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

Spontaneous Bacterial Peritonitis (SBP) Prophylaxis Recommendations

Norfloxacin 400 mg daily is the first-line recommendation for SBP prophylaxis in high-risk patients, with ciprofloxacin 500 mg daily as an acceptable alternative when norfloxacin is unavailable. 1

Patient Selection for SBP Prophylaxis

Secondary Prophylaxis

• All patients who have recovered from an episode of SBP should receive prophylaxis due to high recurrence rates (approximately 70% at one year without prophylaxis) 2
• These patients should be considered for liver transplantation evaluation due to poor long-term survival (30-50% at 1 year, 25-30% at 2 years) 2, 1

Primary Prophylaxis

Primary prophylaxis should be offered to high-risk patients with:

• Low ascitic fluid protein (<1.5 g/dL) AND one of the following: 1
  • Advanced liver failure
  • Impaired renal function
  • Hyponatremia

Patients with Gastrointestinal Bleeding

• All cirrhotic patients with ascites and gastrointestinal bleeding should receive antibiotic prophylaxis 2, 1

Prophylactic Antibiotic Options

First-Line Options:

• Norfloxacin 400 mg once daily - Reduces SBP recurrence from 68% to 20% and decreases gram-negative bacterial infections from 60% to 3% 2, 1
• Ciprofloxacin 500 mg once daily - Commonly used in UK centers where norfloxacin availability is limited 2, 1

Alternative Options:

• Trimethoprim-sulfamethoxazole 800/160 mg daily - Shown to significantly reduce SBP incidence compared to placebo 1
• Rifaximin 550 mg twice daily - Recent evidence shows it may be particularly effective for secondary prophylaxis, with significantly lower SBP recurrence compared to norfloxacin (7% vs 39%) 3

Duration of Prophylaxis

• Prophylaxis should generally be continued indefinitely until liver transplantation or resolution of ascites 1

Monitoring Recommendations

• Regular assessment for signs of infection despite prophylaxis
• Monitor renal function every 1-3 months
• Periodic cultures to detect resistant organisms
• Vigilance for adverse drug effects, particularly with fluoroquinolones 2, 1

Important Considerations and Potential Pitfalls

Antibiotic Resistance

• Long-term quinolone prophylaxis may lead to increased gram-positive bacterial infections (79%), including methicillin-resistant Staphylococcus aureus, compared with predominantly gram-negative infections (67%) in those not on prophylaxis 2
• Consider local bacterial resistance patterns when selecting antibiotics 1

Fluoroquinolone Safety Concerns

• The MHRA issued updated guidance in 2019 on fluoroquinolone antibiotics due to rare reports of disabling side effects affecting musculoskeletal and nervous systems 2
• Renal impairment increases this risk; discontinue treatment at first sign of tendon pain or inflammation 2

Weekly vs Daily Dosing

• While some evidence suggests weekly ciprofloxacin may be as effective as daily norfloxacin for SBP prevention 4, current guidelines still recommend daily dosing regimens 2, 1

Probiotics

• Adding probiotics to norfloxacin does not improve efficacy in SBP prevention 5

SBP prophylaxis significantly reduces morbidity and mortality in high-risk cirrhotic patients with ascites, and the benefits generally outweigh the risks in appropriately selected patients.