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Mesalazine

  • Prescription medicine
  • Prescription only
  • Identity checked
  • Sources last checked 2026-09-04

This page shows what was measured, who it was measured in, and what that does not settle.

What Mesalazine does in the body

Ulcerative colitis — inflammation and ulceration of the lining of the large bowel

Mesalamine is the working half of an older drug called sulfasalazine. In sulfasalazine that half is chained to a sulfa antibiotic, and gut bacteria snap the chain in the colon to release it; the sulfa half was responsible for most of the side effects, so the obvious move was to give the working half on its own. The problem is that on its own it is absorbed high up in the small intestine and never reaches the colon, so every product is an engineering solution to that — coatings that only dissolve at colonic pH, granules that release slowly over hours, enemas and suppositories that go in from the other end. Once it is in contact with inflamed colon lining it damps the inflammation down, though after forty years there is still no agreement on exactly how.

What happened in people

Relapse of ulcerative colitis 37% against 55% on placebo across 44 randomised trials in 9,967 participants (RR 0.68, high-certainty evidence)

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 recorded finding that sits closest to something a person would notice. Written into the record, not signed off, and it carries no population or interval.

The limit that matters most

That mesalamine treats Crohn’s disease — 20 randomised trials in 2,367 patients found high-dose mesalamine no better than placebo

Where it acts
The luminal surface of the colonic epithelium — the drug works from the inside of the bowel outward, which is why the formulation decides which part of the colon it reaches
Kind of result
The kind of result is not recorded
Supervision
RNAWiki has not recorded a supervision or regulatory status for this substance.

What the registries record it as

  • The substance registry classes this as chemical.

    FDA substance registry · 4Q81I59GXC · 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.

A limit recorded against this substance. Not signed off as a reviewed claim.

The four opening statements run to 172 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 peopleRead 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.

Failure to maintain clinical or endoscopic remission at six months or more

The study showed what it set out to show

Who was studied
Cochrane CD000544: oral 5-ASA for maintenance of remission in ulcerative colitis
How many people
9967
Study design
Systematic review and meta-analysis of 44 randomised trials
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Relapse 37% (335 of 907) against 55% (355 of 648) on placebo; risk ratio 0.68 (95% CI 0.61 to 0.76), 8 studies, 1,555 participants, high-certainty evidence
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. The same review grades 5-ASA inferior to sulfasalazine for maintenance with high-certainty evidence (RR 1.14, 95% CI 1.03 to 1.27), which is rarely quoted alongside the placebo comparison.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral delayed-release tablet, extended-release capsule, controlled-release microgranule capsule, rectal suspension enema, and rectal suppository

Interval reported. 95% CI 0

Written into the record, not signed off as a reviewed claim.

Failure to enter clinical remission in active ulcerative colitis

The study showed what it set out to show

Who was studied
Cochrane CD000543: oral 5-ASA for induction of remission in ulcerative colitis
How many people
9612
Study design
Systematic review and meta-analysis of 54 randomised trials
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
71% (1,107 of 1,550) of 5-ASA participants failed to enter remission against 83% (695 of 837) on placebo; risk ratio 0.86 (95% CI 0.82 to 0.89), 11 studies, 2,387 participants, high-certainty evidence
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. The absolute numbers are worth reading directly: even on active treatment, seven in ten patients did not enter clinical remission. This is a modest effect measured precisely, not a large one.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral delayed-release tablet, extended-release capsule, controlled-release microgranule capsule, rectal suspension enema, and rectal suppository

Interval reported. 95% CI 0

Written into the record, not signed off as a reviewed claim.

Induction of remission or clinical response in mildly to moderately active Crohn’s disease

The study did not show it

Who was studied
Cochrane CD008870: aminosalicylates for induction in Crohn’s disease
How many people
2367
Study design
Systematic review and meta-analysis of 20 randomised trials
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
High-dose mesalamine at 3.2 to 4 g daily not more effective than placebo; low-dose mesalamine and olsalazine not superior to placebo; sulfasalazine 45% against 29% on placebo (RR 1.38, 95% CI 1.00 to 1.89) and inferior to corticosteroids (RR 0.68, 95% CI 0.51 to 0.91)
Repeated elsewhere
Failed to Replicate

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. Eight of the 20 studies were at high risk of bias from incomplete outcome data and potential selective reporting. The authors called for definitive large trials, and none has been published in the decade since.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral delayed-release tablet, extended-release capsule, controlled-release microgranule capsule, rectal suspension enema, and rectal suppository

Interval reported. 95% CI 1

Written into the record, not signed off as a reviewed claim.

Percentage of patients remaining in remission at month 6 by the Simple Clinical Colitis Activity Index

The study showed what it set out to show

Who was studied
Once-daily against twice-daily delayed-release mesalamine (NCT00505778)
How many people
1027
Study design
Phase 3, randomised, investigator-blinded, 12-month non-inferiority
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
90.5% once daily against 91.8% twice daily; difference 1.3 percentage points (95% CI -2.3 to 4.9), P=0.5016
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. Investigator-blinded rather than double-blind, and industry-sponsored. The result is nonetheless corroborated by the Cochrane pooled analysis of five studies in 1,761 participants at high certainty.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral delayed-release tablet, extended-release capsule, controlled-release microgranule capsule, rectal suspension enema, and rectal suppository

Interval reported. 95% CI -2

Written into the record, not signed off as a reviewed claim.

What we know
RNAWiki holds 4 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 peopleRead 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.

  1. Living longer, or avoiding a major event Evidence recorded. Death, a heart attack, a stroke, a hospital stay.13 registered measures of this kind. No reviewed result.
  2. What a body can do day to day No evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
  3. Measured performance No evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
  4. Symptoms and quality of life Evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.3 registered measures of this kind.
  5. A number that stands in for health No evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.No registered study measures this.
  6. A step measured inside a person Evidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
  7. Animals Evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse, Rat. A result in animals says what to test next. It does not say what happens in people.
  8. Cells in a dish Evidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
  9. A guess from software No 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 bodyRead 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.

