Skip to content

Chlortalidone

  • 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 Chlortalidone does in the body

THALITONE is a thiazide-like diuretic indicated: • For the treatment of hypertension, to lower blood pressure.

From the FDA-approved label: Chlorthalidone is a long-acting oral diuretic with antihypertensive activity. Chlorthalidone produces diuresis with increased excretion of sodium and chloride. The site of action appears to be the cortical diluting segment of the ascending limb of Henle’s loop of the nephron. The diuretic effects of chlorthalidone lead to decreased extracellular fluid volume, plasma volume, cardiac output, total exchangeable sodium, glomerular filtration rate, and renal plasma flow. Although the mechanism of action of chlorthalidone and related drugs is not wholly clear, sodium and water depletion appear to provide a basis for its antihypertensive effect.

Why people take it. THALITONE is a thiazide-like diuretic indicated: • For the treatment of hypertension, to lower blood pressure.

What happened in people

RNAWiki has not yet published a reviewed conclusion for this use.

A fixed RNAWiki sentence

Where this came from

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

No reviewed claim names a result for any goal on this record.

No source is stored against this line.

The limit that matters most

Not recorded.

Where it acts
Not recorded.
Kind of result
No result is published, so no kind of result applies yet
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 · Q0MQD1073Q · read 2026-08-29

Where each sentence above came from

The use the label states, quoted from it. No plain-language version of this sentence has been written.

The use the label states, quoted from it. It is written for a clinician, not for a reader without medical training.

No statement of the main limit is recorded.

The four opening statements run to 137 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.

Biomarker

A biomarker is a number from a test that stands in for something about health.

A picture of it, and where the picture fails

A biomarker is like a fuel gauge.

Where that stops being true. A gauge is wired to the tank. Many biomarkers are only loosely tied to health.

What people get wrong. A better number is read as a better life. Several medicines improved a number and helped nobody.

A measurable indicator used as a substitute for a clinical outcome of interest.

Stand-in result

A stand-in result is a number measured because the real result takes too long.

A picture of it, and where the picture fails

It is like judging a journey by the speedometer rather than by arriving.

Where that stops being true. Speed does predict arrival. Many stand-in results do not predict the real one.

What people get wrong. A stand-in result is often reported as the result itself.

A surrogate endpoint substituted for a clinical endpoint, valid only where the substitution has been shown to hold.

What happened in peopleRead 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 37 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.
GoalLife outcomeWhat a body can doHow a person feelsA test resultA step in the bodyHarmsHow longWho was studied
Healthy ageingWaiting for a reviewer3 registered study measure of this kind. No reviewed result yet.Nothing in the sources checkedNo registered study lists a performance measure for this goal.Nothing in the sources checkedNo registered study lists a symptom measure for this goal.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.
Blood sugarNothing 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.Nothing in the sources checkedNo registered study lists a symptom measure for this goal.Only a number moved1 registered test measure.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.
Fertility and sexual healthNothing 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.Nothing in the sources checkedNo registered study lists a symptom measure for this goal.Only a number moved1 registered test measure.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
Healthy ageing
all cause hospitalization or all cause mortality; all cause mortality; mortality days in hospital decongestion
Blood sugar
fasting plasma glucose from week 4 to week 16
Fertility and sexual health
urine concentration of testosterone metabolites

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
Waiting for a reviewer
3 registered study measure of this kind. No reviewed result yet.
Nothing in the sources checked
No registered study lists a performance measure for this goal.
Not recorded
Harms were not a registered measure for this goal.
Only a number moved
1 registered test measure.

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.

Time From Randomization to Composite Primary Outcome

The study did not show it

Who was studied
NCT02185417
How many people
20723
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

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. No limitation is recorded for this study.

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

Form and route. Oral

Interval reported. Not recorded in this summary

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

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

First Occurrence of a Major Cardiovascular Event (MCE); Specifically Nonfatal Heart Attack, Nonfatal Stroke, or Cardiovascular Death (Measured Throughout the Study) in the Glycemia Trial.

The study did not show it

Who was studied
NCT00000620
How many people
10251
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

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. No limitation is recorded for this study.

