed a difference that had been discussed for two decades in terms of adherence, body weight, dosing and viral kinetics. It also arrived at almost exactly the moment the direct-acting antivirals made it clinically irrelevant: IL28B testing was briefly standard and is now essentially unused.
Written into the record, not signed off as a reviewed claim
Head to head against its rival in 3,070 patients, the two were the same
In plain words
Two pegylated interferons had been marketed against each other for years. When they were finally compared directly in 3,070 patients, the cure rates were 40.9% and 39.8%, a difference well inside chance.
What was measured
Sustained virologic response and relapse rate, peginterferon alfa-2a against alfa-2b, head to head
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The IDEAL trial randomised 3,070 previously untreated genotype 1 patients at 118 sites to 48 weeks of standard-dose peginterferon alfa-2b, low-dose peginterferon alfa-2b, or peginterferon alfa-2a, each with ribavirin. Sustained virologic response was 39.8%, 38.0% and 40.9%; the estimated difference between standard-dose alfa-2b and alfa-2a was -1.1% (95% CI -5.3 to 3.0), P=0.57. Serious adverse events occurred in 8.6% to 11.7% across the three groups. One difference did emerge: relapse after end of treatment was 31.5% (95% CI 27.9 to 35.2) on alfa-2a against 23.5% (95% CI 19.9 to 27.2) on standard-dose alfa-2b, meaning alfa-2a suppressed more virus during treatment and lost more of it afterwards, ending at the same place.
Written into the record, not signed off as a reviewed claim
A boxed warning that names four categories of fatal disorder
In plain words
The label warns that this class of drug may cause or worsen neuropsychiatric, autoimmune, ischemic and infectious disorders, any of which can be fatal or life-threatening. That is unusually broad for a single warning.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
The boxed warning states that alpha interferons, including PEGASYS, may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic and infectious disorders, that patients should be monitored closely with periodic clinical and laboratory evaluations, and that therapy should be withdrawn in patients with persistently severe or worsening signs or symptoms — adding that in many, but not all, cases these disorders resolve after stopping. The breadth follows directly from the mechanism: the drug acts on a receptor present on essentially every nucleated cell, so there is no anatomical restriction on where its effects appear. In the pivotal hepatitis B trials serious adverse events occurred in 4% to 6% of interferon recipients against 2% on lamivudine.
Source
PEGASYS United States prescribing information, boxed warning: risk of serious disorders (BLA 103964)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Even at its best, it worked in a minority
In plain words
Forty-eight weeks of weekly injections, with all the side effects, cured about four in ten people with the commonest form of hepatitis C. In hepatitis B, three in ten reached the immune milestone that lets treatment stop.
What was measured
Response rates across the pivotal programmes: 40.9% and 46% in hepatitis C genotype 1, 32% and 19% in hepatitis B
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
In genotype 1 hepatitis C, sustained virologic response was 40.9% in the 3,070-patient IDEAL trial and 46% in the 1,121-patient registrational trial. In HBeAg-positive hepatitis B, seroconversion 24 weeks after a 48-week course was 32%. In HBeAg-negative hepatitis B, sustained HBV DNA suppression below 400 copies/mL was 19%. Loss of surface antigen — the closest thing to a functional cure — occurred in 16 of roughly 540 peginterferon-treated patients in one hepatitis B trial and 12 of roughly 356 in the other, which is a real and reproducible effect at a low single-digit rate. These are the numbers that made a 48-week course of injections a rational offer, and they are also the numbers a modern reader should hold beside the direct-acting antivirals.
Written into the record, not signed off as a reviewed claim
Every endpoint is a laboratory value, and the surrogate has never been validated
In plain words
The trials measured virus, antigens and liver enzymes. None of them counted deaths, cancers or transplants.
What was measured
That seroconversion, viral suppression or sustained virologic response on this drug translates into fewer cancers, transplants or deaths — not measured in any of its registrational trials
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The 2017 Cochrane review of 138 randomised direct-acting antiviral trials in 25,232 participants found no usable randomised evidence that sustained virologic response predicts hepatitis C-related morbidity or hepatocellular carcinoma, with mortality data from only 11 trials. The same objection applies with more force to the hepatitis B endpoints used here: HBeAg seroconversion is an immunological marker whose link to survival is inferred from cohort studies, not from randomisation. The one randomised outcome trial in hepatitis B tested lamivudine, not interferon.
Written into the record, not signed off as a reviewed claim
From the whole of hepatitis C treatment to a residual role, in about four years
In plain words
Peginterferon was hepatitis C treatment for fifteen years. Between 2011 and 2015 it was removed from the recommended regimens almost entirely, and it survives mainly in hepatitis B and in hepatitis D.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The displacement was not caused by any new finding about interferon. The direct-acting antivirals reached cure rates above 90% in 8 to 12 weeks without injections, against 40.9% after 48 weeks. The label reflects the change: peginterferon alfa-2a is now indicated in hepatitis C in combination with other hepatitis C antivirals, with monotherapy indicated only if the patient has a contraindication to or significant intolerance of those drugs. Its remaining roles are in selected hepatitis B patients wanting a finite course with a chance of surface antigen loss, and in hepatitis D, where interferon alfa remains the only agent with meaningful activity and no interferon product carries a hepatitis D indication in the United States.
