This page shows what was measured, who it was measured in, and what that does not settle.
What Prazosin does in the body
Hypertension, to lower blood pressure
From the FDA-approved label: The exact mechanism of the hypotensive action of prazosin is unknown. Prazosin causes a decrease in total peripheral resistance and was originally thought to have a direct relaxant action on vascular smooth muscle. Recent animal studies, however, have suggested that the vasodilator effect of prazosin is also related to blockade of postsynaptic alpha-adrenoceptors. The results of dog forelimb experiments demonstrate that the peripheral vasodilator effect of prazosin is confined mainly to the level of the resistance vessels (arterioles). Unlike conventional alpha-blockers, the antihypertensive action of prazosin is usually not accompanied by a reflex tachycardia.
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 · X0Z7454B90 · 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.
No statement of the main limit is recorded.
The four opening statements run to 116 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.
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.
Enzyme
An enzyme is a protein that speeds up one chemical change.
A picture of it, and where the picture fails
An enzyme is like a machine on a production line doing one cut.
Where that stops being true. A machine is switched on and off by a person. Enzymes are controlled by the cell.
What people get wrong. Enzymes are thought to be used up. They are not; they work again and again.
A catalytic protein that lowers the activation energy of a specific reaction.
Receptor
A receptor is a part of a cell that a signal fits into.
A picture of it, and where the picture fails
A receptor is like a lock waiting for one key.
Where that stops being true. A lock either opens or does not. A receptor can be half-triggered, or worn out.
What people get wrong. Fitting a receptor is read as causing a benefit. It causes a step, and nothing more.
A protein that binds a specific ligand and converts that binding into a cellular response.
Pathway
A pathway is a chain of steps inside a cell, each one setting off the next.
A picture of it, and where the picture fails
A pathway is like a row of dominoes.
Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.
What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.
An ordered series of molecular interactions producing a defined cellular change.
What happened in people◇Read from sources, not yet reviewed
What was measured, goal by goal
One row for each goal a registered study measured something for. One column for each kind of thing that could be measured.
Registered studies list 36 outcome measures that RNAWiki could read. A registered study says what someone planned to measure. It does not say what they found. 0 of the matched studies tested this substance, and 0 posted a result.
There is no single score. A strong test result and a weak life result are different facts.
Goals down the side, kinds of measurement across the top. Each cell says what kind of thing was registered, not what was found.
Goal
Life outcome
What a body can do
How a person feels
A test result
A step in the body
Harms
How long
Who was studied
Sleep
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
…Waiting for a reviewer2 registered symptom measure.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Healthy ageing
…Waiting 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.
Mood
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅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.
Which registered measures put each goal on this table
Sleep
pittsburgh sleep quality index; sleep time; insomnia severity index
Healthy ageing
all cause hospitalization or all cause mortality; all cause mortality; mortality
Mood
depression
Sorted by fixed word lists, version v1. A name the rules do not recognise stays unsorted rather than moving to the nearest column.
What each mark on this table means
∅ Nothing in the sources checked
No registered study lists a life outcome for this goal.
… Waiting for a reviewer
2 registered symptom measure.
— Not recorded
Harms were not a registered measure for this goal.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
To evaluate the impact of circadian time of treatment in cardiovascular, cerebrovascular, metabolic, and renal risk assessment.
✗ The study did not show it
Who was studied
NCT00741585
How many people
21983
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
Medical Therapy of Prostatic Symptoms
✗ The study did not show it
Who was studied
NCT00021814
How many people
3407
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
Prognostic value of ABPM, impact of changes in ambulatory BP and impact of circadian time of antihypertensive treatment in cardiovascular, cerebrovascular and renal risk assessment.
✗ The study did not show it
Who was studied
NCT00295542
How many people
3344
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 Participants With Overall Fatal and Non-fatal, Major Adverse Cardiovascular Events (MACEs)"
✗ The study did not show it
Who was studied
NCT00535925
How many people
850
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
Change From Baseline PTSD Checklist- Civilian (PCL-C) Over the Course of the Year After Injury
✗ The study did not show it
Who was studied
NCT02655354
How many people
635
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
brain natriuretic peptide and the urinary albumin excretion/creatinine ratio at 6 months
✗ The study did not show it
Who was studied
NCT00285519
How many people
600
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 people◇Read from sources, not yet reviewed
How close this is to real life
The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.
■Living longer, or avoiding a major eventEvidence recorded. Death, a heart attack, a stroke, a hospital stay.4 registered measures of this kind. No reviewed result.
