This page shows what was measured, who it was measured in, and what that does not settle.
What Olopatadine does in the body
Itchy, red, watering eyes from allergy
When pollen lands on the surface of your eye, mast cells sitting in that membrane burst open and release histamine, and histamine is what makes the eye itch within seconds. This drop does two things: it occupies the receptor histamine acts on, and it makes the mast cells themselves less willing to burst. The second part is what separates it from a plain antihistamine drop, and unlike an older drug in the same category it does that without damaging the cell membrane in the process.
What happened in people
The 0.77% strength better than the 0.2% and 0.1% strengths by 0.3 to 0.5 points at 24 hours (P<0.05)
✎ 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.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
Returned to the nasal route only in fixed combination with mometasone, as Ryaltris, approved 13 January 2022
Where it acts
Conjunctiva — the transparent membrane over the white of the eye and the inside of the eyelids, which carries a dense population of mast cells
Kind of result
Measured performance
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 · 2XG66W44KF · read 2026-08-29
Its recorded molecular formula is C21H23NO3•HCl, weighing 373.88 g/mol.
US prescribing information · 272e8f56-ee4e-456f-ab98-3e40f657c630 · read 2026-08-30
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 119 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.
Placebo
A placebo is a dummy treatment given so the real one can be compared with it.
A picture of it, and where the picture fails
A placebo is like a blank control in an experiment.
Where that stops being true. A blank does nothing. People given a placebo often do get better.
What people get wrong. A placebo effect is read as imaginary. The improvement is measured and real.
An inactive intervention matched in appearance to the test intervention, used to control for non-specific effects.
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.
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.
Ocular itching on a 0-4 scale at 24-hour duration of action against all comparators, and at 3, 5 and 7 minutes against vehicle
Against vehicle: differences in means -0.9 to -1.5 at all post-challenge timepoints, P<0.0001. Against olopatadine 0.2% and 0.1% at 24 hours: -0.3 to -0.5, P<0.05
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. A single topical dose in each eye, in subjects pre-screened for a confirmed positive bilateral challenge response. The model measures a provoked response in a clinic, not symptom control across a season.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Ophthalmic solution (0.1%, 0.2% and 0.7%), formerly also a metered nasal spray now discontinued
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
Participant-reported severity of ocular itching, irritation, tearing and photophobia
✓ The study showed what it set out to show
Who was studied
Cochrane CD009566.pub2 — topical antihistamines and mast cell stabilisers
How many people
4344
Study design
Systematic review of 30 randomised trials across 17 drugs or comparisons
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
All reported agents reduced symptoms and signs against placebo in the short term; meta-analysis possible for one comparison only (olopatadine against ketotifen)
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. Treatment durations of one to eight weeks only, with no long-term efficacy data for any drug in the class. Outcome reporting was highly variable and poor reporting quality challenged synthesis.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Ophthalmic solution (0.1%, 0.2% and 0.7%), formerly also a metered nasal spray now discontinued
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
In vitro membrane biophysics, manufacturer laboratories
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Ketotifen 1-10 mM caused complete haemolysis of bovine erythrocytes; olopatadine 1-10 mM caused under 8%
Repeated elsewhere
Unreplicated
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. Millimolar concentrations, three orders of magnitude above what an eye drop sustains, in bovine erythrocytes rather than human conjunctival mast cells, published by the manufacturer of the favoured compound.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Ophthalmic solution (0.1%, 0.2% and 0.7%), formerly also a metered nasal spray now discontinued
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
RNAWiki holds 3 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Olopatadine
What a person takes: Ophthalmic solution (0.1%, 0.2% and 0.7%), formerly also a metered nasal spray now discontinued.
The measurement behind this step
One drop in each affected eye, once or twice daily depending on strength. Contact lenses should be removed before instillation. The zwitterionic molecule stays largely on the ocular surface rather than penetrating the cornea, which is where the target mast cells are.
Getting in
Dropped onto the surface it needs to treat
An eye drop puts the medicine exactly where the pollen landed. There is no absorption step to wait for and no journey through the body.
╌╌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
Instilled directly onto the conjunctiva. The molecule is a zwitterion at physiological pH — a carboxylic acid and a tertiary amine on the same scaffold — so corneal penetration is limited and the drug remains largely on the ocular surface, which is where the conjunctival mast cell population sits.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
It reaches the mast cells without entering the cell
It works from outside the cell membrane rather than by getting inside and disrupting it. That distinction is the whole argument for this drug over its older rival.
