Medical Information
United States

In order to provide you with relevant and meaningful content we need to know more about you.

Please choose the category that best describes you.

Existe información en español para pacientes y cuidadores, para acceder, haga clic sobre “Select” al lado de “I am a U.S. Patient / Caregiver”.

This content is intended for U.S. Healthcare Professionals. Would you like to proceed?

If you provide additional keywords, you may be able to browse through our database of Scientific Response Documents.

Our scientific content is evidence-based, scientifically balanced and non-promotional. It undergoes rigorous internal medical review and is updated regularly to reflect new information.

ZOSYN®Highlights (piperacillin, tazobactam)


These highlights do not include all the information needed to use ZOSYN safely and effectively. See full prescribing information for ZOSYN.

ZOSYN® (piperacillin and tazobactam) for injection, for intravenous use
ZOSYN® (piperacillin and tazobactam) injection, for intravenous use
Initial U.S. approval: 1993


Dosage and Administration (2)8/2021
Warnings and Precautions, Hemophagocytic Lymphohistiocytosis (5.3)4/2022


ZOSYN is a combination of piperacillin, a penicillin-class antibacterial and tazobactam, a beta-lactamase inhibitor, indicated for the treatment of:

  • Intra-abdominal infections in adult and pediatric patients 2 months of age and older (1.1)
  • Nosocomial pneumonia in adult and pediatric patients 2 months of age and older (1.2)
  • Skin and skin structure infections in adults (1.3)
  • Female pelvic infections in adults (1.4)
  • Community-acquired pneumonia in adults (1.5)

To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZOSYN and other antibacterial drugs, ZOSYN should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. (1.6)


  • If a dose of ZOSYN is required that does not equal 2.25 g, 3.375 g, or 4.5 g, ZOSYN injection in GALAXY Containers is not recommended for use and an alternative formulation of ZOSYN should be considered. (2.1)
  • Adult Patients With Indications Other Than Nosocomial Pneumonia; The usual daily dosage of ZOSYN for adults is 3.375 g every six hours totaling 13.5 g (12.0 g piperacillin/1.5 g tazobactam). (2.2)
  • Adult Patients with Nosocomial Pneumonia: Initial presumptive treatment of patients with nosocomial pneumonia should start with ZOSYN at a dosage of 4.5 g every six hours plus an aminoglycoside, totaling 18.0 g (16.0 g piperacillin/2.0 g tazobactam). (2.3)
  • Adult Patients with Renal Impairment: Dosage in patients with renal impairment (creatinine clearance ≤40 mL/min) and dialysis patients should be reduced, based on the degree of renal impairment. (2.4)
  • Pediatric Patients by Indication and Age: See Table below (2.5)
Recommended Dosage of ZOSYN for Pediatric Patients 2 months of Age and Older, Weighing up to 40 Kg and With Normal Renal Function
AgeAppendicitis and /or PeritonitisNosocomial Pneumonia
2 months to 9 months90 mg/kg (80 mg piperacillin/10 mg tazobactam) every 8 (eight) hours90 mg/kg (80 mg piperacillin/10 mg tazobactam) every 6 (six) hours
Older than 9 months112.5 mg/kg (100 mg piperacillin/12.5 mg tazobactam) every 8 (eight) hours112.5 mg/kg (100 mg piperacillin/12.5 mg tazobactam) every 6 (six) hours
  • Administer ZOSYN by intravenous infusion over 30 minutes to both adult and pediatric patients (2.2, 2.3, 2.4, 2.5).
  • ZOSYN and aminoglycosides should be reconstituted, diluted, and administered separately. Co-administration via Y-site can be done under certain conditions. (2.8)
  • See the full prescribing information for the preparation and administration instructions for ZOSYN for Injection single-dose vials, pharmacy bulk vials and ZOSYN Injection in GALAXY Containers.


  • ZOSYN® for Injection: 2.25 g, 3.375 g, and 4.5 g lyophilized powder for reconstitution in single-dose vials and 40.5 g lyophilized powder for reconstitution in pharmacy bulk vials. (3)
  • ZOSYN® Injection: 2.25 g in 50 mL, 3.375 g in 50 mL, and 4.5 g in 100 mL frozen solution in single-dose GALAXY Containers. (3, 16)


Patients with a history of allergic reactions to any of the penicillins, cephalosporins, or beta-lactamase inhibitors. (4)


  • Serious hypersensitivity reactions (anaphylactic/anaphylactoid) reactions have been reported in patients receiving ZOSYN. Discontinue ZOSYN if a reaction occurs. (5.1)
  • ZOSYN may cause severe cutaneous adverse reactions, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms, and acute generalized exanthematous pustulosis. Discontinue ZOSYN for progressive rashes. (5.2)
  • Hemophagocytic lymphohistiocytosis (HLH) has been reported with the use of ZOSYN. If HLH is suspected, discontinue ZOSYN immediately. (5.3)
  • Hematological effects (including bleeding, leukopenia and neutropenia) have occurred. Monitor hematologic tests during prolonged therapy. (5.4)
  • As with other penicillins, ZOSYN may cause neuromuscular excitability or seizures. Patients receiving higher doses, especially in the presence of renal impairment may be at greater risk. Closely monitor patients with renal impairment or seizure disorders for signs and symptoms of neuromuscular excitability or seizures. (5.5)
  • Nephrotoxicity in critically ill patients has been observed; the use of ZOSYN was found to be an independent risk factor for renal failure and was associated with delayed recovery of renal function as compared to other beta-lactam antibacterial drugs in a randomized, multicenter, controlled trial in critically ill patients. Based on this study, alternative treatment options should be considered in the critically ill population. If alternative treatment options are inadequate or unavailable, monitor renal function during treatment with ZOSYN. (5.6)
  • Clostridioides difficile-associated diarrhea: evaluate patients if diarrhea occurs. (5.8)


The most common adverse reactions (incidence >5%) are diarrhea, constipation, nausea, headache, and insomnia. (6.1)

To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or


  • ZOSYN administration can significantly reduce tobramycin concentrations in hemodialysis patients. Monitor tobramycin concentrations in these patients. (7.1)
  • Probenecid prolongs the half-lives of piperacillin and tazobactam and should not be co-administered with ZOSYN unless the benefit outweighs the risk. (7.2)
  • Co-administration of ZOSYN with vancomycin may increase the incidence of acute kidney injury. Monitor kidney function in patients receiving ZOSYN and vancomycin. (7.3)
  • Monitor coagulation parameters in patients receiving ZOSYN and heparin or oral anticoagulants. (7.4)
  • ZOSYN may prolong the neuromuscular blockade of vecuronium and other non-depolarizing neuromuscular blockers. Monitor for adverse reactions related to neuromuscular blockade. (7.5)


Dosage in patients with renal impairment (creatinine clearance ≤40 mL/min) should be reduced based on the degree of renal impairment. (2.4, 8.6)


Revised: 4/2022

Did you find an answer to your question? Yes No
Didn’t find what you were looking for? Contact us.
Report Adverse Event