This page shows what was measured, who it was measured in, and what that does not settle.
What Morphine does in the body
Pain severe enough to need round-the-clock opioid treatment, when other options are inadequate
Morphine is the substance the opium poppy makes, isolated in 1804 and named after the god of sleep. It binds the mu-opioid receptor, the switch the body’s own endorphins use, and turns it fully on. In the spinal cord that stops the pain signal being handed upward; in the brainstem it strengthens a system that suppresses pain from above; in the limbic brain it separates the sensation of pain from the distress of it. The liver then converts most of a dose into two by-products, one of which is itself an active painkiller and is cleared by the kidneys, which is why morphine behaves differently in someone whose kidneys are failing.
What happened in people
No worse than mild pain in 96% (362/377) of cancer patients with individually reported results, across a Cochrane review of 62 studies and 4,241 participants
✎ 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.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
The limit that matters most
Still the correct answer for severe acute and cancer pain after two centuries, which is not a claim any other class on this site can make
Where it acts
Mu-opioid receptors of the spinal dorsal horn, periaqueductal grey and rostral ventromedial medulla; also the gut wall, where the same receptor stops peristalsis, which is why constipation is the one adverse effect that does not fade
Kind of result
Symptoms and quality of life
Supervision
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
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 153 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 intensity of worst breathlessness on a 0-10 numerical rating scale from baseline to week 1, with 8 mg/day or 16 mg/day extended-release morphine against placebo, in COPD with mMRC grade 3 to 4 breathlessness
Mean difference against placebo −0.3 (95% CI −0.9 to 0.4) at 8 mg/day and −0.3 (95% CI −1.0 to 0.4) at 16 mg/day; not significant at either dose
Repeated elsewhere
Failed to Replicate
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. The secondary outcome of change in mean daily step count at week 3 was not significantly different from placebo at any of 8, 16, 24 or 32 mg/day, and every point estimate was numerically lower than placebo. 156 of 160 randomised were included in the primary analysis and 138 (88%) completed week 1.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral immediate-release tablets and solution; oral extended-release tablets and capsules; solution for intravenous, intramuscular, subcutaneous, epidural and intrathecal use; suppositories. Schedule II controlled substance in the United States.
Interval reported. 95% CI −0
Written into the record, not signed off as a reviewed claim.
Ticagrelor and AR-C124910XX pharmacokinetics and platelet reactivity after a 180 mg ticagrelor loading dose, with intravenous morphine 5 mg or placebo, in acute myocardial infarction
Randomised, double-blind, placebo-controlled, single centre
Compared against
A dummy treatment
Kind of result
A number that stands in for health
What was found
Total ticagrelor exposure 36% lower on morphine (AUC 0-12h 6,307 against 9,791 ng·h/mL, p=0.003); active metabolite 37% lower (p=0.008); time to peak 4 hours against 2 (p=0.004)
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. The trial measured drug exposure and platelet reactivity, not clinical outcomes. Whether the attenuated antiplatelet effect changes infarct size, reinfarction or mortality has not been established in a powered outcome trial.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral immediate-release tablets and solution; oral extended-release tablets and capsules; solution for intravenous, intramuscular, subcutaneous, epidural and intrathecal use; suppositories. Schedule II controlled substance in the United States.
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
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 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.
Where a source records it acting
Brain: Specific CNS opioid receptors for endogenous compounds with opioid-like activity have been identified throughout the brain and spinal cord and are thought to play a role in the analgesic effects
US prescribing information · 07593aa4-f2c4-4d6e-b186-ab2a4ecaa38a · read 2026-08-27
Brainstem: Produces respiratory depression by direct action on brain stem respiratory centers
US prescribing information · 07593aa4-f2c4-4d6e-b186-ab2a4ecaa38a · read 2026-08-27
Intestines: Digestion of food in the small intestine is delayed and propulsive contractions are decreased; propulsive peristaltic waves in the colon are decreased
US prescribing information · 07593aa4-f2c4-4d6e-b186-ab2a4ecaa38a · read 2026-08-27
Start
Morphine
What a person takes: Oral immediate-release tablets and solution; oral extended-release tablets and capsules; solution for intravenous, intramuscular, subcutaneous, epidural and intrathecal use; suppositories. Schedule II controlled substance in the United States..
The measurement behind this step
Oral bioavailability is limited by extensive first-pass glucuronidation, which is why parenteral and oral doses differ several-fold for the same effect. Extended-release oral products are designed for around-the-clock dosing and are explicitly not indicated as an as-needed analgesic. Preservative-free formulations exist specifically for epidural and intrathecal administration, where a preservative would be neurotoxic.
