This page shows what was measured, who it was measured in, and what that does not settle.
What Azithromycin Anhydrous does in the body
Chains that cannot get out cause the machine to stall and drop them, so the bacterium stops growing.
Bacteria make proteins on a machine that feeds the finished protein out through a narrow tunnel. Azithromycin sits in that tunnel like a cork. The drug is also taken up by your own white blood cells and released slowly from them, which is why a short course keeps working after the last tablet.
Why people take it. Chest, throat, skin and sexually transmitted bacterial infections, and mass treatment for trachoma
What happened in people
A hazard ratio of 2.49 for cardiovascular death during 5 days of therapy versus amoxicillin in a propensity-matched cohort of over 2 million treatment episodes
✎ 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.
That the anti-inflammatory properties of macrolides translate into benefit in viral illness — tested directly in RECOVERY and PRINCIPLE, and refuted in both
Where it acts
Bacterial ribosome; drug concentrates in phagocytes and tissue
Kind of result
Living longer, or avoiding a major event
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 · 5FD1131I7S · read 2026-08-29
Its recorded molecular formula is C38H72N2O12, weighing 749.00.
US prescribing information · 7ab854bf-eb04-42c4-a403-096b60581bb4 · 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 110 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.
Aggregate all-cause mortality in children aged 1 to 59 months
✓ The study showed what it set out to show
Who was studied
MORDOR (NCT02047981)
How many people
190238
Study design
Phase 4 cluster-randomised placebo-controlled
Compared against
A dummy treatment
Kind of result
Living longer, or avoiding a major event
What was found
P < 0.001 (13.5% lower mortality, 95% CI 6.7 to 19.8)
Repeated elsewhere
Partially 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. Macrolide resistance was not reported in the primary paper; the prespecified substudy published a year later found nasopharyngeal pneumococcal macrolide resistance of 12.3% versus 2.9%.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral tablet, powder for oral suspension, single-dose powder packet, and intravenous infusion
Interval reported. 95% CI 6
Written into the record, not signed off as a reviewed claim.
RNAWiki holds 5 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
Lungs and airways: Indicated for community-acquired pneumonia caused by designated, susceptible bacteria
US prescribing information · 003307c5-3f73-4a5d-a704-bfdea3c656e8 · read 2026-08-27
Skin: Indicated for uncomplicated skin and skin structure infections caused by designated, susceptible bacteria
US prescribing information · 003307c5-3f73-4a5d-a704-bfdea3c656e8 · read 2026-08-27
Mouth and throat: Indicated for pharyngitis/tonsillitis caused by designated, susceptible bacteria
US prescribing information · 003307c5-3f73-4a5d-a704-bfdea3c656e8 · read 2026-08-27
Start
Azithromycin Anhydrous
What a person takes: Oral tablet, powder for oral suspension, single-dose powder packet, and intravenous infusion.
The measurement behind this step
Once-daily dosing, typically as a three-day or five-day course, or a single dose for some indications. The long tissue half-life is a property of the molecule rather than of the formulation: the dibasic azalide is trapped in acidic intracellular compartments and released slowly, so tissue exposure continues for days after the last dose.
Getting in
Taken up by white blood cells and carried to the infection
Rather than staying in the blood, azithromycin is swallowed up by your own immune cells, which then travel to wherever the infection is.
──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
The dibasic azalide structure traps the drug in acidic intracellular compartments of phagocytes, producing tissue concentrations far above plasma and a terminal half-life of roughly 68 hours. This is why a three-day or five-day course provides about a week of tissue exposure.
Released into the bacterial environment and taken inside
The immune cell releases the drug where bacteria are, and the drug crosses into the bacterium.
╌╌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
Release from phagocytes at the infection site delivers the drug to the bacterial surface. Entry across the Gram-positive cell wall is straightforward; the extra amine relative to erythromycin improves penetration of the Gram-negative outer membrane, which is why azithromycin has activity erythromycin lacks against Haemophilus influenzae.
It binds the exit tunnel of the bacterial ribosome
The drug lodges in the tunnel that a newly made protein has to pass through on its way out of the machine.
──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
Azithromycin binds the 23S ribosomal RNA of the 50S subunit at the nascent peptide exit tunnel, close to the peptidyl transferase centre. Human 80S ribosomes have a different tunnel architecture and are not bound at therapeutic concentrations.
