A Cochrane review on topical antibiotics (excluding steroids) for treating chronically discharging ears (CSOM) included 14 studies with a total of 1 724 subjects or ears. CSOM definitions and severity varied; some included otitis externa, mastoid cavity infections and other diagnoses. Studies were generally poorly reported, follow-up was usually short and handling of bilateral disease inconsistent. Topical quinolone antibiotics were better than no drug treatment at clearing discharge at one week: relative risk (RR) was 0.45 (95% confidence interval [CI] 0.34 to 0.59; two trials, n=197). No statistically significant difference was found between quinolone and non-quinolone antibiotics (without steroids) at weeks one or three: pooled RR were 0.89 (95% CI 0.59 to 1.32; three trials, n=402), and 0.97 (0.54 to 1.72; two trials, n=77), respectively. Topical quinolones were significantly better at curing CSOM than antiseptics: RR 0.52 (95% CI 0.41 to 0.67) at one week (three trials, n=263), and 0.58 (0.47 to 0.72) at two to four weeks (four trials, n=519).
Another Cochrane review (abstract , review ) comparing systemic and topical antiseptics or antibiotics for the treatment of chronic suppurative otitis media included 9 studies with 842 analysed participants or ears. Topical quinolones were better than systemic antibiotics at clearing discharge at 1–2 weeks: relative risk (RR) 3.21 (95% confidence interval [CI] 1.88 to 5.49) when comparing to systemic non-quinolone antibiotics (2 trials, N = 116), and 3.18 (1.87 to 5.43) when using systemic quinolone (3 trials, N = 175). Combining systemic and topical quinolone was better than systemic quinolone alone (RR 2.75, 95% CI 1.38 to 5.46; 2 trials, N = 90).