Getting in
From a poppy, not a reactor
Nearly all medical morphine is extracted from the opium poppy. There is a synthetic route, and it has never been worth using, because the plant makes the molecule for nothing.
╌╌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 pentacyclic phenanthrene alkaloid, C17H19NO3, with five stereocentres of fixed natural configuration. Pharmaceutical supply is by alkaline extraction from concentrate of poppy straw, exploiting the phenolic hydroxyl that morphine has and codeine and thebaine do not.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
Reaching the cell
The liver takes most of it before it ever acts
Swallowed morphine passes the liver first, and most of it is converted before reaching the bloodstream. That is why an oral dose is several times an injected one for the same effect.
──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
Extensive first-pass glucuronidation by UGT2B7. About 50% of a dose becomes morphine-3-glucuronide and 5 to 15% morphine-6-glucuronide; less than 5% is demethylated. Volume of distribution is 3 to 4 L/kg and plasma protein binding 30 to 35%.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
What it acts on
Full agonism at the endorphin receptor
Morphine binds the mu-opioid receptor and turns it fully on — the same receptor and the same switch the body’s own endorphins use, held open far longer than an endorphin would.
╌╌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
Full agonism at the Gi/o-coupled mu-opioid receptor: inhibition of adenylyl cyclase, opening of G-protein-coupled inwardly rectifying potassium channels, closure of N-type voltage-gated calcium channels. The neuron hyperpolarises and releases less transmitter.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
The change it makes
Three sites, and one of them is the gut
The spinal cord stops relaying the signal, the brainstem turns up its own pain suppression, and the bowel stops moving. The first two effects fade with tolerance. The third does not.
╌╌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
Presynaptic inhibition of substance P and glutamate release in the dorsal horn; disinhibition of descending output from the periaqueductal grey through the rostral ventromedial medulla; and mu agonism on myenteric plexus neurons, which suppresses propulsive motility and increases fluid absorption. Tolerance develops to analgesia and sedation but not to the enteric effect.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
What that does for a person
The kidney decides how long it lasts
The active by-product is cleared by the kidneys. In someone whose kidneys are failing it builds up over days, and a dose that worked all week suddenly produces drowsiness.
╌╌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
Elimination is primarily renal excretion of M3G, with about 10% of the dose excreted unchanged. M6G is analgesic but penetrates the blood-brain barrier poorly, so its accumulation shows as delayed sedation rather than immediate potency. Effective half-life 2 to 4 hours, terminal half-life about 15 hours where sampling runs long enough.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
What that does for a person
What it has and has not been shown to do
In cancer pain, 96% of patients with individually reported results got to pain no worse than mild. In breathlessness from lung disease, the largest randomised trial found nothing. Those are two different questions and morphine answers only one of them.
──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
Cochrane review of 62 studies and 4,241 participants: 96% (362/377) reached no worse than mild pain where per-participant data existed, on evidence the reviewers grade as generally poor. BEAMS, 156 analysed: change in worst breathlessness against placebo −0.3 (95% CI −0.9 to 0.4) at 8 mg/day and −0.3 (−1.0 to 0.4) at 16 mg/day.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
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.
People with cancer pain, people after major surgery, people in intensive care, and people at the end of life. It is on the WHO Model List of Essential Medicines.
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 morphine sulfate extended-release capsules in pediatric patients below the age of 18 have not been established.”
US prescribing information · 2da87bfa-11fd-43e3-8fef-d16ebeb15680 · read 2026-08-30
On older people, the label states: “The pharmacokinetics of morphine sulfate extended-release capsules have not been studied in elderly patients.”
US prescribing information · 2da87bfa-11fd-43e3-8fef-d16ebeb15680 · read 2026-08-30
On people who are pregnant, the label states: “No overt malformations were reported in either publication; although only limited endpoints were evaluated.”
US prescribing information · 2da87bfa-11fd-43e3-8fef-d16ebeb15680 · read 2026-08-30
On people who are breastfeeding, the label states: “8.3 Females and Males of Reproductive Potential Infertility Use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential.”
US prescribing information · 2da87bfa-11fd-43e3-8fef-d16ebeb15680 · read 2026-08-30
On people with reduced liver function, the label states: “Morphine pharmacokinetics have been reported to be significantly altered in patients with cirrhosis.”
