The combination of topical ceftazidime and aminoglycosides in the treatment of refractory pseudomonal keratitis

Background: Pseudomonal keratitis is a serious and potentially blinding infection. Methods: We treated 12 patients with culture-positive fulminant pseu domonal keratitis with a topical combination of ceftazidime ophthalmic solution (50 mg/ml) and aminoglycosides (14 mg/ml). None of these patients had responded to the standard initial therapy with topical fortified gentamicin or tobramycin (14 mg/ml) combined with cefazolin (50 mg/ml). Results: Substitution of cefazolin by ceftazidime achieved a remarkable clinical improvement during the first 24-48 h of administration in all cases. The average time of healing after initiation of the combination of ceftazidime and fortified aminoglycosides was 21 ± 15 days. No serious side effects accompanied ceftazidime administration. In vitro susceptibility testing showed resistance to gentamicin or tobramycin in 33% of cases (4/12) and sensitivity to ceftazidime in all cases. Conclusions: The combination of ceftazidime, in a 5% solution, and fortified aminoglycosides (1.4%) may be a useful, safe and effective topical therapy for the treatment of pseudomonal keratitis resistant to aminoglycosides.