Is there evidence to support the use of piperacillin-tazobactam for the treatment of necrotizing pancreatitis?

Background
Acute pancreatitis, characterized by acute inflammation of the pancreas, represents one of the most frequent gastrointestinal conditions requiring hospitalization in the United States.1 Approximately 20% of patients with acute pancreatitis develop complications such as pancreatic necrosis. Necrotizing pancreatitis is characterized by the absence of contrast flow within the pancreas on imaging studies.2 Pancreatic and peripancreatic necrosis becomes infected in an estimated 20% to 40% of individuals with severe acute pancreatitis and is associated with progressive organ dysfunction.3 Mortality due to infected pancreatic necrosis may reach 30%.4,5

The management of necrotizing pancreatitis depends on whether the necrotic tissue is infected or sterile.2 Clinicians evaluate the patient’s clinical presentation, timing of symptom onset, and imaging findings to determine the presence of infection. Infection is suspected when cross-sectional imaging reveals gas within a pancreatic or peripancreatic collection.4 Additional clinical features suggestive of infected necrosis include fever, bacteremia, worsening leukocytosis, persistent systemic illness, or overall clinical deterioration. Given the significant risk of organ failure and mortality, management of pancreatic necrosis places substantial emphasis on the prompt treatment of suspected or confirmed infection.1,3,4 Therefore, antibiotics play a central role in the management of infected necrotizing pancreatitis.

Guideline recommendations on antimicrobial therapy for necrotizing pancreatitis
The American Gastroenterological Association (AGA) issued an updated guideline in 2020 regarding the management of pancreatic necrosis. In cases where infected necrosis is suspected, the AGA recommends initiating broad-spectrum intravenous antibiotics with good pancreatic penetration: carbapenems, quinolones, metronidazole, and third- or higher-generation cephalosporins.4 The 2024 American College of Gastroenterology (ACG) guideline on the management of acute pancreatitis provides similar guidance.1 According to the ACG, for most clinically stable patients, initial management of infected necrosis should involve a 30-day course of antibiotics prior to surgical intervention to allow further organization of the inflammatory process. Antibiotic therapy may be initiated when infection is suspected while awaiting microbiologic confirmation, though its role is best established in cases of confirmed infection. When infection is confirmed, either through positive blood/body fluid cultures or the presence of gas within the necrotic collection, the indication for antimicrobial therapy is clear. Given that infection typically seeds the necrotic tissue and that drug penetration into necrosis can be limited, antibiotics with demonstrated necrotic tissue penetration, including carbapenems, quinolones, cephalosporins, and metronidazole, are recommended. Neither the AGA or ACG guideline includes piperacillin-tazobactam among the suggested agents.1,4

The World Society of Emergency Surgery (WSES) published guidelines in 2019 for the management of severe acute pancreatitis.3 For patients with infected necrosis, the WSES recommends using antibiotics with proven ability to penetrate pancreatic necrotic tissue. Quinolones (ciprofloxacin and moxifloxacin) and carbapenems demonstrate favorable pancreatic tissue penetration and provide excellent anaerobic coverage. However, due to the high global prevalence of resistance to quinolones, their use should be avoided if possible and reserved for patients with beta-lactam allergies. Similarly, carbapenems should be used judiciously, given the increasing incidence of carbapenem-resistant Enterobacteriaceae, and are best reserved for patients who are critically ill. Metronidazole, which offers predominantly anaerobic coverage, also exhibits good pancreatic penetration. Acylureidopenicillins (including piperacillin-tazobactam) and third-generation cephalosporins achieve intermediate pancreatic tissue penetration and provide effective coverage against gram-negative organisms, generally meeting the minimum inhibitory concentration (MIC) requirements for gram-negative pathogens commonly found in pancreatic infections. Among these agents, piperacillin-tazobactam is notable for additionally providing coverage against gram-positive bacteria and anaerobes.

Evidence review of piperacillin-tazobactam for necrotizing pancreatitis
There has been interest in non-carbapenem antipseudomonal agents, including piperacillin-tazobactam, as carbapenem-sparing options in infected necrotizing pancreatitis.2 However, clinical studies evaluating piperacillin-tazobactam for the treatment of infected necrotizing pancreatitis are limited.

