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Zosyn
Piperacillin/tazobactam
$2230.00
4g/0.5g · 10 × 10 · 1 month supply
BrandBranded medicine
$2230.00 per month
Strength
How long a supply?
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Annual cost
$27206a year at this pack size
Prescription required
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4g/0.5g
4.5g
About Zosyn
Overview
Zosyn is an intravenous antibacterial medicine containing piperacillin, a penicillin-class antibiotic, and tazobactam, a beta-lactamase inhibitor. It treats infections inside the abdomen and hospital-acquired pneumonia in adults and children aged 2 months and older. In adults, it also treats skin and related tissue infections, female pelvic infections, and community-acquired pneumonia. It works against bacteria through its antibiotic component, piperacillin, combined with tazobactam, which blocks enzymes called beta-lactamases.
What it treats
• Infections inside the abdomen in adults and children aged 2 months and older. • Hospital-acquired pneumonia in adults and children aged 2 months and older. • Skin and related tissue infections in adults. • Female pelvic infections in adults. • Community-acquired pneumonia in adults. Zosyn should be used only for infections proven or strongly suspected to be caused by bacteria.
Safety information
Side effects
Common side effects include diarrhea, constipation, nausea, headache and difficulty sleeping. Serious side effects include severe allergic reactions, severe skin reactions, hemophagocytic lymphohistiocytosis (HLH), muscle breakdown (rhabdomyolysis), bleeding, low white blood cell counts, seizures and kidney injury or failure. Kidney harm has been observed in critically ill patients. Seizure risk may be greater in people with kidney impairment. Seek urgent medical help for an allergic reaction, a worsening rash or a seizure. Contact a doctor promptly for bleeding or diarrhea, as diarrhea may be associated with Clostridioides difficile infection. Blood tests may be needed during prolonged treatment, and kidney function may need monitoring.
When to call your doctor
If symptoms are severe or getting worse quickly, seek emergency care rather than waiting.
Before taking this medicine
Zosyn must not be used in anyone with a history of allergic reactions to penicillins, cephalosporins or beta-lactamase inhibitors. Extra caution and close monitoring are needed in people with kidney impairment or seizure disorders because of the risk of seizures or increased nerve and muscle excitability. Kidney impairment also requires the prescriber to adjust treatment. In critically ill patients, Zosyn has been linked to kidney failure and delayed recovery of kidney function. Alternative treatment should be considered; if no suitable alternative is available, kidney function should be monitored. Zosyn can cause serious allergic reactions, severe skin reactions, hemophagocytic lymphohistiocytosis (HLH) and muscle breakdown (rhabdomyolysis). Treatment must be stopped if a serious allergic reaction occurs, a rash progresses, HLH is suspected, or signs of muscle breakdown appear. Bleeding and reduced white blood cell counts can occur, so blood tests should be monitored during prolonged treatment. Diarrhea during treatment requires evaluation for Clostridioides difficile-associated diarrhea.
Interactions
Tell your doctor if you are receiving any of these medicines: • Tobramycin: Zosyn can significantly lower tobramycin levels in patients on hemodialysis. Blood levels of tobramycin should be monitored in these patients. • Probenecid: This slows the removal of piperacillin and tazobactam from the body. It should not be used with Zosyn unless the benefit outweighs the risk. • Vancomycin: Using it with Zosyn may increase the risk of acute kidney injury. Kidney function should be monitored. • Heparin or oral anticoagulants (blood thinners): Blood-clotting tests should be monitored during treatment with Zosyn. • Vecuronium or other non-depolarizing muscle relaxants: Zosyn may prolong their muscle-blocking effects. Monitoring for related adverse reactions is needed.
Using Zosyn
Dosing
Dosing is set by your prescriber. Each health care professional may prescribe medication differently according to a patient's medical history and condition, so follow the directions on your prescription label and speak to your doctor or pharmacist before changing anything.
Storage
Store in the original carton below 25°C, protected from light, unless the pack states refrigeration. Do not freeze. Keep all medicines out of the sight and reach of children.
Clinical information on this page is summarised from the US FDA label ZOSYN (PIPERACILLIN SODIUM AND TAZOBACTAM SODIUM) INJECTION, SOLUTION [BAXTER HEALTHCARE CORPORATION] (DailyMed, retrieved 19 September 2026).
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