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

Spontaneous Bacterial Peritonitis Prophylaxis Recommendations

Norfloxacin 400 mg once daily is the first-choice prophylactic antibiotic for spontaneous bacterial peritonitis (SBP) in high-risk patients with cirrhosis and should be continued indefinitely until liver transplantation or resolution of ascites. 1

Indications for SBP Prophylaxis

SBP prophylaxis should be initiated for patients with cirrhosis who have:

1. Prior episode of SBP (secondary prophylaxis)

   • All patients who have recovered from an episode of SBP require indefinite prophylaxis due to high recurrence rates (68% without prophylaxis vs. 20% with prophylaxis) 1

2. High-risk patients without prior SBP (primary prophylaxis):

   • Low ascitic fluid protein (<1.5 g/dL) AND one of the following:
     • Advanced liver disease (Child-Pugh score ≥9 with serum bilirubin >3 mg/dL)
     • Impaired renal function
     • Low serum sodium (<130 mEq/L) 1

3. Acute gastrointestinal hemorrhage

   • Short-term prophylaxis (5-7 days) is recommended regardless of ascites presence 1
   • This is the most frequently overlooked indication for SBP prophylaxis 2

Prophylactic Antibiotic Options

Antibiotic	Dosage	Recommendation
Norfloxacin	400 mg once daily	First choice [1]
Ciprofloxacin	500 mg once daily	Primary alternative [1]
Trimethoprim-sulfamethoxazole	800/160 mg daily	Alternative option, but may cause more adverse events [1]
Rifaximin	400 mg twice daily	Emerging alternative that may be more effective than norfloxacin in secondary prophylaxis [3]

Duration of Prophylaxis

• Secondary prophylaxis: Continue indefinitely until liver transplantation or resolution of ascites 1
• Primary prophylaxis: Long-term use in high-risk patients 1
• GI bleeding: Short-term (5-7 days) 1

Monitoring During Prophylaxis

• Regular assessment of renal function every 1-3 months
• Periodic cultures to detect resistant organisms 1
• Monitor for antibiotic adverse effects, including rare but serious musculoskeletal and nervous system side effects 1

Important Considerations and Pitfalls

1. Medication interactions:

   • Proton pump inhibitors (PPIs) may increase SBP risk and should be restricted to patients with clear indications 1
   • For patients on rifaximin for hepatic encephalopathy, there is insufficient data on whether to add norfloxacin or rely on rifaximin alone 1

2. Antibiotic resistance:

   • Long-term quinolone use may lead to resistant infections
   • Consider discontinuing quinolone prophylaxis if infection with quinolone-resistant bacteria occurs 1
   • Recent studies show increasing prevalence of gram-positive cocci and multi-resistant bacteria in SBP cases 4

3. Compliance and adherence issues:

   • Studies show SBP prophylaxis is underused - 62% of SBP cases could have been prevented with proper adherence to guidelines 2
   • Only one-third of patients who survive SBP receive appropriate long-term outpatient prophylaxis after discharge 2

4. Emerging evidence:

   • Network meta-analyses suggest rifaximin may be more effective than norfloxacin for SBP prophylaxis with fewer adverse events and lower mortality rates 5, 3
   • Weekly ciprofloxacin may be non-inferior to daily norfloxacin with good tolerance and no induced resistance 5

Prognosis

• Patients who have had SBP have poor long-term survival (30-50% at 1 year)
• These patients should be considered for liver transplantation 1
• Despite improvements in infection-related mortality (<10%), hospitalization-related mortality remains high (up to 30%) due to underlying liver disease 6