NEO-CORTEF
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NEO-CORTEF (NEO-CORTEF).
Neomycin is an aminoglycoside antibiotic that binds to the 30S ribosomal subunit, inhibiting bacterial protein synthesis. Hydrocortisone is a corticosteroid that binds to glucocorticoid receptors, modulating gene expression to suppress inflammation and immune response.
| Metabolism | Neomycin: Not significantly metabolized; excreted unchanged in urine. Hydrocortisone: Primarily hepatic via CYP3A4; metabolized to tetrahydrocortisone and other inactive metabolites. |
| Excretion | Renal (70-80% as free drug and metabolites), fecal (20-30% via bile). |
| Half-life | Terminal half-life 2-4 hours for neomycin; hydrocortisone half-life 1-2 hours. Clinical context: q6-8h dosing. |
| Protein binding | Neomycin: 0-30% (low); hydrocortisone: 90-95% (corticosteroid-binding globulin and albumin). |
| Volume of Distribution | Neomycin: 0.3 L/kg (confined to extracellular fluid); hydrocortisone: 0.4 L/kg (distributes into total body water). |
| Bioavailability | Topical/ophthalmic/aural: negligible systemic absorption (~1-5%); oral neomycin: 3% (mainly local effects). |
| Onset of Action | Topical: 2-7 days for anti-inflammatory effect; ophthalmic: 1-2 hours; aural: 2-3 days. |
| Duration of Action | Topical: 1-2 weeks of therapy often needed; ophthalmic: 4-8 hours per dose; aural: 3-7 days for symptom relief. |
| Molecular Weight | Hydrocortisone: 362.47 Da; Neomycin: 332.4 Da (for neomycin base). Combined formulation not applicable. |
Apply a thin layer to the affected area 3 to 4 times daily. Use the 0.5% strength for mild conditions and 1% for more severe conditions.
| Dosage form | OINTMENT |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | No dose adjustment required for hepatic impairment. |
| Pediatric use | Apply a thin layer to affected area 3 to 4 times daily. Use the lowest effective potency and shortest duration due to increased systemic absorption risk. Safety and efficacy in infants < 3 months not established. |
| Geriatric use | Use with caution due to increased risk of skin atrophy and systemic effects. Apply sparingly to limited areas, using the lowest effective potency for the shortest duration. |
| 1st trimester | Corticosteroids are associated with a small increased risk of cleft palate. Use only if clearly needed. |
| 2nd trimester | Use with caution; may impair fetal growth. Monitor fetal development. |
| 3rd trimester | Use near term may increase risk of neonatal adrenal suppression. Use only if clearly needed. |
Clinical note
Comprehensive clinical and safety monograph for NEO-CORTEF (NEO-CORTEF).
| Placental transfer | Corticosteroids cross the placenta. Degree varies by compound; prednisolone is partially inactivated by placental 11β-HSD2, but others less so. NEO-CORTEF contains neomycin and cortef (hydrocortisone); hydrocortisone is partially inactivated. |
| Breastfeeding | Topical corticosteroids, when applied to small areas, are unlikely to produce significant systemic levels. However, avoid application to breast area to prevent infant ingestion. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to any componentPerforated tympanic membrane (for otic use)Systemic fungal infections (for systemic use)
| Precautions | Prolonged use may lead to ocular hypertension (IOP increase), glaucoma, cataract formation, or secondary ocular infections., Neomycin may cause ototoxicity and nephrotoxicity if absorbed systemically, especially with prolonged use or in patients with renal impairment., Avoid use in patients with epithelial herpes simplex keratitis (dendritic keratitis), vaccinia, varicella, mycobacterial infections, or fungal diseases of the eye., Use with caution in patients with perforated tympanic membrane (for otic preparations) due to risk of ototoxicity. |
| Food/Dietary | No significant food interactions. However, corticosteroid component may cause increased appetite and fluid retention; advise moderate sodium intake. Neomycin may rarely cause gastrointestinal disturbances; taking with food may reduce stomach upset. |
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| Lactation Rating | L2 (Probably Compatible) - Topical use on small areas is considered low risk; systemic exposure is minimal. |
| Teratogenic Risk | NEO-CORTEF (neomycin and hydrocortisone) is pregnancy category C. Neomycin: Not teratogenic in animal studies but may cause fetal nephrotoxicity or ototoxicity if absorbed significantly. Hydrocortisone: Corticosteroids are associated with increased risk of orofacial clefts (first trimester), intrauterine growth restriction, and adrenal suppression in the neonate. Avoid topical use on large areas, broken skin, or prolonged use during pregnancy. |
| Fetal Monitoring | Monitor maternal blood pressure, blood glucose, and signs of infection. In prolonged or high-dose use, assess fetal growth via ultrasound. Neonates should be monitored for signs of adrenal suppression (e.g., hypoglycemia, lethargy) if high-potency corticosteroids were used extensively. |
| Fertility Effects | No direct effect on fertility reported with topical corticosteroids or neomycin. Systemic corticosteroids may affect ovulation or sperm parameters at high doses; topical use unlikely to impact fertility. |
| Clinical Pearls | NEO-CORTEF is a combination of neomycin (aminoglycoside antibiotic) and hydrocortisone (corticosteroid). Use cautiously in patients with perforated tympanic membrane due to risk of ototoxicity from neomycin absorption. Prolonged use may lead to secondary infections (fungal or resistant bacteria) or adrenal suppression from systemic absorption of hydrocortisone. Avoid use in viral or fungal infections of the eye or ear. For otic preparations, ensure the ear canal is clean before instillation and avoid touching the dropper to the ear to prevent contamination. |
| Patient Advice | Use only as directed; do not use for longer than prescribed. · Do not use if you have a perforated eardrum (ask your doctor if unsure). · For ear drops: lie on your side with affected ear up, place drops, and remain for 5 minutes. Do not insert cotton into ear canal. · For eye drops: do not touch the dropper tip to your eye or any surface to avoid contamination. · Remove contact lenses before use; wait at least 15 minutes before reinserting. · Inform your doctor if symptoms worsen, do not improve after a few days, or if you experience hearing loss, dizziness, or ear pain. · This medication may weaken immune response; avoid close contact with people who have infections. |