ZOSYN
Combination product
Pronunciation: pi-PER-a-sil-in and ta-zoe-BAK-tam
Combination of Piperacillin and Tazobactam.
Each component keeps its own pharmacology page; the combination itself adds no new mechanism.
Components (2)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Infections other than nosocomial pneumonia (intra-abdominal, skin/skin structure, female pelvic, community-acquired pneumonia) | adults | 3.375 g IV every 6 hours | 3.375 g q6h (13.5 g/day) | 13.5 g/day |
| Nosocomial pneumonia | adults | 4.5 g IV every 6 hours plus an aminoglycoside | 4.5 g q6h (18 g/day) + aminoglycoside | 18 g/day |
| Intra-abdominal infections / nosocomial pneumonia | pediatric ≥2 months (up to 40 kg) | 2–9 mo: 90 mg/kg q8h (pneumonia q6h); >9 mo: 112.5 mg/kg q8h (pneumonia q6h) | weight-based per age/indication | do not exceed adult dose |
Renal CrCl ≤40 mL/min and dialysis patients: reduce dose per degree of renal impairment.
Hepatic No dosage adjustment in hepatic cirrhosis.
Instructions
- Administer by IV infusion over 30 minutes.
- Reconstitute, dilute, and administer aminoglycosides separately from piperacillin/tazobactam.
- Usual duration 7–10 days (7–14 days for nosocomial pneumonia).
Available strengths
- inj 2.25, 3.375, 4.5 g
Contraindications
- History of allergic reactions to any of the penicillins, cephalosporins, or beta-lactamase inhibitors
Cautions
- Serious hypersensitivity (anaphylactic/anaphylactoid) reactions
- Severe cutaneous adverse reactions (SJS, TEN, DRESS, AGEP)
- Hemophagocytic lymphohistiocytosis
- Rhabdomyolysis
- Hematologic effects (bleeding, leukopenia, neutropenia)
- Neuromuscular excitability or seizures (esp. renal impairment)
- Nephrotoxicity in critically ill patients
- Clostridioides difficile-associated diarrhea
- Electrolyte effects (sodium load, hypokalemia)
Adverse reactions
- Diarrhea
- Constipation
- Nausea
- Headache
- Insomnia
Pregnancy Insufficient human data; crosses the placenta; animal fetotoxicity seen with maternal toxicity.
Lactation Undefined
Cost
ZOSYN
What pharmacies pay · NADAC 9/30/26
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 2.25 g | inj | per unit | not offered | |
| 3.375 g | inj | per unit | $3.49/ea | not offered |
| 4.5 g | inj | per unit | not offered |
Part D rank #284.