Should patients with a history of Spontaneous Bacterial Peritonitis (SBP) be on prophylaxis?

Prophylaxis for Patients with History of Spontaneous Bacterial Peritonitis

Patients with a prior episode of Spontaneous Bacterial Peritonitis (SBP) should receive indefinite antibiotic prophylaxis until liver transplantation or resolution of ascites due to the very high risk of recurrence (approximately 70% at 1 year without prophylaxis). 1, 2

Rationale for Secondary Prophylaxis

• Without prophylaxis, patients who survive an episode of SBP have:

  • 70% cumulative recurrence rate at 1 year 1
  • Only 30-50% survival at 1 year 1
  • 25-30% survival at 2 years 1

• Landmark randomized controlled trials have demonstrated:

  • Norfloxacin reduced SBP recurrence from 68% to 20% 1
  • Particularly effective in preventing gram-negative bacterial infections 1

Recommended Prophylactic Regimens

For patients with prior SBP, options include:

1. First choice: Oral ciprofloxacin 500 mg daily 1, 2

   • Reasonable alternative to norfloxacin (which was withdrawn from US market in 2014) 1

2. Alternatives:

   • Trimethoprim-sulfamethoxazole 800/160 mg daily 1, 2
   • Rifaximin (emerging evidence suggests possibly superior efficacy with 4% vs 14% 6-month recurrence compared to norfloxacin) 1

Important Considerations and Monitoring

• Duration: Continue indefinitely until liver transplantation or resolution of ascites 2
• Transplant evaluation: All patients who survive an episode of SBP should be considered for liver transplantation evaluation 3
• Monitoring:
  • Regular renal function assessment every 1-3 months 2
  • Periodic cultures to detect resistant organisms 2
  • Vigilance for adverse effects of long-term antibiotic use 2

Emerging Challenges

• Antibiotic resistance: Long-term prophylaxis has led to increasing gram-positive and multi-drug resistant organisms 1, 2, 3

  • Quinolone prophylaxis is less effective in patients colonized with multi-drug resistant organisms 1
  • Consider alternative antibiotics if infection develops with resistant bacteria 1

• Adverse effects:

  • Fluoroquinolones: Rare but serious musculoskeletal and nervous system side effects 1, 2
  • Trimethoprim-sulfamethoxazole: Rash, hyperkalemia, bone marrow suppression 2

Clinical Implementation Gap

Despite clear guidelines, SBP prophylaxis remains underutilized:

• Only one-third of patients who survive SBP receive appropriate long-term prophylaxis after discharge 4
• 62% of SBP cases in one study were potentially preventable by adhering to guidelines 4
• Only 55% of patients receive guideline-concordant management 5

Conclusion

The evidence strongly supports secondary prophylaxis for all patients with prior SBP. The mortality benefit and reduction in recurrence rates outweigh the risks of long-term antibiotic use. Ciprofloxacin is currently the most widely recommended option in the US, with trimethoprim-sulfamethoxazole and rifaximin as reasonable alternatives.