□What a body can do day to dayNo evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
□Measured performanceNo evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
■Symptoms and quality of lifeEvidence recorded. Pain, tiredness, mood, sleep, as the person rated it.6 registered measures of this kind.
■A number that stands in for healthEvidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.2 registered measures of this kind.
■A step measured inside a personEvidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
■AnimalsEvidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse, Rat, Dog. A result in animals says what to test next. It does not say what happens in people.
■Cells in a dishEvidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
□A guess from softwareNo evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.
Higher on these steps means closer to something a person would feel. It does not mean better done.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
clinical global impression of change
pittsburgh sleep quality index
quality of life
insomnia severity index
neuropsychiatric inventory
alcohol craving
Measured
Things only a test, a scale or a device shows.
decrease in supine systolic blood pressure
urinary sodium excretion rate
Meaningful
Things that change how a life goes, not only a number.
death
all cause hospitalization or all cause mortality
all cause mortality
mortality
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 (24)
depression
sleep time
caps recurrent distressing dreams item
psqi
symptoms improvement
drinking days
clinician administered ptsd scale
alcohol consumption
drinking days per week
heavy drinking days per week
young mania rating scale
heavy drinking days
headache frequency
endothelial function
spatial attentional resource allocation task reaction time
rapid visual information processing task reaction time
change detection task accuracy
change detection reaction time
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
Prazosin hydrochloride capsules are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes, including this drug.
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 people who are pregnant, the label states: “Usage in Pregnancy: Pregnancy Category C.”
US prescribing information · 4870ed0b-abde-5ae5-e063-6394a90ad0ba · read 2026-08-30
On people who are breastfeeding, the label states: “Usage in Children: Safety and effectiveness in children have not been established.”
US prescribing information · 4870ed0b-abde-5ae5-e063-6394a90ad0ba · 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 take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied for a different goal
The studies measured something else entirely.
On this record: Some registered studies measured things that match no goal on this page.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
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 capsule, tablet, extended release, 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 take∅Nothing 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.
Prazosin appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 354 reaction mentions were counted. One report can name several reactions.
The recorded terms (10)
hypotension — 80 reaction mentions
dizziness — 43 reaction mentions
drug hypersensitivity — 37 reaction mentions
syncope — 36 reaction mentions
drug interaction — 30 reaction mentions
acute kidney injury — 28 reaction mentions
fall — 28 reaction mentions
sinus bradycardia — 26 reaction mentions
toxicity to various agents — 24 reaction mentions
atrioventricular block first degree — 22 reaction mentions
open-targets-adr · recorded 2026-06-24 · a recorded source, not a stored snapshot
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
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
123 products list this as an active ingredient in the United States drug directory. 123 of them contain it and nothing else.
FDA National Drug Code directory · 71610-980 · read 2026-08-29
They are sold as capsule, powder and tablet, taken oral.
FDA National Drug Code directory · 71610-980 · read 2026-08-29
The regulator's established pharmacologic class for it is adrenergic alpha-antagonists [moa] and alpha-adrenergic blocker [epc].
FDA National Drug Code directory · 71610-980 · read 2026-08-29
70 published labels name it as an active ingredient. 70 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 4870ed0b-abde-5ae5-e063-6394a90ad0ba · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 4870ed0b-abde-5ae5-e063-6394a90ad0ba · read 2026-08-29
Prazosin Hydrochloride is oral at HOW SUPPLIED Prazosin Hydrochloride Capsules USP, 1 mg are yellow opaque cap and yellow opaque body, hard gelatin capsule shell imprinted “PRA” on cap and “1” on the body filled with white to off white granules., recorded as fda label in effect 2026-01-15 in the United States.
US prescribing information · 4870ed0b-abde-5ae5-e063-6394a90ad0ba · read 2026-08-30
Recorded price in US: 0.08498–0.12929 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 71 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 take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
RNAWiki could not confidently classify this substance, so no self-experiment plan is offered.
Questions worth asking
Which of the trials of Prazosin studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
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 Prazosin are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Where else this substance is registered
FDA substance identifier (UNII)
X0Z7454B90
RxNorm concept
198141
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 unclear◇Read from sources, not yet reviewed
How this medicine reached us
Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.
What the approval register records
30 approved applications cover products containing this substance. The earliest was NDA017442, approved 19760623 to PFIZER.
