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Ophthalmic Antiallergic Agent/Over-the-counter

PATADAY ONCE DAILY RELIEF

PATADAY ONCE DAILY RELIEF

Clinical safety rating

caution

Comprehensive clinical and safety monograph for PATADAY ONCE DAILY RELIEF (PATADAY ONCE DAILY RELIEF).


Mechanism of Action

Olopatadine is a selective histamine H1 receptor antagonist and mast cell stabilizer. It inhibits release of histamine and other mediators from mast cells, reducing allergic conjunctivitis symptoms.

What the body does with it

MetabolismOlopatadine undergoes minimal hepatic metabolism; approximately 60-70% excreted unchanged in urine. Metabolites include N-demethylated and N-oxide derivatives; CYP450 enzymes not significantly involved.
ExcretionPrimarily renal excretion: approximately 60% of dose excreted unchanged in urine; fecal elimination accounts for less than 10%.
Half-lifeTerminal elimination half-life is approximately 9 hours; allows twice-daily dosing for sustained symptom control.
Protein bindingApproximately 70-80% bound to plasma proteins, primarily albumin.
Volume of DistributionVolume of distribution is approximately 1.4 L/kg, indicating distribution into total body water.
BioavailabilityOcular bioavailability is low due to nasolacrimal drainage and systemic absorption; systemic bioavailability from ocular dose is less than 5%.
Onset of ActionOcular administration: onset within 3 minutes after instillation.
Duration of ActionDuration of action is approximately 8-12 hours; clinical efficacy supports twice-daily dosing.
Molecular Weight337.84

Classification & Brands

Dosing & administration

1 drop in each affected eye once daily. The ophthalmic solution is 0.2% (olopatadine hydrochloride).

Dosage formSOLUTION/DROPS
Renal impairmentNo dosage adjustment required for mild to moderate renal impairment. For severe renal impairment (CrCl <30 mL/min), use with caution as safety has not been established.
Liver impairmentNo dosage adjustment required for mild to moderate hepatic impairment. For severe hepatic impairment (Child-Pugh class C), use with caution as safety has not been established.
Pediatric useFor children 2 years of age and older: 1 drop in each affected eye once daily. Safety and efficacy in children under 2 years have not been established.
Geriatric useNo specific dosage adjustment required. Use the same dose as for younger adults. Overall, no differences in safety or efficacy were observed between elderly and younger patients.

Use during pregnancy

1st trimesterAvoid use during first trimester unless potential benefit outweighs risk. No adequate human data; animal studies show no teratogenicity at high doses.
2nd trimesterUse with caution. No known fetal risk from topical ophthalmic use; minimal systemic absorption.
3rd trimesterUse with caution. No known fetal risk from topical ophthalmic use; minimal systemic absorption.

Clinical note

Comprehensive clinical and safety monograph for PATADAY ONCE DAILY RELIEF (PATADAY ONCE DAILY RELIEF).

Placental transferNot studied. Based on molecular weight and topical application, systemic absorption is minimal; placental transfer is expected to be low.
BreastfeedingOphthalmic use results in negligible systemic absorption. It is unlikely to be excreted in breast milk in clinically significant amounts. Use with caution.
Lactation RatingL2
Teratogenic RiskPregnancy Category C. In animal studies, olopatadine (0.4 mg/kg/day SC) produced no teratogenic effects but caused reduced fetal weight and delayed ossification at maternally toxic doses. No adequate human studies exist. Risk cannot be ruled out; use only if benefit outweighs potential fetal risk.
Fetal MonitoringNo specific monitoring required beyond standard prenatal care. Observe for signs of maternal systemic effects (e.g., drowsiness, dry mouth) if used excessively.
Fertility EffectsNo human studies on fertility. In rats, no impairment of fertility at oral doses up to 200 mg/kg/day (3533 times MRHOD). No known effects on human reproduction.

Warnings & precautions

■ FDA Black Box Warning

None.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to olopatadine or any component of the formulation

Clinical Precautions

PrecautionsNot for injection; for topical ophthalmic use only., Do not wear contact lenses if eyes are red; wait at least 10 minutes after instillation before inserting lenses., Contains benzalkonium chloride which may be absorbed by soft contact lenses., May cause transient stinging or burning upon instillation.
Food/DietaryNo known food interactions. No dietary restrictions required.

Clinical Tips & Counseling

Clinical PearlsPataday Once Daily Relief contains olopatadine 0.2%, a mast cell stabilizer and antihistamine. For optimal efficacy, instruct patients to administer one drop in each affected eye once daily. Shake bottle before use. Wait at least 5 minutes before inserting contact lenses due to preservative (benzalkonium chloride). Monitor for transient burning or stinging upon instillation. Not for injection. Patients using additional ophthalmic products should separate by 5 minutes.
Patient AdviceDo not touch dropper tip to any surface to avoid contamination. · Remove contact lenses before use; wait 10 minutes before reinserting. · May cause temporary blurred vision; avoid driving until vision clears. · If you miss a dose, use it as soon as remembered, but skip if near next dose. · Keep bottle tightly closed when not in use; store at room temperature.

PATADAY ONCE DAILY RELIEF Interactions

Loading safety data…

This overview is compiled from peer-reviewed clinical sources and FDA labeling. It's here to support — not replace — clinical judgment. Always verify dosing against your institution's current protocols before prescribing.

On this page

Mechanism of ActionDosing & administrationUse during pregnancyWarnings & precautionsDrug interactions

Compare with

PATADAY TWICE DAILY RELIEF

External sources

DailyMed (NIH) PubMed OpenFDA