╌╌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
Comparative monolayer and erythrocyte work found olopatadine intrinsically surface active but producing smaller surface pressure changes than ketotifen, and minimal membrane perturbation at 0.1 to 10 mM where ketotifen caused concentration-dependent leakage and complete haemolysis. The finding is at millimolar concentrations in bovine cells and is a mechanistic inference rather than a clinical measurement.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
It occupies the histamine receptor on the conjunctiva
It takes the seat histamine needs on the surface of the eye, so the histamine released by mast cells has nowhere to signal.
╌╌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
Selective H1 receptor antagonism on conjunctival vasculature and sensory nerve endings. The label for the once-daily strength claims a 24-hour duration of action, which the registration trial tested directly by grading itch a full day after a single dose.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
Beyond blocking the receiver, it damps down the release of histamine in the first place, so the reaction is smaller as well as less audible.
──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
Stabilisation of human conjunctival mast cells is the claimed second action, and it is what puts this drug in the dual-action category rather than the antihistamine category. The distinguishing evidence is the non-lytic character of that stabilisation, established against ketotifen in membrane models rather than in a clinical comparison.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
Itch falls by about one point out of four, within minutes
On a scale where zero is no itch and four is unbearable, the strongest version lowered the rating by roughly one to one and a half points against a dummy drop, three minutes after allergen was placed in the eye.
──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
Differences in mean ocular itching of -0.9 to -1.5 against vehicle at 3, 5 and 7 minutes post-challenge and at 24 hours (P<0.0001), with conjunctival redness improved by -0.3 to -0.6 and total redness by -0.8 to -2.0 against all comparators at onset (both P<0.05), in 345 randomised subjects.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · a recorded source, not a stored snapshot
Everything above happened in a clinic with a measured amount of allergen. No trial of this drug or any drug in its class has reported long-term efficacy.
──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 Cochrane review of 30 trials in 4,344 participants evaluated only short-term effects, with treatment durations of one to eight weeks, and states that there is no long-term data on efficacy for any topical antihistamine or mast cell stabiliser.
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · 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.
Adults and children, sold without a prescription in the United States since an efficacy supplement was approved on 14 February 2020.
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 olopatadine hydrochloride nasal solution (nasal spray) have not been established in pediatric patients under 6 years of age.”
US prescribing information · 272e8f56-ee4e-456f-ab98-3e40f657c630 · read 2026-08-30
On older people, the label states: “Clinical studies of olopatadine hydrochloride nasal solution (nasal spray) did not include sufficient numbers of patients aged 65 years and older to determine whether they respond differently from younger patients.”
US prescribing information · 272e8f56-ee4e-456f-ab98-3e40f657c630 · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary Published data from postmarketing experience with antihistamines, with similar mechanism of action to olopatadine hydrochloride nasal solution (nasal spray), have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.”
US prescribing information · 272e8f56-ee4e-456f-ab98-3e40f657c630 · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary There are no data on the presence of olopatadine in human milk, the effects on the breastfed infant, or the effects on milk production.”
US prescribing information · 272e8f56-ee4e-456f-ab98-3e40f657c630 · read 2026-08-30
Where the result stopped carrying
The nasal spray formulation, approved as Patanase in April 2008, is discontinued, while its direct competitor azelastine went over-the-counter
Only one of seventeen drug comparisons in the Cochrane review had enough studies to meta-analyse
The mechanistic differentiation from ketotifen has never been demonstrated at clinical concentrations or in the relevant cell type
No trial in this class has reported efficacy beyond eight weeks
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
Prescription only
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Ophthalmic solution (0.1%, 0.2% and 0.7%), formerly also a metered nasal spray now discontinued
✎ 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
One drop in each affected eye, once or twice daily depending on strength. Contact lenses should be removed before instillation. The zwitterionic molecule stays largely on the ocular surface rather than penetrating the cornea, which is where the target mast cells are.
✎ 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
The Cochrane review of 30 trials in 4,344 participants reported no serious adverse events related to topical antihistamines and mast cell stabilisers as a class, and found them safe and well tolerated. No safety concerns were identified for the 0.77% strength in its registration trial. The ophthalmic route keeps systemic exposure minimal, in contrast to nasal antihistamines where about 40% of the delivered amount is absorbed. Transient stinging on instillation and preservative sensitivity are the usual practical limits.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
Where this came from
McLaurin E, Narvekar A, Gomes P, Adewale A, Torkildsen G. Phase 3 randomized double-masked study of efficacy and safety of once-daily 0.77% olopatadine hydro… · a recorded source, not a stored snapshot
Olopatadine 0.77% against 0.2%, 0.1% and vehicle in the conjunctival allergen challenge model, 345 subjects (NCT01743027) · 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
Ophthalmic solution (0.1%, 0.2% and 0.7%), formerly also a metered nasal spray now discontinued
✎ 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
Contact lenses should be removed before instillation. The zwitterionic molecule stays largely on the ocular surface rather than penetrating the cornea, which is where the target mast cells are.
