Penetration of Cefoxitin into Cerebrospinal Fluid of Dogs with and without Experimental Meningitis

Abstract

The penetration of cefoxitin into the cerebrospinalftuid (CSF) after slow intravenous infusion of 50–100 mg/kg over 1 hr was studied in normal dogs and in dogs with meningitis experimentally induced by intrathecal injection of 10⁹Staphylococcus aureus. With healthy dogs the peak CSF concentration of 1 µg of cefoxitinjml was found to correspond with a serum level of 120 µg/ml. With administration of probenecid the CSF level was 1.5 µg of cefoxitin/rnl. Doubling the dose from 50 to 100,mg/kg resulted in a CSF concentration of 2 µg of cefoxitinjml. In the CSF of anhnals with meningitis, a peak concentration of 10 µg of cefoxitinjml was obtained 90 min after the start of the infusion, and 5 µg/ml was still present at 240 min. The peak level in CSF of animals with meningitis was about 10% of the simultaneous level in serum.