A 2024 cohort study is the first and only clinical comparison to date between piperacillin-tazobactam and a carbapenem (meropenem) for the treatment of infected necrotizing pancreatitis.6 This multicenter, retrospective cohort study conducted across 3 institutions included 63 patients with infected pancreatic necrosis who received either meropenem or piperacillin-tazobactam between January 2015 and December 2020. The primary outcome, 90-day clinical failure (composite of mortality and infection recurrence), occurred in 33% of patients in the meropenem group and 50% of patients in the piperacillin-tazobactam group, but the results were not statistically significant (odds ratio, 1.98; 95% confidence interval, 0.57 to 7.01; p=0.259). The investigators note that the study also did not achieve the prespecified statistical power required to demonstrate non-inferiority of piperacillin-tazobactam relative to meropenem. There were also notable differences between treatment groups. Patients receiving meropenem had a significantly higher baseline Beside Index Severity in Acute Pancreatitis (BISAP) score, which may reflect earlier identification of individuals at elevated risk for in-hospital mortality from pancreatitis. No patients in the piperacillin-tazobactam group required ICU admission, whereas 27% of those receiving meropenem were admitted to the ICU. Furthermore, infectious diseases consultation was significantly more frequent among patients treated with meropenem (89% versus 61%). Collectively, the higher BISAP scores, greater number of ICU admissions, and increased rate of infectious diseases consultation suggest that the meropenem group comprised a more critically ill patient population. Although the authors suggested that piperacillin-tazobactam may be used as a carbapenem-sparing option, these aforementioned limitations hinder the ability to draw definitive clinical conclusions.

A prior study evaluated the tissue penetration of piperacillin-tazobactam into pancreatic necrosis in patients who received intravenous infusions of 4.5 g every 8 hours for 14 to 21 days.7 A total of 15 patients were evaluated, and the average necrotic tissue concentration was 120 mg/kg (standard deviation, ±34). A review of pharmacokinetic data highlighted that this concentration was substantially higher than those reported in earlier studies measuring piperacillin or various carbapenems.2 Notably, the study was conducted after multiple doses and exclusively included patients with confirmed infected necrotizing pancreatitis, suggesting that these findings may be more reliable than studies involving a more heterogeneous population or single-dose antibiotic administration.

Conclusion
Current guideline recommendations for the management of infected necrotizing pancreatitis emphasize the use of antibiotics with well-established pancreatic tissue penetration.1,3,4 The WSES guideline acknowledges piperacillin-tazobactam as a potential option due to its broad-spectrum activity against gram-negative, gram-positive, and anaerobic organisms, as well as its demonstrated penetration into necrotic pancreatic tissue.3 However, clinical evidence supporting piperacillin-tazobactam remains limited. The only available cohort study comparing piperacillin-tazobactam with meropenem did not show statistically significant differences in 90-day clinical failure; however, methodological limitations, including small sample size, retrospective design, and differences in baseline disease severity, prevent definitive conclusions.6 Overall, piperacillin-tazobactam may serve as a carbapenem-sparing option in selected patients, but high-quality prospective studies are needed to clarify its efficacy and safety relative to other antibiotics in infected necrotizing pancreatitis.

References

  1. Tenner S, Vege SS, Sheth SG, et al. American College of Gastroenterology guidelines: management of acute pancreatitis. Am J Gastroenterol. 2024;119(3):419-437. doi:10.14309/ajg.0000000000002645
  2. Maguire C, Agrawal D, Daley MJ, Douglass E, Rose DT. Rethinking carbapenems: a pharmacokinetic approach for antimicrobial selection in infected necrotizing pancreatitis. Ann Pharmacother. 2021;55(7):902-913. doi:10.1177/1060028020970124
  3. Leppäniemi A, Tolonen M, Tarasconi A, et al. 2019 WSES guidelines for the management of severe acute pancreatitis. World J Emerg Surg. 2019;14:27. doi:10.1186/s13017-019-0247-0
  4. Baron TH, DiMaio CJ, Wang AY, Morgan KA. American Gastroenterological Association clinical practice update: management of pancreatic necrosis. Gastroenterology. 2020;158(1):67-75.e1. doi:10.1053/j.gastro.2019.07.064
  5. Tan HL, Zhao Y, Chua DW, et al. Comparison of treatment approaches for infected necrotizing pancreatitis: a systematic review and network meta-analysis. J Gastrointest Surg. 2025;29(9):102152. doi:10.1016/j.gassur.2025.102152
  6. Racketa S, Gandhi K, Lambie M. Meropenem versus piperacillin-tazobactam for the treatment of pancreatic necrosis. Diagn Microbiol Infect Dis. 2024;109(2):116209. doi:10.1016/j.diagmicrobio.2024.116209
  7. Otto W, Komorzycki K, Krawczyk M. Efficacy of antibiotic penetration into pancreatic necrosis. HPB (Oxford). 2006;8(1):43-48. doi:10.1080/13651820500467275

Prepared by:
Honey Joseph, PharmD, BCPS
Clinical Assistant Professor, Drug Information Specialist
University of Illinois at Chicago College of Pharmacy

December 2025

The information presented is current as of November 14, 2025. This information is intended as an educational piece and should not be used as the sole source for clinical decision-making.