Preventive effects of trimethoprim/sulphamethoxazole on experimental staphylococcic pyelonephritis in rats.

108 white rats weighing 170-250 G were given trimethoprim, sulphamethoxazole and the combination trimethoprim 1/sulphamethoxazole orally and parenterally in order to test the preventive effect of these substances on experimental hematogenous pyelonephritis due to Staphylococcus aureus. Oral applications of 48 mg/kg/24h of trimethoprim/sulphamethoxazole prevented abscess formation. Intraperitoneal applications of 48mg/24h of the combination did not seem as effective as the oral applications. On the other hand, there was no difference between the effects of oral and parenteral applications when the doses were 96 mg/kg/24h. The preventive effects of trimethoprim and sulphamethoxazole alone were much less than those observed when the combination trimethoprim/sulphamethoxazole was given. No peritoneal or other tissue damage was observed after intraperitoneal injections of trimethoprim/sulphamethoxazole in rats.