ELESTAT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ELESTAT (ELESTAT).
Selective histamine H1 receptor antagonist; inhibits histamine release from mast cells.
| Metabolism | Not extensively metabolized; undergoes some hepatic metabolism via CYP450 enzymes. |
| Excretion | Primarily renal excretion of unchanged drug (approx. 60-70%) and metabolites; biliary/fecal excretion accounts for 20-30%. |
| Half-life | Terminal elimination half-life is approximately 8-12 hours in healthy adults; clinically, twice-daily dosing maintains therapeutic concentrations. |
| Protein binding | Approximately 70-80% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 5-7 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Ophthalmic: Systemic bioavailability is low (≤5%) due to local administration and first-pass metabolism; oral bioavailability not applicable. |
| Onset of Action | Ophthalmic: Onset within minutes after topical application to the eye. |
| Duration of Action | Ophthalmic: Duration of action is approximately 8-12 hours, supporting twice-daily dosing for allergic conjunctivitis. |
| Molecular Weight | 498.6 |
1 drop (0.05% ophthalmic solution) in the affected eye twice daily approximately every 12 hours.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No dose adjustment is required for renal impairment. |
| Liver impairment | No dose adjustment is required for hepatic impairment. |
| Pediatric use | Safety and efficacy in pediatric patients below 3 years of age have not been established. For children 3 years and older, same as adult: 1 drop twice daily. |
| Geriatric use | No specific dose adjustment is required in elderly patients; use same as adult dose. |
| 1st trimester | No adequate studies in pregnant women. Use only if potential benefit justifies risk. No evidence of teratogenicity in animal studies. |
| 2nd trimester | Limited data; use only if clearly needed. |
| 3rd trimester | Avoid near term due to potential for benzalkonium chloride accumulation and effects on neonate. |
Clinical note
Comprehensive clinical and safety monograph for ELESTAT (ELESTAT).
| Placental transfer | Unknown; molecular weight <500 Da suggests possible transfer, but no human data. |
| Breastfeeding | Not recommended during breastfeeding due to possible systemic absorption and lack of safety data in nursing infants. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to epinastine or any component of the formulation
| Precautions | Contains benzalkonium chloride, which may be absorbed by soft contact lenses; remove lenses before administration and wait 10 minutes before reinsertion., Use with caution in patients with ocular infections or corneal abrasions. |
| Food/Dietary | No clinically significant food interactions reported. Systemic absorption is negligible; no dietary restrictions necessary. |
| Clinical Pearls |
Loading safety data…
| L4 (Possibly hazardous) |
| Teratogenic Risk | Pregnancy Category C. No adequate well-controlled studies in pregnant women. In animal studies, intravenous epinastine at doses ≥ 10 mg/kg/day (≥ 160 times the maximum recommended ocular dose) caused increased fetal resorption, reduced fetal weight, and delayed ossification. First trimester: risk cannot be excluded. Second and third trimesters: limited data, but systemic absorption from ocular use is minimal (plasma concentrations < 0.1 ng/mL), suggesting low fetal exposure. Use only if potential benefit justifies risk. |
| Fetal Monitoring | No specific maternal or fetal monitoring required beyond routine prenatal care. Monitor for maternal ocular adverse effects (e.g., ocular irritation, headache). No evidence of need for fetal heart rate or growth monitoring. |
| Fertility Effects | No human data on fertility. In rats, no impairment of fertility was observed at oral doses up to 40 mg/kg/day (approximately 640 times the maximum recommended ocular dose). No clinical studies conducted on fertility effects in humans. |
| ELESTAT (epinastine HCl ophthalmic solution) is a topical antihistamine and mast cell stabilizer for allergic conjunctivitis. Onset of action is within minutes; do not use with contact lenses unless instructed. Avoid touching dropper tip to eye or surfaces. Monitor for discomfort, burning, or conjunctival injection. Efficacy may be reduced if used concurrently with other ophthalmic preparations—separate by at least 10 minutes. |
| Patient Advice | Instill one drop in each affected eye twice daily or as directed. · Remove contact lenses before use; may reinsert after 10 minutes. · Do not touch the dropper tip to any surface to avoid contamination. · Mild burning or stinging may occur upon instillation but usually resolves. · Do not wear contact lenses if eyes are red or irritated. · Avoid driving or operating machinery if vision is blurred after use. · Store at room temperature; keep bottle tightly closed. |