Classification of Zosyn (Piperacillin/Tazobactam)
Zosyn is a beta-lactam/beta-lactamase inhibitor combination antibiotic consisting of piperacillin (a penicillin-class antibacterial) and tazobactam (a beta-lactamase inhibitor). 1
Drug Class Components
- Piperacillin: An extended-spectrum penicillin (ureidopenicillin) that belongs to the beta-lactam class of antibiotics 2, 3
- Tazobactam: A beta-lactamase inhibitor that protects piperacillin from enzymatic degradation by bacterial beta-lactamases 2, 3
Antimicrobial Spectrum
Zosyn provides broad-spectrum coverage against:
- Gram-positive aerobic bacteria including many staphylococcal and streptococcal species 2, 3
- Gram-negative aerobic bacteria including Enterobacteriaceae and Pseudomonas aeruginosa 2, 3
- Anaerobic bacteria providing comprehensive coverage for polymicrobial infections 2, 4
- Beta-lactamase-producing organisms including broad-spectrum beta-lactamase-producing and some extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae 3
Clinical Classification Context
In antimicrobial stewardship frameworks, piperacillin/tazobactam is classified as:
- An antipseudomonal beta-lactam used for empiric coverage of Pseudomonas aeruginosa in hospital-acquired infections 5
- A first-line agent for febrile neutropenia, showing superior outcomes compared to ceftazidime-based regimens 5
- A carbapenem-sparing option for infections caused by ESBL-producing organisms, though this remains controversial for bloodstream infections 5
Important Limitations
Piperacillin/tazobactam does NOT provide adequate coverage against:
- AmpC beta-lactamase-producing Gram-negative bacilli 3
- Carbapenem-resistant Enterobacteriaceae (CRE) 5
- Difficult-to-treat resistant (DTR) Pseudomonas aeruginosa strains that are non-susceptible to piperacillin/tazobactam 5
- Methicillin-resistant Staphylococcus aureus (MRSA) 5
Regulatory Classification
The FDA classifies piperacillin/tazobactam as indicated for: