What is the recommended dosing for Zoysn (generic name not specified)?

Zosyn (Piperacillin-Tazobactam) Dosing

For adults with most infections, administer Zosyn 3.375 g intravenously every 6 hours; for nosocomial pneumonia, increase to 4.5 g every 6 hours plus an aminoglycoside. 1

Standard Adult Dosing

The usual daily dosage for adults is 3.375 g (3 g piperacillin/0.375 g tazobactam) every 6 hours, totaling 13.5 g daily, for most indications including intra-abdominal infections, skin and soft tissue infections, female pelvic infections, and community-acquired pneumonia. 1

Nosocomial Pneumonia Dosing

• For nosocomial pneumonia specifically, use 4.5 g (4 g piperacillin/0.5 g tazobactam) every 6 hours plus an aminoglycoside, totaling 18 g daily. 1
• This higher dose is critical for adequate coverage of resistant organisms commonly encountered in hospital-acquired infections 1

Pediatric Dosing (≥2 Months of Age)

Dosing varies by age and indication: 1

For Appendicitis/Peritonitis:

• Ages 2-9 months: 90 mg/kg (80 mg piperacillin/10 mg tazobactam) every 8 hours 1
• Ages >9 months: 112.5 mg/kg (100 mg piperacillin/12.5 mg tazobactam) every 8 hours 1

For Nosocomial Pneumonia:

• Ages 2-9 months: 90 mg/kg every 6 hours 1
• Ages >9 months: 112.5 mg/kg every 6 hours 1

Renal Impairment Adjustments

Dosage reduction is mandatory for creatinine clearance ≤40 mL/min and dialysis patients, based on degree of renal impairment. 1

• The specific adjusted doses depend on the severity of renal dysfunction and should be calculated based on creatinine clearance 1
• This is particularly important given the increased risk of neurotoxicity and seizures in patients with renal impairment receiving higher doses 1

Administration Guidelines

Administer all doses by intravenous infusion over 30 minutes for both adults and pediatric patients. 1

Critical Compatibility Information:

• Zosyn and aminoglycosides must be reconstituted, diluted, and administered separately 1
• Y-site co-administration with amikacin and gentamicin is possible only under specific conditions with particular doses, concentrations, and diluents 2
• The reformulated product allows Y-site administration with certain aminoglycosides and use of Lactated Ringer's solution for admixture preparation 2

Important Clinical Considerations

Nephrotoxicity Risk:

When combined with vancomycin, Zosyn significantly increases acute kidney injury risk (risk ratio 1.79), particularly in ICU patients; consider alternative gram-negative coverage when possible. 3

• Zosyn plus vancomycin was associated with higher AKI rates compared to cefepime plus vancomycin (risk ratio 1.70) 3
• In critically ill patients, Zosyn was identified as an independent risk factor for renal failure with delayed recovery compared to other beta-lactams 1
• Monitor renal function closely during treatment, especially in ICU patients receiving concomitant vancomycin 1, 3

Thrombocytopenia Monitoring:

• Rapid-onset thrombocytopenia can occur, particularly in patients with renal disease 4
• Platelet counts can drop precipitously within 36 hours of starting therapy 4
• Monitor hematologic parameters during prolonged therapy 1

Seizure Risk:

Patients receiving higher doses, especially with renal impairment, are at greater risk for neuromuscular excitability and seizures; closely monitor these populations. 1