Dosing Frequency for Neomycin/Polymyxin B/Hydrocortisone Otic Drops
Neomycin/polymyxin B/hydrocortisone otic drops should be administered 3-4 drops four times daily for 7-10 days in the affected ear(s). 1
Standard Dosing Regimen
- Frequency: Four times daily 1, 2
- Drops per dose: 3-4 drops depending on age (3 drops for children, 4 drops for adults) 2, 3
- Duration: 7-10 days of treatment 1, 2
Proper Administration Technique
Before administering drops, the ear canal must be cleared of debris and cerumen to ensure medication reaches infected tissues. 4, 1
Step-by-step administration:
- Warm the bottle in your hands for 1-2 minutes to prevent dizziness 4
- Lie with the affected ear facing upward 4, 1
- Instill drops along the side of the ear canal until filled 1
- Maintain this position for 3-5 minutes 4, 1
- Apply gentle to-and-fro movement of the pinna or press the tragus in/out to eliminate trapped air 4, 1
Important Considerations and Limitations
This regimen is less convenient than newer alternatives. The four-times-daily dosing of neomycin/polymyxin B/hydrocortisone is significantly more burdensome than once-daily fluoroquinolone options, which may impact adherence. 5, 2
Emerging resistance is a concern. Studies from 1999-2000 showed that mean MICs for major pathogens (including Pseudomonas aeruginosa) had increased above the breakpoint for polymyxin B (≥4 μg/ml), indicating declining susceptibility to this combination. 6
Contact sensitivity risk is substantial. Neomycin causes allergic contact dermatitis in 13-30% of patients with chronic otitis externa, which can present as persistent symptoms despite treatment. 4, 1
When This Preparation Should NOT Be Used
Avoid in patients with perforated tympanic membranes or tympanostomy tubes due to ototoxicity risk from neomycin and polymyxin B—use only non-ototoxic fluoroquinolones (ofloxacin 0.3% or ciprofloxacin) instead. 4
Avoid in patients with known neomycin hypersensitivity or history of contact dermatitis to topical antibiotics. 4
Superior Alternative Regimens
Once-daily ofloxacin 0.3% is equally effective with better convenience. Clinical cure rates are equivalent (93.8% vs 94.7%) with once-daily ofloxacin compared to four-times-daily neomycin/polymyxin B/hydrocortisone, but with significantly better adherence (98% compliance). 5, 2
Twice-daily ciprofloxacin/dexamethasone demonstrates superior outcomes. Clinical cure rates at day 18 were significantly higher with ciprofloxacin/dexamethasone compared to neomycin/polymyxin B/hydrocortisone (90.9% vs 83.9%, p=0.0375), with better microbiologic eradication (94.7% vs 86.0%, p=0.0057). 7, 3
Expected Clinical Course
Pain typically improves within 48-72 hours of starting treatment. 4 If no improvement occurs within this timeframe, consider treatment failure due to inadequate drug delivery, allergic contact dermatitis to neomycin, fungal co-infection, or incorrect diagnosis. 4, 1