PATADAY TWICE DAILY RELIEF
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PATADAY TWICE DAILY RELIEF (PATADAY TWICE DAILY RELIEF).
Pataday (olopatadine) is a selective histamine H1 receptor antagonist and mast cell stabilizer. It inhibits the release of histamine and other inflammatory mediators from mast cells, reducing allergic conjunctivitis symptoms.
| Metabolism | Olopatadine undergoes minimal hepatic metabolism. Systemic absorption is low after ocular administration; the small absorbed fraction is metabolized by CYP3A4 and other CYP450 enzymes. |
| Excretion | Olopatadine is predominantly eliminated via renal excretion, with approximately 60-70% of the dose recovered as unchanged drug in urine. The remaining 30-40% is eliminated as metabolites (including N-demethylated and N-oxide derivatives) primarily via urine, with minor fecal excretion (<5%). |
| Half-life | The terminal elimination half-life of olopatadine is approximately 8-12 hours in healthy adults, supporting twice-daily dosing for sustained therapeutic effect. |
| Protein binding | Olopatadine is approximately 55% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | The volume of distribution (Vd) of olopatadine is approximately 1.3 L/kg, indicating extensive distribution into tissues beyond plasma volume. |
| Bioavailability | Bioavailability via ocular route: Systemic absorption is minimal; however, following topical ocular administration, the systemic bioavailability is approximately 0.5-1% due to low absorption through the conjunctiva and nasolacrimal duct. |
| Onset of Action | Ocular administration: Onset of action occurs within 30 minutes, with peak effect observed at 2 hours post-dose. |
| Duration of Action | Duration of action is approximately 8-12 hours following a single ocular dose. Twice daily dosing maintains symptom relief over 24 hours. |
1 drop in each affected eye twice daily (approximately every 6-8 hours)
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No dosage adjustment required for any degree of renal impairment. No specific GFR-based recommendations provided by manufacturer. |
| Liver impairment | No dosage adjustment required for any degree of hepatic impairment. No specific Child-Pugh based recommendations provided by manufacturer. |
| Pediatric use | Children 2 years and older: 1 drop in each affected eye twice daily. Safety and efficacy in children under 2 years have not been established. |
| Geriatric use | No specific dosage adjustment required; geriatric patients should use the same dose as younger adults. Elderly may be more susceptible to local adverse effects; monitor for excessive tearing, conjunctival irritation, or dry eye symptoms. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PATADAY TWICE DAILY RELIEF (PATADAY TWICE DAILY RELIEF).
| Breastfeeding | Unknown if excreted in human milk. M/P ratio not determined. Caution advised; consider developmental risks. |
| Teratogenic Risk | No evidence of human teratogenicity. Animal studies show no malformations at clinically relevant doses. Risk cannot be ruled out; use only if clearly needed. |
| Fetal Monitoring | No specific monitoring required. Routine obstetric care. |
■ FDA Black Box Warning
None
| Common Effects | Eye pain Eye irritation Abnormal eye sensation Eye discomfort Sleepiness Weakness Dryness in mouth |
| Serious Effects |
["Hypersensitivity to olopatadine or any component of the formulation"]
| Precautions | ["Not for injection","Patients should not wear contact lenses if eyes are red","May cause transient burning or stinging","Contains benzalkonium chloride which may be absorbed by soft contact lenses"] |
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| Fertility Effects | No human data. Animal studies show no impairment of fertility. |