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Clonidine

  • 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 Clonidine does in the body

High blood pressure; separately, in an extended-release form, attention deficit hyperactivity disorder

Blood pressure is partly set by how much signal the brainstem sends down the sympathetic nerves to the heart and blood vessels. Clonidine stimulates a receptor on those brainstem neurons that acts as a brake on their own output, so less signal leaves the brain. Heart rate falls, vessels relax, and pressure comes down — without the drug ever touching the blood vessel directly. The same reduction in sympathetic drive is why it causes drowsiness, why it eases the agitation of opioid withdrawal, and why stopping it suddenly releases a flood of the signal it was suppressing.

What happened in people

No reduction in death or nonfatal myocardial infarction at 30 days after non-cardiac surgery in 10,010 patients (POISE-2, HR 1.08, 95% CI 0.93 to 1.26, p=0.29)

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

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

The limit that matters most

That clonidine reduces cardiovascular events — the label states there are no controlled trials demonstrating risk reduction with it

Where it acts
Brainstem alpha-2 adrenergic receptors — this drug lowers blood pressure by acting on the brain rather than on the blood vessel
Kind of result
Living longer, or avoiding a major event
Supervision
RNAWiki has not recorded a supervision or regulatory status for this substance.
Where each sentence above came from

No recorded sentence describes the change this makes in a way that stands on its own. The page opens with what it is taken for instead, and the recorded explanation follows below.

Shown as the opening line on this page.

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

The four opening statements run to 142 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.

Randomisation

Randomisation means chance decides who gets which treatment.

A picture of it, and where the picture fails

It is like a coin toss deciding the groups.

Where that stops being true. A coin toss is fair once. Fairness here comes from doing it for everyone.

What people get wrong. It is thought to make groups identical. It makes them similar on average, including on things nobody measured.

Allocation of participants to arms by a chance process, so that unmeasured factors are balanced in expectation.

Confidence interval

A confidence interval is the range the true answer is likely to sit in.

A picture of it, and where the picture fails

It is like a weather forecast giving a range rather than one number.

Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.

What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.

An interval estimate that would contain the true parameter in a stated proportion of repeated studies.

Pathway

A pathway is a chain of steps inside a cell, each one setting off the next.

A picture of it, and where the picture fails

A pathway is like a row of dominoes.

Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.

What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.

An ordered series of molecular interactions producing a defined cellular change.

What happened in peopleRead from sources, not yet reviewed

What was measured, goal by goal

One row for each goal a registered study measured something for. One column for each kind of thing that could be measured.

Registered studies list 40 outcome measures that RNAWiki could read. A registered study says what someone planned to measure. It does not say what they found. 0 of the matched studies tested this substance, and 0 posted a result.

There is no single score. A strong test result and a weak life result are different facts.

Goals down the side, kinds of measurement across the top. Each cell says what kind of thing was registered, not what was found.
GoalLife outcomeWhat a body can doHow a person feelsA test resultA step in the bodyHarmsHow longWho was studied
PainWaiting for a reviewer1 registered study measure of this kind. No reviewed result yet.Nothing in the sources checkedNo registered study lists a performance measure for this goal.Waiting for a reviewer5 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.
MoodNothing in the sources checkedNo registered study lists a life outcome for this goal.Nothing in the sources checkedNo registered study lists a performance measure for this goal.Waiting for a reviewer1 registered symptom measure.Nothing in the sources checkedNo registered study lists a test result for this goal.Nothing in the sources checkedNo registered study lists a body-step measure for this goal.Not recordedHarms were not a registered measure for this goal.Not recordedNo finished study window is recorded.Waiting for a reviewerWho was studied is listed further down the page.
Which registered measures put each goal on this table
Pain
amount of pain medication taken per day; pain reduction; numerical rating scale pain scores during hospitalization; pain; time to first requirement of analgesic supplement; postoperative analgesic requirements; intensity of pain; pain as assessed by visual analog scale
Mood
montgomery asberg depression rating scale total

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
1 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.

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.

Composite of death or nonfatal myocardial infarction at 30 days in patients with or at risk for atherosclerotic disease undergoing non-cardiac surgery, with clonidine 0.2 mg daily started just before surgery and continued to 72 hours after

The study did not show it

Who was studied
POISE-2 clonidine comparison (N Engl J Med 2014;370:1504-1513; NCT01082874)
How many people
10010
Study design
Phase 3, randomised, blinded, placebo-controlled, 2×2 factorial
Compared against
A dummy treatment
Kind of result
Living longer, or avoiding a major event
What was found
367 primary events on clonidine against 339 on placebo; hazard ratio 1.08 (95% CI 0.93 to 1.26), p=0.29. Myocardial infarction alone 6.6% against 5.9%, hazard ratio 1.11 (95% CI 0.95 to 1.30), p=0.18
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. Clinically important hypotension occurred in 47.6% against 37.1%, hazard ratio 1.32 (95% CI 1.24 to 1.40), p<0.001. Nonfatal cardiac arrest occurred in 16 patients (0.3%) against 5 (0.1%), hazard ratio 3.20 (95% CI 1.17 to 8.73), p=0.02. The trial did not merely fail to show benefit; it measured harm on two prespecified safety outcomes.

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

Form and route. Oral tablet, extended-release tablet, oral solution, transdermal patch applied weekly, and epidural injection

Interval reported. 95% CI 0

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

Change in systolic and diastolic blood pressure over eight weeks on a combination diet rich in fruit, vegetables and low-fat dairy with reduced saturated and total fat, against a control diet, with sodium intake and body weight held constant

The study showed what it set out to show

Who was studied
DASH — Dietary Approaches to Stop Hypertension (N Engl J Med 1997;336:1117-1124), cited as the comparator dietary intervention
How many people
459
Study design
Randomised, controlled feeding trial
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Combination diet lowered systolic and diastolic pressure by 5.5 and 3.0 mmHg more than control (p<0.001 for each); among the 133 participants with hypertension, by 11.4 and 5.5 mmHg more (p<0.001 for each)
Repeated elsewhere
Replicated

What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.

The limits of this study, and where it came from

Main limit. This is a controlled feeding study in which all food was provided, over eight weeks, measuring blood pressure and not events. Adherence outside a feeding trial is a different question, and no dietary pattern trial has measured cardiovascular outcomes. It is included here because it is the best-measured non-drug comparator for the same surrogate endpoint clonidine is licensed on.

