Please check your internet connection and try again.
# Piperacillin-Tazobactam (Zosyn)
## Overview
A combination extended-spectrum penicillin antibiotic (piperacillin) and a beta-lactamase inhibitor (tazobactam). Provides broad-spectrum coverage, including *Pseudomonas aeruginosa* and anaerobes.
## Primary Indications
* Moderate to severe infections (e.g., healthcare-associated pneumonia, intra-abdominal infections, skin/soft tissue infections, febrile neutropenia).
## Adult Dosing
Standard dose is **3.375 g IV every 6 hours** (3 g piperacillin / 0.375 g tazobactam).
For severe or nosocomial infections (e.g., *Pseudomonas*), use **4.5 g IV every 6 or 8 hours** (4 g piperacillin / 0.5 g tazobactam).
Maximum dose: 18 g (piperacillin component) per 24 hours.
## Pediatric Dosing
* **Neonates/Infants:** Generally avoided due to limited safety data; dosing is highly weight- and age-dependent (per institution protocol).
* **Children ≥ 9 months:** Typically 80 mg/kg (piperacillin component) every 6 or 8 hours. Max dose: 4 g (piperacillin) per dose.
## Dose Adjustments
* **Renal Impairment:** Mandatory. Adjust both dosing frequency and magnitude based on creatinine clearance (CrCl). If CrCl < 40 mL/min, refer to specific renal dosing charts (e.g., Sanford Guide or Lexicomp).
* **Hepatic Impairment:** No standard adjustment required, but use with caution.
## Contraindications
* History of severe allergic reactions (anaphylaxis) to any penicillin, cephalosporin, or beta-lactamase inhibitor.
## Adverse Effects
* **Common:** Diarrhea, constipation, nausea, headache, injection site reaction.
* **Serious:** *Clostridioides difficile*-associated diarrhea (CDAD), severe hypersensitivity reactions (DRESS, SJS/TEN), leukopenia/neutropenia (with prolonged use), and acute kidney injury (synergistic risk with vancomycin).
## Key Drug Interactions
* **Aminoglycosides:** Potential for inactivation if mixed in the same IV line. Administer at least 1 hour apart.
* **Methotrexate:** May decrease renal clearance, increasing systemic exposure and toxicity risk.
* **Probenecid:** Increases serum concentrations of piperacillin.
* **Warfarin:** Theoretical increase in bleeding risk due to alteration of gut flora, though less common than with other antibiotics.
## Monitoring
* **Renal Function:** Monitor SCr and BUN frequently.
* **CBC:** Monitor for neutropenia or thrombocytopenia if treatment extends > 10–14 days.
* **Electrolytes:** Contains 2.79 mEq (64 mg) of sodium per 1 gram of piperacillin; monitor in patients on sodium-restricted diets.
* **Clinical:** Assessment of infection resolution, signs of hypersensitivity, and CDAD symptoms.
## Clinical Pearls
* **Extended Infusions:** Many institutions utilize prolonged infusions (4-hour infusion time) to maximize the time the drug concentration remains above the Minimum Inhibitory Concentration (T > MIC) for difficult-to-treat organisms.
* **Broad Spectrum:** Does not cover MRSA or atypical pathogens.
* **Vancomycin Interaction:** Increasing literature suggests that co-administration with vancomycin for > 48 hours significantly increases the risk of acute kidney injury compared to other beta-lactams.
***
**Educational Disclaimer:** This summary is for informational purposes for healthcare professionals. Clinical practice varies by institution. Always verify specific doses, contraindications, and compatibility with local hospital protocols, antimicrobial stewardship guidelines, and the most current manufacturer prescribing information.
