2-[(Z)-[2-[[(6R,7R)-3-[[5-amino-4-(2-aminoethylcarbamoylamino)-1-methylpyrazol-2-ium-2-yl]methyl]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl]amino]-1-(5-amino-1,2,4-thiadiazol-3-yl)-2-oxoethylidene]amino]oxy-2-methylpropanoate

Ceftolozane exerts bactericidal activities against susceptible gram-negative and gram-positive infections by interfering with bacterial cell wall synthesis. When it is combined with tazobactam, it exerts further activity against beta-lactamase enzyme producing bacteria, which are normally resistant to beta-lactam antibiotics and interfere with infection treatment. The addition of tazobactam strengthens the therapeutic response to ceftolozane, giving it the ability to treat a broader range of bacterial infections and resistant organisms.

Ceftolozane belongs to the cephalosporin class of antibacterial drugs. Ceftolozane exerts antibacterial effects, preventing the formation of cell walls that protect bacteria from injury and confer resistance to some antibiotics. Its antibacterial activity is also mediated through ceftolozane binding to penicillin-binding proteins (PBPs), which are required for peptidoglycan cross-linking for bacterial cell wall synthesis. As a result of cell wall synthesis inhibition, bacterial cells are killed, treating various infections. Ceftolozane has a particularly high affinity to the penicillin-binding proteins for Pseudomonas aeruginosa and Escherichia coli as well as Klebsiella pneumoniae and other enteric bacteria. In particular, a high affinity has been seen in vitro for penicillin-binding proteins 1b, 1c, 2, and 3 when compared to other antibiotics, ceftazidime and imipenem.

The area under the curve (AUC) of ceftolozane-tazobactam after an injected dose of 1 g/0.5 g every 8 hours for 1 day was 172 mcg•h/mL. The Cmax (peak concentration) and AUC are dose-dependent. The Cmax on day one of the above dose of ceftolozane-tazobactam was 69.1 mcg/mL.