PIPERACILLIN AND TAZOBACTAM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PIPERACILLIN AND TAZOBACTAM (PIPERACILLIN AND TAZOBACTAM).
Piperacillin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), while tazobactam is a beta-lactamase inhibitor that protects piperacillin from degradation by beta-lactamases.
| Metabolism | Piperacillin is partially metabolized to desethyl piperacillin; tazobactam is metabolized to an inactive metabolite. Both are primarily excreted renally. |
| Excretion | Primarily renal: piperacillin ~68% unchanged, tazobactam ~80% unchanged; biliary excretion <10%; fecal <1%. |
| Half-life | Piperacillin ~0.7–1.2 h, tazobactam ~0.7–1.5 h; prolonged in renal impairment (piperacillin up to 3.3 h, tazobactam up to 5.6 h in severe impairment). |
| Protein binding | Piperacillin: ~30% bound to albumin; tazobactam: ~30% bound to albumin. |
| Volume of Distribution | Piperacillin: ~0.27–0.31 L/kg; tazobactam: ~0.21–0.27 L/kg; distributes well into tissues, including lung, bile, and peritoneal fluid. |
| Bioavailability | Oral: not available; IM: >80% absolute bioavailability; IV: 100%. |
| Onset of Action | IV: immediate upon completion of infusion; IM: within 30 minutes. |
| Duration of Action | Bactericidal levels persist for 4–6 h after IV dose; requires frequent dosing (q6h or q8h) due to short half-life and time-dependent killing. |
| Molecular Weight | Piperacillin sodium: 539.5 Da; Tazobactam sodium: 322.3 Da; Combination: average 430.9 Da (as salts). |
3.375 g (piperacillin 3 g + tazobactam 0.375 g) IV every 6 hours, or 4.5 g (piperacillin 4 g + tazobactam 0.5 g) IV every 8 hours for nosocomial pneumonia.
| Dosage form | INJECTABLE |
| Renal impairment | CrCl 20-40 mL/min: 3.375 g IV every 8 hours; CrCl <20 mL/min: 2.25 g IV every 8 hours; Hemodialysis: 2.25 g IV every 12 hours, plus 0.75 g after dialysis. |
| Liver impairment | No dose adjustment required for hepatic impairment; pharmacokinetics not significantly altered in Child-Pugh class A, B, or C cirrhosis. |
| Pediatric use | Neonates <1 week: 100 mg piperacillin component/kg/dose IV every 12 hours; Infants 1-4 weeks: 100 mg/kg/dose IV every 8 hours; Children ≥2 months: 100 mg piperacillin component/kg/dose IV every 8 hours; Maximum 16 g piperacillin/day. |
| Geriatric use | Start at lower end of dosing based on renal function; elderly patients more likely to have decreased renal function, adjust dose according to CrCl; monitor for bleeding risk and nephrotoxicity. |
| 1st trimester | Piperacillin/tazobactam crosses the placenta. Animal studies show no teratogenic effects at clinically relevant doses. No well-controlled human studies in first trimester; however, large body of human experience suggests low risk. Use only if clearly needed. |
| 2nd trimester | Generally considered safe in second trimester when indicated. No evidence of fetal harm. Excretion into amniotic fluid occurs. |
| 3rd trimester | Considered safe in third trimester. Use for maternal infections as indicated. No association with preterm labor or adverse neonatal outcomes. |
Clinical note
Comprehensive clinical and safety monograph for PIPERACILLIN AND TAZOBACTAM (PIPERACILLIN AND TAZOBACTAM).