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

Form and route. Oral

Interval reported. Not recorded in this summary

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

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Persistance and adherence to treatment

The study did not show it

Who was studied
NCT00408512
How many people
2500
Study design
Phase 4
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

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. No limitation is recorded for this study.

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

Form and route. Oral

Interval reported. Not recorded in this summary

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

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Number of Covid-19 positive participants who die, require intubation in ICU, or require hospitalization for non-invasive ventilation (NIV)

The study did not show it

Who was studied
NCT04330300
How many people
2414
Study design
Phase 4
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

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. No limitation is recorded for this study.

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

Form and route. Oral

Interval reported. Not recorded in this summary

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

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Conversion to chlorthalidone, number of patients with primary fills

The study did not show it

Who was studied
NCT02591628
How many people
2027
Study design
Not applicable
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

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. No limitation is recorded for this study.

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

Form and route. Oral

Interval reported. Not recorded in this summary

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

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Blood pressure (mmHg)

The study did not show it

Who was studied
NCT01643434
How many people
2000
Study design
Phase 4
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

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. No limitation is recorded for this study.

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

Form and route. Oral

Interval reported. Not recorded in this summary

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

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
What we know
RNAWiki holds 6 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.3 registered measures of this kind. 1 written-up study measured this and did not show a benefit.
  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 No evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.No registered study measures this.
  5. A number that stands in for health Evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.18 registered measures of this kind.
  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 No evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.No animal record is stored.
  8. Cells in a dish No evidence recorded. Cells or chemistry on a bench, far from a whole body.No cell or bench record is stored.
  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 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.

No registered study measured anything of this kind.

Measured

Things only a test, a scale or a device shows.

  • blood pressure
  • diastolic blood pressure by cuff 8 10 weeks minus baseline
  • blood pressure from baseline to treatment
  • systolic 24 hour ambulatory blood pressure
  • fasting plasma glucose from week 4 to week 16
  • seated automated office systolic blood pressure
  • urinary calcium excretion
  • 24 h systolic blood pressure measured by abpm
  • 24 h diastolic blood pressure measured by abpm
  • urine concentration of bupropion metabolites

and 8 more.

Meaningful

Things that change how a life goes, not only a number.

  • all cause hospitalization or all cause mortality
  • all cause mortality
  • mortality days in hospital decongestion

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 (16)
  • part a auc cmax of telmisartan
  • flow mediated vasodilatation
  • fluorescence intensity of pac 1
  • time from randomization to composite primary outcome
  • had a composite primary outcome
  • auclast
  • cmax
  • bioequivalence study is based on cmax and auc parameters
  • average daytime sbp
  • hypercalcemia
  • hyperglycemia
  • pulse wave velocity
  • stress myocardial perfusion reserve on cardiac mri
  • area under the curve from time zero to infinity calculated
  • elimination rate
  • myocardial flow reserve

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

What it would be like to takeRead from sources, not yet reviewed

How long anything takes

Nine different lengths of time that get confused with each other. None of them is worked out from another.

  1. Before anything is noticed. RNAWiki does not store this separately, and never works it out from another figure on this page.

  2. Before a test result moves. RNAWiki does not store this separately, and never works it out from another figure on this page.

  3. Before performance moves. RNAWiki does not store this separately, and never works it out from another figure on this page.

  4. How long the result was watched. No finished study window is recorded for a study that tested this substance.

  5. How long people took it. How long people actually took it is not stored. The study window is not the same thing.

  6. How long people were followed. Follow-up length is not stored separately. It is never read off the study window, which would be a different thing.

  7. How fast the body clears it. 40 to 60 hours hours

    Read from the label, which states: “Elimination The mean plasma half-life of chlorthalidone is about 40 to 60 hours.”

  8. How long effects linger. RNAWiki does not store this separately, and never works it out from another figure on this page.

  9. Beyond the studies. Nothing is recorded about the long term.

    The longest finished study sets the edge of what anyone measured.

A study window is not how long people took it, and neither is how long they were followed. Where RNAWiki holds only one of the three, it shows one.

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.

  • Diuretics such as chlorthalidone are indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension. Chlorthalidone is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.

