Neomycin-Based Ear Drops
Neomycin-containing ear drops include Cortisporin Otic Suspension (neomycin sulfate/polymyxin B sulfate/hydrocortisone), which is a commonly used neomycin-based otic preparation. 1, 2
Available Neomycin-Based Formulations
- Cortisporin Otic Suspension - Contains neomycin sulfate, polymyxin B sulfate, and hydrocortisone
- Neomycin/Polymyxin B/Hydrocortisone - Generic version of Cortisporin
- Other combination products containing neomycin with various antibiotics and corticosteroids
Important Safety Considerations
Ototoxicity Risk
- Neomycin can cause permanent sensorineural hearing loss due to cochlear damage, primarily through destruction of hair cells in the organ of Corti 2
- Risk of ototoxicity increases with prolonged use; therapy should be limited to 10 consecutive days 2
- Experimental studies in animals have shown that neomycin-containing ear drops cause inner and outer hair cell loss, particularly in the basal turn of the cochlea 3
Contraindications
- Should not be used in patients with perforated tympanic membranes due to risk of ototoxicity 4, 2
- Avoid in patients with tympanostomy tubes or history of recent tympanic membrane perforation 4
- Neomycin's acidity may cause burning and stinging in patients with compromised tympanic membranes 2
Hypersensitivity Reactions
- Neomycin may cause cutaneous sensitization with reported prevalence of 13-30% on patch testing in patients with chronic otitis externa 1
- Manifestations include low-grade reddening, swelling, dry scaling, itching, or failure to heal 2
- Contains potassium metabisulfite, which may cause allergic reactions including anaphylaxis in susceptible individuals 2
Alternative Options
- Ofloxacin otic solution is recommended for patients with confirmed or suspected tympanic membrane perforation 4
- Quinolone ear drops (ciprofloxacin, ofloxacin) provide similar efficacy to neomycin-containing preparations without the risk of ototoxicity 5, 6
- Clinical studies show comparable efficacy between once-daily ofloxacin and four-times-daily neomycin/polymyxin B/hydrocortisone for treating otitis externa 5
Administration Guidelines
- Typical dosing for neomycin-containing ear drops is 3-4 drops administered 3-4 times daily for 7-10 days 5, 6
- Proper administration:
- Position patient with affected ear upward
- Instill prescribed number of drops
- Keep ear upward for 3-5 minutes
- Pump the tragus 4 times to facilitate penetration 4
Clinical Efficacy
- Clinical cure rates are similar between neomycin-containing preparations and quinolone ear drops (81-94.7% vs. 86-93.8% respectively) 5, 6
- Both neomycin-containing preparations and quinolone ear drops provide comparable pain relief 5
- Bacteriologic eradication rates are high for both treatment options, particularly against common pathogens like Pseudomonas aeruginosa and Staphylococcus aureus 7
Important Cautions
- Close clinical observation is required for patients using neomycin-containing ear drops 2
- Discontinue promptly if sensitization or irritation occurs 2
- Serious cases of deafness have been reported after treatment with neomycin-containing ear drops in patients with tympanostomy tubes or perforated tympanic membranes 8
- Consider alternatives like ofloxacin or ciprofloxacin otic solutions when treating patients with compromised tympanic membranes 4