Norfloxacin and silver norfloxacin in the treatment of Pseudomonas corneal ulcer in the rabbit.

Norfloxacin is a new synthetic antibiotic with a broad spectrum of activity against gram-positive and gram-negative bacteria, and is more effective than the aminoglycosides against P aeruginosa. In this study norfloxacin was particularly effective in treatment of P aeruginosa infection of the rabbit cornea, and caused no toxicity in normal rabbit eyes after prolonged administration. The addition of silver to norfloxacin enhances its antipseudomonal activity, and broadens its spectrum to include antifungal activity. In this study, silver norfloxacin appears to be the most effective antibiotic against P aeruginosa corneal ulcer in the rabbit. Because of its broad antibacterial spectrum, silver norfloxacin may be useful in the initial treatment of bacterial corneal ulcer before the identity of the bacteria is known. Because of its low toxicity in topical administration, and its antifungal and antibacterial activity, silver norfloxacin may be helpful in prophylaxis against infection in chronic corneal ulcers.