The role of rifaximin in the primary prophylaxis of spontaneous bacterial peritonitis in patients with liver cirrhosis.

Background: Primary prophylaxis of spontaneous bacterial peritonitis (SBP) may provide a survival advantage in cirrhotic patients with ascites and has become an integral part of clinical practice. Rifaximin is a poorly absorbable antibiotic with a broad spectrum of antibacterial action and has low risk of introducing bacterial resistance.

Aim: To determine whether rifaximin is associated with decreasing the risk of SBP and improving transplant-free survival in cirrhotic patients with ascites.

Methods: The medical records of all adult patients with liver cirrhosis and large ascites justifying paracentesis evaluated in our clinic (2003 to 2007) were reviewed. Patients were stratified into 2 groups by the use of rifaximin. Patients were excluded if they had received another antibiotic for SBP prophylaxis or had a history of SBP before rifaximin therapy.

Results: A total of 404 patients were included, of whom 49 (12%) received rifaximin. The rifaximin and nonrifaximin groups were comparable with regards to age, sex, and race. The median follow-up time was 4.2 [1.0, 17.1] months. During this time period, 89% of patients on rifaximin remained SBP free compared with 68% of those not on rifaximin (P=0.002). After adjusting for Model of End-Stage Liver Disease score, Child-Pugh score, serum sodium, and ascitic fluid total protein, there was a 72% reduction in the rate of SBP in the rifaximin group (hazard ratio=0.28; 95% confidence interval, 0.11-0.71; P=0.007). The group treated with rifaximin also demonstrated a transplant-free survival benefit compared with those not on rifaximin (72% vs. 57%, P=0.045).

Conclusions: Intestinal decontamination with rifaximin may prevent SBP in cirrhotic patients with ascites. Prospective randomized controlled trials are needed to confirm this finding.