Chains that cannot get out of the tunnel jam the machine, and the half-finished protein is released.
╌╌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
Obstruction of the exit tunnel causes context-dependent translational arrest and premature peptidyl-tRNA dissociation. The effect is bacteriostatic against most organisms at achievable concentrations, which matters clinically: it slows growth rather than lysing the cell.
Bacterial growth stops, and resistance is selected for
The infection is controlled. At the same time, any bacterium already carrying a resistance gene now has a survival advantage.
╌╌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
Resistance arises through erm-mediated methylation of the 23S rRNA binding site and through mef-encoded efflux. The MORDOR resistance substudy measured exactly this consequence at community scale: nasopharyngeal pneumococcal macrolide resistance of 12.3% in treated communities versus 2.9% in placebo communities.
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 5 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 and children with the labelled bacterial infections, people treated for chlamydia, adults with severe uncontrolled asthma in some guidelines, and entire communities of preschool children in trachoma and child-survival programmes in sub-Saharan Africa.
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: “[see Clinical Pharmacology (12.3) , Indications and Usage (1.2) , and Dosage and Administration (2.2) ] Safety and effectiveness in the treatment of pediatric patients with acute otitis media, acute bacterial sinusitis and community-acquired pneumonia under 6 months of age have not been established.”
US prescribing information · 7ab854bf-eb04-42c4-a403-096b60581bb4 · read 2026-08-30
On older people, the label states: “In multiple-dose clinical trials of oral azithromycin, 9% of patients were at least 65 years of age (458/4,949) and 3% of patients (144/4,949) were at least 75 years of age.”
US prescribing information · 7ab854bf-eb04-42c4-a403-096b60581bb4 · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary Available data from published literature and postmarketing experience over several decades with azithromycin use in pregnant women have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data ) .”
US prescribing information · 7ab854bf-eb04-42c4-a403-096b60581bb4 · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary Azithromycin is present in human milk (see Data ) .”
US prescribing information · 7ab854bf-eb04-42c4-a403-096b60581bb4 · read 2026-08-30
Where the result stopped carrying
RECOVERY: no effect on mortality, hospital stay, discharge alive or progression to ventilation in hospitalised COVID-19
PRINCIPLE: no meaningful benefit in the community either, with a 0.23 probability of a clinically meaningful gain in time to recovery across 2,265 randomised participants
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, powder for oral suspension, single-dose powder packet, and intravenous infusion
✎ 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
Once-daily dosing, typically as a three-day or five-day course, or a single dose for some indications.
✎ 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: The long tissue half-life is a property of the molecule rather than of the formulation: the dibasic azalide is trapped in acidic intracellular compartments and released slowly, so tissue exposure continues for days after the last dose.
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
The most common adverse effects are gastrointestinal. The class-level concern is QT-interval prolongation and torsades de pointes, quantified observationally by Ray and colleagues as an estimated 47 additional cardiovascular deaths per million five-day courses relative to amoxicillin, concentrated in patients at high baseline cardiovascular risk. Hepatotoxicity and, rarely, severe cutaneous reactions are also described in the label.
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, powder for oral suspension, single-dose powder packet, and intravenous infusion
✎ 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
A recorded note compares this form with the others that are sold. It is kept below, word for word.
§ A fixed RNAWiki sentence
Where this came from
Wording RNAWiki always uses, not a finding about this substance.
The recorded note, unchanged: The long tissue half-life is a property of the molecule rather than of the formulation: the dibasic azalide is trapped in acidic intracellular compartments and released slowly, so tissue exposure continues for days after the last dose.
No source is stored against this line.
What is recorded as being sold
230 products list this as an active ingredient in the United States drug directory. 230 of them contain it and nothing else.
FDA National Drug Code directory · 0527-2395 · read 2026-08-29
They are sold as injection, powder, lyophilized, for solution, powder, powder, for suspension, solution/ drops, suspension and tablet, taken intravenous, ophthalmic, oral and parenteral.
FDA National Drug Code directory · 0527-2395 · read 2026-08-29
The regulator's established pharmacologic class for it is macrolide antimicrobial [epc] and macrolides [cs].
FDA National Drug Code directory · 0527-2395 · read 2026-08-29
163 published labels name it as an active ingredient. 163 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 7ab854bf-eb04-42c4-a403-096b60581bb4 · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 7ab854bf-eb04-42c4-a403-096b60581bb4 · read 2026-08-29
Azithromycin is tablets (film-coated) at 250 mg and 500 mg, recorded as prescription product; fda label in effect 2026-03-16 in the United States.
