This page shows what was measured, who it was measured in, and what that does not settle.
What Metoclopramide does in the body
In the brainstem it blocks the dopamine receptors on the patch of tissue that decides when to vomit, so the signal is suppressed.
Metoclopramide does two jobs with one molecule. In the wall of the stomach it does the opposite of blocking: it switches on a different receptor that makes nerve endings release acetylcholine, and acetylcholine makes the stomach muscle squeeze harder and in the right direction. The problem is that dopamine receptors are also what coordinate movement in the rest of the brain, and blocking them for months can cause a movement disorder that does not always go away.
Why people take it. A stomach that empties too slowly, persistent reflux that other drugs have not helped, and sickness after surgery or chemotherapy
What happened in people
No significant difference from placebo in total gastroparesis symptom score at four weeks in 285 nasal-spray patients
✎ 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.
Still the only drug the FDA has approved for diabetic gastroparesis, forty-five years after its United States approval
Where it acts
Two places at once — the chemoreceptor trigger zone in the area postrema, and the myenteric plexus in the wall of the stomach and upper small intestine
Kind of result
Symptoms and quality of life
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 · W1792A2RVD · read 2026-08-29
Its recorded molecular formula is C14H22ClN3O2∙HCl, weighing 354.3.
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
Where each sentence above came from
A person wrote this explanation into the record, with the studies named in the path below.
The recorded use, written for a reader without medical training. Not signed off.
A limit recorded against this substance. Not signed off as a reviewed claim.
The four opening statements run to 137 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Comparator
A comparator is whatever the treatment was measured against.
A picture of it, and where the picture fails
It is like the other runner in a race.
Where that stops being true. A race has one winner. A study can show both arms improved.
What people get wrong. Results are read without asking what the other group got. Beating nothing is not beating a treatment.
The control condition against which the experimental intervention is assessed.
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.
Absolute difference
An absolute difference is how many more people in a hundred were affected.
A picture of it, and where the picture fails
It is like counting heads in two rooms of a hundred.
Where that stops being true. Heads are easy to count. Study results carry a margin of error too.
What people get wrong. It is confused with a percentage change, which can look far larger.
The arithmetic difference in event rates between arms.
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.
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.
Change in total gastroparesis symptom score (nausea, bloating, early satiety, upper abdominal pain) from baseline to week 4
✗ The study did not show it
Who was studied
NCT00845858 — metoclopramide nasal spray in diabetic gastroparesis (Gimoti)
No statistically significant difference between either metoclopramide dose and placebo overall; women 10 mg P = .0247 and 14 mg P = .0215 in a prespecified subgroup, with men favouring placebo
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. The approved indication rests on the sex subgroup of a trial that missed its overall primary endpoint. Dysgeusia, headache and fatigue were the commonest treatment-emergent effects.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral tablet, orally disintegrating tablet, oral solution, nasal spray, and intravenous or intramuscular injection
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
Metoclopramide -28 mm (95% CI 22 to 34) against saline placebo -23 mm (16 to 30); not significant
Repeated elsewhere
Replicated
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. Rescue medication was needed by 17.9% on metoclopramide against 36.3% on placebo — the largest separation in the trial, and a secondary outcome that the primary endpoint does not capture.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral tablet, orally disintegrating tablet, oral solution, nasal spray, and intravenous or intramuscular injection
Interval reported. 95% CI 22 to 34) against saline placebo -23 mm (16 to 30); not significant
Written into the record, not signed off as a reviewed claim.
Feeding intolerance in critically ill adults receiving enteral nutrition
✓ The study showed what it set out to show
Who was studied
Lewis 2016 (PMID 27527069) — prokinetics in critically ill adults, meta-analysis of 13 randomised trials
How many people
1341
Study design
Systematic review and meta-analysis of randomised trials
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
RR 0.73 (95% CI 0.55 to 0.97), P = 0.03, absolute reduction 17.3% (5 to 26.8), moderate certainty
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. No significant effect on vomiting, diarrhoea, intensive-care length of stay or mortality. The authors state the impact on pneumonia, mortality and length of stay is unclear.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral tablet, orally disintegrating tablet, oral solution, nasal spray, and intravenous or intramuscular injection
Interval reported. 95% CI 0
Written into the record, not signed off as a reviewed claim.