US prescribing information · 2da87bfa-11fd-43e3-8fef-d16ebeb15680 · read 2026-08-30
On people with reduced kidney function, the label states: “Morphine pharmacokinetics are altered in patients with renal failure.”
US prescribing information · 2da87bfa-11fd-43e3-8fef-d16ebeb15680 · read 2026-08-30
Where the result stopped carrying
The primary endpoint of BEAMS, and every dose level of its step-count secondary endpoint
The search for randomised evidence on opioids in children with chronic non-cancer pain, which returned zero eligible trials
The randomised evidence base for morphine itself, which its Cochrane reviewers call small given the importance of the medicine and at high risk of bias
Its role as a routine comfort measure during myocardial infarction, once the antiplatelet interaction was measured
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 immediate-release tablets and solution; oral extended-release tablets and capsules; solution for intravenous, intramuscular, subcutaneous, epidural and intrathecal use; suppositories. Schedule II controlled substance in the United States.
✎ 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
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Suppression classes recorded: S1, S2, S5, S6.
No source is stored against this line.
What is in the pack
Oral bioavailability is limited by extensive first-pass glucuronidation, which is why parenteral and oral doses differ several-fold for the same effect. Extended-release oral products are designed for around-the-clock dosing and are explicitly not indicated as an as-needed analgesic. Preservative-free formulations exist specifically for epidural and intrathecal administration, where a preservative would be neurotoxic.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇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
Class boxed warnings for addiction, abuse and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant benzodiazepines, other CNS depressants and alcohol; and the opioid analgesic REMS. Constipation is near-universal and does not remit with tolerance. Accumulation of the active metabolite M6G in renal impairment produces delayed sedation and respiratory depression. Histamine release can cause itching, flushing and hypotension, which is more prominent with morphine than with the synthetic opioids.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
BEAMS trial registration — ClinicalTrials.gov NCT02720822 (NCT02720822) · a recorded source, not a stored snapshot
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Oral immediate-release tablets and solution; oral extended-release tablets and capsules; solution for intravenous, intramuscular, subcutaneous, epidural and intrathecal use; suppositories. Schedule II controlled substance in the United States.
✎ 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
Extended-release oral products are designed for around-the-clock dosing and are explicitly not indicated as an as-needed analgesic. Preservative-free formulations exist specifically for epidural and intrathecal administration, where a preservative would be neurotoxic.
✎ 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
168 products list this as an active ingredient in the United States drug directory. 168 of them contain it and nothing else.
FDA National Drug Code directory · 76045-007 · read 2026-08-29
They are sold as capsule, extended release, injection, injection, solution, powder, solution and suppository, taken epidural, intramuscular, intrathecal and intravenous.
FDA National Drug Code directory · 76045-007 · read 2026-08-29
The regulator's established pharmacologic class for it is full opioid agonists [moa] and opioid agonist [epc].
FDA National Drug Code directory · 76045-007 · read 2026-08-29
73 published labels name it as an active ingredient. 73 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · ad08cd86-3825-4e77-bbe8-f6333a9ca9d7 · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · ad08cd86-3825-4e77-bbe8-f6333a9ca9d7 · read 2026-08-29
Morphine Sulfate is tablets at Tablets: 15 mg and 30 mg, recorded as prescription opioid; fda label in effect 2025-10-10 in the United States.
US prescribing information · 07593aa4-f2c4-4d6e-b186-ab2a4ecaa38a · read 2026-08-27
Recorded price in US: 2.31331–2.34224 USD per one millilitre, across 2 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.
Self-experiment planning is not offered for a prescription or clinician-supervised medicine. The questions below are for a clinician or pharmacist.
Questions worth asking
Which of the trials of Morphine 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 morphine relieves the chronic breathlessness of COPD — not supported at the doses tested in the largest randomised trial
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 morphine causes the excess mortality associated with it in acute heart failure registries, where the sickest patients are also the ones given 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 published equianalgesic ratios convert reliably between opioids at steady state, when they derive largely from single-dose crossover work
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 a stated milligram dose corresponds to a stable exposure, when most circulating active material is a renally cleared metabolite
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 Morphine 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.
It works in cancer pain, on a literature its own reviewers call poor
In plain words
Where individual patient results were reported, 96% got to pain no worse than mild. The Cochrane authors add that the randomised evidence for morphine is small given how important the medicine is, and that most trials were run to register a formulation rather than to test whether the drug works.
