Efficacy of Norfloxacin Prophylaxis to Prevent Spontaneous Bacterial Peritonitis: A Systematic Review and Meta-Analysis

INTRODUCTION:With the emergence of multidrug-resistant organisms, the efficacy of antibiotic prophylaxis to prevent spontaneous bacterial peritonitis (SBP) has been debated. The aim of this study was to assess factors impacting effectiveness of SBP prophylaxis.METHODS:We searched PubMed, Embase, and the Cochrane Registry from inception to May 2019 to identify randomized controlled trials of patients with liver cirrhosis that assessed SBP occurrence/recurrence during antibiotic prophylaxis with the common antibiotic agents. Network meta-analysis was performed, pooling data with regard to incidence rate ratios (IRRs) of SBP, death, or extraperitoneal infections.RESULTS:Overall, 1,626 patients in 12 randomized controlled trials were included. During primary prophylaxis, the incidence rate of SBP and death in the norfloxacin-treated patients was 0.117 and 0.438 per patient-year, respectively, and IRRs of placebo vs norfloxacin were significantly higher (IRR 5.35, 95% confidence interval 1.99-14.38, P = 0.0009 for SBP and IRR 2.04, 95% confidence interval 1.20-3.44, P = 0.008 for death). The efficacy of norfloxacin to prevent SBP, but not death, decreased over time (annual percent change from 1992 to 2015 8.2%, P = 0.019), The positive treatment effect was lower in studies including patients with increased ascites protein (P = 0.021) or exceedingly high serum bilirubin (P = 0.012) levels. Norfloxacin was not superior to other antibiotics. The incidence rate of SBP was 2.5-fold higher in patients treated with norfloxacin as secondary compared with primary prophylaxis. No significant differences between treatment designs were observed in secondary prophylaxis.DISCUSSION:Norfloxacin remained superior to placebo in preventing SBP, yet the efficacy to prevent SBP, not death, decreased over time. Further studies to understand this phenomenon are urgently needed.