Ceftolozane + tazobactam !

A newer cephalosporin combined with tazobactam for urinary, abdominal and pneumonia infections due to resistant gram-negatives.

Updated 2026-11-01

Class: Beta-lactams
Enzyme: Bacterial PBPs (ceftolozane) and β-lactamases (tazobactam)
ATC code: J01DI54
WHO Model List of Essential Medicines

Also called: ceftolozane–tazobactam

Bacterial PBPs (ceftolozane) and β-lactamases (tazobactam)Ceftolozane + tazobactam

The figure shows the SHV-1 β-lactamase of Klebsiella pneumoniae inhibited by tazobactam (intermediate bound to the active site); no structure of ceftolozane bound to a PBP has been published.

Target in 3D: Bacterial PBPs (ceftolozane) and β-lactamases (tazobactam). PDB structure 1VM1 (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

Ceftolozane is a cephalosporin that acylates the PBPs and stops gram-negative wall synthesis. Tazobactam inhibits many class A β-lactamases, including some ESBLs, and protects ceftolozane. The combination has broad activity with greater stability to chromosomal β-lactamase (AmpC). No combination of this kind works against metallo-β-lactamase producers.

Tazobactam inactivates class A β-lactamases
Ceftolozane, more stable to AmpC, reaches the PBPs
Peptidoglycan cross-linking is blocked
The bacterium lyses

Pharmacokinetics

Absorption: Intravenous only.
Elimination: By the kidney; adjusted in kidney failure.

Indications

Complicated urinary tract infections.
Complicated intra-abdominal infections. Peritonitis →
Certain pneumonias.

Adverse effects

Common

Nausea, vomiting, constipation
Headache, insomnia, anxiety
Abdominal pain

Contraindications

Serious hypersensitivity to any component or to other β-lactams

Key interactions

Other drugs and supplements: The label asks for a full medication review; dose changes or monitoring may be needed.

What is monitored

Creatinine (dose adjustment)
Cultures and susceptibility tests

Administration and safety

Intravenous infusion only.
Do not confuse with piperacillin + tazobactam: both carry tazobactam, but the main antibiotic differs.
Used under the antimicrobial stewardship programme.

Nursing care

Before the first dose: ask about allergy to penicillins, cephalosporins and other β-lactams, and what the reaction was.
Monitor creatinine and urine output.
Teach the patient to report watery or bloody diarrhoea, even weeks after the course ends.

Pregnancy and breastfeeding

Data in pregnant women are limited; it is used only if the benefit justifies the risk, and the team is told about any pregnancy.

Test yourself

Think of the answer, then tap the question to see it.

Against which β-lactamase producers does ceftolozane + tazobactam fail?

Against metallo-β-lactamase (class B) producers.

What does it share with piperacillin + tazobactam, and how does it differ?

Both use tazobactam as the inhibitor; ceftolozane is a cephalosporin more stable to AmpC, while piperacillin is a penicillin.

For which infections was this combination first approved?

For complicated intra-abdominal and urinary tract infections.

Add to my cards (3)

Peritonitis

← Back to the class: Beta-lactams

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: Ceftolozane and Tazobactam Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); RCSB PDB - 1VM1: STRUCTURE OF SHV-1 BETA-LACTAMASE INHIBITED BY TAZOBACTAM (RCSB Protein Data Bank, 2026); Farmacología básica y clínica (Katzung), cap. 43 (McGraw Hill, 2025).

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Representative model, for educational purposes only.