Activities of cefoxitin in vitro and in vivo: a study in patients with biliary tract infection undergoing percutaneous transhepatic biliary drainage.

Activities of cefoxitin and the effect on killing of bacteria in bile from six patients undergoing percutaneous transhepatic biliary drainage were analyzed in relation to in vitro activities of the drug, with particular reference to the incubation time. The bacteriostatic and bactericidal activities of cefoxitin with short term (6 hr) incubation correlated well with the duration of the effective cefoxitin concentration and the decrease of viable bacteria in bile juice from the patients. These timed in vitro activities can be used as well as the conventional MIC and MBC with the prolonged incubation of 24 hr, in the deductive analysis of bacterial response in vivo.