Clinical question: Does ciprofloxacin administered once weekly prevent spontaneous bacterial peritonitis (SBP) as effectively as daily norfloxacin?
Background: Studies have shown that daily administration of norfloxacin is effective for primary prophylaxis as well as secondary prevention of SBP in patients with cirrhosis and ascites. Prior studies have demonstrated efficacy of weekly ciprofloxacin, but no previous studies have compared the two antibiotics.
Study design: Investigator initiated open-label randomized, controlled trial.
Setting: Seven tertiary hospitals in South Korea.
Synopsis: The investigators enrolled 124 patients aged 20-75 with cirrhosis and ascites, ascitic cell count less than 250/mm3, and either ascitic protein less than 1.5g/dL or a history of spontaneous bacterial peritonitis. The patients were randomized to receive norfloxacin 400 mg daily or ciprofloxacin 750 mg weekly, with routine visits during the 12-month study period.
The primary end point of SBP prevention rates at 1 year were 92.7% (51/55) in the norfloxacin group and 96.5% (55/57) in the ciprofloxacin group (P = .712), which met criteria for noninferiority. Other outcomes included no difference in rates of liver transplantation, infectious complications, hepatorenal syndrome, hepatic encephalopathy, variceal bleeding, and hepatocellular carcinoma. A subgroup analysis of patients at higher risk of developing SBP showed 87% prevention rates for the norfloxacin group and 94% for the ciprofloxacin group, although this result was not statistically significant.
The major limitation of this study is that it was not double blinded, so patients were aware of which medication they were taking. Additionally, almost 10% of the cohort was lost to follow-up, but this was accounted for in the sample-size calculation.
Bottom line: Once weekly administration of ciprofloxacin is not inferior to daily norfloxacin for the prevention of SBP in patients with cirrhosis and low ascitic protein levels and may provide a more cost-effective therapy with greater patient compliance.
Citation: Yim HJ et al. Daily norfloxacin vs weekly ciprofloxacin to prevent spontaneous bacterial peritonitis: A randomized controlled trial..
Dr. Angeli is an assistant professor in the division of hospital medicine, University of New Mexico.