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 in children have not been established.”

    US prescribing information · bc5a0299-115b-4e60-bb3f-c75a95c51c15 · read 2026-08-30

  • On older people, the label states: “Clinical studies of THALITONE did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.”

    US prescribing information · bc5a0299-115b-4e60-bb3f-c75a95c51c15 · read 2026-08-30

  • On people who are pregnant, the label states: “Risk Summary Available data over decades from observational studies and reports with chlorthalidone use in pregnant women have not identified a drug-associated risk of major birth defects or miscarriage.”

    US prescribing information · bc5a0299-115b-4e60-bb3f-c75a95c51c15 · read 2026-08-30

  • On people who are breastfeeding, the label states: “Risk Summary Chlorthalidone is present in human milk.”

    US prescribing information · bc5a0299-115b-4e60-bb3f-c75a95c51c15 · read 2026-08-30

Where the result stopped carrying

  • 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

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

Sold as tablet, capsule, given by the oral route.

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 takeNothing found in the sources checked

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.

Nothing found in the sources checked

No harm is recorded against this substance in the sources RNAWiki checked. Finding nothing is not the same as showing there is nothing.

The sources listed were searched and held nothing. That is not the same as nothing existing.

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.

Chlortalidone appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 648 reaction mentions were counted. One report can name several reactions.

The recorded terms (10)
  • hyponatraemia — 121 reaction mentions
  • hypokalaemia — 109 reaction mentions
  • nausea — 91 reaction mentions
  • hypotension — 65 reaction mentions
  • dizziness — 55 reaction mentions
  • acute kidney injury — 50 reaction mentions
  • hypertension — 41 reaction mentions
  • oedema peripheral — 41 reaction mentions
  • syncope — 39 reaction mentions
  • renal failure — 36 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

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

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

Nothing further is recorded about which forms are sold.

No source is stored against this line.

What is recorded as being sold

  • 143 products list this as an active ingredient in the United States drug directory. 114 of them contain it and nothing else.

    FDA National Drug Code directory · 71335-3074 · read 2026-08-29

  • They are sold as powder and tablet, taken oral.

    FDA National Drug Code directory · 71335-3074 · read 2026-08-29

  • The regulator's established pharmacologic class for it is increased diuresis [pe] and thiazide-like diuretic [epc].

    FDA National Drug Code directory · 71335-3074 · read 2026-08-29

  • 91 published labels name it as an active ingredient. 79 of them describe this substance alone, which is where its own label text on this page comes from.

    US prescribing information · a6794dfa-adbb-491b-9d48-f89a44e866c5 · read 2026-08-29

  • Those labels are classed as human prescription drug.

    US prescribing information · a6794dfa-adbb-491b-9d48-f89a44e866c5 · read 2026-08-29

  • Thalitone is oral at 3 DOSAGE FORMS AND STRENGTHS THALITONE 15 mg tablets are white biconvex, kidney shaped tablets with “L” on lower punch and “96” on the upper punch., recorded as fda label in effect 2026-06-25 in the United States.

    US prescribing information · bc5a0299-115b-4e60-bb3f-c75a95c51c15 · read 2026-08-30

  • Recorded price in US: 0.08397–0.12095 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 59 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 Chlortalidone 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

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 Chlortalidone 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.

How many documents were read

  • 78 documents were read for this substance.

    RNAWiki source record

Where else this substance is registered

FDA substance identifier (UNII)
Q0MQD1073Q
RxNorm concept
197499

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: Quoted from a stored source.

  • 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

  • 84 approved applications cover products containing this substance. The earliest was NDA012283, approved 19600407 to SANOFI AVENTIS US.

    Drugs@FDA application register · NDA012283 · read 2026-08-29

  • Marketing status on the register: discontinued and prescription.

    Drugs@FDA application register · NDA012283 · read 2026-08-29

  • The earliest marketing start date recorded for a listed product is 19810226.

    FDA National Drug Code directory · 71335-3074 · 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.

  • The path through the body — 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.
  • Claims that go past the evidence — 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.

Recorded evidence blocks (12)

What did Chlortalidone's largest trial (37939 people) and its longest (13 years) measure?


37939 people in Chlortalidone's largest registered study, 13 years in its longest registered window, measuring All-Cause-Hospitalization or All-Cause Mortality. ClinicalTrials.gov · 2026-09-01

15 phase4, 12 phase3, 9 phase2, 6 na, 6 phase1, 4 na or unstated, 1 early phase1; NCT00000620; 2012-12; no ageing endpoint recorded. Last human test completed 2026, NCT06287580.

Interpretation These counts include studies where Chlortalidone 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
  • phase4
    15
  • phase3
    12
  • phase2
    9
  • na
    6
  • phase1
    6
  • na or unstated
    4
2 more recorded rows
  • early phase1
    1
  • Last recorded human test NCT06287580
    2026-02-20

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

Chlortalidone was tested only in human — what did it show?


human: lifespan (53): the rungs where Chlortalidone has a recorded finding. Europe PMC and ClinicalTrials.gov · organism ladder · 2026-09-01

Interpretation All-Cause-Hospitalization or All-Cause Mortality — the recorded outcome words.

Yeast C. elegans Drosophila Mouse Rat Dog Non-human primate Human lifespan
Show the evidence
  • human NCT04467931
    lifespan; All-Cause-Hospitalization or All-Cause Mortality; 53

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

8 of Chlortalidone's trials stopped: futility/efficacy, accrual/recruitment, other?


futility/efficacy (2), accrual/recruitment (1) and other (5): Chlortalidone's stop wording, clustered. ClinicalTrials.gov · 2026-09-01

"Based on results from an ALTITUDE study interim analysis, testing aliskiren concomitantly with an ACE inhibitor or ARB, in diabetics with renal impairment"; 8 of 53 registered studies

Show the evidence

Trial

  • NCT01368536
    terminated; "Based on results from an ALTITUDE study interim analysis, testing aliskiren concomitantly with an ACE inhibitor or ARB, in diabetics with renal impairment"
  • NCT01748123
    withdrawn; "Slow enrollment"
  • NCT01822860
    withdrawn; "Study subjects were not able to be recruited"
  • NCT02030314
    withdrawn; "The patient population changed. Unable to find patients that meet study criteria"
  • NCT02357004
    withdrawn; "Change in priority of interventional protocols"
  • NCT03325114
    terminated; "COVID restrictions prohibit further study activies"
2 further recorded trials
  • NCT05275907
    withdrawn; "Screened participants did not meet inclusion criteria prior to study completion date"
  • NCT05915286
    terminated; "Personnel/staffing issues."

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

Human studies of Chlortalidone used Chlorthalidone 25mg — over how long?


Human studies of Chlortalidone used "Chlorthalidone 25mg". ClinicalTrials.gov · 2026-09-01

4 recorded entries; human; also "Chlorthalidone 12.5 mg", "Hygroton 25mg", "Chlorthalidone 25 mg"

Show the evidence

human

  • NCT01806363
    Chlorthalidone 25mg
  • NCT01822860
    Chlorthalidone 12.5 mg
  • NCT02496910
    Hygroton 25mg
  • NCT03928145
    Chlorthalidone 25 mg

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

Chlortalidone's half-life is 40 to 60 hours — which schedules were studied?


40 to 60 hours, the half-life Chlortalidone's label states. openfda-label · 5de362df-8fb9-4421-864c-7ea06339d6e7 · 2026-08-30

Show the evidence
  • half life
    40 to 60 hours hours; Elimination The mean plasma half-life of chlorthalidone is about 40 to 60 hours.

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

Could one person measure Chlortalidone's effect on blood pressure?


Blood pressure: measured in Chlortalidone's trials.

Interpretation blood pressure is the recorded endpoint.