Where a source records it acting

  • Intestines: Appears to act as a topical anti-inflammatory on colonic epithelial cells; the label records that the mechanism is not fully understood

    US prescribing information · 00f77203-3615-47e8-ae25-6e1cf8a2a00a · read 2026-08-28

  1. Start

    Mesalazine

    What a person takes: Oral delayed-release tablet, extended-release capsule, controlled-release microgranule capsule, rectal suspension enema, and rectal suppository.

    The measurement behind this step

    The delivery system is the drug’s entire design problem. Free 5-aminosalicylic acid is absorbed in the small intestine and never reaches the colon, so each product engineers a different route to the target: pH-dependent methacrylate coats, time-dependent ethylcellulose microgranules, matrix systems, or rectal administration. Formulation therefore determines anatomical reach — a suppository treats the rectum, an enema reaches to the splenic flexure, and an oral delayed-release product is required for more extensive disease.

  2. Getting in

    The half of an older drug that actually did the work

    Sulfasalazine is two molecules chained together: an anti-inflammatory and a sulfa antibiotic. Gut bacteria break the chain in the colon. The anti-inflammatory half is mesalamine, and the sulfa half caused most of the side effects.

    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

    Sulfasalazine is 5-aminosalicylic acid joined by an azo bond to sulfapyridine. Colonic bacterial azoreductases cleave the bond, releasing both. The therapeutic activity in inflammatory bowel disease resides in the 5-ASA moiety; sulfapyridine is absorbed systemically and accounts for the nausea, headache, rash, haemolysis and reversible male infertility associated with the parent drug.

  3. Getting in

    Given alone, it never reaches the colon

    Free mesalamine is absorbed in the small intestine long before it gets anywhere near the diseased bowel. That single fact is why the drug is sold in half a dozen elaborate formulations.

    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

    Unformulated 5-ASA is rapidly and almost completely absorbed in the proximal jejunum, acetylated in the intestinal mucosa and liver to N-acetyl-5-ASA, and excreted renally. Systemic 5-ASA has no useful anti-inflammatory effect on the colon: the drug acts topically on the mucosa from the luminal side.

  4. Reaching the cell

    The formulation is the invention

    Each product is a different engineering answer to the same problem. Some have coats that dissolve only where the bowel becomes less acidic, some release slowly over hours, and some go in from the other end as an enema or suppository.

    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

    Delayed-release products use methacrylic acid copolymer coats dissolving above pH 6 or pH 7. Ethylcellulose-coated microgranules release continuously from the duodenum onward. Matrix systems disperse the drug through a lipophilic-hydrophilic vehicle for colonic release. Rectal suspension reaches to the splenic flexure and suppositories treat the rectum. Choice of formulation is choice of anatomical reach, which is why the same molecule has six brand names.

  5. What it acts on

    Contact with inflamed lining, by a mechanism still argued about

    Once in contact with the inflamed bowel lining it damps down the inflammation. The best-supported explanation involves a nuclear receptor called PPAR-gamma, shown in mice and in human tissue in a dish. It has never been confirmed in a patient.

    Measured in animals. A result in animals says what to test next. It does not say what happens in people.

    The measurement behind this step

    5-ASA increases PPAR-gamma expression in colonic epithelial cells, drives its nuclear translocation, and induces a conformation permitting coactivator recruitment and PPRE-driven transcription. Heterozygous PPAR-gamma knockout mice lose the benefit that wild-type littermates retain. Competing mechanisms — cyclooxygenase and lipoxygenase inhibition, reactive-oxygen scavenging, NF-kappaB inhibition — remain in the literature and are not excluded.

  6. What that does for a person

    Relapse becomes less likely, in one disease

    In ulcerative colitis it cuts the chance of relapsing over the following year from about 55 in a hundred to about 37. In Crohn’s disease, tested repeatedly, it does not beat a dummy tablet.

    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

    Pooled maintenance relapse was 37% against 55% on placebo (RR 0.68, 95% CI 0.61 to 0.76, high certainty). In Crohn’s disease, high-dose mesalamine at 3.2 to 4 g daily was not more effective than placebo for inducing response or remission across 20 randomised trials in 2,367 patients. Whether that difference reflects disease depth — colitis is mucosal, Crohn’s is transmural — or the drug’s topical mode of action is a plausible account rather than a demonstrated one.

  7. What that does for a person

    What it costs, and what the comparison shows

    The molecule itself is unpatentable and cheap. The delivery systems are patented and are why this is the most expensive drug on any page in this file. Against sulfasalazine, the drug it was meant to improve on, it is graded inferior for maintenance.

    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

    Relapse was 48% on 5-ASA against 43% on sulfasalazine (RR 1.14, 95% CI 1.03 to 1.27, high certainty). The Cochrane authors state that considering relative costs, a clinical advantage to using oral 5-ASA in place of sulfasalazine appears unlikely. The trade the newer drug wins is tolerability, not efficacy, and for men concerned about fertility that trade is decisive.

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 takeRead 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.

  • global symptom at week 12 primary efficacy population
  • quality of life
  • short inflammatory bowel disease questionnaire total

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.

  • rate of remission
  • rate of clinical remission
  • rate of clinical remission after 8 weeks
  • in remission
  • clinical and endoscopic remission
  • rate of clinical remission at week 8
  • response at week 4 and steroid free remission at week 50
  • corticosteroid free remission
  • clinical remission
  • remission

and 3 more.

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 (12)
  • pharmacokinetics
  • who needed additional therapy or colectomy
  • clinical recurrence rates of crohn s disease
  • efficacy
  • compliance treatment
  • apoptotic index
  • who respond to the treatment
  • effective rate
  • surface ctla4 expression
  • changes in fecal calprotectin
  • 2 or more decrease in the mayo from baseline
  • partial mayo

These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.

What is missing or unclearRead 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.

  • Most people with mild to moderate ulcerative colitis, usually for years or for life, because the evidence for maintenance is stronger than the evidence for induction. Also a substantial number of people with Crohn’s disease, where the evidence does not support it.

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: “Safety and effectiveness of mesalamine extended-release capsules in pediatric patients have not been established.”

    US prescribing information · 1e6978d0-01db-477d-a90f-27561777480f · read 2026-08-30

  • On older people, the label states: “Clinical studies of mesalamine extended-release capsules did not include sufficient numbers of subjects aged 65 years and older to determine whether they respond differently than younger subjects.”

