Oral Antibiotics for SBP Treatment
For acute treatment of SBP, IV antibiotics are the standard of care, but oral ciprofloxacin (500 mg every 12 hours for 5-7 days) can be used for uncomplicated community-acquired SBP in clinically stable patients, or as step-down therapy after 2 days of IV ciprofloxacin. 1, 2
Initial Treatment Approach
The 2021 AASLD guidelines are explicit that IV antibiotics should be started empirically in all patients with an ascites PMN count >250/mm³ 1. However, oral options exist for specific clinical scenarios:
Oral Antibiotic Options for SBP
Oral ciprofloxacin is the primary oral option:
- 500 mg every 12 hours for 5-7 days can be used for uncomplicated SBP 1, 3
- Can be given as step-down therapy: IV ciprofloxacin 200 mg every 12 hours for 2 days, followed by oral ciprofloxacin 500 mg every 12 hours for 5 days 3, 4
- This sequential IV-to-oral regimen achieves 78% infection resolution rates, comparable to full IV therapy 4
Oral ofloxacin is an alternative:
- 400 mg every 12 hours for uncomplicated SBP achieves 84% resolution rates, similar to IV cefotaxime 2
Amoxicillin-clavulanate can be used:
- After initial IV therapy, switch to 500 mg/125 mg every 8 hours orally 5, 2
- Provides coverage for both E. coli and Enterococcus 5
Critical Criteria for Oral Therapy
Oral antibiotics should only be considered in patients who meet ALL of the following:
- Community-acquired SBP (not nosocomial or healthcare-associated) 1, 2
- Clinically stable without sepsis or septic shock 1
- No recent broad-spectrum antibiotic exposure 1
- Uncomplicated presentation without acute kidney injury or severe jaundice 2
- Not on quinolone prophylaxis (if using oral quinolones) 6
Important Caveats and Pitfalls
Do NOT use oral antibiotics as first-line in these situations:
- Nosocomial or healthcare-associated SBP requires broad-spectrum IV coverage (meropenem plus daptomycin) due to 35% MDRO rates 2
- Patients with sepsis, septic shock, or hemodynamic instability require IV third-generation cephalosporins 1, 2
- Recent hospitalization or ICU stay mandates broader initial coverage 1
Essential adjunctive therapy regardless of antibiotic route:
- IV albumin is mandatory: 1.5 g/kg at diagnosis, then 1.0 g/kg on day 3 1, 2
- This reduces hepatorenal syndrome from 30% to 10% and mortality from 29% to 10% 2
Monitoring requirements:
- Repeat paracentesis at 48 hours to confirm PMN count decrease >25% from baseline 1, 2
- If PMN fails to decrease adequately, broaden antibiotic coverage and investigate secondary peritonitis 1
Standard IV Treatment (When Oral is Inappropriate)
For community-acquired SBP requiring IV therapy:
- Cefotaxime 2g IV every 8-12 hours (first-line) 1, 2
- Ceftriaxone 1-2g IV every 12-24 hours (alternative) 3, 2
- Duration: 5-7 days total 1, 3
Secondary Prophylaxis After SBP
After surviving an SBP episode, patients require indefinite prophylaxis: