From the Guidelines
For peritonitis, the recommended antibiotic regimen typically includes broad-spectrum coverage targeting both aerobic and anaerobic bacteria, with a suggested regimen of piperacillin-tazobactam (3.375g IV every 6 hours) or meropenem (1g IV every 8 hours) as single-agent therapy, as recommended by the most recent guidelines 1.
Key Considerations
- Initial empiric therapy should target the polymicrobial nature of peritonitis, which commonly involves enteric gram-negative bacilli, enterococci, streptococci, and anaerobes from the gastrointestinal tract.
- The choice of antibiotics should be based on the underlying clinical condition of the patient, the pathogens presumed to be involved, and the risk factors for major antimicrobial resistance patterns.
- For patients with healthcare-associated peritonitis or risk factors for resistant organisms, consider adding vancomycin (15-20mg/kg IV every 12 hours) to the regimen.
Treatment Duration and Adjustment
- Treatment duration typically ranges from 5-14 days depending on the source control and clinical response.
- Antibiotics should be adjusted based on culture results when available, with a focus on de-escalation of therapy to minimize the risk of resistance and promote antimicrobial stewardship.
Surgical Intervention
- Surgical intervention for source control is equally important alongside antibiotic therapy for successful treatment of peritonitis, as emphasized in the guidelines 2, 1.
Microbiological Testing
- Intraperitoneal specimen collection and microbiological testing, including Gram stain, aerobic and anaerobic culture, and antibiotic susceptibility testing, are crucial for guiding antibiotic therapy and detecting epidemiological changes in resistance patterns 3.
From the FDA Drug Label
Piperacillin and tazobactam for injection, USP is indicated in adults and pediatric patients (2 months of age and older) for the treatment of appendicitis (complicated by rupture or abscess) and peritonitis caused by beta-lactamase producing isolates of Escherichia coli or the following members of the Bacteroides fragilis group: B. fragilis, B. ovatus, B. thetaiotaomicron, or B. vulgatus. Meropenem for injection is indicated for the treatment of complicated appendicitis and peritonitis caused by viridans group streptococci, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacteroides fragilis, B. thetaiotaomicron,and Peptostreptococcusspecies.
Antibiotics for peritonitis:
From the Research
Antibiotic Treatment for Peritonitis
The treatment of peritonitis typically involves the use of antibiotics to manage the infection. The choice of antibiotic regimen depends on various factors, including the severity of the infection, the presence of risk factors for resistance, and local epidemiology 6, 7, 8, 9, 10.
Recommended Antibiotic Regimens
Some studies suggest that the following antibiotic regimens may be effective in treating secondary peritonitis:
- Imipenem 500 mg q6h 8
- Cefepime 1 or 2 g q12h, in combination with metronidazole 8
- Ceftazidime 2 g q8h, in combination with metronidazole 8
- Piperacillin/tazobactam 3.375 g q6h 8
- Tigecycline 50 mg q12h, after a loading dose of 100 mg 8
Considerations for Antibiotic Selection
When selecting an antibiotic regimen, it is essential to consider the following factors:
- Local epidemiology and resistance patterns 6, 8
- Presence of risk factors for resistance, such as previous antibiotic use or colonization with resistant organisms 6
- Severity of the infection and the need for broad-spectrum coverage 7, 9
- Potential for adverse reactions and toxicity 7
Specific Considerations for Spontaneous Bacterial Peritonitis
In the case of spontaneous bacterial peritonitis (SBP), the following considerations apply:
- First-line treatment typically involves the use of quinolones, such as norfloxacin 10
- In cases of multidrug-resistant organisms, second-line therapy may include meropenem or piperacillin/tazobactam 10
- Collection of blood, urine, and ascitic fluid for cultures is crucial for guiding antibiotic therapy 10