RNAWiki holds 3 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Metoclopramide
What a person takes: Oral tablet, orally disintegrating tablet, oral solution, nasal spray, and intravenous or intramuscular injection.
The measurement behind this step
The nasal spray exists specifically because the patients the drug is licensed for are the ones least able to absorb a tablet: a stomach that does not empty is a stomach that does not deliver drug to the small intestine. That reasoning is sound and independent of whether the efficacy trial succeeded.
Getting in
Absorbed fast, and into the brain as well as the gut
Swallowed or injected, the drug spreads through the body quickly, and unlike most gut drugs it crosses freely into the brain. That is both why it works on the vomiting centre and why it has a boxed warning.
╌╌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
Metoclopramide crosses the blood-brain barrier, which distinguishes it from later benzamide prokinetics designed not to. The nasal formulation exists because gastric stasis and vomiting make oral absorption unreliable in the population the drug is licensed for — a pharmacokinetic argument that survived even though the efficacy trial did not.
It blocks the dopamine receptors on the brainstem vomiting trigger
A small patch of brainstem outside the brain’s protective barrier samples the blood for anything that ought to be thrown up. Dopamine is one of the signals it uses. The drug blocks that receptor and the trigger stops firing.
╌╌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
D2 antagonism in the chemoreceptor trigger zone of the area postrema is the antiemetic component. It is the same receptor and the same blockade that an antipsychotic performs in the striatum, which is why the adverse-effect profile is an antipsychotic profile rather than a gastrointestinal one.
In the gut wall it does the opposite: it switches a receptor on
The same molecule that blocks one receptor in the brain activates a different one in the stomach wall. Activating it makes nerve endings release acetylcholine, the chemical that tells muscle to contract.
╌╌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
5-HT4 agonism on enteric cholinergic neurons of the myenteric plexus increases acetylcholine release onto smooth muscle. The dual action is what makes this a prokinetic rather than a pure antiemetic: D2 blockade alone would relieve nausea without moving anything.
The stomach contracts harder and empties toward the small intestine
The upper stomach tightens, the lower stomach contracts in a coordinated wave, and the valve at the exit relaxes. Food moves on instead of sitting.
╌╌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
Increased tone in the gastric fundus, stronger antral contractions, relaxation of the pyloric sphincter and the duodenal bulb, and increased peristalsis in the duodenum and jejunum. Accelerated gastric emptying is measurable by scintigraphy; symptom improvement is measured separately on a diary scale, and the correlation between the two is poor across the whole gastroparesis literature.
The same dopamine blockade reaches the movement circuits
The receptors that trigger vomiting are the same family that coordinate movement. Blocking them for long enough can produce involuntary movements of the face, tongue and limbs that sometimes never resolve.
╌╌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
Striatal and nigral D2 blockade produces the full extrapyramidal spectrum: acute dystonia and akathisia early, parkinsonism and tardive dyskinesia in chronic users. Post-mortem binding work estimated that under clinical conditions metoclopramide accumulates in melanised substantia nigra at roughly 21 times the level of haloperidol, with the authors proposing detergent-like membrane damage as the reason its risk exceeds what its receptor affinity predicts.
Because the risk rises with how long you take it and how much in total, the label tells prescribers not to go past twelve weeks. The European regulator went further and said five days.
╌╌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 boxed warning states that risk increases with duration of treatment and total cumulative dosage, that there is no known treatment for tardive dyskinesia, and that treatment beyond 12 weeks should be avoided. The 2013 EMA referral restricted authorised use to 5 days, removed use below 1 year of age and withdrew the long-term motility indications outright.
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 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.
Adults with diabetic gastroparesis, adults with reflux that proton pump inhibitors have not settled, and — far more often, and briefly — people given a single injection for sickness after surgery, after chemotherapy, or during a migraine.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What the label states about particular groups
On pediatric, the label states: “The safety and effectiveness of GIMOTI in pediatric patients have not been established.”
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
On older people, the label states: “Metoclopramide is known to be substantially excreted by the kidney, and the risk of adverse reactions, including tardive dyskinesia (TD), may be greater in patients with impaired renal function [see Warnings and Precautions ( 5.1 ), Use in Specific Populations ( 8.6 ), Clinical Pharmacology ( 12.3 )] .”
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary Published studies, including retrospective cohort studies, national registry studies, and meta-analyses, do not report a consistent pattern or a consistently increased risk of adverse pregnancy-related outcomes with oral use of metoclopramide during pregnancy.”
