Piperacillin and Tazobactam is a fixed-dose combination injectable antibacterial agent. Piperacillin is an extended-spectrum penicillin (ureidopenicillin) with activity against a wide range of Gram-positive and Gram-negative bacteria. Tazobactam is a beta-lactamase inhibitor (a penicillanic acid sulfone derivative) that protects piperacillin from degradation by many beta-lactamase enzymes, thereby extending its spectrum of activity to include many beta-lactamase-producing strains that are otherwise resistant. This combination is a cornerstone of empiric therapy for serious nosocomial infections in the Indian hospital setting.
Adult: 3.375 g (piperacillin 3g + tazobactam 0.375g) IV every 6 hours OR 4.5 g (piperacillin 4g + tazobactam 0.5g) IV every 8 hours for most serious infections. For nosocomial pneumonia, febrile neutropenia, and other life-threatening infections: 4.5 g IV every 6 hours.
Note: For IV use only. Reconstitute powder with a suitable diluent (e.g., Sterile Water for Injection, 0.9% Sodium Chloride, 5% Dextrose). Further dilute in 50-150 mL of compatible IV fluid. Administer by intravenous infusion over 30 minutes. Do not mix with aminoglycosides in the same IV bag/syringe due to potential inactivation; administer separately.
Piperacillin binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, inhibiting the final transpeptidation step of peptidoglycan synthesis. This leads to the formation of defective cell walls and osmotically unstable cells, resulting in bacterial cell lysis and death. Tazobactam has very weak antibacterial activity itself but irreversibly binds to and inhibits a wide variety of beta-lactamases (including many plasmid-mediated and chromosomal enzymes), thereby protecting piperacillin from enzymatic hydrolysis and extending its spectrum.
Pregnancy: Pregnancy Category B. Animal studies have shown no direct harm, but no adequate and well-controlled studies in pregnant women. Use only if clearly needed, as safety is not definitively established.
Driving: Generally safe. However, dizziness has been reported; patients should be cautioned if they experience such effects.
| Probenecid | Inhibits renal tubular secretion of piperacillin, increasing and prolonging serum concentrations of both piperacillin and tazobactam. | Moderate |
| Aminoglycosides (e.g., Gentamicin, Amikacin) | Potential for physical-chemical inactivation if mixed in the same IV solution. Pharmacodynamic synergy against some organisms. | Moderate |
| Methotrexate | Piperacillin may reduce renal clearance of methotrexate, leading to increased methotrexate levels and toxicity. | Major |
| Oral Anticoagulants (Warfarin) | May potentiate anticoagulant effect and increase risk of bleeding due to effects on platelet function and vitamin K metabolism. | Major |
| Vecuronium | May prolong neuromuscular blockade. | Moderate |
| Oral Contraceptives | Potential reduction in efficacy due to altered enterohepatic circulation; advise use of alternative non-hormonal contraception. | Moderate |