Control of burn wound infections by pefloxacin and its silver derivative

As might be anticipated, strains of Pseudomonas aeruginosa resistant to silver sulfadiazine have appeared. We have found an analogue of nalidixic acid (pefloxacin) which, along with its silver derivative, is highly effective against these resistant strains. In vitro the minimal inhibitory concentrations are 10 to 20 times lower than that of silver sulfadiazine against bacteria. In burned mice and rats infected with silver sulfadiazine resistant pseudomonas strains, mortality in groups receiving topical therapy with pefloxacin and silver pefloxacin is about 10 per cent compared to 80 per cent with silver sulfadiazine (100 per cent in untreated controls). There is little systemic absorption of pefloxacin and no absorption of silver from topical treatment. In addition, silver pefloxacin exhibits higher antifungal activity in vitro.