A single topical agent is clinically equivalent to the combination of topical and oral antibiotic treatment for otitis externa.

Objective: To demonstrate clinical equivalence (statistical noninferiority) of topical ciprofloxacin and hydrocortisone (CHC, Cipro HC) and topical neomycin/polymyxin b/hydrocortisone (NPH, Cortisporin) with systemic amoxicillin (AMX, Amoxil), for treatment of acute otitis externa (AOE).

Design: Randomized, active-control, observer-blind, multicenter trial.

Patients: Altogether, 206 patients were enrolled (CHC, 106; NPH + AMX, 100). Patients were > or =1 year of age, had AOE >2 days with at least mild symptoms, and gave informed consent. All were evaluable for safety, and 151 were evaluable for efficacy.

Interventions: Ciprofloxacin and hydrocortisone 3 drops twice daily for 7 days (adults and children) or NPH 4 drops (adults) or 2 drops (children) with AMX 250 mg (adults and children) 3 times daily for 10 days, as directed in approved product labeling.

Main Outcome Measures: The primary efficacy variable was response to therapy 7 days after treatment ended (test of cure). Secondary variables included time to end of pain, symptom scores (otalgia and tenderness) and microbiological eradication. Noninferiority was declared if the lower confidence limit around the measurement difference was above -10 (nearer zero).

Results: Response to therapy was higher for CHC (95.71% vs 89.83%) but was statistically noninferior (lower confidence limit, -4.98) to NPH + AMX. Median time to end of pain was 6 days for both groups. Noninferiority was declared for symptom scores at all measurement periods and for microbiological eradication. No serious adverse events related to treatment were reported.

Conclusions: Ciprofloxacin and hydrocortisone is clinically equivalent to NPH + AMX for the treatment of AOE in adults and children. However, low systemic exposure, absence of ototoxicity, and less frequent dosing clearly favor Cipro HC.