Design and setting
This retrospective cohort study and population PK analysis study screened all adults with a medically confirmed diagnosis of CF that were admitted at the McGill University Health Centre (MUHC), a tertiary care facility, for the treatment of an APE between January 2015 and December 2019. Patients were included if they received IV tobramycin in the antibiotic regimen as treatment for their APE, inhaled tobramycin resulted in exclusion. This study was approved by MUHC ethics committee. Tobramycin dosing regimens vary according to patient characteristics and physician’s personnel assessment of patient severity and risk of adverse events. All dosing regimens were included in this study. Patients who were switched from tobramycin to another aminoglycoside or vice-versa were also included, however, changing antibiotic was considered in the analysis.