Norfloxacin primary prophylaxis of bacterial infections in cirrhotic patients with ascites: a double-blind randomized trial

Background/Aims: Norfloxacin is useful to prevent infections in hospitalized cirrhotic patients with low ascitic fluid protein concentrations. It is also effective in preventing the recurrence of spontaneous bacterial peritonitis. The aim of our study was to determine the efficacy of norfloxacin in the primary prophylaxis of gram-negative bacilli infections in cirrhotic patients with low ascitic fluid protien levels (<15 g/l). Methods: One hundred ans even patients were randomized to receive norfloxacin (400 mg/day; n=53) or placebo (n=54) for 6 months. The patients had no history of infection since cirrhosis diagnosis and no active infection. Results: The probability of gram-negative infection was significantly lower among patients treated with norfloxacin than among those treated with placebo. Six gram-negative bacilli infections occurred in the placebo group and none in the treatment group. Severe infections (spontaneous bacterial peritonitis, neutrocytic ascites and bacteremia) developed in nine patients in the placebo group (17%) and in one patient in the norfloxacin group (2%; p<0.03). There was no between-group difference in the overall rate of infection or in survival. In ten patients from the norfloxacin group, gram-negative bacilli not present in baseline stool cultures were transiently isolated in follow-up cultures. Conclusions: These data show that primary prophylaxis with norfloxacin for 6 months is effective in the prevention of infections caused by gram-negative bacilli in cirrhotic patients with low ascitic fluid total protein levels.