POLY-PRED
Clinical safety rating: caution
Comprehensive clinical and safety monograph for POLY-PRED (POLY-PRED).
Poly-Pred is a combination of neomycin (aminoglycoside antibiotic) and polymyxin B (polypeptide antibiotic) with prednisolone (corticosteroid). Neomycin inhibits bacterial protein synthesis by binding to 30S ribosomal subunit; polymyxin B disrupts bacterial cell membrane permeability; prednisolone suppresses inflammation by inhibiting phospholipase A2, reducing prostaglandin and leukotriene synthesis, and decreasing cytokine production.
| Metabolism | Prednisolone is primarily metabolized in the liver via CYP3A4; neomycin and polymyxin B are not significantly metabolized and are excreted mostly unchanged in urine after systemic absorption. |
| Excretion | Prednisolone acetate is metabolized hepatically and excreted renally (approximately 70% as metabolites and 20% unchanged) and in feces (<10%). Neomycin sulfate and polymyxin B sulfate are minimally absorbed and excreted unchanged in feces. |
| Half-life | Prednisolone acetate has a terminal half-life of 2.1–3.5 hours. Neomycin and polymyxin B have negligible systemic absorption; their local half-life is not clinically relevant. |
| Protein binding | Prednisolone acetate: 70–90% bound to corticosteroid-binding globulin (CBG) and albumin. Neomycin: minimal binding. Polymyxin B: limited binding. |
| Volume of Distribution | Prednisolone acetate: Vd approximately 0.6–1.1 L/kg, indicating distribution into total body water. Neomycin and polymyxin B: negligible Vd due to lack of systemic absorption. |
| Bioavailability | Base: Topical ophthalmic (eye drops) — the systemic bioavailability of prednisolone acetate from ocular administration is low (<1%). Neomycin and polymyxin B are essentially non-absorbed systemically via this route. |
| Onset of Action | Topical ophthalmic: Onset of anti-inflammatory effect within 24–48 hours; antibacterial effect begins within 1–2 hours after instillation. |
| Duration of Action | Topical ophthalmic: Duration of anti-inflammatory effect is 12–24 hours; antibacterial effect persists for 6–12 hours. Dosing typically every 3–4 hours for initial therapy. |
| Molecular Weight | 360.44 |
1-2 drops into the affected eye(s) every 3-4 hours, or more frequently as directed by physician. Do not use more than 6 times daily.
| Dosage form | SUSPENSION/DROPS |
| Renal impairment | No adjustment required. Systemic absorption is minimal. |
| Liver impairment | No adjustment required. Systemic absorption is minimal. |
| Pediatric use | 1 drop into the affected eye(s) every 4-6 hours, as needed. Do not exceed 4 times daily. |
| Geriatric use | Use lowest effective dose to avoid intraocular pressure elevation. Monitor intraocular pressure closely. |
| 1st trimester | Prednisolone acetate and neomycin sulfate combination: Prednisolone crosses the placenta; risk of cleft palate if used in first trimester, but data limited. Avoid unless essential. |
| 2nd trimester | Use only if potential benefit justifies risk to fetus; monitor for maternal adrenal suppression. |
| 3rd trimester | Prolonged use may cause fetal adrenal suppression; use lowest effective dose. |
Clinical note
Comprehensive clinical and safety monograph for POLY-PRED (POLY-PRED).
| Placental transfer | Prednisolone crosses placenta; neomycin has minimal transfer due to poor absorption. Degree: Moderate for prednisolone. |
| Breastfeeding | Prednisolone enters breast milk in low amounts; neomycin is poorly absorbed orally. Doses up to 40 mg/day prednisolone produce low levels in milk; monitor infant for growth suppression. Use caution and prefer alternative if possible. |
■ FDA Black Box Warning
None explicitly assigned by FDA.
| Serious Effects |
Hypersensitivity to any componentUntreated ocular infections (e.g., herpes simplex keratitis)Fungal or viral eye infectionsOcular tuberculosis
| Precautions | Prolonged use may lead to ocular hypertension/glaucoma, cataract formation, secondary ocular infections, and delayed wound healing, Neomycin may cause sensitization and allergic reactions; cross-sensitivity with other aminoglycosides, Systemic absorption of neomycin and polymyxin B may cause nephrotoxicity and ototoxicity, especially with prolonged use or in patients with renal impairment, Use with caution in patients with herpes simplex keratitis, Prolonged use may suppress host immune response and increase risk of secondary fungal infections |
| Food/Dietary | No significant food interactions. Avoid alcohol if concurrent oral corticosteroids are used. |
Loading safety data…
| Lactation Rating | L2 |
| Teratogenic Risk | Category C: Prednisolone and sulfacetamide cross placenta. First trimester: Increased risk of cleft palate (OR 3.4). Second/third trimesters: Adrenal suppression, intrauterine growth restriction, premature rupture of membranes. Sulfacetamide: Risk of kernicterus if used near term. |
| Fetal Monitoring | Monitor maternal blood pressure, blood glucose, and signs of infection. Fetal ultrasound for growth restriction and adrenal suppression. Neonatal monitoring for adrenal insufficiency and jaundice. |
| Fertility Effects | No direct effect on fertility. Underlying conditions (e.g., inflammatory eye disease) may affect fertility. Systemic corticosteroids may disrupt menstrual cycles. |
| Clinical Pearls | Shake well before use. Instruct patient to apply pressure over nasolacrimal duct for 1 minute after instillation to minimize systemic absorption. Not for prolonged use due to risk of secondary infections, cataracts, and increased IOP. |
| Patient Advice | Shake the bottle before each use. · Remove contact lenses before applying and wait at least 15 minutes before reinserting. · Do not touch the dropper tip to any surface to avoid contamination. · Apply prescribed number of drops into the affected eye and keep eye closed for 1-2 minutes. · Do not use for longer than prescribed; prolonged use can cause serious side effects. · Report any vision changes, eye pain, or worsening redness immediately. |