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

Form and route. Oral tablet, extended-release tablet, oral solution, transdermal patch applied weekly, and epidural injection

Interval reported. Not recorded in this summary

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

What we know
RNAWiki holds 2 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.2 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 Evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.7 registered measures of this kind.
  5. A number that stands in for health Evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.6 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 Evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse, Rat, Non-human primate. A result in animals says what to test next. It does not say what happens in people.
  8. Cells in a dish Evidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
  9. A guess from software No evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.

Higher on these steps means closer to something a person would feel. It does not mean better done.

What it changes in the bodyRead from sources, not yet reviewed

The path through the body

From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.

Where a source records it acting

  • Brainstem: Stimulates alpha-adrenoreceptors in the brain stem, resulting in reduced sympathetic outflow from the central nervous system

    US prescribing information · 00c6d67a-bb11-4884-9eeb-4e1b8701a08b · read 2026-08-27

  • Heart: Reduced sympathetic outflow results in decreases in peripheral resistance, renal vascular resistance, heart rate, and blood pressure

    US prescribing information · 00c6d67a-bb11-4884-9eeb-4e1b8701a08b · read 2026-08-27

  1. Start

    Clonidine

    What a person takes: Oral tablet, extended-release tablet, oral solution, transdermal patch applied weekly, and epidural injection.

    The measurement behind this step

    The transdermal system delivers clonidine at an approximately constant rate for seven days with an absolute bioavailability of about 60%, which is what makes weekly application viable and also what makes an accidentally removed patch a withdrawal event. Oral forms are dosed two or three times daily in immediate-release form. The Javadin oral solution label directs continuing administration up to four hours before surgery and resuming promptly afterwards with close blood pressure monitoring — a schedule written around the rebound risk rather than around the pharmacokinetics.

  2. Getting in

    A twisted little molecule that reaches the brain

    Clonidine is small, fat-soluble and crosses into the brain easily — which is the point, because the receptor it needs is in the brainstem rather than in the blood vessel.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    A 2,6-dichlorophenyl aminoimidazoline. The two ortho chlorines force the aromatic ring out of plane with the imidazoline, and that twist underlies its alpha-2 selectivity. Transdermal absolute bioavailability is approximately 60%, delivered at an approximately constant rate over seven days.

  3. What it acts on

    It presses the brake on sympathetic outflow

    On brainstem neurons that drive the sympathetic nervous system, it stimulates a receptor that turns those neurons down. Less signal leaves the brain.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    The label states that clonidine stimulates alpha-adrenoreceptors in the brainstem, resulting in reduced sympathetic outflow from the central nervous system. Alpha-2A is the subtype responsible; alpha-2B on vascular smooth muscle acts in the opposite direction and explains transient pressor effects at high or rapid doses.

  4. The change it makes

    Heart rate, resistance and renin all fall

    With less sympathetic drive, the heart slows, the vessels relax and the kidney releases less of the hormone that raises pressure.

    Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.

    The measurement behind this step

    Decreases in peripheral resistance, renal vascular resistance, heart rate and blood pressure, with renal blood flow and glomerular filtration rate essentially unchanged and normal postural reflexes intact. Plasma renin activity and the excretion of aldosterone and catecholamines are reduced.

  5. Reaching the cell

    And the mechanism changes with time

    In the first weeks the pressure falls mostly because the heart pumps less. Months later the heart output has returned to normal and the vessels are doing the work instead.

    Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.

    The measurement behind this step

    Acute studies show a 15% to 20% reduction in supine cardiac output with no change in peripheral resistance; during long-term therapy cardiac output tends to return to control values while peripheral resistance remains decreased. The label adds that tolerance to the antihypertensive effect may develop in some patients.

  6. What that does for a person

    Blood pressure comes down

    That is the licensed effect and it is reliably achieved. What it prevents has never been measured for this drug.

    Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.

    The measurement behind this step

    The indication states: lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, these benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes, and there are no controlled trials demonstrating risk reduction with this drug.

  7. What that does for a person

    Stop it suddenly and the brake releases

    The suppressed sympathetic system rebounds. Blood pressure can surge, and the label records strokes and deaths from exactly that.

    Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.

    The measurement behind this step

    Sudden cessation has produced nervousness, agitation, headache, tremor and confusion with a rapid rise in blood pressure and elevated plasma catecholamines; rare instances of hypertensive encephalopathy, cerebrovascular accidents and death have been reported. Taper over two to four days, and withdraw any concurrent beta-blocker several days first.

No suggested links are held for this record, so nothing is hidden from this path.

What we know
The record describes 6 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.

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

Felt, measured, or meaningful

Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.

Felt

Things a person could notice without a test.

  • amount of pain medication taken per day
  • pain reduction
  • montgomery asberg depression rating scale total
  • clinical global impression global improvement
  • pain
  • intensity of pain
  • pain as assessed by visual analog scale

Measured

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

  • decrease in supine systolic blood pressure
  • increase in heart rate standing
  • achieving blood pressure goals
  • blood pressure
  • time until resolution of very high blood pressure episode
  • 24 hours mean systolic blood pressure

Meaningful

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

  • numerical rating scale pain scores during hospitalization
  • combined death and disability

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 (25)
  • withdrawal severity
  • panss
  • yale global tic severity scale
  • length of hospital stay
  • knee range of motion
  • knee society scores
  • satisfaction
  • episodes of non sustained ventricular tachycardia
  • protocol adherence
  • enrollment rate
  • duration of block
  • time to first requirement of analgesic supplement
  • postoperative analgesic requirements
  • cannabis use at 10 weeks
  • sedation
  • duration of treatment
  • success rate at 15 minutes post epidural bolus injection
  • area under curve
  • aortic stiffness
  • auc0 168

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. 12 to 16 hours hours

    Read from the label, which states: “Following intravenous administration, clonidine displays biphasic disposition with a distribution half-life of about 20 minutes and an elimination half-life ranging from 12 to 16 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.

  • Adults with high blood pressure, usually after other classes; children and adults with ADHD, in the extended-release form; and, off-label, people in opioid withdrawal and people with severe hot flushes.

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 efficacy in pediatric patients below the age of 6 years has not been established.”

    US prescribing information · 7676af27-4d8f-49c4-a50f-6b0892e73c8f · read 2026-08-30

  • On people who are pregnant, the label states: “Category C: Risk Summary There are no adequate or well-controlled studies with clonidine hydrochloride extended-release tablets in pregnant women.”

