ALREX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ALREX (ALREX).
Corticosteroid that binds to glucocorticoid receptors, inhibiting phospholipase A2, reducing prostaglandin and leukotriene synthesis, and suppressing inflammatory mediators.
| Metabolism | Hepatic metabolism via CYP3A4; main metabolite is 6β-hydroxy-loteprednol etabonate. |
| Excretion | Primarily hepatic metabolism; less than 5% excreted unchanged in urine. Fecal elimination accounts for the remainder via biliary excretion. |
| Half-life | Approximately 1.6 hours (range 1.2–2.2 hours) for the active metabolite loteprednol etabonate; short half-life allows for BID dosing with minimal systemic accumulation. |
| Protein binding | Approximately 88% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Not clinically meaningful for ophthalmic administration; systemic Vd is approximately 0.8 L/kg, indicating limited distribution into tissues. |
| Bioavailability | Topical ophthalmic: Systemic bioavailability is very low (<1%) due to limited absorption through the cornea and extensive first-pass metabolism. |
| Onset of Action | Topical ophthalmic: Onset within 2–4 hours for reduction of ocular inflammation; peak effect at 12–24 hours. |
| Duration of Action | Topical ophthalmic: Duration approximately 6–12 hours, requiring twice-daily dosing for sustained anti-inflammatory effect. |
1-2 drops in the affected eye(s) four times daily; in severe cases, may be increased to 1-2 drops every hour during the first 24-48 hours.
| Dosage form | SUSPENSION/DROPS |
| Renal impairment | No dose adjustment required for renal impairment; systemic absorption is minimal. |
| Liver impairment | No dose adjustment required for hepatic impairment; systemic absorption is minimal. |
| Pediatric use | Safety and efficacy in pediatric patients have not been established; use only if potential benefit outweighs risk. |
| Geriatric use | No specific dose adjustment recommended; use with caution due to increased risk of intraocular pressure elevation and cataract formation. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ALREX (ALREX).
| Breastfeeding | Unknown if loteprednol etabonate is excreted in human milk. Systemic absorption after ocular administration is low (10%) of plasma levels. The M/P ratio is not established. Use with caution, weighing benefits to mother against potential risk to infant (immunosuppression, growth suppression). |
| Teratogenic Risk | Category C: First trimester studies in animals show fetal abnormalities (cleft palate, increased fetal death) at topical doses 0.5-1.5 times maximum human ocular dose; no adequate human studies. Risk cannot be ruled out. Second and third trimester: systemic absorption minimal, but chronic use may increase risk of fetal hypothalamic-pituitary-adrenal axis suppression. Avoid if possible, especially first trimester. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to loteprednol etabonate or any component","Active ocular infections (bacterial, viral, fungal)","Verticillate keratitis"]
| Precautions | ["May increase intraocular pressure (IOP), monitor in patients with glaucoma","Risk of secondary infection and cataract formation","Prolonged use may lead to corneal thinning or perforation","May mask signs of infection","Use with caution in patients with ocular herpes simplex"] |
| Food/Dietary | No known food interactions. Avoid alcohol if it exacerbates underlying condition (e.g., allergic conjunctivitis). |
| Clinical Pearls |
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| Fetal Monitoring | Monitor intraocular pressure (IOP) at baseline and regularly, especially in patients with glaucoma. For prolonged use (>2 weeks), assess for secondary ocular infections, corneal thinning. In pregnancy, monitor for signs of maternal adrenal suppression if used chronically; fetal growth and development can be assessed via ultrasound. |
| Fertility Effects | In animal studies, loteprednol etabonate at topical doses up to 50 μg/day (0.5 times human ocular dose) showed no impairment of fertility. No human data on fertility effects. Theoretical risk of spermatogenesis disruption or menstrual irregularities with systemic absorption, but minimal with ocular use. |
| Loteprednol etabonate is a site-specific corticosteroid designed for ophthalmic use with lower intraocular pressure (IOP) elevation risk than prednisolone acetate. Always measure IOP before and during therapy, especially in patients with glaucoma. Use cautiously in patients with history of herpes simplex keratitis; contraindicated in epithelial herpes simplex keratitis (dendritic keratitis). Avoid in patients with fungal or viral infections of the eye. Discontinue if rash, itching, or other signs of hypersensitivity occur. |
| Patient Advice | Shake the bottle well before each use. · Do not touch the dropper tip to any surface, including your eye, to avoid contamination. · Remove contact lenses before instillation and wait at least 15 minutes before reinserting. · Report any eye pain, redness, vision changes, or worsening symptoms immediately. · Do not use this medication for longer than prescribed; prolonged use can increase risk of eye infections or glaucoma. · Avoid driving or operating machinery if vision is blurry after use. |