Source
PEGASYS United States prescribing information, Indications and Usage 1.1 (BLA 103964)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Where else this substance is registered
FDA substance identifier (UNII)
Q46947FE7K
RxNorm concept
351270
Checks this page had to pass
✓ Passed
Identity resolved
no open identity hold
✓ Passed
No unresolved merge across substance families
no quarantine open
✓ Passed
Every public sentence names a source
The opening statement carries the origin: Reviewed first-read answer.
✗ Not passed
Trial roles classified for highlighted evidence
No registered study is classified as testing this substance.
✓ Passed
No internal keys in reader text
enforced by the copy-contract test over the rendered page
✓ Passed
Safety mode resolved
Suppression classes recorded: S6.
✓ Passed
Canonical metadata present
slug and display name present
What is missing or unclear◇Read from sources, not yet reviewed
How this medicine reached us
Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.
What the approval register records
1 approved application covers products containing this substance. The earliest was BLA103964, approved 20021016 to Pharmaand GmbH.
This order is fixed in code and does not count clicks or time on the page.
What is not here
4 questions this page could not answer
These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.
How long anything takes — found nothing in the sources checked.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
What changed on this page — found nothing in the sources checked.
The record as stored
The full record, for auditing
Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
A recombinant human interferon with a 40 kDa branched polyethylene glycol chain bolted on to slow its clearance, which does not touch the virus at all but switches on the patient’s own antiviral genes — producing sustained virologic response in 40.9% of 3,070 genotype 1 hepatitis C patients after 48 weeks of weekly injections, HBeAg seroconversion in 32% against 19% on lamivudine in 814 hepatitis B patients, and a boxed warning that alpha interferons may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic and infectious disorders.
Recorded evidence blocks (9)
Q2
What did Peginterferon alfa-2a's largest trial (10228 people) and its longest (18 years) measure?
10228 people in Peginterferon alfa-2a's largest registered study, 18 years in its longest registered window, measuring Different blood interferon biomarkers (such as 2,5-OAS, neopterin). ClinicalTrials.gov · 2026-09-01
123 phase2, 79 phase3, 67 phase4, 30 phase1, 29 na or unstated, 13 na, 1 early phase1; NCT00452023; 2023-05-26; no ageing endpoint recorded. Last human test completed 2024, NCT02583685.
These counts include studies where Peginterferon alfa-2a was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.
Show the evidence
phase2
123
phase3
79
phase4
67
phase1
30
na or unstated
29
na
13
2 more recorded rows
early phase1
1
Last recorded human testNCT02583685
2024-10-31
recorded 2026-09-01 · last checked 2026-09-04
Q3
From mouse to human: where has Peginterferon alfa-2a shown biomarker?
"Enrollment stopped for safety issues"; 23 of 315 registered studies
Show the evidence
Trial
NCT00412750
terminated; "Enrollment stopped for safety issues"
NCT00571714
withdrawn; "lack of enrollment"
NCT00641654
terminated; "Recruitment problems in Denmark and Norway"
NCT00662220
terminated; "Due to the arrival of DAAs replacing standard of care for genotype 1 patients the VIRID study had to be terminated."
NCT00814606
withdrawn; "no one ever enrolled"
NCT00882193
terminated; "new medications with improved response released"
14 further recorded trials
NCT01080222
terminated; "Study discontinued"
NCT01153919
terminated; "Approval of several new agents for the treatment of HCV infection would mitigate the future need for interferon HCV treatment"
NCT01273064
terminated; "Risk-benefit ratio"
NCT01392170
terminated; "Slow Accrual"
NCT01415141
withdrawn; "Lack of funding"
NCT01459913
terminated; "The study was terminated early by the sponsor on 13 January 2014 due to a decision to modify the drug development plan."
NCT01467479
terminated; "It was decided by Sponsor on 13 January 2014 to terminate study early at primary efficacy endpoint as part of a decision to modify drug development plan."
NCT01592006
terminated; "Low accrual"
NCT01641926
terminated; "This study was terminated early due to poor recruitment"
NCT01718301
terminated; "Difficulty in patient recruitment"
NCT01758588
terminated; "This study was suspended due to insufficient subject accrual."
NCT02118597
terminated; "Study terminated due to the Sponsor's decision."
NCT02577029
terminated; "Company decision to discontinue trial"
NCT02762383
terminated; "Low recruitment"
recorded 2026-09-01 · last checked 2026-09-04
Q5
Human studies of Peginterferon alfa-2a used peginterferon alfa-2a 180μg — over how long?