    US prescribing information · 1e6978d0-01db-477d-a90f-27561777480f · read 2026-08-30

  • On people who are pregnant, the label states: “Risk Summary Published data from meta-analyses, cohort studies and case series on the use of mesalamine during pregnancy have not reliably informed an association with mesalamine and major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data ) .”

    US prescribing information · 1e6978d0-01db-477d-a90f-27561777480f · read 2026-08-30

  • On people who are breastfeeding, the label states: “Risk Summary Data from published literature report the presence of mesalamine and its metabolite, N-acetyl-5-aminosalicylic acid in human milk in small amounts with relative infant doses (RID) of 2% or less (see Data ) .”

    US prescribing information · 1e6978d0-01db-477d-a90f-27561777480f · read 2026-08-30

  • On people with reduced kidney function, the label states: “Mesalamine is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function.”

    US prescribing information · 1e6978d0-01db-477d-a90f-27561777480f · read 2026-08-30

Where the result stopped carrying

  • Crohn’s disease, repeatedly and across every dose tested
  • The comparison against sulfasalazine for maintenance, graded high-certainty inferiority
  • Even at its best, seven in ten patients on active treatment did not enter clinical remission in the pooled induction analysis
  • Interstitial nephritis and an acute intolerance syndrome that mimics a colitis flare, both label-recorded, both easy to miss
  • 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 takeRead 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 takeRead 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

Prescription only

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

Oral delayed-release tablet, extended-release capsule, controlled-release microgranule capsule, rectal suspension enema, and rectal suppository

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

RNAWiki has not recorded a supervision or regulatory status for this substance.

Quoted from a source

Where this came from

Copied from a source RNAWiki stored, with the source named.

No register row and no identity class settled the question.

No source is stored against this line.

What is in the pack

The delivery system is the drug’s entire design problem.

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. The rest of the recorded wording: Free 5-aminosalicylic acid is absorbed in the small intestine and never reaches the colon, so each product engineers a different route to the target: pH-dependent methacrylate coats, time-dependent ethylcellulose microgranules, matrix systems, or rectal administration. Formulation therefore determines anatomical reach — a suppository treats the rectum, an enema reaches to the splenic flexure, and an oral delayed-release product is required for more extensive disease.

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 takeRead 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

The labels direct that renal function be evaluated before starting and periodically during treatment, because of reported minimal change nephropathy, acute and chronic interstitial nephritis and rarely renal failure — harms that are usually silent until advanced. A mesalamine-induced acute intolerance syndrome of cramping, abdominal pain, bloody diarrhoea and sometimes fever, headache and rash can be indistinguishable from a flare of the disease. Hepatic failure has been reported in patients with pre-existing liver disease, and cardiac hypersensitivity reactions including myocarditis and pericarditis are recorded. Commonest adverse effects in trials are headache, abdominal pain, nausea, flatulence and diarrhoea, at rates similar to placebo.

Nobody counted how many people took this and were fine, so this cannot be turned into a rate.

Where this came from

Reports sent to a regulator

  • 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.

Mesalazine appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 3487 reaction mentions were counted. One report can name several reactions.

The recorded terms (10)
  • colitis ulcerative — 505 reaction mentions
  • diarrhoea — 471 reaction mentions
  • condition aggravated — 367 reaction mentions
  • pyrexia — 363 reaction mentions
  • haematochezia — 337 reaction mentions
  • abdominal pain — 331 reaction mentions
  • crohn's disease — 293 reaction mentions
  • colitis — 279 reaction mentions
  • drug hypersensitivity — 272 reaction mentions
  • weight decreased — 269 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 unclearRead 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

Oral delayed-release tablet, extended-release capsule, controlled-release microgranule capsule, rectal suspension enema, and rectal suppository

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

A recorded note compares this form with the others that are sold. It is kept below, word for word.

A fixed RNAWiki sentence

Where this came from

Wording RNAWiki always uses, not a finding about this substance.

The recorded note, unchanged: Free 5-aminosalicylic acid is absorbed in the small intestine and never reaches the colon, so each product engineers a different route to the target: pH-dependent methacrylate coats, time-dependent ethylcellulose microgranules, matrix systems, or rectal administration. Formulation therefore determines anatomical reach — a suppository treats the rectum, an enema reaches to the splenic flexure, and an oral delayed-release product is required for more extensive disease.

No source is stored against this line.

What is recorded as being sold

  • 109 products list this as an active ingredient in the United States drug directory. 109 of them contain it and nothing else.

    FDA National Drug Code directory · 72162-2213 · read 2026-08-29

  • They are sold as capsule, capsule, delayed release, capsule, extended release, enema, powder and suppository, taken oral and rectal.

    FDA National Drug Code directory · 72162-2213 · read 2026-08-29

  • The regulator's established pharmacologic class for it is aminosalicylate [epc] and aminosalicylic acids [cs].

    FDA National Drug Code directory · 72162-2213 · read 2026-08-29

  • 65 published labels name it as an active ingredient. 65 of them describe this substance alone, which is where its own label text on this page comes from.

    US prescribing information · 1e6978d0-01db-477d-a90f-27561777480f · read 2026-08-29

  • Those labels are classed as human prescription drug.

    US prescribing information · 1e6978d0-01db-477d-a90f-27561777480f · read 2026-08-29

  • Mesalamine is delayed-release tablets, usp at Delayed-release tablets: 800 mg, recorded as prescription product; fda label in effect 2024-05-23 in the United States.

    US prescribing information · 00f77203-3615-47e8-ae25-6e1cf8a2a00a · read 2026-08-28

  • Recorded price in US: 0.09744–0.1789 USD per one millilitre, across 6 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..

    Recorded source · 2026-08-26 · read 2026-08-28

  • Recorded price in US: 1.2867–135.18908 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 21 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..

    Recorded source · 2026-08-26 · read 2026-08-28

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 takeRead 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.

RNAWiki could not confidently classify this substance, so no self-experiment plan is offered.

