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.
## 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 dose:** 3.375 grams every 6 hours (equivalent to 3 grams piperacillin/0.375 grams tazobactam) intravenously (IV).
* **High dose:** 4.5 grams every 6 or 8 hours (equivalent to 4 grams piperacillin/0.5 grams tazobactam) IV. Higher doses and/or more frequent administration may be considered for severe infections, particularly those caused by *Pseudomonas aeruginosa* or in critically ill patients with altered pharmacokinetics.
Dosing frequency and duration depend on the indication, severity of infection, and patient response. Specific dosing regimens for certain indications may vary by institutional protocol.
## Pediatric Dosing
Dosing is based on piperacillin component.
* **3 months to < 12 years:** 90 mg piperacillin/12.5 mg tazobactam per kg per dose IV every 6 hours.
* **12 to 17 years:** 3.375 grams every 6 hours (equivalent to 3 grams piperacillin/0.375 grams tazobactam) IV.
* **Neonates and infants < 3 months:** Dosing is complex and requires careful consideration of gestational and chronological age; consult specialized pediatric guidelines or formulary.
Maximum doses should not exceed the adult maximum.
## Dose Adjustments
* **Renal Impairment (CrCl < 20 mL/min):** Reduce dose frequency. For standard 6-hour dosing, administer every 8 hours. For high-dose 6-hour dosing, administer every 8-12 hours. For high-dose 8-hour dosing, administer every 12 hours. Consider further dose reduction or increased frequency based on severity of renal impairment and clinical response.
* **Hepatic Impairment:** No specific dose adjustment is recommended, but caution is advised.
## Contraindications
* Known serious allergy to piperacillin, tazobactam, other penicillins, or beta-lactamase inhibitors.
## Adverse Effects
* Diarrhea (most common)
* Nausea, vomiting
* Rash, pruritus
* Headache
* Insomnia
* Hypersensitivity reactions (including anaphylaxis)
* *Clostridioides difficile*-associated diarrhea
* Hematologic abnormalities (neutropenia, thrombocytopenia)
* Elevated liver enzymes
* Seizures (rare, particularly with high doses or renal impairment)
## Key Drug Interactions
* **Probenecid:** May increase and prolong piperacillin serum concentrations.
* **Neuromuscular blocking agents (e.g., vecuronium):** Piperacillin may prolong the neuromuscular blockade.
* **Warfarin:** May decrease the anticoagulant effect of warfarin. Monitor INR closely.
* **Methotrexate:** Piperacillin may decrease methotrexate clearance. Monitor methotrexate levels.
## Monitoring
* Renal function (baseline and periodically)
* Liver function tests (baseline and periodically)
* Complete blood count with differential (especially with prolonged therapy)
* Electrolytes
* Signs and symptoms of infection
* Signs of hypersensitivity reactions
## Clinical Pearls
* Reconstitute and dilute according to manufacturer instructions. Administer as IV infusion over at least 30 minutes.
* Consider the potential for cross-reactivity in patients with penicillin allergies.
* Ensure adequate hydration and monitor for signs of fluid overload, especially in patients with heart failure.
* Empirical use in febrile neutropenia should be guided by local resistance patterns and patient risk factors.
* The beta-lactamase inhibitor tazobactam broadens the spectrum of activity against many beta-lactamase-producing organisms, but resistance can still develop.
***
**Disclaimer:** This information is intended for healthcare professionals. Always verify current prescribing information and consult institutional protocols before use.