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What is not here
6 questions this page could not answer
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The full record, for auditing
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Recorded evidence blocks (13)
Q1
What did Prazosin's largest trial (22213 people) and its longest (16 years) measure?
22213 people in Prazosin's largest registered study, 16 years in its longest registered window, measuring All-Cause-Hospitalization or All-Cause Mortality. ClinicalTrials.gov · 2026-09-01
19 na, 17 phase2, 11 phase1, 10 phase4, 4 phase3, 1 early phase1, 1 na or unstated; NCT00223717; 2017-01; no ageing endpoint recorded. Last human test completed 2026, NCT07231978.
Interpretation These counts include studies where Prazosin 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
na
19
phase2
17
phase1
11
phase4
10
phase3
4
early phase1
1
2 more recorded rows
na or unstated
1
Last recorded human testNCT07231978
2026-04-30
recorded 2026-09-01 · last checked 2026-09-04
Q2
From mouse to human: where has Prazosin shown lifespan?
Interpretation All-Cause-Hospitalization or All-Cause Mortality — the recorded outcome words.
Show the evidence
mouse
mechanism-only
rat
mechanism-only
dog
mechanism-only
humanNCT04467931
lifespan; All-Cause-Hospitalization or All-Cause Mortality; 59
recorded 2026-09-01 · last checked 2026-09-04
Q3
12 of Prazosin's trials stopped: safety, accrual/recruitment, funding/business, other?
safety (1), accrual/recruitment (5), funding/business (2) and other (4): Prazosin's stop wording, clustered. ClinicalTrials.gov · 2026-09-01
"Insufficient Enrollment"; 12 of 59 registered studies
Show the evidence
Trial
NCT00183430
terminated; "Insufficient Enrollment"
NCT00202449
terminated; "recruitment difficulties"
NCT00240227
terminated; "Experimental procedure did not induce sufficient craving to determine any possible effect of medication."
NCT00890643
withdrawn; "Primary investigator left VA employment"
NCT01621165
withdrawn; "unable to recruit subjects given short length of stay in hospital"
NCT03010995
withdrawn; "Study discontinued due to lack of study funding."
6 further recorded trials
NCT03221751
terminated; "staffing issues and COVID"
NCT03416569
withdrawn; "Unanticipated staff changes are preventing completion within funding period."
NCT03894345
suspended; "COVID-19"
NCT03997864
withdrawn; "COVID recruitment issues"
NCT04365257
terminated; "Lack of recruitment"
NCT05189977
terminated; "The decision to terminate the trial early was not based on safety concerns. The trial was terminated early due to some implausible blood pressure values being captured, which was the primary endpoint of the study."
recorded 2026-09-01 · last checked 2026-09-04
Q4
Human studies of Prazosin used Prazosin HCl 2mg — over how long?
6 recorded entries; human; capsule; also "Minipress 2 mg capsule.", "Prazosin HCl 1 mg", "Minipress 1 mg capsule."
Show the evidence
human
NCT04967443
Prazosin HCl 2mg
NCT04967443
capsule; Minipress 2 mg capsule.
NCT04967443
Prazosin HCl 1 mg
NCT04967443
capsule; Minipress 1 mg capsule.
NCT04967443
Prazosin HCl 5 mg
NCT04967443
capsule; Minipress 5 mg capsule.
recorded 2026-09-01 · last checked 2026-09-04
Q5
More Prazosin was worse in human: at what point?
U-shaped in human: "Prazosin decreased female responses to male starling song in a linear dose-response fashion; whereas, it affected responses to purple martin song in a U-shaped dose-response fashion." Europe PMC · dose-response search · 2026-05-19
5 recorded sentences naming Prazosin; U-shaped, dose-response, biphasic
Show the evidence
U-shapedPMID 21463661
"Prazosin decreased female responses to male starling song in a linear dose-response fashion; whereas, it affected responses to purple martin song in a U-shaped dose-response fashion."
dose-response
PMID 42154104
"The experimental design consisted of: 1) establishing a dose-response relationship for insulin (2.5, 5, and 10 ng), followed by 2) investigating potential interactions between insulin (10 ng) and selective adrenergic receptor antagonists including prazosin (α<sub>1</sub>, 10 nmol), yohimbine (α<sub>2</sub>, 13 nmol), metoprolol (β<sub>1</sub>, 24 nmol), ICI 118,551 (β<sub>2</sub>, 5 nmol), and…"
PMID 37045561
"Cumulative dose-response curves for TMA and TMAO were obtained before and after incubation with atropine, yohimbine, prazosin, indomethacin, verapamil, and Ca<sup>+2</sup> -free Krebs-Henselite solution."