What was measured
Proportion of participants achieving pain no worse than mild (≤30/100 mm on a visual analogue scale) on oral morphine for cancer pain
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Wiffen, Wee and Moore reviewed 62 studies with 4,241 participants. Thirty-six used a cross-over design of one to fifteen days. Fifteen compared oral modified-release morphine with immediate-release morphine, fourteen compared modified-release strengths, and fifteen compared modified-release morphine with other opioids. Eighteen studies achieved an average of no worse than mild pain — 30/100 mm or less on a visual analogue scale — and no study reported failure to attain good pain relief. Where results were given per participant in 17 studies, 96% (362/377) reached no worse than mild pain and 63% (400/638) reached an outcome equivalent to treatment success. Daily doses ranged from 25 mg to 2,000 mg. About 6% discontinued for intolerable adverse effects. The reviewers judged the included studies at high risk of bias because randomisation and allocation concealment were poorly reported, described the quality of the evidence as generally poor, and concluded that studies were old, often small, and largely carried out for registration purposes and therefore designed only to show equivalence between formulations.
Written into the record, not signed off as a reviewed claim
Breathlessness: the palliative use that failed its largest randomised test
In plain words
Low-dose slow-release morphine is widely given for the breathlessness of advanced lung disease. The largest randomised trial of it, in 160 people at twenty Australian centres, found no significant difference from placebo at either dose after a week.
What was measured
Change in intensity of worst breathlessness on a 0-10 numerical rating scale after one week
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
BEAMS was a multicentre, double-blind, placebo-controlled trial in people with COPD and chronic breathlessness at modified Medical Research Council grade 3 to 4, at 20 centres in Australia. Participants were randomised 1:1:1 to 8 mg/day or 16 mg/day of oral extended-release morphine or placebo for week 1, with further 1:1 randomisation to added 8 mg/day increments in weeks 2 and 3. Of 160 randomised, 156 were included in the primary analysis (median age 72, IQR 67 to 78; 48% women) and 138 (88%) completed week 1. Change in the intensity of worst breathlessness on a 0-10 numerical rating scale did not differ significantly from placebo at 8 mg/day (mean difference −0.3, 95% CI −0.9 to 0.4) or at 16 mg/day (mean difference −0.3, 95% CI −1.0 to 0.4). The secondary outcome of change in daily step count at week 3 did not differ at any dose. The authors concluded the findings do not support the use of these doses of extended-release morphine to relieve breathlessness. An earlier, smaller trial in the same field — MORDYC, 111 analysed participants — had found a 2.18-point improvement in COPD Assessment Test score (95% CI −4.14 to −0.22, p=0.03) with breathlessness itself unchanged, which is the kind of result BEAMS was built to adjudicate.
Written into the record, not signed off as a reviewed claim
Acute heart failure: an association that is not a trial
In plain words
Morphine has been given in acute heart failure for a century. A registry of 147,362 admissions found that the people who received it died four to five times as often after adjustment. It is an observational finding, and the sickest patients are the ones most likely to be given it.
What was measured
Adjusted odds ratio for in-hospital mortality with intravenous morphine in 147,362 heart failure hospitalisations
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Peacock and colleagues analysed the ADHERE registry as of December 2004: 147,362 hospitalisations, of which 20,782 (14.1%) received intravenous morphine and 126,580 (85.9%) did not. Baseline age, heart rate, blood pressure, urea, creatinine, haemoglobin, ejection fraction and atrial fibrillation did not differ clinically between the groups, but rest dyspnoea, radiographic congestion, rales and raised troponin were all more prevalent in the morphine group. Morphine recipients received more inotropes and vasodilators, were more likely to require mechanical ventilation (15.4% against 2.8%), had longer median stay (5.6 against 4.2 days), more ICU admissions (38.7% against 14.4%) and higher mortality (13.0% against 2.4%), all p<0.001. After risk adjustment and exclusion of ventilated patients, morphine remained an independent predictor of mortality (OR 4.84, 95% CI 4.52 to 5.18, p<0.001). The honest reading is confounding by indication: the finding is strong, consistent and observational, and no randomised trial of morphine in acute decompensated heart failure of comparable size exists to settle it.
Written into the record, not signed off as a reviewed claim
It blunts the antiplatelet drug given beside it in a heart attack
In plain words
Given during a heart attack for pain, morphine slows the stomach down — and the antiplatelet tablet swallowed at the same time is absorbed more slowly and less completely. In a randomised trial of 70 patients, total ticagrelor exposure fell by 36%.