Questions worth asking

  • Which of the trials of Mesalazine 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 unclearRead 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 mesalamine treats Crohn’s disease — 20 randomised trials in 2,367 patients found high-dose mesalamine no better than placebo

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 PPAR-gamma agonism is the operative mechanism in patients, shown in a mouse knockout and in cultured human biopsies and never tested clinically

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 mesalamine prevents colorectal cancer in colitis, an observational association inseparable from the effect of controlling inflammation

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 newer, more expensive drug improved on the older one; it improved tolerability and lost efficacy

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 unclearRead 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 Mesalazine 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 peopleRead 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.

For keeping ulcerative colitis in remission it works, on high-certainty evidence: 37% relapse against 55%
In plain words
Pooling 44 randomised trials in nearly ten thousand people, about 37 in a hundred taking mesalamine relapsed within six to twelve months against about 55 in a hundred on placebo. Cochrane graded the certainty of that finding as high, which is the top of their scale and rare.
What was measured
Failure to maintain clinical or endoscopic remission at six to twelve months, against placebo, pooled across 44 randomised trials
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The Cochrane review identified 44 studies in 9,967 participants, most at low risk of bias. For maintenance of clinical or endoscopic remission, 37% (335 of 907) of 5-ASA participants relapsed at six to twelve months against 55% (355 of 648) of placebo participants — risk ratio 0.68 (95% CI 0.61 to 0.76), 8 studies, 1,555 participants, high-certainty evidence. Serious adverse events were 1% (6 of 550) against 2% (5 of 276), risk ratio 0.60 (95% CI 0.19 to 1.84), low-certainty evidence, and there is probably little or no difference in adverse events overall (RR 0.93, 95% CI 0.73 to 1.18, moderate certainty). Once-daily dosing had a similar benefit and harm profile to conventional two- or three-times-daily dosing.
Source
Murray A et al., Cochrane Database Syst Rev 2020;8:CD000544
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
It is graded inferior to the older, cheaper drug it was invented to replace
In plain words
Mesalamine exists because sulfasalazine caused side effects from the half of the molecule that does nothing useful. Removing that half also made it work slightly less well. Cochrane rates the inferiority as high-certainty evidence, and points out that once cost is considered the case for the newer drug is hard to make.
What was measured
Failure to maintain remission, 5-ASA against sulfasalazine, pooled across 12 randomised trials in 1,655 participants
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
In the maintenance review, 48% (416 of 871) of 5-ASA participants relapsed at six to eighteen months against 43% (336 of 784) of sulfasalazine participants — risk ratio 1.14 (95% CI 1.03 to 1.27), 12 studies, 1,655 participants, graded high-certainty evidence of inferiority. For induction, the two were equivalent: 54% (150 of 279) of 5-ASA participants failed to enter remission against 58% (144 of 247) on sulfasalazine, risk ratio 0.90 (95% CI 0.77 to 1.04), moderate certainty. Commonly reported adverse events — flatulence, abdominal pain, nausea, diarrhoea, headache, dyspepsia — showed probably little or no difference between the two. The authors state that considering relative costs, a clinical advantage to using oral 5-ASA in place of sulfasalazine appears unlikely. The counter-argument is real and is not in the pooled numbers: sulfapyridine causes reversible reduction in male fertility, and that matters enormously to some patients and not at all to others.
Source
Murray A et al., Cochrane Database Syst Rev 2020;8:CD000544; Murray A et al., Cochrane Database Syst Rev 2020;8:CD000543
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
contested
Review state
Written into the record, not signed off as a reviewed claim
It does not work in Crohn’s disease, and it is prescribed there anyway
In plain words
Twenty randomised trials in 2,367 patients have asked whether aminosalicylates help active Crohn’s disease. High-dose mesalamine was no better than placebo. Low-dose mesalamine was no better than placebo. Sulfasalazine showed a trend and lost to steroids.
What was measured
Induction of remission or clinical response in mildly to moderately active Crohn’s disease, pooled across 20 randomised trials in 2,367 patients
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
The Cochrane review included 20 studies in 2,367 patients, ten at low risk of bias. Sulfasalazine showed a non-significant trend over placebo for inducing remission, with benefit confined mainly to Crohn’s colitis: 45% (63 of 141) entered remission at 17 to 18 weeks against 29% (43 of 148) on placebo, risk ratio 1.38 (95% CI 1.00 to 1.89), two studies, moderate certainty on sparse data. Sulfasalazine was significantly less effective than corticosteroids: 43% (55 of 128) against 60% (79 of 132), risk ratio 0.68 (95% CI 0.51 to 0.91). Olsalazine and low-dose mesalamine at 1 to 2 g daily were not superior to placebo. High-dose mesalamine at 3.2 to 4 g daily was not more effective than placebo for inducing response or remission. Trials of 4 to 4.5 g daily against budesonide yielded conflicting results and no firm conclusion. The authors called for large randomised trials to provide definitive evidence, and none has since arrived.
Source
Lim WC et al., Cochrane Database Syst Rev 2016;7:CD008870
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
After forty years the mechanism is a hypothesis supported in mice and cultured biopsies
In plain words
Nobody has established how this drug works. The best evidence points to a nuclear receptor called PPAR-gamma: mice bred to have less of it stopped responding to the drug, and human bowel tissue in culture behaves the way the theory predicts. Neither of those is a measurement in a patient.
What was measured
That PPAR-gamma agonism is the mechanism by which mesalamine treats ulcerative colitis in humans — demonstrated in a mouse knockout and in cultured human biopsies, never tested in patients
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Rousseaux and colleagues induced colitis in heterozygous PPAR-gamma knockout mice and in wild-type littermates and treated both with 5-ASA. The drug was beneficial in wild-type animals and not in heterozygotes. In epithelial cells 5-ASA increased PPAR-gamma expression, promoted translocation from cytoplasm to nucleus, and induced a conformational change permitting coactivator recruitment and activation of a peroxisome-proliferator response element. The findings were validated in organ cultures of human colonic biopsies. That is a strong, mechanistically specific result and it is not evidence in living patients: no trial has stratified response by PPAR-gamma genotype or expression, and competing accounts — cyclooxygenase and lipoxygenase inhibition, reactive-oxygen scavenging, NF-kappaB inhibition — remain in the literature alongside it. A drug in use since the 1980s with high-certainty efficacy evidence and an unsettled mechanism is unusual and worth stating plainly.
Source
Rousseaux C et al., J Exp Med 2005;201:1205-1215
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
Once daily works as well as twice daily, in 1,027 randomised patients
In plain words
A twelve-month trial gave people either the whole daily amount at once or split across two doses. Remission at six months was 90.5% and 91.8% — a difference of just over one percentage point, well within the range of chance. Fewer doses is easier to keep taking.
What was measured
Percentage remaining in remission at month 6 by Simple Clinical Colitis Activity Index, once-daily against twice-daily dosing
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
A multicentre, investigator-blinded, randomised, 12-month, parallel-group non-inferiority study compared 1.6 to 2.4 g of delayed-release mesalamine once daily against the same total split twice daily in 1,027 patients with ulcerative colitis in remission. The percentage remaining in remission at month 6 by the Simple Clinical Colitis Activity Index was 90.5% against 91.8%, a difference of 1.3 percentage points (95% CI -2.3 to 4.9, P=0.5016). At month 3 the figures were 94.8% and 95.6%, difference 0.8 points (95% CI -1.8 to 3.5, P=0.5426). The Cochrane review reached the same conclusion across five studies in 1,761 participants with high-certainty evidence: 60% of once-daily participants failed to enter clinical remission against 61% on conventional dosing (RR 0.99, 95% CI 0.93 to 1.06). This is one of the cleaner adherence results in gastroenterology and it took a 1,027-patient trial to establish something the pharmacology already implied.
Source
Warner Chilcott, once-daily against twice-daily delayed-release mesalamine (NCT00505778), posted results; Murray A et al., Cochrane Database Syst Rev 2020;8:CD000543
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
It can damage the kidneys silently, and can mimic the flare it is treating
In plain words
Two harms matter more than the rest. The drug can inflame the kidneys with no symptoms until the damage is advanced, which is why blood tests are meant to be repeated. And it can cause a sudden bout of cramping and bloody diarrhoea that looks exactly like the colitis getting worse — the instinct is to take more, which makes it worse.
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 United States labels for mesalamine products carry a Warnings and Precautions instruction to evaluate renal function prior to initiation and periodically during treatment, on the basis of reported renal impairment including minimal change nephropathy, acute and chronic interstitial nephritis and, rarely, renal failure. The injury is typically insidious and asymptomatic until substantial function is lost. Separately, the labels describe an acute intolerance syndrome — cramping, acute abdominal pain, bloody diarrhoea, sometimes fever, headache and rash — that is clinically indistinguishable from an exacerbation of the underlying ulcerative colitis, and that resolves on withdrawal. Hepatic failure has been reported in patients with pre-existing liver disease. Mesalamine-induced cardiac hypersensitivity reactions, myocarditis and pericarditis are also recorded. None of these are common; all are the kind of harm that a decades-long prescription makes worth naming.
Source
Mesalamine United States prescribing information, Warnings and Precautions — renal impairment, mesalamine-induced acute intolerance syndrome, hepatic failure and cardiac hypersensitivity (Rowasa NDA 019618 and the oral delayed-release products)
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
The cancer-prevention claim is observational and has never been randomised
In plain words
Long-standing ulcerative colitis raises the risk of bowel cancer, and mesalamine is often described as reducing it. That belief comes from observational studies of people who happened to be taking the drug, not from any trial that randomly assigned it and counted cancers.
What was measured
That mesalamine reduces colorectal cancer risk in ulcerative colitis — an observational association inseparable, by design, from the effect of better-controlled inflammation
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
No randomised controlled trial has tested mesalamine against placebo with colorectal cancer or dysplasia as a primary endpoint. The chemoprevention hypothesis rests on observational cohort and case-control data, which is subject to a specific and severe confounder in this disease: people who take maintenance therapy reliably have better-controlled inflammation, and inflammatory burden is itself the strongest known driver of colitis-associated dysplasia. Separating a direct chemopreventive effect of the molecule from the effect of simply having less inflammation is not possible in an observational design. The Cochrane reviews of this drug do not report cancer as an outcome, because the randomised literature does not contain it. The claim may well be true. It has not been measured the way an efficacy claim in this file is measured.
Source
Murray A et al., Cochrane Database Syst Rev 2020;8:CD000544 and 2020;8:CD000543 — neither review reports colorectal cancer or dysplasia among the outcomes available in the randomised literature
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
contested
Review state
Written into the record, not signed off as a reviewed claim

