RESUMEN
BACKGROUND: Selective intestinal decontamination has been proposed to prevent bacterial infection in cirrhosis. AIMS: To evaluate the efficacy of ciprofloxacin as selective intestinal decontaminant. PATIENTS AND METHODS: Quantitative microbiological studies on serial faeces were carried out in 15 cirrhotic patients. Ciprofloxacin was given orally at the starting dose of 250 mg every 12 hours for 7 days followed by a single dose of 250 mg/day from day 7 to day 14 and 125 mg/day for the next 3 weeks. Total stool samples were examined in basal conditions and on days 7, 14, 21, 28 and 35 of treatment and 3 and 7 days after treatment withdrawal. RESULTS: Gram-negative flora was completely eliminated in all patients by ciprofloxacin given at doses of 500 and 250 mg/day. When the drug was tapered to 125 mg/day, Escherichia coli reappeared in stools of 7 patients (antibiotic-resistant in one patient) and Klebsiella oxytoca in two patients (antibiotic-resistant in one patient). Faecal concentration of Group D Streptococcus was significantly increased at the end of therapy (basal mean 7.7 +/- 1.2 log CFU vs post treatment mean 9.6 +/- 0.5 log CFU, p < 0.05) while the faecal concentration of anaerobic flora and Candida albicans showed no change. CONCLUSIONS: Results of this study demonstrate the efficacy of oral ciprofloxacin as a selective intestinal decontaminant and ciprofloxacin 250 mg/day is the recommended dose for maintaining Selective Intestinal Decontamination. However, the risks of inducing antibiotic resistance in Gram-negative flora and promoting overgrowth of Gram-positive flora must be carefully considered in all patients chronically treated with oral quinolones.