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary There are no data on the presence of metoclopramide in human milk following nasal administration; however, published data report the presence of metoclopramide in human milk in variable amounts following oral administration (see Data ) .”
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
On people with reduced liver function, the label states: “Patients with severe hepatic impairment (Child-Pugh C) have reduced systemic metoclopramide clearance (by approximately 50%) compared to patients with normal hepatic function [see Clinical Pharmacology ( 12.3 )] .”
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
On people with reduced kidney function, the label states: “The clearance of metoclopramide is decreased and the systemic exposure is increased in patients with moderate to severe renal impairment compared to patients with normal renal function, which may increase the risk of adverse reactions [see Clinical Pharmacology ( 12.3 )] .”
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
Where the result stopped carrying
The nasal spray missed its primary endpoint in 285 patients, and the licence granted covers only the sex subgroup in which it did not
No statistically significant benefit over saline placebo for undifferentiated emergency-department nausea, in the trial and in the Cochrane review
The European Union removed the long-term gastrointestinal motility indications entirely in 2013 and capped authorised use at five days
Contraindicated in epilepsy, in phaeochromocytoma, and in anyone with a previous dystonic reaction — three populations discovered by adverse experience rather than by design
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 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 (11)
It was studied for a different goal
The studies measured something else entirely. Nothing in this record points to this reason.
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Given by a clinician
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Oral tablet, orally disintegrating tablet, oral solution, nasal spray, and intravenous or intramuscular 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 nasal spray exists specifically because the patients the drug is licensed for are the ones least able to absorb a tablet: a stomach that does not empty is a stomach that does not deliver drug to the small intestine.
✎ 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: That reasoning is sound and independent of whether the efficacy trial succeeded.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇Read from sources, not yet reviewed
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
·Worth asking a clinician aboutWritten into the record from the studies named on this page
Boxed warning for tardive dyskinesia — often irreversible, with no known treatment, risk rising with duration and cumulative dose, and treatment beyond 12 weeks to be avoided. Contraindicated in a history of tardive dyskinesia or dystonic reaction to metoclopramide; where stimulating gut motility would be dangerous (haemorrhage, mechanical obstruction, perforation); in phaeochromocytoma or catecholamine-releasing paraganglioma, because of hypertensive crisis; in epilepsy, because it increases seizure frequency and severity; and in hypersensitivity, which has included laryngeal and glossal angioedema and bronchospasm. Acute dystonia and akathisia occur early; parkinsonism and tardive dyskinesia in chronic users. In the European Union authorised use is capped at 5 days.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
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 tablet, orally disintegrating tablet, oral solution, nasal spray, and intravenous or intramuscular 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
That reasoning is sound and independent of whether the efficacy trial succeeded.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on which forms are sold and how they compare.
No source is stored against this line.
What is recorded as being sold
89 products list this as an active ingredient in the United States drug directory. 89 of them contain it and nothing else.
FDA National Drug Code directory · 71872-7076 · read 2026-08-29
They are sold as crystal, injection, injection, solution, powder, solution and spray, taken intramuscular, intravenous, nasal and oral.
FDA National Drug Code directory · 71872-7076 · read 2026-08-29
The regulator's established pharmacologic class for it is dopamine d2 antagonists [moa] and dopamine-2 receptor antagonist [epc].
FDA National Drug Code directory · 71872-7076 · read 2026-08-29
66 published labels name it as an active ingredient. 66 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 7cd1dc35-2fb2-4f1d-8769-24c3c3aa34fa · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 7cd1dc35-2fb2-4f1d-8769-24c3c3aa34fa · read 2026-08-29
GIMOTI is nasal at 3 DOSAGE FORMS AND STRENGTHS Nasal Spray: 15 mg of metoclopramide in each 70 microliter spray., recorded as fda label in effect 2026-02-20 in the United States.
US prescribing information · 95269b1f-779c-4ca0-9f86-e74e677f9900 · read 2026-08-30
Recorded price in US: 0.03541–0.04383 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 27 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..
Recorded source · 2026-08-26 · read 2026-08-28
Recorded price in US: 0.12882–0.52896 USD per one millilitre, across 8 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 Metoclopramide studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
Claims that go past the evidence
Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.
