A fixed-dose combination topical preparation containing an aminoglycoside antibiotic (Neomycin) and a potent glucocorticoid (Dexamethasone). It is primarily used for the treatment of superficial bacterial infections of the eye and external ear canal, where inflammation is a significant component. Neomycin provides bactericidal action against susceptible gram-negative and some gram-positive organisms, while Dexamethasone exerts potent anti-inflammatory, anti-allergic, and immunosuppressive effects to control swelling, redness, and itching.
Adult: Eye: Instill 1-2 drops into the conjunctival sac every 4 to 6 hours. In severe cases, may be used hourly initially, tapering frequency. Ear: Instill 2-3 drops into the affected ear 3-4 times daily.
Note: Shake suspension well before use. Wash hands. Do not touch dropper tip to any surface. For eyes: Tilt head back, pull lower lid down, instill drops, close eye gently for 1-2 minutes. For ears: Lie on side, instill drops, remain positioned for 5 minutes. Do not share medication. Wait at least 5-10 minutes between instilling different eye drops.
Neomycin binds irreversibly to the 30S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis and causing bactericidal effect. Dexamethasone is a potent glucocorticoid that binds to cytoplasmic glucocorticoid receptors, modulating gene transcription. It inhibits phospholipase A2, reducing the production of pro-inflammatory mediators like prostaglandins and leukotrienes, and suppresses migration of polymorphonuclear leukocytes.
Pregnancy: Category C (US FDA). Dexamethasone may cross placenta. Topical use during pregnancy only if potential benefit justifies potential risk to fetus. Avoid large amounts or long-term use. Not recommended in first trimester unless absolutely necessary.
Driving: May cause temporary blurred vision after ophthalmic instillation. Do not drive or operate machinery until vision clears.
| Other Aminoglycosides (Gentamicin, Tobramycin) systemic | Increased risk of ototoxicity and nephrotoxicity | Moderate |
| Loop Diuretics (Furosemide, Ethacrynic acid) | Potentiates ototoxicity of Neomycin | Moderate |
| Neuromuscular Blocking Agents (Succinylcholine, Tubocurarine) | Neomycin may potentiate neuromuscular blockade | Moderate |
| Other Ocular Corticosteroids | Additive risk of IOP rise and cataract | Moderate |
| CYP3A4 Inducers (Phenobarbital, Rifampin) | May reduce Dexamethasone efficacy | Mild |
Same composition (Neomycin (0.5% w/v) + Dexamethasone (0.1% w/v)), different brands: