Eighty cirrhotic patients who had recovered from an episode of spontaneous bacterial
peritonitis were included in a multicenter, double-blind trial aimed at comparing long-term
norfloxacin administration (400 mg/day; 40 patients) vs. placebo (40 patients) in the prevention of spontaneous bacterial
peritonitis recurrence. At entry, both groups were similar with respect to clinical and laboratory data, ascitic fluid
protein and polymorphonuclear concentrations, number of previous episodes of spontaneous bacterial
peritonitis and causative organisms of the index spontaneous bacterial
peritonitis.
Norfloxacin administration produced a selective intestinal decontamination (elimination of aerobic gram-negative bacilli from the fecal flora without significant changes in other microorganisms) throughout the study in six patients in whom the effect of
norfloxacin on the fecal flora was periodically assessed. Fourteen patients from the placebo group (35%) and five from the
norfloxacin group (12%) developed spontaneous bacterial
peritonitis recurrence during follow-up (chi 2 = 5.97; p = 0.014) (mean follow-up period = 6.4 +/- 0.6 mo; range = 1 to 19 mo). Ten of the 14 spontaneous bacterial
peritonitis recurrences in the placebo group and only one of the five spontaneous bacterial
peritonitis recurrences in the
norfloxacin group were caused by aerobic gram-negative bacilli (chi 2 = 8.87; p = 0.0029). The overall probability of spontaneous bacterial
peritonitis recurrence at 1 yr of follow-up was 20% in the
norfloxacin group and 68% in the placebo group (p = 0.0063) and the probability of spontaneous bacterial
peritonitis recurrence caused by aerobic gram-negative bacilli at 1 yr of follow-up was 3% and 60%, respectively (p = 0.0013).(ABSTRACT TRUNCATED AT 250 WORDS)