✗Goes past the evidence
That the 1-10% tardive dyskinesia figure the boxed warning was built on is the true incidence — the review that tested it puts the risk under 1%, and no community-prevalence study has settled 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 faster gastric emptying means fewer symptoms; the two are measured separately and correlate poorly across the whole gastroparesis literature
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 better tolerance of tube feeding in intensive care means fewer pneumonias or fewer deaths — neither moved
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 an FDA indication for a chronic condition and an EMA restriction to five days can both be the straightforward reading of the same evidence
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Metoclopramide are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
The boxed warning was written on a 1-10% risk figure; a review the following year put it under 1%
In plain words
In 2009 the FDA added its strongest warning to metoclopramide for a movement disorder that is often permanent. The figure in the guidelines at the time was that between one and ten in every hundred long-term users would get it. A review published the next year concluded the real figure is probably fewer than one in a hundred.
What was measured
That the 1-10% figure in the guidelines the boxed warning drew on is the true incidence — the review that examined it puts the figure an order of magnitude lower, and no community-prevalence study has since settled it in either direction
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Rao and Camilleri reviewed the pharmacology, pharmacokinetics and epidemiology after the 2009 boxed warning and concluded that the risk of tardive dyskinesia from metoclopramide is likely to be under 1%, "much less than the estimated 1-10% risk previously suggested in national guidelines". They proposed that metoclopramide-induced tardive dyskinesia may be an idiosyncratic response, with pharmacogenetic determinants — the DRD3 Ser9Gly polymorphism, cytochrome P450 variation, P-glycoprotein — rather than a straightforward dose-response phenomenon, and called for community-prevalence work to define the benefit-risk ratio properly. That work has not been reported. The boxed warning stands unchanged: it instructs prescribers to avoid treatment longer than 12 weeks and states that there is no known treatment for tardive dyskinesia.
Written into the record, not signed off as a reviewed claim
It causes nearly a third of all drug-induced movement disorders, and the risk factors describe its own indication
In plain words
Whatever the exact percentage, metoclopramide is responsible for close to a third of every movement disorder caused by a drug. The people most at risk are women, older people and people with diabetes — which is exactly who is prescribed it for a slow-emptying stomach.
What was measured
Share of all drug-induced movement disorders attributable to a single agent, and the demographic risk factors for them
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Pasricha and colleagues reviewed the indications and adverse neurological effects of metoclopramide and reported that it accounts for nearly a third of all drug-induced movement disorders. The full spectrum occurs: akathisia and acute dystonia early in the course, tardive dyskinesia and parkinsonism in chronic users. Female sex, age and diabetes are identified as the major risk factors. The label’s contraindications reflect the same pharmacology from another angle — it is contraindicated in epilepsy because it increases seizure frequency and severity, and in phaeochromocytoma or catecholamine-releasing paraganglioma because it can precipitate hypertensive crisis.
Written into the record, not signed off as a reviewed claim
The nasal spray missed its primary endpoint and was approved for women on a subgroup
In plain words
A nasal spray version was developed for people too nauseated to keep a tablet down. In its trial of 285 patients it did not beat placebo. It did beat placebo in the women, and not in the men, and that is the licence it now has.
What was measured
Change in total gastroparesis symptom score from baseline to week 4, against placebo
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Parkman and colleagues ran a multicentre, double-blind phase 2b trial of 10 mg and 14 mg metoclopramide nasal spray against placebo in 285 subjects (71% female) with type 1 or type 2 diabetes and previously diagnosed gastroparesis, dosed before meals and at bedtime for 28 days. Primary endpoint was change in total symptom score at week 4 from a daily diary of nausea, bloating, early satiety and upper abdominal pain. There was no statistically significant difference between either metoclopramide group and placebo overall. In the prespecified sex subgroup, women improved significantly on both doses (10 mg: mean reduction 1.2 ± 1.18, P = .0247; 14 mg: 1.3 ± 0.94, P = .0215); in men, symptom scores fell more on placebo than on either dose. Gimoti was approved under NDA 209388 on 19 June 2020 with an indication restricted to adult women.
Written into the record, not signed off as a reviewed claim
Europe deleted the indication the United States still licenses, on the ground that it should not be taken long
In plain words
The two regulators looked at the same drug and reached opposite conclusions. The FDA licenses it for a chronic condition with a twelve-week ceiling. The European regulator restricted it to five days, banned it below age one, and removed the long-term gut-motility indications entirely.