✎ 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
136 products list this as an active ingredient in the United States drug directory. 134 of them contain it and nothing else.
FDA National Drug Code directory · 72476-851 · read 2026-08-29
They are sold as powder, solution, solution/ drops, spray and spray, metered, taken nasal and ophthalmic.
FDA National Drug Code directory · 72476-851 · read 2026-08-29
The regulator's established pharmacologic class for it is decreased histamine release [pe], histamine h1 receptor antagonists [moa] and histamine-1 receptor antagonist [epc].
FDA National Drug Code directory · 72476-851 · read 2026-08-29
114 published labels name it as an active ingredient. 112 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 1c7d2342-ba1c-4244-9814-d92a05725d4e · read 2026-08-29
Those labels are classed as human otc drug and human prescription drug.
US prescribing information · 1c7d2342-ba1c-4244-9814-d92a05725d4e · read 2026-08-29
olopatadine hydrochloride is nasal at 3 DOSAGE FORMS AND STRENGTHS Nasal spray: 665 mcg olopatadine hydrochloride per spray supplied in a white plastic bottle with a metered-dose manual spray pump, a white nasal applicator, a blue overcap and a blue clip., recorded as fda label in effect 2024-05-10 in the United States.
US prescribing information · 272e8f56-ee4e-456f-ab98-3e40f657c630 · read 2026-08-30
Recorded price in US: 0.86777 USD per one gram, across 3 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: 1.26767–2.99675 USD per one millilitre, across 14 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 Olopatadine 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 a challenge-booth itch score describes benefit across a pollen season — no long-term efficacy data exists for any drug in this class
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 non-lytic mast cell stabilisation established at millimolar concentrations in bovine erythrocytes operates at eye-drop concentrations in human conjunctival mast cells
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 dual-action label distinguishes this drop clinically from a plain antihistamine drop — the Cochrane review found only one poolable head-to-head comparison in the entire class
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 successive strength increases represent successive therapeutic advances rather than successive applications
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 Olopatadine are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
The 0.77% strength beat vehicle by up to 1.5 points on a 4-point itch scale
In plain words
In the trial that supported the strongest version, allergen was placed in 345 people’s eyes and they rated the itch on a scale from none to unbearable. The drop lowered that rating by up to one and a half points against a dummy drop, both minutes after the challenge and a full day later.
What was measured
Ocular itching on a 0-4 scale at 3, 5 and 7 minutes and at 24 hours after conjunctival allergen challenge
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
A five-week, multicentre, double-masked phase 3 trial randomised 345 subjects aged 18 and over with a history of allergic conjunctivitis and a confirmed positive bilateral conjunctival allergen challenge response 2:2:2:1 to olopatadine 0.77%, 0.2%, 0.1% or vehicle, following a single topical dose in each eye. The primary objective was superiority of 0.77% over all comparators on ocular itching, graded 0 to 4 where 4 is incapacitating itch, at 24-hour duration of action, and over vehicle only at onset of action 3, 5 and 7 minutes after challenge. Olopatadine 0.77% was superior to vehicle at all post-challenge timepoints at onset and at 24 hours, with differences in means of -0.9 to -1.5 (P<0.0001), and superior to both 0.2% and 0.1% at 24 hours, with differences of -0.3 to -0.5 (P<0.05). It also improved conjunctival redness and total redness against all comparators at onset (-0.3 to -0.6 and -0.8 to -2.0 respectively, both P<0.05).
Written into the record, not signed off as a reviewed claim
Almost the whole evidence base is a challenge booth, not a pollen season
In plain words
The trials that establish this drug work by putting a measured amount of allergen into the eye in a clinic and asking how much it itches a few minutes later. That is a clean experiment. It is not the same thing as living through a spring.
What was measured
That a 0.9-to-1.5-point advantage on itch minutes after a controlled allergen challenge describes the benefit of using the drop through an allergy season — no long-term efficacy data exists for any drug in this class
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The conjunctival allergen challenge model titrates allergen to produce a reproducible bilateral response, then measures itching and redness at fixed short intervals under masked grading. Its advantages are exactly what limit its external validity: a single controlled exposure, a highly selected population screened for a confirmed positive response, an endpoint recorded within minutes, and no natural variability in allergen load, humidity, wind or concurrent nasal disease. The registration trial for the 0.77% strength followed a single topical dose in each eye. The Cochrane review of the entire topical antihistamine and mast cell stabiliser class found 30 randomised trials in 4,344 participants covering 17 different drugs or comparisons, evaluated only short-term effects with treatment ranging from one to eight weeks, and stated that there is no long-term data on efficacy for any drug in the class.
