SBP Prophylaxis in Patients with Cirrhosis and Ascites
Patients with cirrhosis and ascites require antibiotic prophylaxis for spontaneous bacterial peritonitis (SBP) if they have a history of previous SBP episode, low ascitic fluid protein, or acute gastrointestinal bleeding. 1, 2
Indications for SBP Prophylaxis
Secondary Prophylaxis
- All patients who have recovered from an episode of SBP should receive continuous prophylaxis with norfloxacin 400 mg daily or ciprofloxacin 500 mg daily 3, 1
- Without prophylaxis, the recurrence rate of SBP at 1 year is approximately 70%, and mortality at 1 year after an episode of SBP is 50-70% 1, 2
- Secondary prophylaxis with norfloxacin reduces the probability of SBP recurrence from 68% to 20% 3, 1
Primary Prophylaxis
- Patients with low ascitic fluid protein (<15 g/L) and one of the following should receive primary prophylaxis 4, 2:
- Child-Pugh score ≥9 with serum bilirubin ≥3 mg/dL
- Impaired renal function
- Hyponatremia (serum sodium ≤130 mEq/L)
- Primary prophylaxis with norfloxacin reduces the one-year probability of developing SBP from 61% to 7% and improves three-month survival 4, 5
Gastrointestinal Bleeding
- All cirrhotic patients with gastrointestinal hemorrhage should receive antibiotic prophylaxis, as bacterial infection occurs in 25-65% of these patients 3, 2
- Antibiotic prophylaxis has been shown to prevent infection and decrease rebleeding rates in patients with gastrointestinal bleeding 3
Recommended Antibiotic Regimens
First-line Options
- Norfloxacin 400 mg orally once daily is the most extensively studied agent for SBP prophylaxis 1, 2
- Ciprofloxacin 500 mg orally once daily is an acceptable alternative, especially in regions where norfloxacin availability is limited 3, 2
Alternative Options
- Co-trimoxazole (800 mg sulfamethoxazole and 160 mg trimethoprim) once daily can be used as an alternative for patients who cannot tolerate fluoroquinolones 1
Important Considerations and Monitoring
- All patients with a history of SBP should be considered for liver transplantation evaluation due to poor long-term survival (30-50% at 1 year, 25-30% at 2 years) 3, 1
- Regular monitoring of renal function is recommended in patients on prophylactic antibiotics 1, 4
- Long-term quinolone prophylaxis may increase the risk of gram-positive bacterial infections, including methicillin-resistant Staphylococcus aureus 3, 2
- Bacterial resistance is an increasing concern with long-term fluoroquinolone use, and local bacterial resistance patterns should be considered when selecting prophylactic antibiotics 1, 2
Clinical Pitfalls
- Failure to recognize high-risk patients who would benefit from prophylaxis can lead to preventable episodes of SBP and increased mortality 4, 5
- Low ascitic fluid protein (<15 g/L) is a significant risk factor for SBP development and should prompt consideration of prophylaxis in patients with other risk factors 6, 7
- Proton pump inhibitor use should be restricted in cirrhotic patients on SBP prophylaxis, as PPIs may increase SBP risk 1
- Weekly ciprofloxacin regimens (as opposed to daily) may lead to higher rates of quinolone-resistant organisms 1, 8