| Placental transfer | Piperacillin and tazobactam cross the placenta; therapeutic concentrations achieved in fetal serum and amniotic fluid. Transfer is proportional to maternal dose and gestational age. |
| Breastfeeding |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
History of hypersensitivity to penicillins, cephalosporins, or beta-lactamase inhibitorsUse of piperacillin/tazobactam in neonates with hyperbilirubinemia (due to risk of bilirubin displacement)
| Precautions | Hypersensitivity reactions (including anaphylaxis), Clostridioides difficile-associated diarrhea, Renal impairment (dosage adjustment required), Hematologic effects (leukopenia, neutropenia), Electrolyte disturbances (hypokalemia), Neurologic events (seizures, especially with high doses or renal failure) |
| Food/Dietary | No significant food interactions. Administer without regard to meals. However, maintaining adequate hydration is recommended to prevent nephrotoxicity. Avoid alcohol during therapy due to potential disulfiram-like reaction (though rare with penicillins, caution advised). |
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| Piperacillin and tazobactam are excreted into breast milk in low concentrations. Amounts are unlikely to be clinically relevant to the nursing infant. The American Academy of Pediatrics considers piperacillin compatible with breastfeeding. Monitor infant for potential gastrointestinal disturbances (e.g., diarrhea, candidiasis). |
| Lactation Rating | L1 (Safe) |
| Teratogenic Risk | PIPERACILLIN/TAZOBACTAM IS FDA PREGNANCY CATEGORY B. ANIMAL STUDIES SHOW NO FETAL HARM, BUT ADEQUATE HUMAN STUDIES ARE LACKING. INTRAPARTUM USE HAS NOT BEEN ASSOCIATED WITH CONGENITAL DEFECTS. THEORETICAL RISK OF BILIRUBIN DISPLACEMENT IN NEONATES EXISTS, BUT CLINICAL SIGNIFICANCE UNLIKELY AT USUAL DOSES. NO SPECIFIC TRIMESTER-SPECIFIC RISKS IDENTIFIED. |
| Fetal Monitoring | MONITOR MATERNAL RENAL FUNCTION, HEPATIC FUNCTION, AND COMPLETE BLOOD COUNT (CBC) WITH DIFFERENTIAL DURING PROLONGED THERAPY. ASSESS FOR SIGNS OF HYPERSENSITIVITY OR NEUROTOXICITY. FETAL MONITORING IS NOT ROUTINELY REQUIRED, BUT ULTRASOUND MAY BE CONSIDERED IF MATERNAL INFECTION POSES FETAL RISK. |
| Fertility Effects | NO STUDIES HAVE EVALUATED THE EFFECTS OF PIPERACILLIN/TAZOBACTAM ON HUMAN FERTILITY. ANIMAL STUDIES DID NOT DEMONSTRATE IMPAIRED FERTILITY. UNLIKELY TO CAUSE CLINICALLY SIGNIFICANT REPRODUCTIVE IMPAIRMENT. |
| Clinical Pearls | Piperacillin/tazobactam is a beta-lactam/beta-lactamase inhibitor combination with activity against Pseudomonas aeruginosa, anaerobes, and many ESBL-producing Enterobacteriaceae. Dose adjustment required for creatinine clearance <40 mL/min (e.g., for CrCl 20-40 mL/min, extend dosing interval to q6h; for CrCl <20 mL/min, q8h). Prolonged infusion (4-hour) may improve outcomes in critically ill patients. Monitor for bleeding risk due to piperacillin's effect on platelet aggregation. Consider cross-reactivity in patients with severe penicillin allergy; avoid if history of anaphylaxis. Therapeutic drug monitoring is not routine but may be considered in renal impairment or obesity. Common adverse effects include diarrhea, nausea, rash, and injection site reactions. Clostridioides difficile infection potential requires vigilance. |
| Patient Advice | Take this medication exactly as prescribed by your healthcare provider, usually every 6 hours. · Complete the full course of therapy even if you feel better to ensure the infection is fully treated. · Report any signs of allergic reaction immediately (rash, itching, swelling, severe dizziness, trouble breathing). · Inform your doctor if you experience severe diarrhea, especially if it contains blood or mucus, as this could indicate a Clostridioides difficile infection. · This medication may increase the risk of bleeding; notify your healthcare provider if you notice unusual bruising or bleeding. · Do not take this medication with any other penicillin-type antibiotics without your doctor's approval. · If you have kidney disease, your dose may need to be adjusted; ensure your doctor is aware of your kidney function. |