What was measured
That an FDA indication and an EMA indication for the same molecule reflect the same reading of the evidence — here they diverge completely, and the divergence is about duration rather than about mechanism
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
After a review requested by the French agency ANSM over both safety and efficacy, the CHMP concluded on 26 July 2013, and confirmed after re-examination on 24 October 2013, that the risks of neurological effects outweighed the benefits in conditions requiring long-term treatment. The recommendations: authorisation for short-term use only, up to 5 days; no use below 1 year of age; second-choice use only in children over 1, restricted to prevention of delayed chemotherapy-induced nausea and vomiting and treatment of postoperative nausea and vomiting; in adults, restriction to prevention and treatment of nausea and vomiting from chemotherapy, radiotherapy, surgery and migraine; reduced maximum doses; and withdrawal of oral liquids above 1 mg/mL, which had been associated with paediatric overdose. The United States label continues to carry symptomatic gastro-oesophageal reflux for 4 to 12 weeks and acute and recurrent diabetic gastroparesis.
Source
European Medicines Agency, metoclopramide-containing medicines Article 31 referral — CHMP opinion 26 July 2013, confirmed on re-examination 24 October 2013, European Commission final decision
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
No better than saline for undifferentiated nausea in the emergency department
In plain words
For someone who arrives at hospital feeling sick without a known cause, this drug performed the same as salt water in a randomised trial, and the Cochrane review found the same.
What was measured
Mean change in 100 mm nausea visual analogue scale at 30 minutes against saline placebo
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
In the three-arm Melbourne trial of 270 adults, 20 mg intravenous metoclopramide produced a mean fall of 28 mm (95% CI 22 to 34) on the 100 mm nausea visual analogue scale at 30 minutes, against 23 mm (16 to 30) for saline placebo — not significant. The Cochrane review pooling three trials and 301 participants gave a mean difference against placebo of -5.27 mm (95% CI -11.33 to 0.80), also not significant. Metoclopramide was the only agent in the trial with a numerically lower rescue-medication rate (17.9% against 36.3% on placebo and 34.5% on ondansetron), which is a secondary outcome and is reported here as such.
Written into the record, not signed off as a reviewed claim
In intensive care, prokinetics move the feeding surrogate and not the outcomes
In plain words
Given to critically ill patients to help them tolerate tube feeding, these drugs do reduce feeding problems. They do not reduce vomiting, shorten the intensive-care stay, or reduce deaths.
What was measured
That better tolerance of tube feeding translates into fewer pneumonias, shorter intensive-care stays or fewer deaths — the meta-analysis measured all three and moved none of them
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Lewis and colleagues meta-analysed 13 randomised trials enrolling 1,341 critically ill adults given a prokinetic agent or placebo. Feeding intolerance fell — RR 0.73 (95% CI 0.55 to 0.97), P = 0.03, an absolute reduction of 17.3% (5 to 26.8), moderate certainty. High gastric residual volumes fell (RR 0.69, 0.52 to 0.91) and post-pyloric tube placement succeeded more often (RR 1.60, 1.17 to 2.21). There was no significant improvement in vomiting, diarrhoea, intensive-care length of stay or mortality, and the authors state that the impact on pneumonia, mortality and length of stay is unclear.
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What is not here
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How close this is to real life — found nothing in the sources checked.
Felt, measured, or meaningful — found nothing in the sources checked.
How long anything takes — found nothing in the sources checked.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
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The record as stored
The full record, for auditing
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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 dopamine D2 blocker that also switches on 5-HT4 receptors in the gut wall, so it stops the brainstem vomiting signal and pushes the stomach to empty at the same time — the only FDA-approved drug for diabetic gastroparesis, carrying a boxed warning for irreversible tardive dyskinesia written on a 1-10% risk estimate that a 2010 review put at likely under 1%, and deleted from every long-term indication in the European Union in 2013.
Recorded evidence blocks (10)
Q1
On the Metoclopramide label: indicated for what?
"Metoclopramide tablets are indicated for the: Treatment for 4 to 12 weeks of symptomatic, documented gastroesophageal reflux in adults who fail to respond to conventional therapy. Relief of symptoms in adults with acute and recurrent diabetic gastroparesis.": indications and usage on Metoclopramide's label. DailyMed label · 595439ae-cf01-821c-e063-6294a90af16a · 2026-08-18
Q2
130 registered trials of Metoclopramide — at which phases?
Registered studies posting no result
90 of 130
130 registered studies of Metoclopramide: 44 phase4, 30 na, 28 phase3, 23 phase2, 9 phase1, 1 early phase1, 1 na or unstated. CLINICALTRIALS_SNAPSHOT · 2026-09-01
1378 with a PubMed record
Show the evidence
phase4
44
na
30
phase3
28
phase2
23
phase1
9
early phase1
1
8 more recorded rows
na or unstated
1
completed
80
unknown
15
terminated
13
not yet recruiting
9
withdrawn
7
recruiting
5
active not recruiting
1
recorded 2026-09-01 · last checked 2026-09-04
Q3
15 of Metoclopramide's trials stopped: safety, accrual/recruitment, funding/business, other?
safety (2), accrual/recruitment (8), funding/business (1) and other (4): Metoclopramide's stop wording, clustered. CLINICALTRIALS_SNAPSHOT · 2026-09-01
"Terminated for futility on 11/30/09 based on the recommendation of the DSMB"; 15 of 130 registered studies
Show the evidence
Trial
NCT00395161
terminated; "Terminated for futility on 11/30/09 based on the recommendation of the DSMB"
NCT00655642
terminated; "Conditional analysis showed observed differences were significantly less than power calculations"
NCT01148264
terminated; "poor enrolment"
NCT01289938
terminated; "To unsuccessful recruitment of rare UM-genotype. All other planned genotype groups are completed (EM, IM and PM)."
NCT01569633
withdrawn; "very poor enrollment"
NCT01631994
terminated; "No support to run the study"
9 further recorded trials
NCT01785459
terminated; "Unable to enroll adequate number of patients."
NCT01843868
withdrawn; "Study halted prematurely, prior to enrollment of first participant due to protracted logistical and subsequent funding matters."
NCT02098499
withdrawn; "No recruitment occurred and PI retired"
NCT02459275
terminated; "Funding discontinued"
NCT02972502
terminated; "PI lapsed institutional training"
NCT03477903
terminated; "Insufficient enrollment; No safety concerns"
NCT04027348
terminated; "low accrual"
NCT04726592
terminated; "It has been determined that continuing with enrollments in this study is no longer justified due to the lack of significant impact on the expected outcomes."
NCT04766996
terminated; "Loss of surgery team member deemed the study procedures impossible to achieve, and no replacement could be found in a timely manner to complete trial as initially planned."
recorded 2026-09-01 · last checked 2026-09-04
Q4
Human studies of Metoclopramide used metoclopramide 10 mg — over how long?
Human studies of Metoclopramide used "metoclopramide 10 mg". ClinicalTrials.gov · 2026-09-01
11 recorded entries; human; IV; also "Metoclopramide 20 mg", "Metoclopramide 10 mg IV", "Metoclopramide 10 mg"
Show the evidence
human
NCT00475306
metoclopramide 10 mg
NCT00475306
Metoclopramide 20 mg
NCT00778011
IV; Metoclopramide 10 mg IV
NCT01934192
Metoclopramide 10 mg
NCT02098499
Metoclopramide 10mg
NCT02314351
Metoclopramide 10 mg (2 mL) in 100 mL normal saline
5 more recorded rows
humanNCT02681211
Metoclopramide 0.1 mg/kg, max 10mg
humanNCT03331965
Metoclopramide 5 MG/ML Injectable Solution
humanNCT03934294
Metoclopramide 10mg/ per 8 hours in the case of poor digestion
humanNCT04682691
metoclopramide (10mg)
humanNCT05876585
Metoclopramide 10 mg ampoule
recorded 2026-09-01 · last checked 2026-09-04
Q5
Metoclopramide's half-life is 5 to 6 hours — which schedules were studied?
5 to 6 hours; The mean elimination half-life in subjects with normal renal function was 5 to 6 hours.
tmaxpharmacokinetics
1 to 2 hours; Peak plasma concentrations occurred at about 1 to 2 hours after a single oral dose.
bioavailabilitypharmacokinetics
80 %; Absorption Relative to an intravenous dose of 20 mg, the absolute bioavailability of oral metoclopramide is 80% ± 15.5% as demonstrated in a crossover study of 18 subjects.
metabolismpharmacokinetics
Elimination Metabolism: Metoclopramide undergoes enzymatic metabolism via oxidation as well as glucuronide and sulfate conjugation reactions in the liver.
recorded 2026-08-18 · last checked 2026-09-04
Q6
Which 42 trials of Metoclopramide posted no result?
