Excretion of ciprofloxacin into the large bowel of the rabbit

Abstract

The intestinal elimination of ciprofloxacin in the large bowel was studied in a rabbit model. Segments from the cecum, colon, and sigmoid colon along with their intact blood vessels were isolated and perfused, and their contents were collected over a 90-min period following the administration of a single parenteral dose of 27 mg of ciprofloxacin per kg of body weight. The elimination rates of ciprofloxacin were 0.126 +/- 0.084 micrograms.min-1.cm-2 in the cecum and 0.264 +/- 0.126, 0.11 +/- 0.07, and 0.21 +/- 0.141 micrograms.min-1.cm-2 in the proximal colon, distal colon, and sigmoid colon, respectively. The calculated fraction of ciprofloxacin eliminated in the large bowel was 3% of the parenteral dose administered. The elimination pattern of ciprofloxacin in the large bowel may explain the unusual activity of this fluoroquinolone in modifying the colonic flora.

Ciprofloxacin at low levels disrupts colonization resistance of human fecal microflora growing in chemostats

“…In particular, extended exposure to CI is significantly associated with increased risk of C. difficile-antibiotic associated diarrhea (Lai et al, 1997), a serious and sometimes fatal nosocomial disease. One explanation may be that non-biliary excretion, through the mucosa into the bowel, leads to significant tissue concentrations of CI (Ramon et al, 1994(Ramon et al, , 1996. For example Brismar et al (1990) found 38 lg/g in human colorectal mucosa, a high level possibly inhibitory to members of the normal flora intimately linked by mucin degradation to the intestinal mucosa.…”