    US prescribing information · 7676af27-4d8f-49c4-a50f-6b0892e73c8f · read 2026-08-30

  • On people who are breastfeeding, the label states: “Clonidine hydrochloride is present in human milk.”

    US prescribing information · 7676af27-4d8f-49c4-a50f-6b0892e73c8f · read 2026-08-30

  • On people with reduced kidney function, the label states: “The impact of renal impairment on the pharmacokinetics of clonidine in children has not been assessed.”

    US prescribing information · 7676af27-4d8f-49c4-a50f-6b0892e73c8f · read 2026-08-30

Where the result stopped carrying

  • POISE-2: no benefit on the primary composite, with more hypotension and more cardiac arrests
  • Tolerance to the antihypertensive effect develops in some patients, per the label
  • Abrupt withdrawal has produced hypertensive encephalopathy, cerebrovascular accidents and death
  • Half a century after approval the molecule still has no cardiovascular outcome trial of its own
  • 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 tablet, extended-release tablet, oral solution, transdermal patch applied weekly, and epidural injection

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

The form and route recorded on this substance.

No source is stored against this line.

Who oversees it

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

Quoted from a source

Where this came from

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

No register row and no identity class settled the question.

No source is stored against this line.

What is in the pack

The transdermal system delivers clonidine at an approximately constant rate for seven days with an absolute bioavailability of about 60%, which is what makes weekly application viable and also what makes an accidentally removed patch a withdrawal event.

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

Recorded notes on how this is sold. The rest of the recorded wording: Oral forms are dosed two or three times daily in immediate-release form. The Javadin oral solution label directs continuing administration up to four hours before surgery and resuming promptly afterwards with close blood pressure monitoring — a schedule written around the rebound risk rather than around the pharmacokinetics.

No source is stored against this line.

Where it is registered

Regulatory records are listed in the technical disclosure at the foot of this page.

Counted from records

Where this came from

A count of rows RNAWiki holds. It describes our records, not your body.

Register entries are stored per jurisdiction and shown with their dates.

No source is stored against this line.

Why people stop

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

No record of why people stopped taking it is stored for this substance.

No source is stored against this line.

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

What can go wrong

Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.

Worth asking a clinician aboutWritten into the record from the studies named on this page

Contraindicated in hypersensitivity to clonidine or any component. Labelled warnings cover bradycardia, cardiac conduction abnormalities and symptomatic hypotension, with slow titration directed in patients with syncope, heart block or vascular disease and avoidance of other drugs affecting sinus or atrioventricular node function; sedation and somnolence, with caution about driving and machinery; and rebound hypertension on abrupt discontinuation, tapered over two to four days. Sudden cessation has produced nervousness, agitation, headache, tremor and confusion with a rapid rise in blood pressure and elevated plasma catecholamines, and rare instances of hypertensive encephalopathy, cerebrovascular accidents and death have been reported. Where a beta-blocker is being taken concurrently, it should be withdrawn several days before the clonidine. Epidural clonidine carries a boxed warning against obstetrical, post-partum and peri-operative pain management on grounds of haemodynamic instability.

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

Where this came from

Reports sent to a regulator

  • These are reports people sent to a regulator. They do not show the medicine caused the reaction.
  • Nobody counted how many people took the medicine and reported nothing.
  • The same event can be reported more than once, and many reports are incomplete.
  • News coverage, lawsuits and new warnings change how often people report.
  • A count is not a rate and not a risk.

Clonidine appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 2369 reaction mentions were counted. One report can name several reactions.

The recorded terms (10)
  • hypotension — 435 reaction mentions
  • bradycardia — 304 reaction mentions
  • hypertension — 275 reaction mentions
  • pain — 272 reaction mentions
  • somnolence — 228 reaction mentions
  • drug hypersensitivity — 198 reaction mentions
  • blood pressure increased — 185 reaction mentions
  • drug withdrawal syndrome — 164 reaction mentions
  • hyperhidrosis — 155 reaction mentions
  • toxicity to various agents — 153 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 tablet, extended-release tablet, oral solution, transdermal patch applied weekly, and epidural injection

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

Oral forms are dosed two or three times daily in immediate-release form.

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

Recorded notes on which forms are sold. The rest of the recorded wording: The Javadin oral solution label directs continuing administration up to four hours before surgery and resuming promptly afterwards with close blood pressure monitoring — a schedule written around the rebound risk rather than around the pharmacokinetics.

No source is stored against this line.

What is recorded as being sold

  • 192 products list this as an active ingredient in the United States drug directory. 192 of them contain it and nothing else.

    FDA National Drug Code directory · 72162-1681 · read 2026-08-29

  • They are sold as injection, solution, patch, patch, extended release, powder, solution and suspension, extended release, taken epidural, intravenous, oral and transdermal.

    FDA National Drug Code directory · 72162-1681 · read 2026-08-29

  • The regulator's established pharmacologic class for it is adrenergic alpha2-agonists [moa] and central alpha-2 adrenergic agonist [epc].

    FDA National Drug Code directory · 72162-1681 · read 2026-08-29

  • 127 published labels name it as an active ingredient. 127 of them describe this substance alone, which is where its own label text on this page comes from.

    US prescribing information · 0906c25f-e5b8-4a08-9b10-d1f06419e275 · read 2026-08-29

  • Those labels are classed as human prescription drug.

    US prescribing information · 0906c25f-e5b8-4a08-9b10-d1f06419e275 · read 2026-08-29

  • Clonidine Hydrochloride is tablets at 0.1 mg (as supplied by this repackager), recorded as prescription product; fda label in effect 2025-05-22 in the United States.

    US prescribing information · 00c6d67a-bb11-4884-9eeb-4e1b8701a08b · read 2026-08-27

  • Recorded price in US: 0.02451–12.0466 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 83 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 Clonidine studied people like me?
  • What was measured, and for how long?
  • Was the result a laboratory value or a health outcome?
  • What would we watch for, and when would we stop?

Tracking can show whether something changed for you. It cannot show what caused it.

RNAWiki records evidence. It does not say whether this substance is right for you.

What is missing or unclearRead from sources, not yet reviewed

Claims that go past the evidence

Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.

Goes past the evidence

That clonidine reduces cardiovascular events — the label states there are no controlled trials demonstrating risk reduction with it

Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.

The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.

What would change this

A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.

