What is the proper dosing and administration of Neomycin (antibiotic) polymyxin otic ear drops for outer ear infections?

Neomycin-Polymyxin B Otic Dosing and Administration for Outer Ear Infections

For outer ear infections (otitis externa), neomycin-polymyxin B otic solution should be administered as four drops into the affected ear canal 3-4 times daily for adults and three drops 3-4 times daily for children, with therapy limited to 10 consecutive days. 1

Proper Administration Technique

The effectiveness of topical ear drops depends greatly on proper administration:

1. Preparation:

   • Thoroughly cleanse and dry the external auditory canal with a sterile cotton applicator 1
   • Have the patient lie with the affected ear upward 1

2. Administration:

   • For adults: Instill 4 drops into the affected ear 3-4 times daily
   • For children: Instill 3 drops into the affected ear 3-4 times daily 1
   • Maintain position with affected ear upward for 5 minutes to facilitate penetration 1
   • Repeat for opposite ear if necessary

3. Alternative wick method:

   • If the ear canal is significantly edematous, a cotton wick may be inserted and saturated with the solution 2, 1
   • Keep the wick moist by adding more solution every 4 hours
   • Replace the wick at least once every 24 hours 1
   • Do not have patients remove the wick themselves unless instructed to do so 2

Duration of Treatment

• Use eardrops for at least 7 days, even if symptoms improve sooner, to prevent relapse 2
• If symptoms persist beyond 7 days, notify your doctor and continue the drops until symptoms resolve for a maximum of 7 additional days 2
• The FDA label specifically limits therapy with neomycin-polymyxin B to 10 consecutive days 1

Enhancing Medication Delivery

To improve penetration of the medication:

• A gentle to-and-fro movement of the ear can help the drops reach their intended destination 2
• Alternatively, press with an in/out movement on the tragus (small piece of cartilage in front of the ear) 2
• If drops do not easily run into the ear canal, the patient may need professional cleaning or wick placement 2

Important Considerations and Precautions

• Perforated eardrum: If the patient tastes the eardrops, it likely indicates a hole or perforation of the eardrum; inform the doctor immediately 2
• Ototoxicity concerns: Neomycin-containing products can cause sensitization in 5-15% of patients with chronic otitis externa 3
• Alternative options: Fluoroquinolone ear drops (e.g., ciprofloxacin 0.2% or ofloxacin 0.3%) are recommended as first-line treatment with cure rates of 77-96% 3 and don't carry the risk of ototoxicity associated with neomycin 4
• Resistance concerns: Studies have shown declining susceptibility to neomycin and polymyxin B among pathogens recovered in otitis externa 5

Pain Management

• Pain relief typically takes approximately 48 hours after starting treatment 3
• Acetaminophen or NSAIDs are recommended for immediate pain relief until the infection is controlled 3
• Pain-relieving (anesthetic) eardrops are not recommended as they can mask symptoms of delayed response to therapy 2

Prevention of Recurrence

• Keep the ear dry during treatment 2
• Avoid scratching or touching the ear and do not insert anything into the ear canal, including cotton-tipped swabs 2, 3
• Cover the ear canal opening with an earplug or cotton with petroleum jelly prior to showering or hair washing 2

When to Seek Further Medical Attention

• If no improvement is seen within 48-72 hours 3
• If drops become painful or unexpected symptoms develop 2
• If symptoms worsen or persist beyond the treatment period 2