Cortisporin Otic Dosage and Treatment Regimen
For acute otitis externa, instill 4 drops in adults (3 drops in children) into the affected ear 3-4 times daily for a maximum of 10 consecutive days, with the patient lying with the affected ear upward for 5 minutes after instillation. 1
Standard Dosing Protocol
Adults
- Instill 4 drops into the affected ear 3-4 times daily 1
- Treatment duration should be limited to 10 consecutive days maximum 1
- The external auditory canal must be thoroughly cleansed and dried with a sterile cotton applicator before administration 1
Infants and Children
- Instill 3 drops into the affected ear 3-4 times daily due to the smaller capacity of the pediatric ear canal 1
- Same 10-day maximum duration applies 1
Administration Technique
The patient must lie with the affected ear upward during instillation and maintain this position for 5 minutes to facilitate penetration of the drops into the ear canal. 1
- Drops should be instilled along the side of the ear canal until filled 2
- Gentle to-and-fro movement of the pinna may eliminate trapped air 2
- Alternative method includes tragal pumping to aid drop penetration 2
Cotton Wick Method (Alternative)
- A cotton wick may be inserted into the canal and saturated with the solution 1
- Keep the wick moist by adding solution every 4 hours 1
- Replace the wick at least once every 24 hours 1
Critical Contraindications and Warnings
Do NOT use Cortisporin in patients with non-intact tympanic membranes (perforations or tympanostomy tubes) due to significant ototoxicity risk. 2
- Neomycin causes cochlear hair cell damage in 66% of cases when exposed to the middle ear, compared to only 1% with safer alternatives like ofloxacin 3
- Cortisporin produces granulation tissue, effusion, and focal hemorrhage in the middle ear due to topical irritant effects 4
- Neomycin causes contact sensitivity in 13-30% of patients with chronic otitis externa 2
Expected Clinical Response
Patients should demonstrate improvement within 48-72 hours of initiating therapy. 2
- If no improvement occurs within this timeframe, consider treatment failure, allergic contact dermatitis to neomycin, fungal co-infection, or misdiagnosis 2
- Clinical cure rates of 94-95% are achieved when used appropriately for uncomplicated otitis externa 5, 6
Important Clinical Pitfalls
The four-times-daily dosing requirement significantly reduces compliance compared to once-daily alternatives like ofloxacin, which achieves equivalent efficacy with once-daily dosing. 5
- Cortisporin contains ototoxic neomycin that poses serious risks if the tympanic membrane is not intact 2, 3
- The propylene glycol vehicle causes inflammatory responses including granulation tissue formation in the middle ear 4
- Ensure adequate aural toilet before administration, as debris prevents adequate drug penetration 2
Safer Alternative Considerations
For patients with tympanostomy tubes, perforated tympanic membranes, or suspected middle ear involvement, fluoroquinolone otic solutions (ofloxacin 0.3%) are safer alternatives that avoid neomycin's ototoxicity while providing equivalent or superior efficacy with once-daily dosing. 5, 6, 3