Posted no result
42 of 42 completed trials
Registrations
NCT00003213, NCT00242450, NCT00778011, NCT00364806, NCT01069536 and NCT00477776, and 36 more
Completion dates
oldest 1999-08; newest 2024-06-01
Show the evidence
Trial
NCT00003213
1999-08
NCT00242450
2005-07
NCT00778011
2006-12
NCT00364806
2007-03
NCT01069536
2008-05
NCT00477776
2009-03
14 further recorded trials
NCT00264719
2009-05
NCT01858090
2010-01
NCT01191645
2010-11
NCT02253524
2013-05
NCT01837394
2013-09
NCT01243736
2013-11
NCT01781377
2013-12
NCT01596166
2014-04
NCT02222220
2014-05
NCT02410460
2014-06
NCT01937234
2016-09
NCT02314351
2017-01
NCT01522326
2017-03-30
NCT03383315
2017-09-30
Q7
At the median, Metoclopramide's trials enrolled 86.5 people — anything larger?
Median enrolment
86.5
Largest enrolment
27034
Registered trials counted
128
Q8
What do 2071 spontaneous reports say about Metoclopramide — 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.
Metoclopramide appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 2071 reaction mentions were counted: drug hypersensitivity 435; nausea 419; dystonia 178; serotonin syndrome 176. FAERS via Open Targets · CHEMBL1200940 · 2026-06-24
Show the evidence
drug hypersensitivity
435
nausea
419
dystonia
178
serotonin syndrome
176
electrocardiogram qt prolonged
169
tremor
154
4 more recorded rows
confusional state
145
premature baby
137
extrapyramidal disorder
133
tardive dyskinesia
125
recorded 2026-06-24 · last checked 2026-09-04
Q9
Which 10 reactions does Metoclopramide's label not list?
( 7.1 ) Strong CYP2D6 inhibitors (e.g., quinidine, bupropion, fluoxetine, and paroxetine) : See Full Prescribing Information for recommended dosage reductions.
drug_interactions
Strong CYP2D6 Inhibitors, not Included in Antipsychotic Category Above Clinical Impact Increased plasma concentrations of metoclopramide; risk of exacerbation of extrapyramidal symptoms [see Clinical Pharmacology ( 12.3 )] .
pharmacokinetics
Monodeethylmetoclopramide, a major oxidative metabolite, is formed primarily by CYP2D6, an enzyme subject to genetic variability [see Dosage and Administration ( 2.1 , 2.2 ), Use in Specific Populations ( 8.9 )] .
pharmacokinetics
Drug Interaction Studies Effect of Metoclopramide on CYP2D6 Substrates Although in vitro studies suggest that metoclopramide can inhibit CYP2D6, metoclopramide is unlikely to interact with CYP2D6 substrates in vivo at therapeutically relevant concentrations.
pharmacokinetics
Effect of CYP2D6 Inhibitors on Metoclopramide In healthy subjects, 20 mg of metoclopramide and 60 mg of fluoxetine (a strong CYP2D6 inhibitor) were administered, following prior exposure to 60 mg fluoxetine orally for 8 days.
clinical_pharmacology
Monodeethylmetoclopramide, a major oxidative metabolite, is formed primarily by CYP2D6, an enzyme subject to genetic variability [see Dosage and Administration ( 2.1 , 2.2 ), Use in Specific Populations ( 8.9 )] .
2 more recorded rows
Interaction statementclinical_pharmacology
Drug Interaction Studies Effect of Metoclopramide on CYP2D6 Substrates Although in vitro studies suggest that metoclopramide can inhibit CYP2D6, metoclopramide is unlikely to interact with CYP2D6 substrates in vivo at therapeutically relevant concentrations.
Interaction statementclinical_pharmacology
Effect of CYP2D6 Inhibitors on Metoclopramide In healthy subjects, 20 mg of metoclopramide and 60 mg of fluoxetine (a strong CYP2D6 inhibitor) were administered, following prior exposure to 60 mg fluoxetine orally for 8 days.
ChEMBL 37 — CC BY-SA 3.0 Unported · ClinicalTrials.gov — US Government work · Open Targets 26.06 — CC0 · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
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✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 6 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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