How many documents were read

  • 61 documents were read for this substance.

    RNAWiki source record

  • 10 of them state the same halfLife, and they agree.

    RNAWiki source record

  • 17 of them state the same tMax, and they agree.

    RNAWiki source record

Where else this substance is registered

FDA substance identifier (UNII)
4Q81I59GXC
CAS registry number
89-57-6
PubChem compound
4075
RxNorm concept
52582

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: Written into the record, not signed off.

  • 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

  • Not passed

    Safety mode resolved

    No register row and no identity class settled the question.

  • Passed

    Canonical metadata present

    slug and display name present

What is missing or unclearRead 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

  • 44 approved applications cover products containing this substance. The earliest was NDA019618, approved 19871224 to MYLAN SPECIALITY LP.

    Drugs@FDA application register · NDA019618 · read 2026-08-29

  • Marketing status on the register: discontinued and prescription.

    Drugs@FDA application register · NDA019618 · read 2026-08-29

  • The earliest marketing start date recorded for a listed product is 19880321.

    FDA National Drug Code directory · 72162-2213 · read 2026-08-29

What is missing or unclearRead from sources, not yet reviewed

What to learn next

Ordered by what would most change how you read this page, starting with what is easiest to misunderstand.

This order is fixed in code and does not count clicks or time on the page.

What is not here

5 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.

  • What was measured, goal by goal — found nothing in the sources checked.
  • 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.

The anti-inflammatory half of sulfasalazine, released directly into the colon so the sulfa half that caused the side effects can be left out — probably acting through PPAR-gamma, a mechanism shown in mice and in cultured human biopsies and never confirmed in a patient: it prevents relapse in ulcerative colitis with high-certainty evidence, 37% relapsing against 55% on placebo across 44 trials in 9,967 people, and the same Cochrane reviews grade it inferior to the older sulfasalazine it replaced and find no benefit at all in Crohn’s disease.

