Piperacillin Tazobactam

# Piperacillin Tazobactam ## Overview A fixed-combination penicillin-class antibacterial (extended-spectrum penicillin) plus a beta-lactamase inhibitor. It provides broad-spectrum coverage against Gram-positive, Gram-negative (including *Pseudomonas aeruginosa*), and anaerobic organisms. ## Primary Indications * Hospital-acquired and ventilator-associated pneumonia. * Complicated intra-abdominal infections. * Complicated skin and skin structure infections. * Febrile neutropenia (often in combination with an aminoglycoside). * Complicated urinary tract infections. ## Adult Dosing The standard dose is **3.375 g (3 g piperacillin/0.375 g tazobactam) IV every 6 hours**. * **Severe Infections:** 4.5 g (4 g piperacillin/0.5 g tazobactam) IV every 6 hours. * **Maximum Dose:** 18 g (piperacillin component) per day. * *Note: Extended or continuous infusion protocols vary by institution for severe infections (e.g., 4.5 g infused over 4 hours every 8 hours).* ## Pediatric Dosing * **Infants/Children (≥9 months to 12 years):** 100 mg/12.5 mg per kg IV every 8 hours. * **Patients >40 kg:** Use adult dosing. * *Note: Safety and efficacy in children <9 months have not been established. Always consult institutional weight-based protocols.* ## Dose Adjustments * **Renal Impairment:** Requires dose reduction or interval extension based on creatinine clearance (CrCl). * CrCl 20–40 mL/min: 2.25 g every 6 hours (or 3.375 g every 8 hours). * CrCl <20 mL/min: 2.25 g every 8 hours. * **Hemodialysis:** Max 2.25 g every 8 hours, with an additional 0.75 g dose following each dialysis session. * **Hepatic Impairment:** No dosage adjustment necessary. ## Contraindications * Known hypersensitivity to piperacillin, tazobactam, or any beta-lactam (e.g., penicillins, cephalosporins) due to the risk of anaphylaxis. ## Adverse Effects * **Common:** Diarrhea, constipation, nausea, headache, insomnia. * **Serious:** *Clostridioides difficile*-associated diarrhea, hypersensitivity reactions (anaphylaxis, SJS/TEN), leukopenia/neutropenia (with prolonged use), and seizure activity (especially in setting of renal impairment). ## Key Drug Interactions * **Aminoglycosides:** Inactivation of aminoglycosides can occur if mixed in the same IV line. Administer at least 1 hour apart. * **Probenecid:** Increases serum concentrations of piperacillin/tazobactam. * **Warfarin/Anticoagulants:** May increase bleeding risk due to inhibition of platelet aggregation. * **Methotrexate:** May increase serum levels of methotrexate by reducing renal clearance. ## Monitoring * **Renal Function:** Monitor CrCl, especially in elderly or renally impaired patients. * **Hematology:** CBC with differential (baseline and periodically for courses >14 days) for potential neutropenia. * **Electrolytes:** Periodic monitoring of potassium and sodium levels (contains ~2.8 mEq sodium per gram of piperacillin). * **Infection markers:** Fever, WBC count, and clinical site assessment. ## Clinical Pearls * **Spectrum:** Does not cover MRSA, *Acinetobacter* (variable/poor), or extended-spectrum beta-lactamase (ESBL) producing organisms in all contexts; cross-resistance is possible. * **Stability:** Once reconstituted, stability varies by diluent and temperature; check facility-specific IV compatibility charts. * **Vancomycin association:** Studies have suggested an increased risk of acute kidney injury when piperacillin/tazobactam is co-administered with vancomycin compared to other beta-lactams; monitor renal function closely. *** **Educational Disclaimer:** This information is for educational purposes only and does not constitute medical advice. Dosing and clinical practices may vary by institution. Always verify current prescribing information, institutional protocols, and patient-specific factors with a licensed pharmacist or the provider’s clinical guidelines before administration.