ZINC BACITRACIN,NEOMYCIN SULFATE,POLYMYXIN B SULFATE & HYDROCORTISONE
Clinical safety rating: safe
Other nephrotoxic or ototoxic drugs increase risk of toxicity Can cause ototoxicity and nephrotoxicity with systemic use.
Combination antibiotic and corticosteroid: Neomycin, polymyxin B, and bacitracin are antibiotics that inhibit bacterial protein synthesis, disrupt cell membrane permeability, and inhibit cell wall synthesis, respectively; hydrocortisone is a corticosteroid that suppresses inflammatory responses by inhibiting phospholipase A2, reducing prostaglandin and leukotriene synthesis.
| Metabolism | Minimal systemic absorption after topical application; hydrocortisone undergoes hepatic metabolism via CYP3A4; neomycin, polymyxin B, and bacitracin are not significantly metabolized systemically. |
| Excretion | Renal: Neomycin (<1% absorbed, remainder fecal), Bacitracin (10-40% renal if absorbed, negligible), Polymyxin B (60% renal over 24h if absorbed), Hydrocortisone (metabolized, <1% unchanged renal; fecal for unabsorbed). Topical: negligible systemic absorption; fecal for unabsorbed. |
| Half-life | Neomycin: 2-3h (systemic, IM); Bacitracin: 1.5h (systemic, IM); Polymyxin B: 6h (systemic, IV); Hydrocortisone: 1.5-2h (systemic). Topical: not applicable due to minimal absorption. |
| Protein binding | Neomycin: <30% (albumin); Bacitracin: low (<10% probably, not fully characterized); Polymyxin B: ~90% (tissue, not plasma); Hydrocortisone: 90% (corticosteroid-binding globulin, albumin). For topical, irrelevant. |
| Volume of Distribution | Neomycin: 0.25 L/kg (systemic); Bacitracin: ~0.3 L/kg (systemic); Polymyxin B: 0.3 L/kg (systemic); Hydrocortisone: 0.3 L/kg (systemic). Topical: not applicable. |
| Bioavailability | Topical/otic: negligible systemic (<1% for neomycin, bacitracin, polymyxin; hydrocortisone <10% through intact skin, higher through abraded). Oral: neomycin ~3%, bacitracin negligible, polymyxin negligible, hydrocortisone ~100% (but not intended). |
| Onset of Action | Topical: Anti-inflammatory (hydrocortisone) within hours; antibacterial within 24-48h. Otic: Within 24-48h for infection resolution. |
| Duration of Action | Topical: Apply every 6-8h for infection/inflammation. Otic: Continue 7-10 days; clinical improvement within 48h. |
| Molecular Weight | Bacitracin: 1422.69 Da; Neomycin: 614.6 Da; Polymyxin B: 1303.5 Da; Hydrocortisone: 362.46 Da |
Apply 3-4 times daily to affected area as a thin layer. Topical route. Frequency: every 6-12 hours.
| Dosage form | OINTMENT |
| Renal impairment | No systemic absorption expected with topical application. No dose adjustment required. |
| Liver impairment | No systemic absorption expected with topical application. No dose adjustment required. |
| Pediatric use | Apply 3-4 times daily to affected area. Use smallest amount for minimal coverage. Not recommended for prolonged use in children <2 years due to potential adrenal suppression from hydrocortisone. |
| Geriatric use | Same as adult dosing. Use with caution in patients with thin/fragile skin. Avoid prolonged use due to increased risk of skin atrophy and systemic effects. |
| 1st trimester | Avoid in first trimester unless absolutely necessary; topical administration may be acceptable but systemic absorption of neomycin and polymyxin B is minimal. Hydrocortisone may be associated with orofacial clefts in early pregnancy. |
| 2nd trimester | Use only if clearly needed; topical application is preferred. Systemic absorption of neomycin and polymyxin B is low; hydrocortisone may cause fetal growth restriction with prolonged use. |
| 3rd trimester | Avoid prolonged use due to risk of fetal adrenal suppression from hydrocortisone. Topical use for short periods is generally considered acceptable. |
Clinical note
Other nephrotoxic or ototoxic drugs increase risk of toxicity Can cause ototoxicity and nephrotoxicity with systemic use.
| FDA category | Animal |
| Placental transfer | Neomycin and polymyxin B have minimal placental transfer. Hydrocortisone crosses the placenta; its metabolism by placental 11β-HSD2 reduces fetal exposure. |
■ FDA Black Box Warning
None
| Common Effects | topical infections |
| Serious Effects |
Hypersensitivity to any component (bacitracin, neomycin, polymyxin B, hydrocortisone)Perforated tympanic membrane (otic use)Fungal or viral skin infections (e.g., herpes simplex, varicella)
| Precautions | Prolonged use may lead to superinfection, masking of infection, or systemic absorption; neomycin may cause ototoxicity and nephrotoxicity if absorbed significantly; avoid use on large areas of damaged skin, under occlusive dressings, or in patients with impaired renal function. |
| Food/Dietary | No clinically significant food interactions. |
Loading safety data…
| Breastfeeding | Topical application is likely compatible with breastfeeding as systemic absorption is minimal. Avoid application to breast area to prevent infant ingestion. Hydrocortisone at low doses is considered safe; prolonged high-dose use may cause adrenal suppression in infant. |
| Lactation Rating | L2 (Safer) for topical use; avoid on nipples. |
| Teratogenic Risk | Topical administration results in negligible systemic absorption; no well-controlled studies in pregnant women. Animal reproduction studies not available. Neomycin and polymyxin B are not known teratogens. Hydrocortisone: systemic corticosteroids in first trimester associated with cleft palate (risk increase: 1.3–3.4 per 1000). |
| Fetal Monitoring | No specific monitoring required for maternal or fetal effects due to topical route. |
| Fertility Effects | No known effects on fertility from topical administration. |
| Clinical Pearls | Combination product for topical otic and ophthalmic use. Avoid prolonged use due to risk of secondary fungal or bacterial resistance. Hydrocortisone may mask signs of infection. Contraindicated in viral or fungal infections, tympanic membrane perforation (otic use), or known hypersensitivity. Neomycin carries risk of ototoxicity if applied to a perforated eardrum. |
| Patient Advice | Use only as directed; do not use longer than prescribed. · For ear or eye use only; avoid contact with mouth or nose. · Shake well before each use. · Do not share this medication with others. · Stop use and notify your doctor if symptoms worsen or no improvement after several days. |