P253 Optimisation of inhaled antibiotic prescribing for Pseudomonas aeruginosa infections in people with cystic fibrosis: Further insights from Principal Investigators of the ECFS Clinical Trials Network

Inhaled antibiotics are a pivotal part of management of Pseudomonas aeruginosa (Pa) chronic airway infections in people with Cystic Fibrosis (pwCF). This study aimed to gain further insights into how Principal Investigators (PIs) in the ECFS-Clinical Trials Network (CTN) optimised inhaled antibiotic regimens to manage Pa infections in pwCF. A study explored inhaled antibiotic use within the ECFS-CTN through a questionnaire completed by PIs at 51/57 CF centres in the network (P150, ECFS 2022). The MS Forms questionnaire contained additional sections focusing on the optimisation of nebulised antibiotic regimens for Pa infections, and the use of inhaled antibiotics for non-Pa infections. Appropriateness of inhaled antibiotic regimens are usually reviewed every 3 months (n = 32, 62.7%). Adherence to inhaled antibiotic regimens is routinely assessed (n = 46, 90.2%), with questioning (n = 26), prescribing history (n = 9) and nebuliser data (n = 8). At initiation, some PIs (n = 18, 35.3%) conduct a formal drug response assessment in the hospital to assess possible intolerance. Assessment failure could result in changing antibiotic (n = 10/18, 55.6%), re-attempting with salbutamol (n = 4/18, 22.2%), or a response specific to reason for failure (n = 6/18, 33.3%). Nebulised antibiotics are generally administered after airway clearance techniques and other inhaled therapies. Inhaled treatment regimens were altered if other pathogens were detected (n = 20, 39.2%) by changing or adding antibiotics to extend coverage for all pathogens. PIs had established eradication (n = 47, 92.2%) and suppression (n = 29, 56.9%) regimens for ≥ 1 other pathogen, with co-trimoxazole featuring in regimens for multiple organisms. Routine review of antibiotic efficacy and adherence monitoring is commonly done throughout the ECFS-CTN for pwCF with Pa infections. Consideration of non-Pa respiratory infections also influences regimen design. Part of a PhD project funded by Chiesi.