PMID 32453770
"A contractile response was observed in both canine uterine and testicular arteries to epinephrine and phenylephrine, and prazosin caused a dose-dependent parallel rightward shift in the phenylephrine dose-response curve (pA2 values of 7.97 and 8.39, respectively)."
biphasicPMID 31669796
"The biphasic nerve-mediated contraction was elicited by ATP and noradrenaline as NF449 (10 μM) and prazosin (100 nM) completely prevented the respective peaks."
recorded 2026-05-19 · last checked 2026-09-04
Q6
Could one person measure Prazosin's effect on clinical global impression of change?
Clinical global impression of change: measured in Prazosin's trials.
Interpretation clinical global impression of change is the recorded endpoint.
Show the evidence
biomarkers
clinical global impression of change; 2026-09-01
pittsburgh sleep quality index; 2026-09-01
depression; 2026-09-01
quality of life; 2026-09-01
sleep time; 2026-09-01
decrease in supine systolic blood pressure; 2026-09-01
0; NCT00890643; NA; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; WITHDRAWN
Q7
Which of alcohol consumption, alcohol craving and all cause hospitalization or all cause mortality did Prazosin's trials measure?
alcohol consumption, alcohol craving and all cause hospitalization or all cause mortality lead 36 outcome terms across Prazosin's trials. ClinicalTrials.gov · 2026-09-01
Interpretation quality of life, sleep time, decrease in supine systolic blood pressure, caps recurrent distressing dreams item, insomnia severity index and psqi follow.
Show the evidence
clinical global impression of change
1
pittsburgh sleep quality index
1
depression
1
quality of life
1
sleep time
1
decrease in supine systolic blood pressure
1
14 more recorded rows
caps recurrent distressing dreams item
1
insomnia severity index
1
psqi
1
symptoms improvement
1
drinking days
1
clinician administered ptsd scale
1
alcohol consumption
1
neuropsychiatric inventory
1
drinking days per week
1
heavy drinking days per week
1
young mania rating scale
1
heavy drinking days
1
alcohol craving
1
urinary sodium excretion rate
1
recorded 2026-09-01 · last checked 2026-09-04
Q8
Which of Prazosin's 4 ongoing trials reports first?
Change in total PTSD Checklist for DSM 5 (PCL5) score; Percent Heavy Drinking Days; latest 2027-06-30
Show the evidence
Trial
NCT03539614
"Predicting Responses to PTSD Treatment With Iris and Cardiovascular Tests"; n 87; "Change in total PTSD Checklist for DSM 5 (PCL5) score"; 2026-12-31
NCT04793685
"Prazosin for Alcohol Use Disorder With Withdrawal Symptoms"; n 150; "Percent Heavy Drinking Days"; 2027-06-30
NCT06629077
"Brain Blood Vessel Responses to Changes in Blood Flow"; n 36; "Change in blood flow"; 2027-01
NCT06629090
"Brain Blood Vessel Responses to Changes in Blood Flow: Younger Cohort"; n 36; "Change in blood velocity"; 2027-05
recorded 2026-09-01 · last checked 2026-09-04
Q9
Which 12 trials of Prazosin posted no result?
Posted no result
12 of 12 completed trials
Registrations
NCT00450164, NCT00108420, NCT00167687, NCT00148837, NCT00487032 and NCT00261729, and 6 more
Completion dates
oldest 2004-06; newest 2022-01-31
Show the evidence
Trial
NCT00450164
2004-06
NCT00108420
2007-03
NCT00167687
2007-10
NCT00148837
2008-12
NCT00487032
2009-05
NCT00261729
2009-12
6 further recorded trials
NCT00175682
2011-07-28
NCT02193256
2015-06
NCT00223717
2017-01
NCT02431936
2019-04-16
NCT04467931
2020-12-31
NCT04108104
2022-01-31
Q10
At the median, Prazosin's trials enrolled 36 people — anything larger?
Median enrolment
36
Largest enrolment
22213
Registered trials counted
58
Q11
What do 354 spontaneous reports say about Prazosin — 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.
