Please check your internet connection and try again.
# Piperacillin-Tazobactam (Zosyn)
## Overview
Piperacillin-tazobactam is an extended-spectrum penicillin antibiotic combined with a beta-lactamase inhibitor. It is active against many Gram-positive, Gram-negative (including *Pseudomonas aeruginosa*), and anaerobic bacteria.
## Primary Indications
* Complicated intra-abdominal infections
* Complicated skin and skin-structure infections
* Community-acquired pneumonia
* Hospital-acquired pneumonia (including ventilator-associated pneumonia)
* Febrile neutropenia (empiric treatment)
## Adult Dosing
Standard dosing is **3.375 g (3 g piperacillin/0.375 g tazobactam) or 4.5 g (4 g piperacillin/0.5 g tazobactam) intravenously every 6 or 8 hours**. Dosing frequency and duration depend on the indication, severity of infection, and patient's clinical response. Higher doses may be used for severe infections or *Pseudomonas aeruginosa* infections.
## Pediatric Dosing
Dosing is based on piperacillin component.
* **1 month to 12 years:** 80-100 mg/kg/day of piperacillin, divided into 3 or 4 doses, administered every 6 or 8 hours. Maximum dose not to exceed 4 g of piperacillin per dose.
* **Greater than or equal to 12 years:** Dosing is the same as adults.
* **Neonates and infants younger than 1 month:** Dosing is complex due to immature renal function and is typically based on gestational and postnatal age. Consult specialized pediatric guidelines or pharmacy.
## Dose Adjustments
* **Renal Impairment:** Adjust dose based on creatinine clearance (CrCl).
* CrCl 20-40 mL/min: 2.25 g (2 g piperacillin/0.25 g tazobactam) or 3.375 g (3 g piperacillin/0.375 g tazobactam) IV every 8 hours.
* CrCl < 20 mL/min: 2.25 g (2 g piperacillin/0.25 g tazobactam) IV every 8 hours.
* Hemodialysis: Administer dose every 8 hours, plus an additional dose of 2.25 g (2 g piperacillin/0.25 g tazobactam) after each dialysis session.
* **Hepatic Impairment:** No specific dose adjustment is typically required.
## Contraindications
* Known severe hypersensitivity to piperacillin, tazobactam, other penicillin antibiotics, or beta-lactamase inhibitors.
## Adverse Effects
* **Common:** Diarrhea, nausea, vomiting, rash, headache, insomnia, constipation, pruritus, fever, eosinophilia.
* **Serious:** *Clostridioides difficile*-associated diarrhea, hypersensitivity reactions (including anaphylaxis), seizures (especially with high doses or renal impairment), neutropenia, thrombocytopenia, elevated liver enzymes.
## Key Drug Interactions
* **Probenecid:** May increase and prolong piperacillin-tazobactam serum concentrations.
* **Neuromuscular blocking agents:** Piperacillin may prolong the action of vecuronium.
* **Warfarin:** May decrease the effect of warfarin; increased monitoring of INR is recommended.
* **Methotrexate:** Piperacillin may reduce methotrexate clearance; monitor methotrexate levels.
## Monitoring
* **Renal function:** Monitor serum creatinine and electrolytes, especially in patients with pre-existing renal dysfunction or receiving concurrent nephrotoxic agents.
* **Liver function:** Monitor liver enzymes, particularly with prolonged therapy.
* **Hematologic parameters:** Monitor complete blood count, especially with prolonged therapy or in patients with known hematologic abnormalities.
* **Signs and symptoms of infection:** Clinical response to therapy.
* **Signs and symptoms of hypersensitivity reactions.**
* **Signs and symptoms of *C. difficile*-associated diarrhea.**
## Clinical Pearls
* The ratio of piperacillin to tazobactam is 8:1 in both 2.25 g and 3.375 g formulations, and 8:1 in the 4.5 g formulation.
* Doses should be administered over at least 30 minutes by IV infusion. Rapid infusion may increase the risk of hypersensitivity reactions.
* Piperacillin-tazobactam does not cover atypical pathogens (e.g., *Legionella*, *Mycoplasma*, *Chlamydia*).
* Consider combination therapy for severe infections, especially when broader coverage is needed or resistance is suspected.
* Reconstituted solutions should be used within 24 hours when refrigerated or within 12 hours at room temperature, depending on the diluent.
**Disclaimer:** This information is intended for healthcare professionals. Always consult the current prescribing information and institutional protocols before administering any medication.