Recorded evidence blocks (12)

What did Mesalazine's largest trial (11385 people) and its longest (24 years) measure?


11385 people in Mesalazine's largest registered study, 24 years in its longest registered window, measuring Area Under the Plasma Concentration Versus Time Curve From Time Zero to Infinity (AUC 0→∞) of Ciprofloxacin XR. ClinicalTrials.gov · 2026-09-01

54 phase3, 31 phase2, 18 phase4, 17 phase1, 9 na, 7 na or unstated, 2 early phase1; NCT04920149; 2045-09-30; no ageing endpoint recorded. Last human test completed 2025, NCT05753267.

Interpretation These counts include studies where Mesalazine 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
  • phase3
    54
  • phase2
    31
  • phase4
    18
  • phase1
    17
  • na
    9
  • na or unstated
    7
2 more recorded rows
  • early phase1
    2
  • Last recorded human test NCT05753267
    2025-09-20

recorded 2026-09-01 · last checked 2026-09-04

From mouse to human: where has Mesalazine shown biomarker?


mouse: mechanism-only, rat: mechanism-only and human: biomarker (128): the rungs where Mesalazine has a recorded finding. Europe PMC and ClinicalTrials.gov · organism ladder · 2026-09-01

Area Under the Plasma Concentration Versus Time Curve From Time Zero to Infinity (AUC 0→∞) of Ciprofloxacin XR — the recorded outcome words.

Yeast C. elegans Drosophila Mouse mechanism-onlyRat mechanism-onlyDog Non-human primate Human biomarker
Show the evidence
  • mouse
    mechanism-only
  • rat
    mechanism-only
  • human NCT01402947
    biomarker; Area Under the Plasma Concentration Versus Time Curve From Time Zero to Infinity (AUC 0→∞) of Ciprofloxacin XR; 128

recorded 2026-09-01 · last checked 2026-09-04

15 of Mesalazine's trials stopped: safety, futility/efficacy, accrual/recruitment, funding/business, sponsor decision unspecified, other?


safety (1), futility/efficacy (1), accrual/recruitment (8), funding/business (2), sponsor decision unspecified (1) and other (2): Mesalazine's stop wording, clustered. ClinicalTrials.gov · 2026-09-01

"Study terminated due to lack of eligible patients"; 15 of 128 registered studies

Show the evidence

Trial

  • NCT00245505
    terminated; "Study terminated due to lack of eligible patients"
  • NCT00254618
    terminated; "Slow enrollment."
  • NCT00349388
    terminated; "none enrolled in second arm, therfore no analysis"
  • NCT00862121
    terminated; "Terminated due to poor recruitment"
  • NCT00984568
    terminated; "Due to slow recruitment the study was stopped prematurely."
  • NCT01004185
    terminated; "Pediatric enrollment very slow."
9 further recorded trials
  • NCT01016262
    terminated; "The decision was taken solely for business/administrative reasons, no safety considerations entered into this. Ongoing randomized patients to complete."
  • NCT01038739
    terminated; "Stopped due to futility."
  • NCT01172444
    terminated; "Enrollment difficulties"
  • NCT01696942
    terminated; "Lack of accrual"
  • NCT02190526
    withdrawn; "Study stopped due to lack of volunteer patients."
  • NCT02769494
    withdrawn; "Lack of funds"
  • NCT03070574
    terminated; "Due to poor patient recruitment and insufficient financing."
  • NCT03415711
    terminated; "Administrative reasons"
  • NCT05316220
    withdrawn; "strategic considerations"

recorded 2026-09-01 · last checked 2026-09-04

Human studies of Mesalazine used Asacol 800 mg (mesalamine) — over how long?


Human studies of Mesalazine used "Asacol 800 mg (mesalamine)". ClinicalTrials.gov · 2026-09-01

15 recorded entries; human; tablet; also "Asacol 400 mg (mesalamine)", "SPD476, MMX™ mesalazine, 1.2g extended release tablet", "SPD476, MMX™ mesalazine, 2.4g extended release tablet"

Show the evidence

human

  • NCT00073021
    Asacol 800 mg (mesalamine)
  • NCT00073021
    Asacol 400 mg (mesalamine)
  • NCT00545103
    tablet; SPD476, MMX™ mesalazine, 1.2g extended release tablet
  • NCT00545103
    tablet; SPD476, MMX™ mesalazine, 2.4g extended release tablet
  • NCT00545103
    tablet; SPD476, MMX™ mesalazine, 4.8g extended release tablet
  • NCT00679432
    Asacol® 400 mg
9 more recorded rows
  • human NCT00713310
    Asacol 400 mg
  • human NCT00747110
    Salofalk 1000mg granules
  • human NCT00946946
    Salofalk 500mg tablets
  • human NCT01534754
    Mesalazine 800 mg
  • human NCT01903252
    Mesalazine 1600 mg
  • human NCT02190526
    Mesalazine(asacol 800 mg)
  • human NCT03412682
    Mesalazine (3,600 mg)
  • human NCT03441893
    Mesalazine 250Mg Tablet and nitazoxanide 500Mg Oral Tablet
  • human NCT03441893
    Mesalazine 250Mg

recorded 2026-09-01 · last checked 2026-09-04

Could one person measure Mesalazine's effect on pharmacokinetics?


Pharmacokinetics: measured in Mesalazine's trials.

Interpretation pharmacokinetics is the recorded endpoint.

