Predictive factors of intolerance to nebulized antibiotics. A multicentre retrospective cohort study (Inbreathing study)

Intolerance to nebulized antibiotics (NA) represents a critical factor leading to treatment suspension and associated risks. Our objective is to identify predictors of intolerance within a cohort of patients with chronic structural lung diseases. We conducted a retrospective observational multicentric study across 8 centres in Spain including patients who initiated NA therapy between January 2018 and December 2022. We collected demographic, clinical and microbiological data from the 12 months preceding and following the NA initiation. Information on adverse effects, treatment discontinuation, and the underlying reason for discontinuation (intolerance) were collected. Stepwise multiple logistic regression was employed. We constructed a nomogram with these variables to predict the likelihood of tolerance to NA. A total of 308 patients were included, female (50.3%), with a median age of 73 years [61;80].76.6% of them with bronchiectasis and 32.1% with COPD. Among them, 59(19%) patients exhibited intolerance to NA, commonly presenting with dyspnoea (76%) and cough (37.3%) as the primary adverse effects. There were no differences in tolerance observed when comparing different NA. Factors associated with intolerance included: female sex (OR:2.05;p=0.036), COPD GOLD 3-4 (OR:6.05;p<0.001)and non-concomitant treatment with hypertonic saline solution (OR:0.36;p=0.065). A nomogram incorporating these variables was developed. Our study suggests that female sex, COPD GOLD 3-4, and the absence of adjunctive hypertonic saline solution are predictive factors for intolerance to NA. We created a nomogram as a practical tool for use in routine clinical settings among these patients.