Written into the record, not signed off as a reviewed claim
Each new strength beat the one before it, and each got its own application and exclusivity
In plain words
The same molecule was approved three times at three strengths across nineteen years, and each time the new strength was shown better than the old one in the same booth. That is a real finding and also a commercial pattern worth naming.
What was measured
Difference in mean ocular itching at 24 hours, 0.77% against 0.2% and 0.1%
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
NDA 020688 approved the 0.1% ophthalmic solution on 18 December 1996; NDA 021545 approved the 0.2% once-daily solution on 22 December 2004; NDA 206276 approved the 0.7% solution on 30 January 2015. The 2015 registration trial compared the new strength against both older strengths as active comparators and against vehicle, and found the differences over the older strengths at 24 hours were -0.3 to -0.5 points on the 0-4 itch scale (P<0.05) — statistically clear and a third to a half of one point on a four-point scale. An efficacy supplement approved on 14 February 2020 moved the once-daily product to over-the-counter status.
Written into the record, not signed off as a reviewed claim
The mast-cell-stabilising claim rests on membrane work at concentrations no eye reaches
In plain words
The distinguishing claim is that this drug calms mast cells without damaging them, unlike an older rival. The experiment behind that used concentrations thousands of times higher than a drop delivers, in cow red blood cells.
What was measured
That olopatadine stabilises mast cells non-lytically where ketotifen does not — a mechanism inferred from millimolar membrane experiments in bovine erythrocytes, published by the manufacturer, and not from a clinical comparison
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Comparative work from the manufacturer’s laboratories examined olopatadine and ketotifen against phospholipid monolayers and against erythrocyte membranes. Both compounds were surface active and interacted with monolayers, but olopatadine produced smaller surface pressure changes. Exposure of bovine erythrocytes to ketotifen at 1 to 10 mM produced complete haemolysis while olopatadine at the same 1 to 10 mM produced under 8%; in erythrocyte ghosts, olopatadine at 0.1 to 10 mM minimally perturbed the membrane while ketotifen at 1 to 10 mM caused concentration-dependent marker leakage. The authors offered this as an explanation for ketotifen’s biphasic non-specific cytotoxic effect on histamine release and for olopatadine’s non-lytic mast cell stabilising activity. Millimolar is three orders of magnitude above the concentration a 0.1% to 0.7% eye drop sustains on the ocular surface, and the cells are bovine erythrocytes rather than human conjunctival mast cells.
Written into the record, not signed off as a reviewed claim
The nasal spray was approved in 2008 and is discontinued
In plain words
The same molecule was developed as a nose spray for hay fever, approved in 2008, and is no longer marketed. Azelastine, its direct competitor in that form, went the other way and became the first over-the-counter antihistamine nasal spray.
What was measured
Regulatory marketing status of the nasal formulation, Drugs@FDA product listings
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Patanase, olopatadine hydrochloride nasal spray, was approved under NDA 021861 on 15 April 2008 for the symptoms of seasonal allergic rhinitis in adults and children aged 6 and over, and is listed in Drugs@FDA as discontinued. The competing nasal antihistamine azelastine, first approved in 1996, was granted over-the-counter status under NDA 213872 on 17 June 2021. Olopatadine returned to the nasal route only in combination, as Ryaltris with mometasone furoate, approved as NDA 211746 on 13 January 2022 — the same combination strategy that produced Dymista from azelastine a decade earlier.
Source
Drugs@FDA: PATANASE, NDA 021861, approved 15 April 2008, Novartis, discontinued; RYALTRIS, NDA 211746, approved 13 January 2022, Glenmark
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
The class as a whole works, and only one head-to-head could be pooled
In plain words
A systematic review of every eye-drop antihistamine and mast cell stabiliser found that all of them beat a dummy drop in the short term and none of them had long-term data. Out of seventeen different drug comparisons, only one had enough studies to combine statistically — and it happened to be this drug against its main rival.
What was measured
Participant-reported severity of ocular itching, irritation, tearing and photophobia against placebo, 30 trials
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The Cochrane review identified 30 randomised trials with 4,344 participants covering 17 different drugs or treatment comparisons, including nedocromil, sodium cromoglicate, olopatadine, ketotifen, azelastine, emedastine, levocabastine, mequitazine and bepotastine. Risk of bias was low overall but reporting quality was variable and outcome reporting highly heterogeneous. Meta-analysis was possible for only one comparison — olopatadine against ketotifen. The review concluded that all reported topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis against placebo in the short term, that there is no long-term efficacy data, that direct comparisons need cautious interpretation, and that no serious adverse events related to this class were reported.