What was measured
Area under the ticagrelor concentration-time curve over 12 hours, and platelet reactivity, with and without 5 mg intravenous morphine
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
IMPRESSION was a single-centre, randomised, double-blind trial in patients with acute myocardial infarction assigned 1:1 to intravenous morphine 5 mg or placebo, followed by a 180 mg ticagrelor loading dose; pharmacokinetics and pharmacodynamics were assessed in 70 patients, 35 per group. Morphine lowered total exposure to ticagrelor by 36% (AUC 0-12h 6,307 against 9,791 ng·h/mL, p=0.003) and to its active metabolite AR-C124910XX by 37% (1,503 against 2,388 ng·h/mL, p=0.008), and delayed maximal plasma concentration from 2 to 4 hours (p=0.004). All three platelet function tests showed a stronger antiplatelet effect on placebo and more high platelet reactivity on morphine. Multiple regression associated lower ticagrelor exposure independently with morphine administration (p=0.004) and with ST-elevation infarction (p=0.014). What was measured is drug exposure and platelet reactivity; whether the interaction changes infarct size, reinfarction or death has not been established in a powered outcome trial.
Written into the record, not signed off as a reviewed claim
The patient carries three drugs, and the kidney decides the mix
In plain words
Most of a morphine dose is converted into two by-products. One of them is a painkiller in its own right and leaves the body through the kidneys. When the kidneys fail, it builds up, and the person becomes drowsy on a dose that was fine last week.
What was measured
That a stated morphine dose corresponds to a stable degree of mu-receptor occupancy — true only where renal clearance is stable, because most of the circulating active material is a renally excreted metabolite
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The MS CONTIN label states that the major pathways of morphine metabolism are glucuronidation to morphine-3-glucuronide, M3G (about 50%) and morphine-6-glucuronide, M6G (about 5 to 15%), plus sulfation, with less than 5% demethylated; that M6G has analgesic activity but crosses the blood-brain barrier poorly while M3G has no significant analgesic activity; and that elimination occurs primarily as renal excretion of M3G, with about 10% of the dose excreted unchanged. Effective half-life after intravenous administration is 2 to 4 hours, with a longer terminal half-life of about 15 hours reported in studies sampling long enough to see it. The consequence for practice is that the "morphine level" is a three-molecule quantity whose composition shifts with renal clearance, and that the poor blood-brain penetration of M6G is what makes its accumulation a delayed effect rather than an immediate one.
Source
MS CONTIN (morphine sulfate extended-release tablets) United States prescribing information, Clinical Pharmacology 12.3
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
For chronic pain in children there is not one eligible randomised trial
In plain words
A Cochrane team searched the entire literature for randomised trials of opioids in children and adolescents with long-term non-cancer pain. They found none at all.
What was measured
Number of randomised controlled trials eligible for inclusion: zero, from a search of the whole indexed literature
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Cooper and colleagues searched CENTRAL, MEDLINE and Embase from inception to 6 September 2016, plus reference lists and trial registries, for randomised controlled trials of any opioid at any dose by any route against placebo or an active comparator for chronic non-cancer pain in people from birth to 17 years. No studies were eligible for inclusion. The authors rated the quality of evidence as very low, downgraded by three levels for the total absence of reported data, and concluded that there was no evidence from randomised controlled trials to support or refute the use of opioids in this population. This is not a null result: it is the absence of the experiment. Morphine, codeine and their relatives are nonetheless given to children with chronic pain across the world.
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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
Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
The reference opioid: a full mu-agonist that in the Cochrane review of 62 studies and 4,241 participants left 96% of individually reported cancer patients with pain no worse than mild, on evidence the reviewers themselves describe as generally poor and small given the importance of the medicine — and which failed its two most-cited non-analgesic uses, breathlessness in COPD (BEAMS, 160 patients, no significant effect) and acute heart failure, where a 147,362-hospitalisation registry found it an independent predictor of death.
Recorded evidence blocks (9)
Q2
On the Morphine label: indicated for what?
"Morphine Sulfate Oral Solution 2 mg/mL and 4 mg/mL is indicated for the management of: adults with acute and chronic pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. pediatric patients 2 years of age and older with acute pain severe enough to require an opioid…": indications and usage on Morphine's label. DailyMed label · 67f0ee8d-696e-4c08-9007-3df0e3988bad · 2026-08-26
Q3
652 registered trials of Morphine — at which phases?