US prescribing information · 003307c5-3f73-4a5d-a704-bfdea3c656e8 · read 2026-08-27
Recorded price in US: 0.20952–0.39009 USD per one millilitre, across 24 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: 0.26759–0.75519 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 58 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 Azithromycin Anhydrous 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 anti-inflammatory properties of macrolides translate into benefit in viral illness — tested directly in RECOVERY and PRINCIPLE, and refuted in both
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the MORDOR mortality benefit generalises across settings, when the country-level estimates ranged from 18.1% in Niger to 3.4% in Tanzania with confidence intervals crossing zero in two of three countries
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 Azithromycin Anhydrous 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.
MORDOR: 13.5% lower all-cause childhood mortality across 1,533 communities
In plain words
Giving every preschool child in a community two doses a year of azithromycin reduced deaths from all causes by about one in seven, in a placebo-controlled trial covering 190,238 children.
What was measured
All-cause mortality in children aged 1 to 59 months, per 1,000 person-years
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Cluster-randomised, placebo-controlled trial in Malawi, Niger and Tanzania. 1,533 communities, 190,238 children identified at census, 323,302 person-years monitored, mean coverage 90.4%. Annual mortality was 14.6 per 1,000 person-years with azithromycin and 16.5 with placebo, a 13.5% reduction overall (95% CI 6.7 to 19.8; P<0.001). Country effects differed sharply: 18.1% lower in Niger (95% CI 10.0 to 25.5), 5.7% in Malawi (95% CI -9.7 to 18.9) and 3.4% in Tanzania (95% CI -21.2 to 23.0). The largest effect was in infants aged 1 to 5 months, at 24.9% (95% CI 10.6 to 37.0).
Written into the record, not signed off as a reviewed claim
RECOVERY: no survival benefit in 7,763 patients hospitalised with COVID-19
In plain words
Azithromycin was given to hospitalised COVID-19 patients on the theory that it calms inflammation. In the largest randomised test, exactly 22% died in each group.
What was measured
28-day all-cause mortality
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Randomised, controlled, open-label platform trial at 176 UK hospitals. 2,582 patients allocated azithromycin 500 mg daily for 10 days and 5,181 to usual care alone. 28-day all-cause mortality was 561 of 2,582 (22%) versus 1,162 of 5,181 (22%), rate ratio 0.97 (95% CI 0.87 to 1.07; P=0.50). No difference in duration of hospital stay, in discharge alive by 28 days, or in the composite of invasive ventilation or death. The conclusion was explicit: azithromycin use in this setting should be restricted to patients with a clear antimicrobial indication.
Written into the record, not signed off as a reviewed claim
PRINCIPLE: no benefit in community treatment of suspected COVID-19 either
In plain words
The same question was asked in people at home rather than in hospital, and the answer was the same.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
A UK primary-care adaptive platform trial in people aged 65 and over, or 50 and over with at least one comorbidity, unwell for 14 days or less with suspected COVID-19. 2,265 participants were randomised, 540 to azithromycin plus usual care and 875 to usual care alone. The hazard ratio for time to first self-reported recovery was 1.08 (95% Bayesian credible interval 0.95 to 1.23), an estimated 0.94 days of benefit, and the probability of a clinically meaningful benefit of at least 1.5 days was 0.23. Hospitalisation occurred in 3% of each group and there were no deaths in either. Taken with RECOVERY, this closes the question in both settings for which the drug was proposed.
Written into the record, not signed off as a reviewed claim
The mortality benefit was bought at the price of measurable macrolide resistance
In plain words
In the same trial that showed fewer child deaths, resistance to macrolides in the treated communities rose about fourfold.
What was measured
That the community mortality benefit can be scaled up indefinitely without the resistance cost scaling with it
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
A prespecified resistance substudy within MORDOR I in Niger sampled 3,371 children across 30 communities. Macrolide resistance in nasopharyngeal Streptococcus pneumoniae was 12.3% in azithromycin communities versus 2.9% in placebo communities, and macrolide resistance determinants in the intestinal flora were present in 68.0% versus 46.7%. The mortality benefit and the resistance cost were measured in the same trial and are not separable by choosing to report only one.
