Effect of ciprofloxacin/dexamethasone versus ciprofloxacin/hydrocortisone on lipopolysaccharide-induced experimental otitis media.

OBJECTIVES: The purpose of this study is to compare the effect of topical ciprofloxacin/dexamethasone versus topical ciprofloxacin/hydrocortisone on the outcome of lipopolysaccharide (LPS)­induced otitis media with effusion in chinchillas. STUDY DESIGN: A randomized experimental animal study. SETTING: Jerry L. Pettis Veteran's Medical Center. SUBJECTS AND METHODS: Otitis media with effusion was induced in 5 groups of chinchillas, 6 per group, by injecting 0.3 mL (1 mg/mL) of Salmonella enteric LPS into the superior bullae of each chinchilla with a venting needle in place. Each group was treated with 0.2 mL of test substance at ­2, 24, 48, and 72 hours relative to the 0-hour LPS induction. Group 1 was treated with vehicle control. Groups 2 to 5 received 0.3% ciprofloxacin with either 0.1% dexamethasone (group 2), 1% dexamethasone (group 3), 0.1% hydrocortisone (group 4), or 1% hydrocortisone (group 5). The outcome of each treatment was measured by the amount of middle ear effusion present and mucosal thickness at 120 hours posttreatment. RESULTS: Ciprofloxacin/dexamethasone 1% significantly (P = .0150) reduced middle ear effusion compared with control. Ciprofloxacin/dexamethasone 1% significantly reduced the mucosal thickness when compared with vehicle control (P = .0005), ciprofloxacin/dexamethasone 0.1% (P = .0240), and ciprofloxacin/hydrocortisone 0.1% (P = 1.00). Results also showed a dose-response effect between the ciprofloxacin/dexamethasone concentrations. CONCLUSIONS: This study demonstrated that treatment with a combination of topical ciprofloxacin and corticosteroid decreased the middle ear effusion when compared with the control group and that ciprofloxacin/dexamethasone suspension reduced the severity of LPS-induced experimental otitis media more than ciprofloxacin/hydrocortisone did.