Show the evidence

biomarkers

  • pharmacokinetics; 2026-09-01
  • rate of remission; 2026-09-01
  • rate of clinical remission; 2026-09-01
  • rate of clinical remission after 8 weeks; 2026-09-01
  • in remission; 2026-09-01
  • global symptom at week 12 primary efficacy population; 2026-09-01
14 more recorded rows
  • biomarkers
    clinical and endoscopic remission; 2026-09-01
  • biomarkers
    rate of clinical remission at week 8; 2026-09-01
  • biomarkers
    response at week 4 and steroid free remission at week 50; 2026-09-01
  • biomarkers
    corticosteroid free remission; 2026-09-01
  • biomarkers
    who needed additional therapy or colectomy; 2026-09-01
  • biomarkers
    clinical recurrence rates of crohn s disease; 2026-09-01
  • biomarkers
    efficacy; 2026-09-01
  • biomarkers
    compliance treatment; 2026-09-01
  • biomarkers
    apoptotic index; 2026-09-01
  • biomarkers
    who respond to the treatment; 2026-09-01
  • biomarkers
    quality of life; 2026-09-01
  • biomarkers
    clinical remission; 2026-09-01
  • biomarkers
    short inflammatory bowel disease questionnaire total; 2026-09-01
  • biomarkers
    remission; 2026-09-01
  • half life
    2026-09-04; halfLife; 2026-08-03
  • human trials at or under30
    31
  • smallest human trial
    0; NCT00514982; PHASE2; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; WITHDRAWN

Which of 2 or more decrease in the mayo from baseline, achieving clinical remission and apoptotic index did Mesalazine's trials measure?


2 or more decrease in the mayo from baseline, achieving clinical remission and apoptotic index lead 28 outcome terms across Mesalazine's trials. ClinicalTrials.gov · 2026-09-01

rate of clinical remission after 8 weeks, in remission, global symptom at week 12 primary efficacy population, clinical and endoscopic remission, rate of clinical remission at week 8 and response at week 4 and steroid free remission at week 50 follow.

Show the evidence
  • pharmacokinetics
    1
  • rate of remission
    1
  • rate of clinical remission
    1
  • rate of clinical remission after 8 weeks
    1
  • in remission
    1
  • global symptom at week 12 primary efficacy population
    1
14 more recorded rows
  • clinical and endoscopic remission
    1
  • rate of clinical remission at week 8
    1
  • response at week 4 and steroid free remission at week 50
    1
  • corticosteroid free remission
    1
  • who needed additional therapy or colectomy
    1
  • clinical recurrence rates of crohn s disease
    1
  • efficacy
    1
  • compliance treatment
    1
  • apoptotic index
    1
  • who respond to the treatment
    1
  • quality of life
    1
  • clinical remission
    1
  • short inflammatory bowel disease questionnaire total
    1
  • remission
    1

recorded 2026-09-01 · last checked 2026-09-04

Which of Mesalazine's 14 ongoing trials reports first?


14 registered trials of Mesalazine are open; earliest completion 2025-05. ClinicalTrials.gov · 2026-09-01

Clinical remission in patient as assessed using Mayo score; Change in the occurrence of any colorectal neoplasia in LS patients; latest 2045-09-30

Show the evidence

Trial

  • NCT03804931
    "Fecal Microbiota Transplantation for Ulcerative Colitis"; n 120; "Clinical remission in patient as assessed using Mayo score"; 2030-12-31
  • NCT04920149
    "Mesalamine for Colorectal Cancer Prevention Program in Lynch Syndrome"; n 150; "Change in the occurrence of any colorectal neoplasia in LS patients"; 2045-09-30
  • NCT05119140
    "Administration of Hydroxychloroquine (Plaquenil) to African Americans and Hispanics for the Treatment of Mild to Severe Ulcerative Colitis"; n 3; "Change in surface CTLA4 expression"; 2025-05
  • NCT05663775
    "Prophylactic Mesalamine to Prevent Colitis Following Treatment With Ipilimumab/Nivolumab (Ipi/Nivo)"; n 20; "Incidence of Treatment Related Diarrhea"; 2027-08
  • NCT05986136
    "Activation of Autophagy and Suppression of Apoptosis by Dapagliflozin Attenuates Inflammatory Bowel Disease"; n 50; "The primary endpoint is the change in mayo score"; 2028-07-20
  • NCT06213857
    "Beneficial Effect of Silymarin in Ulcerative Colitis"; n 44; "2 points or more decrease in the Mayo score from baseline"; 2025-06
8 further recorded trials
  • NCT06525974
    "Clinical Study to Evaluate the Possible Efficacy and Safety of Febuxostat in Patients With Ulcerative Colitis Treated With Mesalamine"; n 46; "Assessment of disease activity using Partial Mayo Scoring Index (PMSI) assessment for Ulcerative Colitis Activity."; 2026-12-30
  • NCT06993974
    "Nitazoxanide in Patients With Ulcerative Colitis"; n 70; "change in partial mayo score."; 2026-12-20
  • NCT07064707
    "Rupatadine in Patients With Ulcerative Colitis"; n 60; "change in partial mayo score"; 2026-10-21
  • NCT07333716
    "Desloratadine in Patients With Ulcerative Colitis"; n 44; "Change in disease activity and severity"; 2027-03
  • NCT07349472
    "Pentoxifylline in Patients With Ulcerative Colitis"; n 60; "Change in partial Mayo score"; 2027-02-20
  • NCT07389824
    "Efficacy of Acupuncture-Mesalazine Combination Therapy in Ulcerative Colitis."; n 66; "Clinical remission rate"; 2027-12-31
  • NCT07767370
    "ND-12 Combined With H-6 for Adult Chronic Inflammatory Diarrhea"; n 36; "Fecal calprotectin of patients 14 days after treatment compared to the baseline level"; 2028-08-31
  • NCT07782242
    "Comaprison of Efficacy and Safety Between Etrasimod vs Mesalazine in Chinese Adults With Active UC"; n 320; "Percentage of participants achieving clinical remission"; 2027-12-31

recorded 2026-09-01 · last checked 2026-09-04

Which 53 trials of Mesalazine posted no result?


Posted no result
53 of 53 completed trials
Registrations
NCT00802451, NCT00545389, NCT00548574, NCT00774007, NCT01627262 and NCT00449722, and 47 more
Completion dates
oldest 2003-03; newest 2024-05-01
Show the evidence

Trial

  • NCT00802451
    2003-03
  • NCT00545389
    2004-10-20
  • NCT00548574
    2004-10-20
  • NCT00774007
    2005-11
  • NCT01627262
    2006-04
  • NCT00449722
    2006-06
14 further recorded trials
  • NCT00343850
    2007-03
  • NCT00751699
    2007-04
  • NCT00092508
    2007-05
  • NCT00350415
    2007-05
  • NCT00209300
    2007-06
  • NCT00194818
    2007-08
  • NCT00952952
    2007-11
  • NCT00746447
    2008-03
  • NCT00300118
    2008-05
  • NCT00622375
    2008-05
  • NCT00946946
    2009-07
  • NCT01045018
    2009-08
  • NCT00737789
    2010-06
  • NCT00808977
    2010-06

At the median, Mesalazine's trials enrolled 74 people — anything larger?


