Gentamicin and cefsulodin efficacy in a rat abscess model.

The pharmacokinetics and therapeutic efficacy of gentamicin and cefsulodin were studied in an abscess model in the rat induced by Pseudomonas aeruginosa and a foreign body. Both agents reached therapeutic concentrations in the abscess fluid and its ultrafiltrate and persisted longer in the abscess fluid than in blood. Gentamicin did not prevent the development of abscesses or reduce the bacterial inoculum when administered immediately following the induction of the abscesses. Cefsulodin sterilized 82.7 per cent of abscesses in 61.5 per cent of injected rats. Low oxygen tension present in the abscess was probably responsible for the inefficacy of gentamicin in this model, while not significantly diminishing the antibacterial activity of cefsulodin.