Indication

Ocular inflammation, Otitis externa

Adult Dose

Ophthalmic\r\nOcular inflammation with suspected or confirmed bacterial infection\r\nAdult: 1-2 drops every 3-4 hrly as indicated. \r\n\r\nOtic/Aural\r\nOtitis externa\r\nAdult: As combination containing neomycin sulfate 3.5 mg as neomycin base, polymyxin B sulfate 10,000 units, hydrocortisone 10 mg (1%) per ml: \r\nInstill 4 drops into affected ear 3-4 times daily; \r\ninstill drop with the affected ear upward and remain in this position for 5 minutes. \r\nAlternatively insert a cotton wick into the canal and saturate wick with solution, add solution every 4 hr to keep wick moist and replace wick at least once daily.

Child Dose

Otic/Aural\r\nOtitis externa\r\nChild: 2-16 yr: As combination containing neomycin sulfate 3.5 mg as neomycin base, polymyxin B sulfate 10,000 units, hydrocortisone 10 mg (1%) per ml: \r\nInstill 3 drops into affected ear 3-4 times daily; instill drop with the affected ear upward and remain in this position for 5 minutes. \r\nAlternatively insert a cotton wick into the canal and saturate wick with solution, add solution every 4 hr to keep wick moist and replace wick at least once daily.

Contraindication

Hypersensitivity to aminoglycosides and any of its components. Pre-existing nerve deafness. TB, fungal or viral infections. Do not use in external eardrum if tympanic membrane is perforated.

Mode of Action

Neomycin, an aminoglycoside with spectrum similar to gentamicin, binds to the 30S subunits of the bacterial ribosome, inhibiting protein synthesis and thereby disrupting DNA synthesis. It is active against many Gram-negative aerobes and some strains of staphylococci. Polymyxin B disrupts bacterial cell membrane and has bactericidal action against most Gram-negative bacilli. It is inactive against Gram-positive bacteria, obligate anaerobes and Neisseria spp. When used together, they are active against Staphylococcus aureus, Escherichia coli, Haemophilus influenzae, Klebsiella-Enterobacter species, Neisseria species, and Pseudomonas aeruginosa but have inadequate coverage against Serratia marcescens and streptococci, including Streptococcus pneumoniae. Hydrocortisone, a corticosteroid with mainly glucocorticoid activity, suppresses inflammatory response.

Precaution

Ophthalmic: Glaucoma; monitor intraocular pressure regularly if used for >10 days.\r\nOtic: Limit use to ≤10 days to reduce risk of ototoxicity. May cause burning and stinging if product enters the middle ear.

Side Effect

Ophthalmic: Irritation, increased intraocular pressure, glaucoma, posterior subcapsular cataract formation, delayed wound healing, secondary infections.

Interaction

Additive toxicity with neurotoxic, ototoxic or nephrotoxic drugs. Increased neuromuscular blockade and possibly respiratory depression with neuromuscular blocking agents if significant amounts of neomycin absorbed significantly.