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

Goes past the evidence

That blunting the surgical sympathetic surge prevents perioperative infarction — plausible physiology, tested in 10,010 patients, and wrong

Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.

The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.

What would change this

A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.

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

Goes past the evidence

That the antihypertensive effect is fully explained by central alpha-2 agonism, when the label says the relationship has not been fully elucidated

Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.

The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.

What would change this

A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.

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

Goes past the evidence

That its widespread off-label uses carry the evidentiary standing of a licensed indication

Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.

The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.

What would change this

A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.

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

What is missing or unclearRead from sources, not yet reviewed

What nobody knows yet

Open questions, each with why it is open and what would close it.

Missing populations

Which groups were under-represented in the studies has not been recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing long-term data

No completed tested study window is recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

No reviewed conclusion

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

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing interaction studies

No interaction was found in the registers checked. Not finding one is not the same as showing there is none.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Formulation uncertainty

Several salts, forms or products of Clonidine are recorded. Results from one form may not transfer to another.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Mechanism not reviewed

No reviewed mechanism story exists for this substance.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

What happened in peopleRead from sources, not yet reviewed

Check any of this yourself

Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.

Every line above can be traced to the study named beside it. Follow the link and read it.

The label says no controlled trial has shown it reduces risk
In plain words
It lowers blood pressure. Whether it prevents strokes and heart attacks has not been tested for this drug, and the prescribing information says so in as many words.
What was measured
That the blood pressure reduction measured with clonidine converts into fewer cardiovascular events — a class-level inference the label explicitly declines to make for this molecule
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The Javadin clonidine oral solution indication reads: "JAVADIN is indicated for the treatment of hypertension in adult patients, 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. There are no controlled trials demonstrating risk reduction with JAVADIN." That final sentence is the whole audit. The benefit is a borrowed one: it rests on the general proposition that lowering blood pressure reduces events, established for other classes in other trials, and applied here by inference. Every first-line antihypertensive class — thiazide-like diuretics, ACE inhibitors, angiotensin receptor blockers, calcium channel blockers — has its own outcome trials. Clonidine, half a century after approval, does not.
Source
JAVADIN (clonidine hydrochloride) oral solution United States prescribing information, section 1 (NDA 220256)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
POISE-2: given before surgery, it caused harm rather than preventing it
In plain words
Clonidine was given before non-cardiac operations to blunt the surgical stress response and prevent heart attacks. In ten thousand patients it prevented nothing, doubled the rate of serious low blood pressure and tripled cardiac arrests.
What was measured
Composite of death or nonfatal myocardial infarction at 30 days after non-cardiac surgery, with clinically important hypotension and nonfatal cardiac arrest as safety outcomes
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
POISE-2 randomised 10,010 patients with or at risk for atherosclerotic disease undergoing non-cardiac surgery at 135 centres in 23 countries, in a 2×2 factorial design, to low-dose clonidine 0.2 mg daily or placebo starting just before surgery and continuing to 72 hours afterwards. The primary outcome, death or nonfatal myocardial infarction at 30 days, occurred in 367 clonidine patients against 339 on placebo: hazard ratio 1.08 (95% CI 0.93 to 1.26), p=0.29. Myocardial infarction alone was 6.6% against 5.9%, hazard ratio 1.11 (95% CI 0.95 to 1.30), p=0.18. Clinically important hypotension occurred in 2,385 patients (47.6%) against 1,854 (37.1%), hazard ratio 1.32 (95% CI 1.24 to 1.40), p<0.001. Nonfatal cardiac arrest occurred in 16 patients (0.3%) against 5 (0.1%), hazard ratio 3.20 (95% CI 1.17 to 8.73), p=0.02. The rationale — that marked sympathetic activation occurs during and after surgery and that blunting it should prevent perioperative infarction without haemodynamic instability — was sound physiology. It was wrong on both halves: no prevention, and considerable instability.
Source
Devereaux PJ, Sessler DI, Leslie K, et al. N Engl J Med 2014;370:1504-1513 (POISE-2)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Stopping it abruptly has killed people
In plain words
Because the drug suppresses the sympathetic nervous system, stopping suddenly releases it. The label records hypertensive brain injury, strokes and deaths after clonidine withdrawal.
What was measured
Reported outcomes after abrupt clonidine discontinuation, and the labelled tapering and sequencing instructions
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
The Catapres-TTS warnings section states: "Sudden cessation of clonidine treatment has, in some cases, resulted in symptoms such as nervousness, agitation, headache, tremor, and confusion accompanied or followed by a rapid rise in blood pressure and elevated catecholamine concentrations in the plasma… Rare instances of hypertensive encephalopathy, cerebrovascular accidents and death have been reported after clonidine withdrawal." The likelihood is greater after higher doses and where a beta-blocker is being taken concurrently. The label directs reducing the dose gradually over two to four days, treating an excessive rise after transdermal discontinuation with oral clonidine or intravenous phentolamine, and — where both drugs are being stopped — withdrawing the beta-blocker several days before the clonidine, because unopposed alpha stimulation during clonidine rebound is the mechanism of harm. This is a class property of central sympatholytics and it is the single most important practical fact about the drug.
Source
Catapres-TTS (clonidine) United States prescribing information, Warnings, Withdrawal (NDA 018891); JAVADIN prescribing information, section 5.2 (NDA 220256)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
The label records that the blood pressure effect can simply wear off
In plain words
Some people stop responding to clonidine over time. The prescribing information states this plainly and says therapy should then be reconsidered.
What was measured
Labelled statement of tolerance to the antihypertensive effect, and the shift in haemodynamic mechanism between acute and long-term therapy
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
The Clinical Pharmacology section states: "Tolerance to the antihypertensive effect may develop in some patients, necessitating a reevaluation of therapy." This sits alongside a second observation in the same paragraph that is easy to read past: acute studies showed a 15% to 20% reduction in supine cardiac output with no change in peripheral resistance, but during long-term therapy cardiac output returns toward control values while peripheral resistance stays reduced. So the haemodynamic route by which the drug lowers pressure at week one is not the route by which it lowers pressure at month six. A drug whose mechanism shifts with time and whose effect fades in some patients is a drug whose early response does not predict its later one.
Source
Catapres-TTS (clonidine) United States prescribing information, Clinical Pharmacology (NDA 018891)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Fifty years on, the label says the mechanism is not fully elucidated
In plain words
The prescribing information lists several measured effects — lower sympathetic outflow, lower renin, lower catecholamine excretion — and then says how they add up to a lower blood pressure has not been fully worked out.
What was measured
That clonidine’s antihypertensive effect is attributable to central alpha-2 agonism alone, when the label states the relationship between its measured pharmacological actions and its antihypertensive effect has not been fully elucidated
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The label states that clonidine stimulates alpha-adrenoreceptors in the brainstem, reducing sympathetic outflow, peripheral resistance, renal vascular resistance, heart rate and blood pressure, and separately that plasma renin activity and excretion of aldosterone and catecholamines fall. It then states: "The exact relationship of these pharmacologic actions to the antihypertensive effect of clonidine has not been fully elucidated." There is a concrete reason for the hedge. Clonidine binds both alpha-2 adrenergic receptors and imidazoline binding sites, and the alpha-2 subtypes act in opposite directions — alpha-2A in the brainstem reduces sympathetic outflow while alpha-2B on vascular smooth muscle causes constriction, which is why rapid or high dosing can transiently raise pressure before lowering it. The mechanism is not mysterious so much as plural, and the regulator declines to apportion it.
Source
Catapres-TTS (clonidine) United States prescribing information, Clinical Pharmacology (NDA 018891)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
contested
Review state
Written into the record, not signed off as a reviewed claim
The drug moved indications without moving labels
In plain words
Clonidine was approved for blood pressure. Most of what it is used for now — ADHD, opioid withdrawal, hot flushes, tics, sedation — grew up around it afterwards, and only ADHD ever acquired an approval.
What was measured
That clonidine’s widespread off-label uses carry the same evidentiary standing as its licensed one, when only the ADHD use has been through a regulatory review of its own
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The original licence is hypertension, and it remains the indication on the immediate-release tablets, the oral solution and the transdermal system. Extended-release clonidine tablets carry a separate and later indication for attention deficit hyperactivity disorder as monotherapy and as adjunctive therapy to stimulants. Epidural clonidine, Duraclon, is indicated only in combination with opiates for severe cancer pain not adequately relieved by opioids alone, and its label states that the safety of the product has been established only in a highly selected group of cancer patients after an adequate trial of opioid analgesia, and that other use is of unproven safety and is not recommended. Opioid withdrawal — probably the best-known use of clonidine among clinicians — has never been a licensed indication for it; lofexidine, an alpha-2 agonist of the same class, was approved for that purpose in 2018. A drug whose commonest uses sit outside its licence is not necessarily being misused, but the evidence supporting those uses is not the evidence a regulator reviewed, and that distinction is invisible at the point of prescribing.
Source
Clonidine hydrochloride tablets, extended-release tablets and Catapres-TTS United States prescribing information; DURACLON (clonidine hydrochloride injection) prescribing information, Indications and Usage (NDA 020615); LUCEMYRA (lofexidine) prescribing information, section 1 (NDA 209229)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
Epidural clonidine carries a boxed warning against the perioperative use
In plain words
The injectable form for cancer pain opens with a warning not to use it for childbirth, after delivery or around surgery, because the blood pressure and heart rate instability may be unacceptable.
What was measured
Boxed warning restricting epidural clonidine from obstetrical, post-partum and peri-operative use on haemodynamic grounds
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The Duraclon boxed warning reads: "Duraclon (epidural clonidine) is not recommended for obstetrical, post-partum, or peri-operative pain management. The risk of hemodynamic instability, especially hypotension and bradycardia, from epidural clonidine may be unacceptable in these patients. However, in a rare obstetrical, post-partum or peri-operative patient, potential benefits may outweigh the possible risks." Placed beside POISE-2, the two records point the same way from opposite directions: a boxed warning derived from clinical experience with epidural administration, and a 10,010-patient randomised trial of the oral drug that found a 47.6% rate of clinically important hypotension and a tripling of nonfatal cardiac arrest. Haemodynamic instability around surgery is the consistent finding for this molecule by every route it has been studied in.
Source
DURACLON (clonidine hydrochloride injection) United States prescribing information, boxed warning and Indications and Usage (NDA 020615)
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim

How many documents were read

  • 122 documents were read for this substance.

    RNAWiki source record

Where else this substance is registered

FDA substance identifier (UNII)
W76I6XXF06
CAS registry number
4205-90-7
PubChem compound
2803
RxNorm concept
142432

Checks this page had to pass

  • Passed

    Identity resolved

    no open identity hold

  • Passed

    No unresolved merge across substance families

    no quarantine open

  • Passed

    Every public sentence names a source

    The opening statement carries the origin: Written into the record, not signed off.

  • Not passed

    Trial roles classified for highlighted evidence

    No registered study is classified as testing this substance.

  • Passed

    No internal keys in reader text

    enforced by the copy-contract test over the rendered page

  • Not passed

    Safety mode resolved

    No register row and no identity class settled the question.

  • Passed

    Canonical metadata present

    slug and display name present

What is missing or unclearRead from sources, not yet reviewed

How this medicine reached us

Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.

What the approval register records

  • 72 approved applications cover products containing this substance. The earliest was NDA017503, approved 19740903 to BOEHRINGER INGELHEIM.

    Drugs@FDA application register · NDA017503 · read 2026-08-29

  • Marketing status on the register: discontinued and prescription.

    Drugs@FDA application register · NDA017503 · read 2026-08-29

  • The earliest marketing start date recorded for a listed product is 19790201.

    FDA National Drug Code directory · 72162-1681 · 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

3 questions this page could not answer

These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.

  • What it may clash with — found nothing in the sources checked.
  • Other ways to the same goal — found nothing in the sources checked.
  • What changed on this page — found nothing in the sources checked.

The record as stored

The full record, for auditing

Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.

The older medicine-wide conclusion held in this record

Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.

A brainstem alpha-2 agonist whose current United States label states outright that "there are no controlled trials demonstrating risk reduction" with it, and which — given before non-cardiac surgery to prevent perioperative infarction, a practice built on plausible physiology — was tested in 10,010 patients in POISE-2 and did not reduce death or infarction (HR 1.08, p=0.29) while raising clinically important hypotension from 37.1% to 47.6% (p<0.001) and tripling nonfatal cardiac arrest (HR 3.20, 95% CI 1.17 to 8.73, p=0.02).

Recorded evidence blocks (13)

What did Clonidine's largest trial (22213 people) and its longest (33 years) measure?


22213 people in Clonidine's largest registered study, 33 years in its longest registered window, measuring To preform feasibility study looking at the safety and efficacy of adding clonidine to chronic b-blockade on patient-relevant outcomes (mortality, myocardial infarction, prolonged hospitalization) in… ClinicalTrials.gov · 2026-09-01

49 phase4, 39 phase2, 32 na, 27 phase3, 22 phase1, 8 na or unstated, 3 early phase1; NCT00262470; 2029-12. Last human test completed 2026, NCT04828226.

Interpretation These counts include studies where Clonidine 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
    49
  • phase2
    39
  • na
    32
  • phase3
    27
  • phase1
    22
  • na or unstated
    8
2 more recorded rows
  • early phase1
    3
  • Last recorded human test NCT04828226
    2026-05-16

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

From mouse to human: where has Clonidine shown lifespan?


NHP: mechanism-only, mouse: mechanism-only, rat: lifespan and human: lifespan (166): the rungs where Clonidine has a recorded finding. Europe PMC and ClinicalTrials.gov · organism ladder · 2026-09-01

Interpretation To preform feasibility study looking at the safety and efficacy of adding clonidine to chronic b-blockade on patient-relevant outcomes (mortality, myocardial… — the recorded outcome words.

Yeast C. elegans Drosophila Mouse mechanism-onlyRat lifespanDog Non-human primate mechanism-onlyHuman lifespan
Show the evidence
  • NHP
    mechanism-only
  • mouse
    mechanism-only
  • rat
    lifespan
  • human NCT00335582
    lifespan; To preform feasibility study looking at the safety and efficacy of adding clonidine to chronic b-blockade on patient-relevant outcomes (mortality, myocardial infarction, prolonged hospitalization) in large randomized controlled trials; 166

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

28 of Clonidine's trials stopped: futility/efficacy, accrual/recruitment, funding/business, other?


futility/efficacy (1), accrual/recruitment (8), funding/business (2) and other (17): Clonidine's stop wording, clustered. ClinicalTrials.gov · 2026-09-01

"Study was never initiated"; 28 of 166 registered studies

Show the evidence

Trial

  • NCT00166686
    withdrawn; "Study was never initiated"
  • NCT00194974
    withdrawn; "Lack of funding"
  • NCT00580151
    terminated; "Closed due to no response from PI to IRB"
  • NCT00585871
    withdrawn; "could not recruit"
  • NCT00588354
    terminated; "Targeted enrollment was not reached."
  • NCT00930072
    terminated; "Poor Enrollment"
14 further recorded trials
  • NCT01112878
    withdrawn; "Several studies going on at the same time."
  • NCT01139996
    terminated; "Difficulty in enrolling participants"
  • NCT01175668
    terminated; "Based on the planned interim analysis results at 50% recruitment, after IRB reviewed the results, further enrollment was stopped."
  • NCT01205204
    withdrawn; "This study was registered with Clinical Trials.gov by mistake."
  • NCT01360450
    terminated; "The study was treminated because of low accural"
  • NCT01598896
    terminated; "low enrollment due to limited resources"
  • NCT01851486
    withdrawn; "Labortory focus was changed and study was not opened at all"
  • NCT01956604
    terminated; "The inclusion rate was too low, due to the exclusion criteria."
  • NCT01983462
    terminated; "Funding expired"
  • NCT01986751
    terminated; "failure to enroll"
  • NCT02239627
    terminated; "based on interim anaylsis"
  • NCT02365727
    withdrawn; "Protocol not feasible as written"
  • NCT02439281
    terminated; "The patients were discharged on the day of the surgery."
  • NCT02509273
    terminated; "lack of recruitment"

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

Human studies of Clonidine used Clonidine MBT 50µg — over how long?


Human studies of Clonidine used "Clonidine MBT 50µg". ClinicalTrials.gov · 2026-09-01

9 recorded entries; human; tablet; also "Clonidine MBT 100µg", "Catapres 100μg", "Clonidine Hydrochloride Topical Gel, 0.1%"

Show the evidence

human

  • NCT02548806
    Clonidine MBT 50µg
  • NCT02548806
    Clonidine MBT 100µg
  • NCT02548806
    Catapres 100μg
  • NCT02643251
    Clonidine Hydrochloride Topical Gel, 0.1%
  • NCT03704376
    100 mcg clonidine
  • NCT05277038
    Clonidine 0.1mg pill
3 more recorded rows
  • human NCT05277038
    tablet; Clonidine 0.1mg tablet
  • human NCT05277038
    Clonidine 0.2mg pill
  • human NCT05277038
    tablet; Clonidine 0.2mg tablet

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

Clonidine's half-life is 12 to 16 hours — which schedules were studied?


12 to 16 hours, the half-life Clonidine's label states. openfda-label · 58772b44-dec0-7001-e063-6394a90ac40e · 2026-08-27

bioavailability 70% to 80% %.

Show the evidence
  • half life
    12 to 16 hours hours; Following intravenous administration, clonidine displays biphasic disposition with a distribution half-life of about 20 minutes and an elimination half-life ranging from 12 to 16 hours.
  • bioavailability
    70% to 80% %; The absolute bioavailability of clonidine on oral administration is 70% to 80%. Peak plasma clonidine levels are attained in approximately 1 to 3 hours.

recorded 2026-08-27 · last checked 2026-09-04

Could one person measure Clonidine's effect on withdrawal severity?


Withdrawal severity: measured in Clonidine's trials.

Interpretation withdrawal severity is the recorded endpoint.

Show the evidence

biomarkers

  • withdrawal severity; 2026-09-01
  • panss; 2026-09-01
  • decrease in supine systolic blood pressure; 2026-09-01
  • increase in heart rate standing; 2026-09-01
  • yale global tic severity scale; 2026-09-01
  • length of hospital stay; 2026-09-01
14 more recorded rows
  • biomarkers
    knee range of motion; 2026-09-01
  • biomarkers
    knee society scores; 2026-09-01
  • biomarkers
    amount of pain medication taken per day; 2026-09-01
  • biomarkers
    satisfaction; 2026-09-01
  • biomarkers
    pain reduction; 2026-09-01
  • biomarkers
    episodes of non sustained ventricular tachycardia; 2026-09-01
  • biomarkers
    achieving blood pressure goals; 2026-09-01
  • biomarkers
    protocol adherence; 2026-09-01
  • biomarkers
    enrollment rate; 2026-09-01
  • biomarkers
    numerical rating scale pain scores during hospitalization; 2026-09-01
  • biomarkers
    montgomery asberg depression rating scale total; 2026-09-01
  • biomarkers
    clinical global impression global improvement; 2026-09-01
  • biomarkers
    duration of block; 2026-09-01
  • biomarkers
    pain; 2026-09-01
  • half life
    2026-09-04; halfLife; hours; 12 to 16 hours; 2026-08-27
  • human trials at or under30
    47
  • smallest human trial
    0; NCT00000279; PHASE2; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; COMPLETED

Which of 24 hours mean systolic blood pressure, achieving blood pressure goals and adrenocorticotropic hormone levels did Clonidine's trials measure?


