Efficacy of oral ciprofloxacin as selective intestinal decontaminant in cirrhosis

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 250 mg/day is the recommended dose for maintaining Selective Intestinal Decontamination. However, the risks of inducing antibiotic resistance in Gram-positive flora and promoting overgrowth of Gram-positive flora must be carefully considered in all patients chronically treated with oral quinolones.