CONTinuous Infusion Versus Intermittent Dosing of ceftaZidime/AVIbactam in Critically Ill Patients

Ceftazidime/avibactam (CZA) is an essential treatment option for managing infections caused by multidrug-resistant (MDR) gram-negative (G-) bacteria, including Klebsiella pneumoniae OXA-48 and carbapenem-resistant Pseudomonas aeruginosa. Critically ill intensive care unit (ICU) patients frequently exhibit altered pharmacokinetics (PK) of CZA, potentially compromising optimal PK/pharmacodynamic (PD) target attainment with standard dosing regimens. This study compares the efficacy of continuous infusion (CI) versus conventional intermittent dosing (ID) of CZA in critically ill ICU patients with severe infections caused by K. pneumoniae OXA-48 or P. aeruginosa. This single-centre, randomized, open-label trial will be conducted at a tertiary care hospital within the University Hospital Centre in Zagreb, Croatia, with a 1:1 allocation ratio. One hundred forty critically ill ICU patients requiring CZA treatment will be randomized to receive either ID (2 g/0.5 g every 8 hours over 2 hours) or an equivalent dose in CI (6 g/1.5 g continuously over 24 hours). The primary outcome is the microbiological success rate. Secondary outcomes include clinical success rate, time to symptom improvement, length of ICU and hospital stay, 28-day all-cause mortality, pathogen recurrence rate, time to weaning from mechanical ventilation, cumulative vasoactive-inotropic score, adverse events, and the ratio of ceftazidime plasma concentration to the pathogen's minimum inhibitory concentration (C/MIC). This trial seeks to provide evidence on the optimal administration strategy for CZA in critically ill ICU patients with severe infections due to MDR G- pathogens.