piperacillintazobaktaam

Piperacillin/tazobactam is a fixed-dose combination antibiotic that pairs piperacillin, a broad-spectrum penicillin, with tazobactam, a beta-lactamase inhibitor. It is marketed under names such as Zosyn in the United States and Tazocin in several other countries. The product is typically administered by intravenous infusion.

The combination works by inhibiting bacterial cell wall synthesis through piperacillin’s action on penicillin-binding proteins, while tazobactam protects piperacillin from degradation by many beta-lactamases produced by some resistant bacteria. This broadens the spectrum of piperacillin to include several Gram-negative and some anaerobic organisms. It is not active against most methicillin-resistant Staphylococcus aureus (MRSA) and has limited activity against certain resistant Enterococcus species or ESBL-producing organisms. It is commonly used for mixed infections where a beta-lactamase–producing pathogen or anaerobe is suspected.

Indications include moderate to severe intra-abdominal infections, gynecologic infections, pneumonia (including some hospital-acquired cases), complicated skin and soft tissue infections, and complicated urinary tract infections. Dosing is usually 4.5 g of piperacillin with 0.5 g of tazobactam every six to eight hours, given by IV infusion; extended or shorter intervals may be used depending on infection severity and renal function. Renal impairment requires dose adjustment.

Common adverse effects are diarrhea, rash, and hypersensitivity reactions; serious adverse events can include Clostridioides difficile infection, liver enzyme elevations, and neutropenia. It should be avoided in patients with a known penicillin allergy or severe beta-lactam hypersensitivity, and caution is advised in pregnancy and lactation.