Show the evidence

biomarkers

  • blood pressure; 2026-09-01
  • diastolic blood pressure by cuff 8 10 weeks minus baseline; 2026-09-01
  • blood pressure from baseline to treatment; 2026-09-01
  • systolic 24 hour ambulatory blood pressure; 2026-09-01
  • part a auc cmax of telmisartan; 2026-09-01
  • flow mediated vasodilatation; 2026-09-01
14 more recorded rows
  • biomarkers
    fluorescence intensity of pac 1; 2026-09-01
  • biomarkers
    time from randomization to composite primary outcome; 2026-09-01
  • biomarkers
    had a composite primary outcome; 2026-09-01
  • biomarkers
    auclast; 2026-09-01
  • biomarkers
    cmax; 2026-09-01
  • biomarkers
    bioequivalence study is based on cmax and auc parameters; 2026-09-01
  • biomarkers
    average daytime sbp; 2026-09-01
  • biomarkers
    fasting plasma glucose from week 4 to week 16; 2026-09-01
  • biomarkers
    seated automated office systolic blood pressure; 2026-09-01
  • biomarkers
    urinary calcium excretion; 2026-09-01
  • biomarkers
    hypercalcemia; 2026-09-01
  • biomarkers
    hyperglycemia; 2026-09-01
  • biomarkers
    pulse wave velocity; 2026-09-01
  • biomarkers
    24 h systolic blood pressure measured by abpm; 2026-09-01
  • half life
    2026-09-04; halfLife; hours; 40 to 60 hours; 2026-08-30
  • human trials at or under30
    14
  • smallest human trial
    0; NCT01748123; PHASE4; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; WITHDRAWN

Which of 24 h diastolic blood pressure measured by abpm, 24 h systolic blood pressure measured by abpm and all cause hospitalization or all cause mortality did Chlortalidone's trials measure?


24 h diastolic blood pressure measured by abpm, 24 h systolic blood pressure measured by abpm and all cause hospitalization or all cause mortality lead 37 outcome terms across Chlortalidone's trials. ClinicalTrials.gov · 2026-09-01

systolic 24 hour ambulatory blood pressure, part a auc cmax of telmisartan, flow mediated vasodilatation, fluorescence intensity of pac 1, time from randomization to composite primary outcome and had a composite primary outcome follow.

Show the evidence
  • blood pressure
    1
  • diastolic blood pressure by cuff 8 10 weeks minus baseline
    1
  • blood pressure from baseline to treatment
    1
  • systolic 24 hour ambulatory blood pressure
    1
  • part a auc cmax of telmisartan
    1
  • flow mediated vasodilatation
    1
14 more recorded rows
  • fluorescence intensity of pac 1
    1
  • time from randomization to composite primary outcome
    1
  • had a composite primary outcome
    1
  • auclast
    1
  • cmax
    1
  • bioequivalence study is based on cmax and auc parameters
    1
  • average daytime sbp
    1
  • fasting plasma glucose from week 4 to week 16
    1
  • seated automated office systolic blood pressure
    1
  • urinary calcium excretion
    1
  • hypercalcemia
    1
  • hyperglycemia
    1
  • pulse wave velocity
    1
  • 24 h systolic blood pressure measured by abpm
    1

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

Which of Chlortalidone's 3 ongoing trials reports first?


3 registered trials of Chlortalidone are open; earliest completion 2027-06-30. ClinicalTrials.gov · 2026-09-01

Change in myocardial flow reserve; Primary outcome component 1 - calcium oxalate supersaturation in urine; latest 2027-12-31

Show the evidence

Trial

  • NCT05593055
    "Mineralocorticoid Receptor, Coronary Microvascular Function, and Cardiac Efficiency in Hypertension"; n 75; "Change in myocardial flow reserve"; 2027-12-31
  • NCT06111885
    "Indapamide and Chlorthalidone to Reduce Urine Supersaturation for Kidney Stone Prevention"; n 99; "Primary outcome component 1 - calcium oxalate supersaturation in urine"; 2027-06-30
  • NCT07225764
    "CaOx Stone Prevention"; n 80; "Changes in super saturation of calcium oxalate"; 2027-12-31

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

Which 17 trials of Chlortalidone posted no result?


