What is the recommended duration of prophylaxis for spontaneous bacterial peritonitis?

Duration of Prophylaxis for Spontaneous Bacterial Peritonitis

For patients with a prior episode of spontaneous bacterial peritonitis (SBP), prophylactic antibiotics should be continued indefinitely until liver transplantation or death, unless there is significant improvement in liver function. 1

Secondary Prophylaxis (After an Episode of SBP)

• Patients who survive an episode of SBP have a very high risk of recurrence, with a cumulative 1-year recurrence rate of approximately 70% without prophylaxis 1
• Long-term, indefinite antibiotic prophylaxis is recommended for all patients who have recovered from an episode of SBP until liver transplantation or death 1
• The European Association for the Study of the Liver (EASL) guidelines note that it is uncertain whether prophylaxis could be discontinued in patients showing significant improvement of liver disease, but do not provide specific criteria for discontinuation 1
• The American Association for the Study of Liver Diseases (AASLD) recommends continuous prophylaxis following SBP, with no specified endpoint except liver transplantation 1, 2

Recommended Prophylactic Regimens

• Norfloxacin 400 mg daily is the most extensively studied regimen, reducing the probability of SBP recurrence from 68% to 20% 1
• Since norfloxacin is no longer available in some markets, alternatives include:
  • Ciprofloxacin 500 mg daily 1, 2
  • Trimethoprim-sulfamethoxazole (800/160 mg daily) 2, 3
  • Rifaximin (emerging evidence suggests efficacy with potentially fewer adverse events) 1, 3

Primary Prophylaxis (For High-Risk Patients Without Prior SBP)

• For patients with low ascitic fluid protein (<15 g/L) and advanced liver disease, prophylaxis should be continued indefinitely until liver transplantation or death 1
• The duration of primary antibiotic prophylaxis has not been definitively established in clinical trials 1
• In practice, primary prophylaxis is typically continued indefinitely in high-risk patients until liver transplantation or death 1, 2

Special Considerations

• Increasing bacterial resistance is a significant concern with long-term antibiotic prophylaxis, particularly with quinolones 1, 2
• Patients who develop infection with quinolone-resistant bacteria while on prophylaxis may need to switch to an alternative antibiotic based on susceptibility testing, though formal evidence for this approach is lacking 1
• Regular monitoring for the development of resistant organisms may be prudent in patients on long-term prophylaxis 2, 3
• Prophylactic antibiotics should be used judiciously and reserved only for those at highest risk of infection to minimize development of resistance 1, 4

Pitfalls and Caveats

• There are no randomized controlled trials specifically addressing the optimal duration of prophylaxis for SBP 1
• The decision to continue prophylaxis indefinitely must be balanced against the risk of developing resistant organisms 4, 5
• Despite stable guideline recommendations since 2012, adherence to SBP prophylaxis guidelines remains suboptimal, with only about 55% of patients receiving guideline-concordant management 5
• Patients on long-term prophylaxis should be monitored for adverse effects of antibiotics and development of resistant organisms 2, 3