Trimethoprim-sulfamethoxazole versus norfloxacin in the prophylaxis of spontaneous bacterial peritonitis in cirrhosis.

BACKGROUND The prognosis of patients with chronic liver disease and spontaneous bacterial peritonitis is poor, being of great importance its prevention. AIM To compare the effectiveness of trimethoprim-sulfamethoxazole versus norfloxacin for prevention of spontaneous bacterial peritonitis in patients with cirrhosis and ascites. PATIENTS AND METHODS Fifty seven patients with cirrhosis and ascites were evaluated between March 1999 and March 2001. All of them had a previous episode of spontaneous bacterial peritonitis or had ascitic fluid protein concentration < or = 1 g/dL and/or serum bilirubin > or = 2.5 mg/dL. The patients were randomly assigned to receive either 800/160 mg/day of trimethoprim-sulfamethoxazole 5 days a week or 400 mg of norfloxacin daily. The mean time of observation was 163 days for the norfloxacin group and 182 days for the trimethoprim-sulfamethoxazole group. In the statistical analysis, differences were considered significant at the level of 0.05. RESULTS According to the inclusion criteria, 32 patients (56%) were treated with norfloxacin and 25 (44%) with trimethoprim-sulfamethoxazole. Spontaneous bacterial peritonitis occurred in three patients receiving norfloxacin (9.4%) and in four patients receiving trimethoprim-sulfamethoxazole (16.0%). Extraperitoneal infections occurred in 10 patients receiving norfloxacin (31.3%) and in 6 patients receiving trimethoprim-sulfamethoxazole (24.0%). Death occurred in seven patients (21.9%) who received norfloxacin and in five (20.0%) who received trimethoprim-sulfamethoxazole. Side effects occurred only in the trimethoprim-sulfamethoxazole group. CONCLUSION In spite of the reduced number of patients and time of observation, trimethoprim-sulfamethoxazole and norfloxacin were equally effective in spontaneous bacterial peritonitis prophylaxis, suggesting that trimethoprim-sulfamethoxazole is a valid alternative to norfloxacin.