What is the recommended prophylaxis for Spontaneous Bacterial Peritonitis (SBP) in high-risk patients?

Recommended Prophylaxis for Spontaneous Bacterial Peritonitis (SBP) in High-Risk Patients

Antibiotic prophylaxis should be administered to high-risk cirrhotic patients with ascites based on three specific risk categories: patients with prior SBP (secondary prophylaxis), patients with acute gastrointestinal hemorrhage, and selected patients without prior SBP but with high-risk features (primary prophylaxis). 1

Secondary Prophylaxis (Prior SBP Episode)

• All patients who have recovered from a previous episode of SBP should receive continuous antibiotic prophylaxis due to the high risk of recurrence (68% at 1 year without prophylaxis) 1, 2
• Recommended regimens:
  • First-line: Norfloxacin 400 mg orally once daily (reduces recurrence from 68% to 20%) 1, 2
  • Alternatives (if norfloxacin unavailable):
    • Ciprofloxacin 500 mg orally once daily 1, 2
    • Trimethoprim-sulfamethoxazole (800/160 mg) orally once daily 2, 3
    • Rifaximin 400 mg twice daily (may be more effective than norfloxacin with 4% vs 14% recurrence rate at 6 months) 1, 4

Prophylaxis During Acute Gastrointestinal Hemorrhage

• All cirrhotic patients with acute gastrointestinal bleeding should receive antibiotic prophylaxis regardless of ascites presence 1
• Recommended regimen:
  • IV ceftriaxone until bleeding resolves and vasoactive drugs are discontinued 1
  • This is preferred over oral quinolones due to increasing quinolone resistance 1

Primary Prophylaxis (No Prior SBP)

• Prophylaxis should be reserved for high-risk patients with all of the following criteria 1, 5:

  • Low ascitic fluid protein (<1.5 g/dL)
  • Plus at least one of:
    • Advanced liver failure (Child-Pugh score ≥9 with serum bilirubin >3 mg/dL)
    • Impaired renal function (serum creatinine ≥1.2 mg/dL, BUN ≥25 mg/dL)
    • Hyponatremia (serum sodium ≤130 mEq/L)

• Recommended regimen:

  • Norfloxacin 400 mg orally once daily (reduces SBP occurrence from 61% to 7%) 2, 5
  • Alternatives: same as for secondary prophylaxis 2, 5

Important Considerations

• Prophylaxis should continue indefinitely until liver transplantation or resolution of ascites 2
• Monitor for quinolone side effects including tendon inflammation, particularly in patients with renal impairment 2, 5
• Bacterial resistance is an increasing concern with long-term fluoroquinolone use 1, 2
• Consider restricting proton pump inhibitor use in patients on SBP prophylaxis as PPIs may increase SBP risk 2, 5
• Regular monitoring of renal function is recommended in patients on prophylactic antibiotics 2

Common Pitfalls

• Failure to identify high-risk patients requiring prophylaxis (particularly those with GI bleeding) 6
• Inadequate duration of prophylaxis after an episode of SBP 6
• Not considering bacterial resistance patterns when selecting prophylactic antibiotics 2, 4
• Overlooking the need for albumin administration (1.5 g/kg at diagnosis and 1g/kg on day 3) during active SBP treatment 1

The evidence strongly supports that appropriate prophylaxis significantly reduces SBP occurrence and improves survival in high-risk cirrhotic patients with ascites 1, 2.