NEO-SYNALAR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NEO-SYNALAR (NEO-SYNALAR).
Neomycin (aminoglycoside) binds to bacterial 30S ribosomal subunit, inhibiting protein synthesis. Fluocinolone acetonide (corticosteroid) binds to glucocorticoid receptor, inducing anti-inflammatory proteins and suppressing inflammatory mediators.
| Metabolism | Not significantly metabolized topically; absorbed systemically in small amounts. |
| Excretion | Renal (primarily as metabolites): ~80%; biliary/fecal: ~20%. |
| Half-life | Approximately 2-4 hours for the corticosteroid component; clinical effect persists beyond due to cellular actions. |
| Protein binding | ~70% bound primarily to albumin and corticosteroid-binding globulin. |
| Volume of Distribution | 0.5-1.0 L/kg, indicating distribution into total body water. |
| Bioavailability | Topical: minimal systemic absorption (<1%); intranasal: <1% systemic; oral (not typical): ~20%. |
| Onset of Action | Topical: hours to days for anti-inflammatory effect; intranasal: 12-24 hours. |
| Duration of Action | Topical: effect lasts 1-2 days after single application; intranasal: up to 24 hours after dosing. |
| Molecular Weight | 534.6 |
Apply a thin layer to affected area twice daily. Maximum 60 g per week.
| Dosage form | CREAM |
| Renal impairment | No dosage adjustment required for renal impairment due to minimal systemic absorption when used topically. |
| Liver impairment | No dosage adjustment required for hepatic impairment due to minimal systemic absorption when used topically. |
| Pediatric use | Apply a thin layer to affected area twice daily. Use smallest amount needed. Limit to 15 g per week in children under 12 years. |
| Geriatric use | Use with caution due to increased skin fragility. Apply sparingly to affected area twice daily; reduce frequency if irritation occurs. |
| 1st trimester | Avoid during first trimester due to potential teratogenic effects of corticosteroids. |
| 2nd trimester | Use only if clearly needed; prolonged use may cause fetal growth restriction. |
| 3rd trimester | Use with caution; may cause neonatal adrenal suppression if used late in pregnancy. |
Clinical note
Comprehensive clinical and safety monograph for NEO-SYNALAR (NEO-SYNALAR).
| Placental transfer | Corticosteroids cross the placenta; degree depends on potency and formulation. |
| Breastfeeding | Topical application to small areas is unlikely to result in significant systemic absorption. Avoid application to breast or nipple area to prevent infant ingestion. |
| Lactation Rating |
■ FDA Black Box Warning
Neomycin can cause nephrotoxicity and ototoxicity, even with topical use on damaged skin or prolonged use.
| Serious Effects |
Hypersensitivity to any componentUntreated bacterial, fungal, or viral infections at application site
| Precautions | Prolonged use may lead to skin atrophy, striae, and systemic corticosteroid effects., Neomycin may cause allergic contact dermatitis., Avoid use on large body surface areas, open wounds, or occlusive dressings., Monitor for signs of secondary infection worsening. |
| Food/Dietary | None known. No dietary restrictions associated with topical neomycin/fluocinolone. |
| Clinical Pearls |
Loading safety data…
| L3 |
| Teratogenic Risk | Category C. First trimester: No adequately controlled studies; animal studies show potential risk. Second and third trimesters: Prolonged use may cause adrenal suppression in neonate; avoid use for extended periods or high doses. |
| Fetal Monitoring | Monitor for maternal adrenal suppression, hyperglycemia, hypertension, and signs of infection. In neonate, monitor for adrenal suppression if used chronically during third trimester. |
| Fertility Effects | No significant human data; corticosteroids in high doses may impair fertility in animal studies. |
| Neo-Synalar (neomycin sulfate + fluocinolone acetonide) is a topical combination antibiotic and corticosteroid. Avoid use on infected skin lesions without proper diagnosis; neomycin carries a risk of contact sensitization. Limit treatment duration to 2 weeks to minimize corticosteroid-induced skin atrophy and antibiotic resistance. Do not use in patients with known neomycin allergy or viral/fungal infections. |
| Patient Advice | Apply a thin layer to affected area 2-4 times daily, as directed. · Do not use on large areas of skin, broken skin, or for longer than prescribed. · Avoid covering the treated area with bandages or dressings unless instructed. · Report any signs of skin irritation, rash, or worsening infection. · Do not use this medication in the eyes, mouth, or vaginal area. · Inform your doctor if you have a history of neomycin allergy or other antibiotic allergies. |