Intestinal microflora changes induced by ciprofloxacin and treatment of portal-systemic encephalopathy (PSE).

The modifications of colon microflora in 14 patients under oral ciprofloxacin therapy for intercurrent UTIs or RTIs, at the dose of 250 mg b.i.d. or 500 mg o.d. were examined. All patients were affected by liver cirrhosis. A marked decrease in enterobacteria with both doses was noticed in the first few days, with a complete disappearance from days 3-6 of therapy and a return to normal within 2 weeks after interruption of treatment. Gram-positive and Gram-negative aerobic and anaerobic flora were not affected significantly. As a consequence of these results, the treatment of six patients affected by PSE (grade 2-3) was studied, testing the colon microflora changes, the presence of circulating endotoxins and blood ammonium levels before, during and after 12 days of therapy. A marked reduction or suppression of enterobacteria was observed, and a prompt normalization of blood ammonium levels, the disappearance of circulating endotoxins and a clear clinical improvement in 5 out of 6 patients.