Registered studies posting no result
491 of 652
652 registered studies of Morphine: 214 phase4, 166 na, 116 phase3, 113 phase2, 50 phase1, 15 na or unstated, 11 early phase1. CLINICALTRIALS_SNAPSHOT · 2026-09-01
safety (3), accrual/recruitment (46), funding/business (4), sponsor decision unspecified (1) and other (41): Morphine's stop wording, clustered. CLINICALTRIALS_SNAPSHOT · 2026-09-01
"We believe regional anesth better for TKR,90% patients got epidural. Last year we started spinal morphine one shot, and found it very promissing."; 95 of 652 registered studies
Show the evidence
Trial
NCT00270322
terminated; "We believe regional anesth better for TKR,90% patients got epidural. Last year we started spinal morphine one shot, and found it very promissing."
NCT00349401
withdrawn; "Study was not initiated. No subjects were screened or enrolled."
terminated; "Protocol was terminated due to enrollment + feasibility issues. Aim 2 not conducted. Aims 1 + 3 were conducted in part. During Aim 3 the IRB requested that the study be transitioned under a new protocol (2018-9208) in order to simplify…"
NCT00681174
terminated; "Failure to enroll sufficient patients by expected deadline."
NCT00726830
terminated; "Low Accrual."
NCT00762554
withdrawn; "Uncertain safety of one of the study medications."
NCT00839787
withdrawn; "Unable to enroll more patients"
NCT00895531
terminated; "Investigator left institution"
NCT00916890
suspended; "difficulties in patients enrolment"
NCT00934661
terminated; "Drug was discontinued by manufacturer"
NCT00955877
terminated; "The manufacturer decided to stop drug production."
NCT01037335
withdrawn; "No participants enrolled"
NCT01146457
terminated; "Principal Investigator"
recorded 2026-09-01 · last checked 2026-09-04
Q5
Human studies of Morphine used Morphine - .25 mg — over how long?
studies of Morphine used the recorded amount. ClinicalTrials.gov · 2026-09-01
20 recorded entries; human; oral; also "Morphine - .25 mg", "Morphine 50 mcg/kg", "Morphine 100 mcg/kg"
2 hours; The effective terminal half-life of morphine sulfate after IV administration is reported to be approximately 2 hours.
bioavailabilitypharmacokinetics
40 %; The oral bioavailability of morphine sulfate is less than 40% and shows large inter-individual variability due to extensive pre-systemic metabolism.
metabolismpharmacokinetics
The oral bioavailability of morphine sulfate is less than 40% and shows large inter-individual variability due to extensive pre-systemic metabolism.
recorded 2026-08-26 · last checked 2026-09-04
Q7
Which 254 trials of Morphine posted no result?
Posted no result
254 of 254 completed trials
Registrations
NCT00000335, NCT00004696, NCT00003000, NCT00625911, NCT00708318 and NCT00020618, and 248 more
Completion dates
oldest 1996-05-20; newest 2024-08-24
Show the evidence
Trial
NCT00000335
1996-05-20
NCT00004696
1998-07
NCT00003000
2001-06
NCT00625911
2002-03
NCT00708318
2002-06
NCT00020618
2004-02
14 further recorded trials
NCT00782548
2004-06
NCT00195910
2005-01
NCT00477061
2005-03
NCT00000273
2005-11
NCT00142896
2005-12
NCT00378937
2006-02
NCT00237731
2006-03
NCT00994942
2006-04
NCT00768183
2006-07
NCT00390039
2006-09
NCT00636415
2006-12
NCT01082471
2006-12
NCT01665209
2006-12
NCT01665222
2006-12
Q8
At the median, Morphine's trials enrolled 74.5 people — anything larger?
Median enrolment
74.5
Largest enrolment
27034
Registered trials counted
650
Q9
What do 11748 spontaneous reports say about Morphine — 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.
Morphine appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 11748 reaction mentions were counted: drug hypersensitivity 7740; pain 862; somnolence 622; constipation 530. FAERS via Open Targets · CHEMBL2103744 · 2026-06-24
Show the evidence
drug hypersensitivity
7740
pain
862
somnolence
622
constipation
530
confusional state
447
depressed level of consciousness
392
4 more recorded rows
sedation
349
drug dependence
282
respiratory depression
274
coma
250
recorded 2026-06-24 · last checked 2026-09-04
Q10
Which 10 reactions does Morphine's label not list?
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
✗ required summary fields resolved: 4 required field(s) not terminal: Why people use it, Best-supported result, Biggest unanswered question, Human evidence
✓ 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
This is a record of evidence. It is not medical advice, and it does not say this substance suits you. Nothing here says any substance on RNAWiki is appropriate for a child.