Ceftolozane is a potent antimicrobial against Pseudomonas aeruginosa, including carbapenem-resistant and multidrug-resistant strains, and is also active against Enterobacteriaceae. It MIC (minimal inhibitory concentration) and MPC (mutant preventive concentration) are close together, allowing to avoid the mutant selection window specifically in the treatment of Pseudomonas aeruginosa infection. The molecule is time-dependent and stable when reconstituted at room temperature, facilitating safe and effective dosage optimization in frail and critically ill patients. It has been shown to be non-inferior to meropenem in the treatment of nosocomial infection in the ASPECT-NP study but superior in post-hoc studies in the subgroup of patients with ventilator-associated pneumonia, without the emergence of resistance during treatment. It is FDA approved at a dose of 3 g every 8 hours in the treatment of nosocomial pneumonia (HABP/VABP) in adults.