Posted no result
17 of 17 completed trials
Registrations
NCT00000499, NCT00000522, NCT00000513, NCT00000514, NCT00000542 and NCT00006294, and 11 more
Completion dates
oldest 1983-05; newest 2023-10
Show the evidence

Trial

  • NCT00000499
    1983-05
  • NCT00000522
    1994-05
  • NCT00000513
    1994-11
  • NCT00000514
    1996-10
  • NCT00000542
    2002-03
  • NCT00006294
    2005-08
11 further recorded trials
  • NCT01806363
    2013-06
  • NCT02152969
    2014-11
  • NCT02496910
    2015-09
  • NCT02644395
    2016-12-19
  • NCT01083017
    2017-05
  • NCT02711670
    2017-06
  • NCT03560804
    2017-09-15
  • NCT05090449
    2020-05-25
  • NCT04467931
    2020-12-31
  • NCT04757532
    2021-03-10
  • NCT02847338
    2023-10

At the median, Chlortalidone's trials enrolled 71 people — anything larger?


Median enrolment
71
Largest enrolment
37939
Registered trials counted
47

What do 648 spontaneous reports say about Chlortalidone — 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.

Chlortalidone appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 648 reaction mentions were counted: hyponatraemia 121; hypokalaemia 109; nausea 91; hypotension 65. open-targets-adr · CHEMBL1055 · 2026-06-24

Show the evidence
  • hyponatraemia
    121
  • hypokalaemia
    109
  • nausea
    91
  • hypotension
    65
  • dizziness
    55
  • acute kidney injury
    50
4 more recorded rows
  • hypertension
    41
  • oedema peripheral
    41
  • syncope
    39
  • renal failure
    36

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

Was Chlortalidone studied with fasting and exercise?


fasting and exercise are named in Chlortalidone's label sentences: "In participants with metabolic syndrome, at 4 years of follow-up, the incidence of newly diagnosed diabetes (fasting glucose >or=126 mg/dl) was 17.1% for chlorthalidone, 16.0% for amlodipine (P = 0.49, chlorthalidone vs. amlodipine) and 12.6% for lisinopril (P < 0.05, lisinopril vs. chlorthalidone)." openfda-label+europepmc · 2020-11-01

2 recorded statements; fasting, exercise

Show the evidence
  • fasting
    In participants with metabolic syndrome, at 4 years of follow-up, the incidence of newly diagnosed diabetes (fasting glucose >or=126 mg/dl) was 17.1% for chlorthalidone, 16.0% for amlodipine (P = 0.49, chlorthalidone vs. amlodipine) and 12.6% for lisinopril (P < 0.05, lisinopril vs. chlorthalidone).
  • exercise
    One fair-quality trial, conducted from 1979 to 1981 in the United States and using a combination of a pharmacological treatment (low-dose propranolol/chlorthalidone) and lifestyle interventions (dietary and exercise modifications for children and parents), reported a statistically significant reduction of SBP (−7.6 mmHg) and DBP (−6.9 mmHg) after 6 months.

recorded 2020-11-01 · last checked 2026-09-04

Where it is registered
Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL1055
PubChem CID
2732
CAS number
77-36-1
RxCUI
2409
InChIKey
JIVPVXMEBJLZRO-UHFFFAOYSA-N
Also called
CHLORTHALIDONE, Chlortalidonum, Clortalidona, Natriuran, Phthalamudine, ctd, 3-Hydroxy-3-[4-chloro-3-sulfamylphenyl]phthalimidine, CHLORTALIDONUM [WHO-IP LATIN], CLORPRES COMPONENT CHLORTHALIDONE, COMBIPRES COMPONENT CHLORTHALIDONE, Chlortalidone [EP IMPURITY], Chlortalidone [EP MONOGRAPH]
Trade name
Chlorthalidone component of clorpres, Chlorthalidone component of combipres, Chlorthalidone component of demi-regroton, Chlorthalidone component of edarbyclor, Chlorthalidone component of kerledex, Chlorthalidone component of lopressidone, Chlorthalidone component of regroton, Chlorthalidone component of tenoretic, Hygroton, Thalitone, Chlorthalidone Chlorthalidone, Hemiclor
Development code
G-33182, NSC-69200
Sources (9)

Sources

3 more sources
  • openfda-label 5de362df-8fb9-4421-864c-7ea06339d6e7 ·
  • openfda-label+europepmc K1:Q0MQD1073Q ·
  • national registers US, CA ·

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: 9 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

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.