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, 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
The typical dose is 3.375 grams (piperacillin 3 g / tazobactam 0.375 g) every 6 hours or 4.5 grams (piperacillin 4 g / tazobactam 0.5 g) every 6 or 8 hours administered intravenously.
* Dosing frequency and duration are dependent on the indication, severity of infection, and clinical response.
* Higher doses may be used for severe infections or infections caused by less susceptible organisms.
## Pediatric Dosing
Dosing in pediatric patients is complex and often based on piperacillin weight-based dose.
* **Patients 0 to 6 months:** Dosing varies widely and should be guided by local protocols and specific indications, often in the range of 50-100 mg piperacillin/kg/day divided into 3 or 4 doses.
* **Patients > 6 months:** Dosing is typically 100 mg piperacillin/kg/dose every 8 hours, not to exceed the adult dose of 4.5 grams per dose. For patients with cystic fibrosis, higher doses may be used.
* Consult specific pediatric guidelines or institutional protocols for precise dosing in neonates and children.
## Dose Adjustments
* **Renal Impairment:**
* CrCl > 40 mL/min: No dose adjustment needed.
* CrCl 20-40 mL/min: 2.25 grams (piperacillin 2 g / tazobactam 0.25 g) every 6 hours or 3.375 grams (piperacillin 3 g / tazobactam 0.375 g) every 8 hours.
* CrCl < 20 mL/min: 2.25 grams (piperacillin 2 g / tazobactam 0.25 g) every 8 hours.
* For patients on intermittent hemodialysis, administer a dose after each dialysis session. The dose should be adjusted based on CrCl.
* **Hepatic Impairment:** No dose adjustment is typically required.
## Contraindications
* Hypersensitivity to piperacillin, tazobactam, other penicillinase-resistant penicillins, or any component of the formulation.
* History of immediate or severe allergic reaction to a beta-lactam antibiotic.
## Adverse Effects
* **Common:** Diarrhea, nausea, vomiting, rash, headache, insomnia, constipation, abdominal pain, fever.
* **Serious:** Anaphylaxis, Clostridioides difficile-associated diarrhea, seizures (especially with high doses or renal impairment), interstitial nephritis, hematologic effects (neutropenia, thrombocytopenia, leukopenia, prolonged bleeding time).
## Key Drug Interactions
* **Probenecid:** May increase and prolong piperacillin/tazobactam serum concentrations.
* **Neuromuscular Blocking Agents:** May prolong neuromuscular blockade.
* **Warfarin:** May decrease the anticoagulant effect of warfarin. Monitor INR closely.
* **Methotrexate:** May decrease methotrexate serum levels. Monitor methotrexate levels.
* **Aminoglycosides:** While often co-administered, consider potential for antagonism in vitro. Separate administration if possible.
## Monitoring
* Renal function (baseline and during therapy).
* Liver function tests (baseline and during therapy).
* Complete blood count, including platelet count (especially with prolonged therapy).
* Electrolytes.
* Signs and symptoms of infection for clinical efficacy.
* Signs and symptoms of hypersensitivity reactions.
## Clinical Pearls
* Piperacillin/tazobactam is a broad-spectrum agent often used for serious infections, including those involving Pseudomonas aeruginosa and anaerobes.
* Ensure adequate hydration to minimize risk of crystalluria, especially with higher doses.
* Reconstitute and dilute according to manufacturer instructions. Infuse over at least 30 minutes.
* The ratio of piperacillin to tazobactam is fixed at 8:1.
* Dosing for febrile neutropenia often involves extended infusion (e.g., over 4 hours) to achieve higher target concentrations.
---
*Please verify current prescribing information and local institutional protocols before administering this medication.*
