Suppression of colonic microflora by cefoperazone and evaluation of the drug as potential prophylaxis in bowel surgery.

We evaluated the activity of cefoperazone (CPZ) on the intestinal flora in terms of its use as a single prophylactic drug in colon surgery. Twenty-four healthy male volunteers between the ages of 20 and 40 were assigned to receive either CPZ, oral neomycin-erythromycin, or no antibiotics. A mechanical bowel preparation, Golytely, was also given to each of the subjects. With intravenous CPZ, antibiotic levels in the stool ranged from less than 2 to 649 micrograms/ml and the total fecal bacterial counts dropped 3 to 4 log10 CFU/g. Higher levels of CPZ were detected in the stools when an oral dose was added, 1,446 to 5,445 micrograms/ml, and the bacterial counts were reduced maximally 4 to 6 log10 CFU/g. The combination of the oral and intravenous doses produced suppression of the microflora and high levels in blood, all with a single antibiotic.