Median enrolment
74
Largest enrolment
11385
Registered trials counted
127

What do 3487 spontaneous reports say about Mesalazine — 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.

Mesalazine appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 3487 reaction mentions were counted: colitis ulcerative 505; diarrhoea 471; condition aggravated 367; pyrexia 363. open-targets-adr · CHEMBL704 · 2026-06-24

Show the evidence
  • colitis ulcerative
    505
  • diarrhoea
    471
  • condition aggravated
    367
  • pyrexia
    363
  • haematochezia
    337
  • abdominal pain
    331
4 more recorded rows
  • crohn's disease
    293
  • colitis
    279
  • drug hypersensitivity
    272
  • weight decreased
    269

recorded 2026-06-24 · last checked 2026-09-04

Mesalazine and CYP1A2, CYP2C19 and CYP2C9: shared by which compounds?


CYP1A2, CYP2C19 and CYP2C9 appear in Mesalazine's recorded interaction sentences, 10 in all. openfda-label+europepmc · 2026-08-30

Interpretation pharmacokinetics

Show the evidence

CYP1A2

  • pharmacokinetics
    Therefore, mesalamine and its metabolite are not expected to inhibit the metabolism of other drugs that are substrates of CYP1A2, CYP2C9, CYP2C19, CYP2D6, or CYP3A4.
  • pharmacokinetics
    Drug Interaction Studies In an in vitro study using human liver microsomes, 5-ASA and its metabolite, N-Ac-5-ASA, were shown not to inhibit the major CYP enzymes evaluated (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4).

CYP2C19

  • pharmacokinetics
    Therefore, mesalamine and its metabolite are not expected to inhibit the metabolism of other drugs that are substrates of CYP1A2, CYP2C9, CYP2C19, CYP2D6, or CYP3A4.
  • pharmacokinetics
    Drug Interaction Studies In an in vitro study using human liver microsomes, 5-ASA and its metabolite, N-Ac-5-ASA, were shown not to inhibit the major CYP enzymes evaluated (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4).

CYP2C9

  • pharmacokinetics
    Therefore, mesalamine and its metabolite are not expected to inhibit the metabolism of other drugs that are substrates of CYP1A2, CYP2C9, CYP2C19, CYP2D6, or CYP3A4.
  • pharmacokinetics
    Drug Interaction Studies In an in vitro study using human liver microsomes, 5-ASA and its metabolite, N-Ac-5-ASA, were shown not to inhibit the major CYP enzymes evaluated (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4).

CYP2D6

  • pharmacokinetics
    Therefore, mesalamine and its metabolite are not expected to inhibit the metabolism of other drugs that are substrates of CYP1A2, CYP2C9, CYP2C19, CYP2D6, or CYP3A4.
  • pharmacokinetics
    Drug Interaction Studies In an in vitro study using human liver microsomes, 5-ASA and its metabolite, N-Ac-5-ASA, were shown not to inhibit the major CYP enzymes evaluated (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4).

CYP3A4

  • pharmacokinetics
    Therefore, mesalamine and its metabolite are not expected to inhibit the metabolism of other drugs that are substrates of CYP1A2, CYP2C9, CYP2C19, CYP2D6, or CYP3A4.
  • pharmacokinetics
    Drug Interaction Studies In an in vitro study using human liver microsomes, 5-ASA and its metabolite, N-Ac-5-ASA, were shown not to inhibit the major CYP enzymes evaluated (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4).

recorded 2026-08-30 · last checked 2026-09-04

What is recorded about Mesalazine and AMPK?


"Notably, the commonly used anti-inflammatory 5-aminosalicylic acid (ie, mesalazine) and sodium salicylate ameliorated dextran sodium sulfate-induced colitis through the activation of macrophage AMPK targeting the β1 subunit." — where Mesalazine and AMPK appear together. Europe PMC · pathway abstract search · 2021-05-01

AMPK; PMID 33252129

Show the evidence
  • AMPK PMID 33252129
    "Notably, the commonly used anti-inflammatory 5-aminosalicylic acid (ie, mesalazine) and sodium salicylate ameliorated dextran sodium sulfate-induced colitis through the activation of macrophage AMPK targeting the β1 subunit."

recorded 2021-05-01 · last checked 2026-09-04

Where it is registered
Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL704
PubChem CID
4075
CAS number
89-57-6
RxCUI
52582
InChIKey
KBOPZPXVLCULAV-UHFFFAOYSA-N
Also called
MESALAMINE, Benzoic acid, 5-amino-2-hydroxy-, Fisalamine, Iialda, Mesalazina, 5-amino salicylic acid, 5-aminosalicylate, 5-aminosalicylates, 5-aminosalicylic acid, 5-asa, 5asa, emg
Trade name
Apriso, Asacol, Asacol hd, Canasa, Coltec ec, Delzicol, Ipocol, Lialda, Mesren mr, Mezavant xl, Octasa, Pentasa
Development code
MAX-002, NSC-38877
Salt form
pentasa tablets
Sources (11)

Sources

  • ClinicalTrials.gov clinicaltrials.gov ·
  • ClinicalTrials.gov ClinicalTrials.gov API v2 snapshot 2026-09-01T09:00:05 ·
  • this record's own fields 2,3,5 ·
  • Europe PMC dose-response search ·
  • Europe PMC pathway abstract search ·
  • Europe PMC search ·
5 more sources

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

How these records are assembled · Which registers were checked

Index-quality checks
  • identity passed: no open identity hold
  • 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: 11 source rows
  • no critical contamination: no quarantine open
  • canonical metadata passed: slug and display name present
  • no raw internal fields: enforced by the copy-contract test over the rendered page

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