From the Guidelines
For intra-abdominal abscess, the recommended dose of Zosyn (piperacillin-tazobactam) is 3.375 grams administered intravenously every 6 hours for adults with normal renal function. This dosage is based on the guidelines by the Surgical Infection Society and the Infectious Diseases Society of America, as outlined in the study published in Clinical Infectious Diseases 1.
Key Considerations
- The dose may be increased to 3.375 g every 4 h or 4.5 g every 6 h for Pseudomonas aeruginosa infection, as indicated in the study 1.
- Each dose should be infused over 30 minutes to minimize the risk of adverse reactions.
- The typical duration of therapy is 7-14 days, depending on the clinical response and source control measures.
Dose Adjustments
- For patients with renal impairment, dose adjustment is necessary:
- For creatinine clearance 20-40 mL/min, use 2.25 grams every 6 hours.
- For clearance <20 mL/min, use 2.25 grams every 8 hours.
Rationale
Zosyn provides broad-spectrum coverage against many gram-positive, gram-negative, and anaerobic bacteria commonly found in intra-abdominal infections. The tazobactam component inhibits beta-lactamases that would otherwise inactivate piperacillin, making this combination effective against many resistant organisms. Surgical drainage of the abscess is typically necessary alongside antibiotic therapy for optimal treatment outcomes, as emphasized in the guidelines 1.
From the FDA Drug Label
In a prospective, randomized, comparative, open-label clinical trial of pediatric patients, 2 to 12 years of age, with intra-abdominal infections (including appendicitis and/or peritonitis), 273 patients were treated with piperacillin and tazobactam 112.5 mg/kg given IV every 8 hours
The dose of Zosyn (piperacillin/tazobactam) for an intra-abdominal abscess is 112.5 mg/kg given IV every 8 hours in pediatric patients 2 to 12 years of age 2.
From the Research
Dosing Information for Zosyn (Piperacillin/Tazobactam)
- The dose of Zosyn (piperacillin/tazobactam) for an intra-abdominal abscess is typically 4g/0.5g every 8 hours, as seen in studies comparing its efficacy to other antibiotics 3, 4.
- This dosing regimen has been shown to be effective in treating intra-abdominal infections, including those caused by gram-negative aerobes and anaerobes 5.
- In one study, piperacillin/tazobactam 4g/0.5g every 8 hours was compared to imipenem/cilastatin 500mg/500mg every 6 hours, and both regimens were found to be equally effective in treating intra-abdominal infections 3.
- Another study compared piperacillin/tazobactam 4g/0.5g every 8 hours to cefuroxime 1.5g every 8 hours plus metronidazole 1.5g every 24 hours, and found both regimens to be effective in treating intra-abdominal infections 4.
Efficacy of Piperacillin/Tazobactam
- Piperacillin/tazobactam has been shown to be effective in treating a range of intra-abdominal infections, including perforated or abscessed appendicitis 6.
- The antibiotic has a broad spectrum of activity, including against gram-negative rods and anaerobes, and reaches therapeutic levels rapidly after parenteral administration 5.
- In one study, piperacillin/tazobactam was found to provide adequate concentrations in all except the largest abscesses, making it a suitable option for treating intra-abdominal infections 7.