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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
Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
A dibenzoxepin H1 antagonist that also stabilises human conjunctival mast cells without lysing them — in a 345-subject phase 3 challenge study the 0.77% strength beat vehicle on ocular itching by 0.9 to 1.5 points on a 0-to-4 scale (P<0.0001) and beat the 0.1% and 0.2% strengths that preceded it by 0.3 to 0.5 points at 24 hours (P<0.05), all of it measured minutes after allergen was placed in the eye rather than during a pollen season.
Recorded evidence blocks (10)
Q1
On the Olopatadine label: indicated for what?
"Olopatadine hydrochloride nasal spray is indicated for the relief of the symptoms of seasonal allergic rhinitis in adults and pediatric patients 6 years of age and older. Olopatadine hydrochloride nasal spray is an H 1 receptor antagonist indicated for the relief of the symptoms of seasonal allergic rhinitis in adults…": indications and usage on Olopatadine's label. DailyMed label · 3aa27224-7b72-38eb-0c21-b8d73525ee85 · 2025-11-05
Q2
33 registered trials of Olopatadine — at which phases?
8 to 12 hours; Elimination The plasma elimination half-life of olopatadine is 8 to 12 hours.
tmaxpharmacokinetics
30 minutes; Absorption Healthy Subjects: Olopatadine was absorbed with individual peak plasma concentrations observed between 30 minutes and 1 hour after twice daily intranasal administration of olopatadine hydrochloride nasal spray.
bioavailabilitypharmacokinetics
57 %; The average absolute bioavailability of intranasal olopatadine is 57%.
metabolismpharmacokinetics
Metabolism Olopatadine is not extensively metabolized.
recorded 2025-11-05 · last checked 2026-09-04
Q6
Which 11 trials of Olopatadine posted no result?
Posted no result
11 of 11 completed trials
Registrations
NCT00655109, NCT00836485, NCT00987272, NCT01037179, NCT01258309 and NCT01326858, and 5 more
Completion dates
oldest 2008-03; newest 2021-09-02
Show the evidence
Trial
NCT00655109
2008-03
NCT00836485
2009-03
NCT00987272
2009-11
NCT01037179
2010-05
NCT01258309
2011-01
NCT01326858
2011-06
5 further recorded trials
NCT01294969
2011-10
NCT01272089
2011-12
NCT01450176
2011-12
NCT01344083
2012-02
NCT04708821
2021-09-02
Q7
At the median, Olopatadine's trials enrolled 110 people — anything larger?
Median enrolment
110
Largest enrolment
1260
Registered trials counted
33
Q8
What do 151 spontaneous reports say about Olopatadine — 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.
Olopatadine appears in spontaneous reports to regulators. Across the 2 most-reported reaction terms, 151 reaction mentions were counted: treatment failure 138; hypersensitivity 13. FAERS via Open Targets · CHEMBL1189432 · 2026-06-24
Show the evidence
treatment failure
138
hypersensitivity
13
recorded 2026-06-24 · last checked 2026-09-04
Q9
Which 2 reactions does Olopatadine's label not list?
In in vitro studies with cDNA-expressed human cytochrome P450 isoenzymes (CYP) and flavin-containing monooxygenases (FMO), N-desmethyl olopatadine (Ml) formation was catalyzed mainly by CYP3A4, while olopatadine N-oxide (M3) was primarily catalyzed by FMO1 and FMO3.
pharmacokinetics
Olopatadine at concentrations up to 33,900 ng/mL did not inhibit the in vitro metabolism of specific substrates for CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4.
pharmacokinetics
Olopatadine did not inhibit the in vitro metabolism of specific substrates for CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4.
clinical_pharmacology
In in vitro studies with cDNA-expressed human cytochrome P450 isoenzymes (CYP) and flavin-containing monooxygenases (FMO), N-desmethyl olopatadine (Ml) formation was catalyzed mainly by CYP3A4, while olopatadine N-oxide (M3) was primarily catalyzed by FMO1 and FMO3.
clinical_pharmacology
Olopatadine at concentrations up to 33,900 ng/mL did not inhibit the in vitro metabolism of specific substrates for CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4.
clinical_pharmacology
Olopatadine did not inhibit the in vitro metabolism of specific substrates for CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4.
ChEMBL 37 — CC BY-SA 3.0 Unported · ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Open Targets 26.06 — CC0 · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
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✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 6 source rows
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