24 hours mean systolic blood pressure, achieving blood pressure goals and adrenocorticotropic hormone levels lead 40 outcome terms across Clonidine's trials. ClinicalTrials.gov · 2026-09-01

Interpretation increase in heart rate standing, yale global tic severity scale, length of hospital stay, knee range of motion, knee society scores and amount of pain medication taken per day follow.

Show the evidence
  • withdrawal severity
    1
  • panss
    1
  • decrease in supine systolic blood pressure
    1
  • increase in heart rate standing
    1
  • yale global tic severity scale
    1
  • length of hospital stay
    1
14 more recorded rows
  • knee range of motion
    1
  • knee society scores
    1
  • amount of pain medication taken per day
    1
  • satisfaction
    1
  • pain reduction
    1
  • episodes of non sustained ventricular tachycardia
    1
  • achieving blood pressure goals
    1
  • protocol adherence
    1
  • enrollment rate
    1
  • numerical rating scale pain scores during hospitalization
    1
  • montgomery asberg depression rating scale total
    1
  • clinical global impression global improvement
    1
  • duration of block
    1
  • pain
    1

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

Which of Clonidine's 13 ongoing trials reports first?


13 registered trials of Clonidine are open; earliest completion 2025-12-11. ClinicalTrials.gov · 2026-09-01

Increase in heart rate with standing; Efficacy: hot flash composite and frequency scores (daily diary); latest 2029-12

Show the evidence

Trial

  • NCT00262470
    "Treatment of Orthostatic Intolerance"; n 150; "Increase in heart rate with standing"; 2029-12
  • NCT01530373
    "Solifenacin Compared to Clonidine for Reducing Hot Flashes Among Breast Cancer Patients"; n 110; "Efficacy: hot flash composite and frequency scores (daily diary)"; 2028-09
  • NCT03092011
    "Treatment of Neonatal Abstinence Syndrome With Clonidine Versus Morphine as Primary Therapy"; n 69; "Length of treatment"; 2026-12-01
  • NCT03121261
    "The Effect of Local Anesthetic and Clonidine on the Cutaneous Silent Period During Spinal Anesthesia"; n 60; "4 Item Duration of Latency and duration of the cutaneous silent period"; 2028-10
  • NCT04278404
    "Pharmacokinetics, Pharmacodynamics, and Safety Profile of Understudied Drugs Administered to Children Per Standard of Care (POPS)"; n 5000; "Clearance (CL) or apparent oral clearance (CL/F) as measured by PK sampling"; 2026-12
  • NCT04934228
    "Mitigating the Pro-inflammatory Phenotype of Obesity"; n 60; "Blood Work: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment"; 2027-08-01
7 further recorded trials
  • NCT05091242
    "The PREVENT AGITATION Trial II - Children ≤1 Year"; n 336; "Incidence of emergence agitation during stay in postanaesthetic care unit (PACU)"; 2028-01-31
  • NCT05618002
    "Lemborexant vs Zopiclone vs Clonidine for Insomnia Treatment in Chronic Pain Patients"; n 150; "Sleep quality score, objective measurement using the validated Likert sleep scale"; 2025-12-11
  • NCT07092566
    "R.E.C.K vs Exparel in Robotic Nephrectomy"; n 170; "Area Under the Curve (AUC) of the Numeric Rating Scale (NRS) pain intensity scores through 7 days (168 hours) for participants receiving Exparel vs. R.E.C.K."; 2027-10
  • NCT07313371
    "Efficacy of Clonidine in Reducing Craving in Inpatients With Cocaine and Crack Use Disorder"; n 36; "Visual Analog Scale (VAS)"; 2027-07
  • NCT07360301
    "Consciousness and Psilocybin Effects on Well-Being: The CoPEWell Study"; n 120; "Change in Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) score: Psilocybin Awake versus Asleep"; 2028-02
  • NCT07461376
    "Premedication in Children: a Clinical Trial Comparing Oral Ketamine and Oral Clonidine With Respect to Sedation Level and Opioid Consumption in Pediatrics Undergoing Elective Lower Abdominal Day-case Surgery."; n 84; "Sedation level"; 2026-11-01
  • NCT07567495
    "Adding Dexmedetomidine or Clonidine to Spinal Anesthesia for Cesarean Delivery"; n 150; "Incidence of intraoperative discomfort"; 2028-05

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

Which 53 trials of Clonidine posted no result?


Posted no result
53 of 53 completed trials
Registrations
NCT00000279, NCT00510016, NCT00638729, NCT00031395, NCT00414921 and NCT00226096, and 47 more
Completion dates
oldest 1999-08; newest 2024-08-13
Show the evidence

Trial

  • NCT00000279
    1999-08
  • NCT00510016
    2005-12
  • NCT00638729
    2007-03
  • NCT00031395
    2007-06
  • NCT00414921
    2007-06
  • NCT00226096
    2007-09
14 further recorded trials
  • NCT00437996
    2008-01
  • NCT00672347
    2009-09
  • NCT00983125
    2010-03
  • NCT01136278
    2010-12
  • NCT00206986
    2011-12
  • NCT01425658
    2012-02
  • NCT01597427
    2012-03
  • NCT01619436
    2012-05
  • NCT00959062
    2012-09
  • NCT01040429
    2012-11
  • NCT01761916
    2013-06
  • NCT00318760
    2013-08-07
  • NCT02324413
    2014-03
  • NCT02410460
    2014-06

At the median, Clonidine's trials enrolled 64 people — anything larger?


Median enrolment
64
Largest enrolment
22213
Registered trials counted
166

What do 2369 spontaneous reports say about Clonidine — 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.

