What is the recommended prophylaxis for Spontaneous Bacterial Peritonitis (SBP)?

Spontaneous Bacterial Peritonitis (SBP) Prophylaxis

Long-term norfloxacin 400 mg once daily is the first-choice prophylaxis for patients who have had an episode of SBP, with ciprofloxacin 500 mg daily being the primary alternative when norfloxacin is unavailable. 1

Indications for SBP Prophylaxis

Secondary Prophylaxis (Prior SBP)

• All patients who survive an episode of SBP should receive indefinite antibiotic prophylaxis until liver transplantation or resolution of ascites due to the high recurrence rate (70% at 1 year) 1
• Without prophylaxis, survival rates are poor (30-50% at 1 year, 25-30% at 2 years) 1

Primary Prophylaxis (No Prior SBP)

Primary prophylaxis should be initiated in patients with:

• Low ascitic fluid protein (<1.5 g/dL) AND advanced liver disease (Child-Pugh score ≥9 with serum bilirubin >3 mg/dL, impaired renal function, or serum sodium <130 mEq/L) 1
• Cirrhotic patients with acute gastrointestinal hemorrhage (short-term prophylaxis for 5-7 days) 2, 1

Recommended Prophylactic Regimens

First-Line Options

• Norfloxacin 400 mg once daily - Most extensively studied regimen, reduces SBP recurrence from 68% to 20% 1

Alternative Options

• Ciprofloxacin 500 mg once daily - Primary alternative when norfloxacin is unavailable 2, 1
• Trimethoprim-sulfamethoxazole 800/160 mg daily - Alternative with similar efficacy to norfloxacin but potentially more adverse events 1
• Rifaximin - Emerging evidence suggests possibly superior efficacy compared to norfloxacin (4% vs 14% 6-month recurrence rate) 2, 1

Special Considerations

Gastrointestinal Bleeding

• All cirrhotic patients with ascites and acute GI hemorrhage should receive short-term antibiotic prophylaxis (5-7 days) 2, 1
• This reduces infection rates, decreases rebleeding risk, and improves survival 1
• This is the most frequently overlooked indication for SBP prophylaxis 3

Monitoring During Prophylaxis

• Regular assessment of renal function every 1-3 months 1
• Periodic cultures to detect resistant organisms 1
• Monitor for adverse effects of antibiotics, including:
  • Fluoroquinolones: musculoskeletal and nervous system side effects
  • Trimethoprim-sulfamethoxazole: rash, hyperkalemia, bone marrow suppression 1

Antibiotic Resistance Concerns

• Quinolone prophylaxis is less effective in patients colonized with multidrug-resistant organisms (MDRO) 2
• Healthcare-associated and nosocomial SBP infections may require alternative antibiotic coverage 4

Liver Transplantation Evaluation

• All patients who survive an episode of SBP should be considered for liver transplantation evaluation, as SBP represents a significant decompensating event with poor long-term prognosis 1

Common Pitfalls in SBP Prophylaxis

• Underutilization of prophylaxis - studies show up to 62% of SBP cases could have been prevented with proper adherence to guidelines 3
• Failure to recognize gastrointestinal hemorrhage as an indication for prophylaxis (44% of preventable cases) 3
• Inadequate long-term outpatient prophylaxis after discharge - only one-third of SBP survivors receive appropriate prophylaxis 3
• Overlooking high bilirubin levels (≥2.5 mg/dL) as an indication for prophylaxis 3

By following these evidence-based recommendations for SBP prophylaxis, clinicians can significantly reduce morbidity and mortality in patients with cirrhosis and ascites.