Prazosin appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 354 reaction mentions were counted: hypotension 80; dizziness 43; drug hypersensitivity 37; syncope 36. open-targets-adr · CHEMBL1558 · 2026-06-24
Show the evidence
hypotension
80
dizziness
43
drug hypersensitivity
37
syncope
36
drug interaction
30
acute kidney injury
28
4 more recorded rows
fall
28
sinus bradycardia
26
toxicity to various agents
24
atrioventricular block first degree
22
recorded 2026-06-24 · last checked 2026-09-04
Q12
Was Prazosin studied with exercise?
exercise is named in Prazosin's label sentences: "In a double-blinded, counterbalanced, randomized and placebo-controlled design, nine healthy participants performed a maximal-exercise test, and two 30 min sessions of semi-recumbent cycling exercise at 50% peak output following either placebo or α<sub>1</sub> -adrenergic blockade (prazosin; 0.05…" openfda-label+europepmc · 2016-12-29
1 recorded statement; exercise
Show the evidence
exercise
In a double-blinded, counterbalanced, randomized and placebo-controlled design, nine healthy participants performed a maximal-exercise test, and two 30 min sessions of semi-recumbent cycling exercise at 50% peak output following either placebo or α<sub>1</sub> -adrenergic blockade (prazosin; 0.05 mg kg<sup> -1</sup> ).
recorded 2016-12-29 · last checked 2026-09-04
Q13
What is recorded about Prazosin and mTOR?
"The activation of PI3K/Akt/mTOR signaling pathway was significantly suppressed by prazosin via reducing the phosphorylation of Akt and mTOR." — where Prazosin and mTOR appear together. Europe PMC · pathway abstract search · 2020-01-17
"The activation of PI3K/Akt/mTOR signaling pathway was significantly suppressed by prazosin via reducing the phosphorylation of Akt and mTOR."
PMID 31954876
"These results highlight an anti-cancer activity of prazosin on AML by inhibiting the PI3K/Akt/mTOR pathway and targeting TNS1."
PMID 21614555
"Western blot analysis of phosphorylated proteins showed that exposure to prazosin increased the levels of phospho-p53 and phospho-adenosine monophosphate-activated protein kinase (AMPK) but dramatically decreased the levels of phospho-mammalian target of rapamycin (mTOR), phospho-protein kinase B (Akt), and phospho-ribosomal protein S6 kinase (p70S6K)."
AMPKPMID 21614555
"Western blot analysis of phosphorylated proteins showed that exposure to prazosin increased the levels of phospho-p53 and phospho-adenosine monophosphate-activated protein kinase (AMPK) but dramatically decreased the levels of phospho-mammalian target of rapamycin (mTOR), phospho-protein kinase B (Akt), and phospho-ribosomal protein S6 kinase (p70S6K)."
autophagy
PMID 21614555
"Furthermore, although pretreatments with the pharmacological autophagy inhibitor 3-methyladenine and the p53 inhibitor pifithrin-α suppressed prazosin-induced AVO formation, they did not reverse prazosin-induced decline in cell viability but enhanced prazosin-induced caspase-3 activation."
PMID 21614555
"From these results we suggest that prazosin induces autophagic cell death via a p53-mediated mechanism."
PMID 21614555
"When the autophagy pathway was inhibited, prazosin still induced programmed cell death, at least in part through apoptotic caspase-3 cascade enhancement."
NAD+
PMID 11287819
"To address this controversy, we evaluated the effects of two vasoactive compounds, alpha(1)-adrenoceptor antagonist prazosin and antioxidant DL-alpha-lipoic acid, as well as sorbitol dehydrogenase inhibitor (SDI-157) and aldose reductase inhibitor (sorbinil) on retinal free mitochondrial and cytosolic NAD+/NADH ratios in streptozotocin-diabetic rats."
PMID 16113694
"Except in the thoracic aortas of alpha(1BD)-KO mice, the competitive antagonist prazosin inhibited the contraction response to NAd with high affinity."
AMPKPMID 15127134
"With beta-AR activation by ISO or NE (pretreated with a selective blocker of the alpha(1)-adrenoceptor prazosin) for 48 h, both the glucose uptake and AMPK phosphorylation increased significantly compared with unstimulated cardiomyocytes."
NAD+PMID 9650801
"Spiperone and methiothepin inhibited the 3H-NAD-299 accumulation at 10 micromol/kg s.c. The alpha1-adrenoceptor antagonist, prazosin at 2 micromol/kg s.c. increased significantly the specific accumulation of 3H-NAD-299."
recorded 2020-01-17 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · Open Targets 26.06 — CC0 · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
✗ required summary fields resolved: 5 required field(s) not terminal: Why people use it, Best-supported result, Most important common problem, Biggest unanswered question, Human evidence
✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 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
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.