3 recorded entries; human; also "peginterferon alfa-2a 180μg", "peginterferon alfa-2a 90μg", "PEGASYS 180μg (Interféron pégylé alpha -2a)"
Show the evidence
human
NCT00304551
peginterferon alfa-2a 180μg
NCT00304551
peginterferon alfa-2a 90μg
NCT00391638
PEGASYS 180μg (Interféron pégylé alpha -2a)
recorded 2026-09-01 · last checked 2026-09-04
Q6
Which of achieving sustained virological response, adverse events and ascites did Peginterferon alfa-2a's trials measure?
achieving sustained virological response, adverse events and ascites lead 40 outcome terms across Peginterferon alfa-2a's trials. ClinicalTrials.gov · 2026-09-01
sustained virologic response, progression free survival, virological response, sustained virologic response rate, montgomery asberg depression scale a of 13 or higher and sustained virological response follow.
Show the evidence
death from any cause
1
ascites
1
hepatic encephalopathy
1
sustained virologic response
1
progression free survival
1
virological response
1
14 more recorded rows
sustained virologic response rate
1
montgomery asberg depression scale a of 13 or higher
1
sustained virological response
1
early virological response
1
complete response or partial response
1
sustained viral response
1
experiencing an adverse event
1
undetectable hcv rna level
1
who experienced at least 1 adverse event
1
who experienced an adverse event
1
who experienced a serious adverse event
1
who discontinued study treatment due to an adverse event
1
early virologic response
1
hcv rna
1
recorded 2026-09-01 · last checked 2026-09-04
Q7
Which 125 trials of Peginterferon alfa-2a posted no result?
Posted no result
125 of 125 completed trials
Registrations
NCT00221624, NCT00048945, NCT00144469, NCT00055341, NCT00038974 and NCT02604823, and 119 more
Completion dates
oldest 2004-04; newest 2024-06-24
Show the evidence
Trial
NCT00221624
2004-04
NCT00048945
2004-10
NCT00144469
2005-03
NCT00055341
2005-06
NCT00038974
2005-11
NCT02604823
2005-11
14 further recorded trials
NCT00262483
2006-04
NCT00381953
2006-07
NCT00008463
2006-08
NCT00172809
2007-01
NCT02570191
2007-02
NCT00629967
2007-05
NCT02864199
2007-09
NCT00433069
2008-01
NCT00612755
2008-01
NCT00948220
2008-03
NCT00377182
2008-08
NCT00421434
2008-09
NCT00763568
2008-09
NCT00411385
2008-10
Q8
At the median, Peginterferon alfa-2a's trials enrolled 120 people — anything larger?
Median enrolment
120
Largest enrolment
10228
Registered trials counted
314
Q9
What do 16684 spontaneous reports say about Peginterferon alfa-2a — and not say?
These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.
Peginterferon alfa-2a appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 16684 reaction mentions were counted: anaemia 3638; fatigue 2280; rash 1878; white blood cell count decreased 1720. open-targets-adr · CHEMBL1201560 · 2026-06-24
Show the evidence
anaemia
3638
fatigue
2280
rash
1878
white blood cell count decreased
1720
pyrexia
1299
platelet count decreased
1223
4 more recorded rows
depression
1181
haemoglobin decreased
1171
asthenia
1161
pruritus
1133
recorded 2026-06-24 · last checked 2026-09-04
Q10
Peginterferon alfa-2a and CYP1A2 and Cytochrome P450: shared by which compounds?
CYP1A2 and Cytochrome P450 appear in Peginterferon alfa-2a's recorded interaction sentences, 2 in all. openfda-label+europepmc · 2026-07-07
Interpretation drug_interactions
Show the evidence
CYP1A2drug_interactions
7 DRUG INTERACTIONS Drugs metabolized by CYP1A2: monitor for increased serum levels of theophylline and adjust dose accordingly ( 7.2 ) Methadone: monitor for signs and symptoms of methadone toxicity ( 7.3 ) Nucleoside analogues: closely monitor for toxicities.
Cytochrome P450drug_interactions
Reduce or discontinue the dose of PEGASYS or ribavirin or both should the events worsen ( 7.4 ) Zidovudine: monitor for worsening neutropenia and/or anemia with PEGASYS and/or ribavirin ( 7.4 ) 7.1 Drugs Metabolized by Cytochrome P450 There was no effect on the pharmacokinetics of representative drugs metabolized by CYP 2C9, CYP 2C19, CYP 2D6 or CYP 3A4.
recorded 2026-07-07 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · Open Targets 26.06 — CC0 · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
✗ required summary fields resolved: 5 required field(s) not terminal: Why people use it, Best-supported result, Most important common problem, Biggest unanswered question, Human evidence
✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 9 source rows
✓ no critical contamination: no quarantine open
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This is a record of evidence. It is not medical advice, and it does not say this substance suits you. Nothing here says any substance on RNAWiki is appropriate for a child.