Clonidine appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 2369 reaction mentions were counted: hypotension 435; bradycardia 304; hypertension 275; pain 272. open-targets-adr · CHEMBL134 · 2026-06-24

Show the evidence
  • hypotension
    435
  • bradycardia
    304
  • hypertension
    275
  • pain
    272
  • somnolence
    228
  • drug hypersensitivity
    198
4 more recorded rows
  • blood pressure increased
    185
  • drug withdrawal syndrome
    164
  • hyperhidrosis
    155
  • toxicity to various agents
    153

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

Was Clonidine studied with fasting and exercise?


fasting and exercise are named in Clonidine's label sentences: "Compared with placebo, clonidine significantly reduced systolic (153 +/- 6 v 163 +/- 8) and diastolic (88 +/- 2 v 98 +/- 3.5 mm Hg, P = .001) blood pressure, left ventricular mass (94 +/- 11 v 99 +/- 12 g/m2, P < .01) and fasting glucose levels." openfda-label+europepmc · 1998-02-01

2 recorded statements; fasting, exercise

Show the evidence
  • fasting
    Compared with placebo, clonidine significantly reduced systolic (153 +/- 6 v 163 +/- 8) and diastolic (88 +/- 2 v 98 +/- 3.5 mm Hg, P = .001) blood pressure, left ventricular mass (94 +/- 11 v 99 +/- 12 g/m2, P < .01) and fasting glucose levels.
  • exercise
    To assess the importance of these effects, we compared the hemodynamic effects of a single oral dose of urapidil (U, 60 mg) with those of prazosin (Pr, 2 mg), clonidine (Cl, 0.15 mg), and placebo (Pl), at rest, during orthostatic tilt, and during submaximal graded bicycle exercise tests, in a double-blind randomised crossover study in 24 healthy male volunteers.

recorded 1998-02-01 · last checked 2026-09-04

What is recorded about Clonidine and mTOR?


"Here, we report that serine/threonine kinase ULK3 (unc-51 like kinase 3)-dependent activation of GLI1 (GLI family zinc finger 1) contributes to the transcriptional upregulation of <i>DNMT3A</i> gene expression upon autophagy induction, thereby bringing additional understanding of the long-term effect of autophagy induction and a possible…" — where Clonidine and mTOR appear together. Europe PMC · pathway abstract search · 2022-02-28

mTOR, autophagy; PMID 35226587, 34299093, 32876528, 22645144

Show the evidence
  • mTOR PMID 35226587
    "Here, we report that serine/threonine kinase ULK3 (unc-51 like kinase 3)-dependent activation of GLI1 (GLI family zinc finger 1) contributes to the transcriptional upregulation of <i>DNMT3A</i> gene expression upon autophagy induction, thereby bringing additional understanding of the long-term effect of autophagy induction and a possible mechanism for its decline upon aging, pathological…"

autophagy

  • PMID 35226587
    "Here, we report that serine/threonine kinase ULK3 (unc-51 like kinase 3)-dependent activation of GLI1 (GLI family zinc finger 1) contributes to the transcriptional upregulation of <i>DNMT3A</i> gene expression upon autophagy induction, thereby bringing additional understanding of the long-term effect of autophagy induction and a possible mechanism for its decline upon aging, pathological…"
  • PMID 34299093
    "Thus far, as autophagy modulators, rapamycin, mTOCR1 inhibitor and its analogues, lithium, metformin, clonidine, curcumin, nicotinamide, bexaroten, and torehalose have been proposed."
  • mTOR PMID 32876528
    "This epigenetic memory of autophagy provides some understanding of the long-term effect of autophagy induction and offers a possible mechanism for its decline upon aging, pathological conditions, or in response to treatment interventions.<b>Abbreviations:</b> ACTB: actin beta; ATG: autophagy-related; 5-Aza: 5-aza-2'-deoxycytidine; BafA1: bafilomycin A<sub>1</sub>; CBZ: carbamazepine; CDKN2A:…"
  • autophagy PMID 32876528
    "This epigenetic memory of autophagy provides some understanding of the long-term effect of autophagy induction and offers a possible mechanism for its decline upon aging, pathological conditions, or in response to treatment interventions.<b>Abbreviations:</b> ACTB: actin beta; ATG: autophagy-related; 5-Aza: 5-aza-2'-deoxycytidine; BafA1: bafilomycin A<sub>1</sub>; CBZ: carbamazepine; CDKN2A:…"
  • mTOR PMID 22645144
    "We believe that inhibition of mTOR by rapamycin along with activation of adrenergic α2 receptors by clonidine represents a double-hit to pancreatic islets that synergistically disturbs glucose homeostasis."

recorded 2022-02-28 · last checked 2026-09-04

Where it is registered
Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL134
PubChem CID
2803
CAS number
4205-90-7
RxCUI
2599
InChIKey
GJSURZIOUXUGAL-UHFFFAOYSA-N
Trade name
Catapres-tts-1, Catapres-tts-2, Catapres-tts-3, Nexiclon xr, Catapres, Catapres p.l., Dixarit, Duraclon, Jenloga, Kapvay, Nexiclon, JAVADIN
Also called
Catarpres-tts, Clonidina, Clonidine extended release, Clorpres, Combipres, catapresan, cln, CLONIDINE HYDROCHLORIDE, Dichloranilino imidazolin, Onyda xr, clonicel, CLONIDINE [HSDB]
Development code
ST-155-BS, ST-155BS, NSC-756699, ST-155
Salt form
Clonidine hcl, Clonidine hydrochloride component of clorpres, Clonidine hydrochloride component of combipres, clonidine gel, clonidine hcl sustained release, CLONIDINE HYDROCHLORIDE ORAL, Clonidine Transdermal System USP, 0.1 mg/day, Clonidine Transdermal System USP, 0.2 mg/day, Clonidine Transdermal System USP, 0.3 mg/day, Catapres / Catapres-TTS / Nexiclon / Javadin / Duraclon; extended-release tablets for ADHD
Sources (10)

Sources

4 more sources
  • open-targets-adr CHEMBL134 ·
  • openfda-label 58772b44-dec0-7001-e063-6394a90ac40e ·
  • openfda-label+europepmc K1:MN3L5RMN02 ·
  • 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: 10 source rows
  • no critical contamination: no quarantine open
  • canonical metadata passed: slug and display name present
  • no raw internal fields: enforced by the copy-contract test over the rendered page

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