Written into the record, not signed off as a reviewed claim
A small absolute excess of cardiovascular death during a five-day course
In plain words
In a large observational cohort, five days of azithromycin was associated with about 47 extra cardiovascular deaths per million courses compared with amoxicillin.
What was measured
Hazard ratio for cardiovascular death during 5 days of therapy
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
A Tennessee Medicaid cohort covering 347,795 azithromycin prescriptions, 1,391,180 propensity-matched no-antibiotic control periods, and 1,348,672 amoxicillin, 264,626 ciprofloxacin and 193,906 levofloxacin prescriptions. During the 5 days of therapy, azithromycin versus no antibiotics gave a hazard ratio for cardiovascular death of 2.88 (95% CI 1.79 to 4.63) and versus amoxicillin 2.49 (95% CI 1.38 to 4.50), an estimated 47 additional cardiovascular deaths per million courses, rising to 245 per million in the highest decile of baseline cardiovascular risk. Amoxicillin showed no such increase. This is an observational cohort, so it establishes association with careful confounding control rather than randomised causation.
Written into the record, not signed off as a reviewed claim
AVENIR then narrowed the child-survival result to infants
In plain words
A second, much larger trial in Niger repeated the child-survival question and found the benefit concentrated in the youngest children.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
AVENIR was a double-blind, response-adaptive, cluster-randomised, placebo-controlled trial in Niger with 864,493 participants registered, comparing twice-yearly azithromycin to children aged 1 to 59 months, twice-yearly azithromycin to infants aged 1 to 11 months with placebo for older children, and twice-yearly placebo to all. It is the largest randomised test of the MORDOR hypothesis and was designed to separate the age groups that MORDOR had pooled.
Written into the record, not signed off as a reviewed claim
AMAZES: fewer asthma exacerbations on long-term azithromycin
In plain words
In adults with persistent uncontrolled asthma, taking azithromycin three times a week for a year roughly halved the rate of flare-ups.
What was measured
Not recorded
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
A randomised, double-blind, placebo-controlled trial of azithromycin 500 mg three times weekly for 48 weeks in 420 adults with symptomatic asthma despite inhaled corticosteroid and long-acting bronchodilator. Exacerbations fell from 1.86 per patient-year on placebo to 1.07 on azithromycin, incidence rate ratio 0.59 (95% CI 0.47 to 0.74; P<0.0001), and asthma-related quality of life improved by an adjusted mean 0.36 (95% CI 0.21 to 0.52; P=0.001). Diarrhoea was more common on azithromycin (34% versus 19%; P=0.001). This is the strongest evidence for a use that depends on effects other than killing a specific pathogen, and it carries the same resistance-selection question as mass administration.
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What is not here
7 questions this page could not answer
These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.
What was measured, goal by goal — found nothing in the sources checked.
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.
What changed on this page — found nothing in the sources checked.
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 macrolide that stalls bacterial protein synthesis, with a 13.5% reduction in all-cause childhood mortality across 1,533 randomised communities in the MORDOR trial and no benefit whatever in hospitalised COVID-19 across 7,763 randomised patients in RECOVERY.
Recorded evidence blocks (8)
Q1
On the Azithromycin Anhydrous label: indicated for what?
"Azithromycin tablets are a macrolide antibacterial indicated for mild to moderate infections caused by designated, susceptible bacteria: Mycobacterial Infections ( 1.2 ) To reduce the development of drug-resistant bacteria and maintain the effectiveness of azithromycin tablets and other antibacterial drugs,…": indications and usage on Azithromycin Anhydrous's label. DailyMed label · c9990a1d-5238-403e-9221-72a9314d7b5e · 2026-08-18
Q2
430 registered trials of Azithromycin Anhydrous — at which phases?
Registered studies posting no result
322 of 430
430 registered studies of Azithromycin Anhydrous: 112 phase3, 112 phase4, 88 phase2, 67 na, 44 phase1, 20 na or unstated, 7 early phase1. CLINICALTRIALS_SNAPSHOT · 2026-09-01
"Principal Investigator moved institutions"; 66 of 430 registered studies
Show the evidence
Trial
NCT00181272
terminated; "Principal Investigator moved institutions"
NCT00245440
terminated; "Sponsor Terminated"
NCT00245453
withdrawn; "Terminated by sponsor"
NCT00286026
withdrawn; "Prevalence of infection for screened population too low (\<7%) to enroll anyone."
NCT00315003
terminated; "Pediatric development program terminated by sponsor"
NCT00315601
terminated; "Sanofi-Aventis wanted the study terminated."
14 further recorded trials
NCT00524095
terminated; "we decided not to go on treatment phase"
NCT00599053
terminated; "Enrollment was terminated early due to a change in practice on the obstetrical side that included administering azithromycin to women with preterm labor."
NCT00610623
terminated; "The sponsor decided to stop the study prematurely because of financial issues"
NCT00682656
terminated; "Efficacy issues on test arm"
NCT01217099
terminated; "terminated"
NCT01323582
terminated; "Original investigator left this institution, replacement investigator retired."
NCT01327625
terminated; "Preliminary reports of this study was too bad."
NCT01379196
withdrawn; "Patients were not interested in enrolling"
NCT01432080
terminated; "Not meeting recruitment targets"
NCT01556334
withdrawn; "Terminated before starting due to need for IND determined by FDA."
NCT01560962
terminated; "research staffs unable to continue."
NCT01721616
withdrawn; "Poor enrollment"
NCT01783340
withdrawn; "No funding"
NCT01797107
withdrawn; "Lack of enrollment"
recorded 2026-09-01 · last checked 2026-09-04
Q4
Human studies of Azithromycin Anhydrous used Azithromycin 500 mg — over how long?
Human studies of Azithromycin Anhydrous used "Azithromycin 500 mg". ClinicalTrials.gov · 2026-09-01
20 recorded entries; human; also "Azithromycin 1000 mg", "azithromycin 250 mg tablets", "1% Azithromycin and 0.1% Dexamethasone"
34 hr; The mean half-lives for 6 males and 6 females were 34 hr and 57 hr, respectively.
bioavailabilitypharmacokinetics
34 %; The absolute bioavailability of two 600 mg tablets was 34% (CV=56%).
metabolismpharmacokinetics
Metabolism In vitro and in vivo studies to assess the metabolism of azithromycin have not been performed.
recorded 2026-08-18 · last checked 2026-09-04
Q6
Which running trial of Azithromycin Anhydrous could settle lifespan?
NCT04716712 measures All-cause mortality, reading out 2026-01-30.
5 open trials; n 694400; "Infant Mortality Reduction by the Mass Administration of Azithromycin"
Show the evidence
Trial
NCT04716712
"Infant Mortality Reduction by the Mass Administration of Azithromycin"; n 694400; "All-cause mortality"; 2026-01-30
NCT04235816
"Improving Care Through Azithromycin Research for Infants in Africa"; n 20560; "The rate of all-cause mortality"; 2026-04-30
NCT06358872
"Azithromycin for Child Survival in Niger II"; n 3300000; "All-cause mortality"; 2028-04-29
NCT05580666
"Reducing Mortality in Adults With Advanced HIV Disease (REVIVE)"; n 8000; "All-cause mortality"; 2029-05-31
NCT04381936
"Randomised Evaluation of COVID-19 Therapy"; n 70000; "Community-acquired pneumonia: All-cause mortality (with subsidiary analyses of cause of death and of death at various timepoints following discharge)"; 2038-09-30
Q7
Which 131 trials of Azithromycin Anhydrous posted no result?
Posted no result
131 of 131 completed trials
Registrations
NCT00000641, NCT00001023, NCT00000947, NCT00000895, NCT00000811 and NCT00357539, and 125 more
Completion dates
oldest 1994-12; newest 2024-02-27
Show the evidence
Trial
NCT00000641
1994-12
NCT00001023
1998-07
NCT00000947
2000-07
NCT00000895
2001-08
NCT00000811
2001-11
NCT00357539
2002-03
14 further recorded trials
NCT00357292
2002-04
NCT00035347
2002-06
NCT00356850
2002-06
NCT00245908
2002-09
NCT00357383
2002-10
NCT00356772
2003-03
NCT00649831
2003-06
NCT00643539
2003-07
NCT00359970
2003-08
NCT00648726
2003-08
NCT00865670
2003-09
NCT00644293
2004-04
NCT00127504
2004-05
NCT00229944
2004-05
Q8
At the median, Azithromycin Anhydrous's trials enrolled 116 people — anything larger?
Median enrolment
116
Largest enrolment
3300000
Registered trials counted
413
Where it is registeredIdentifiers, relations and other names
ClinicalTrials.gov — US Government work · 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: 5 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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