Background Inhaled colistin (IC) is formally indicated to treat Pseudomonas aeruginosa bronchial infections in cystic fibrosis (CF) patients. In patients without CF it is not indicated and must be prescribed off-label if they have pseudomonas-infected bronchiectasis.

Purpose To evaluate the way inhaled colistin is used, its effectiveness and economic impact for patients who do not have CF in our hospital.

Materials and methods Retrospective study. 24 patients’medical records were evaluated. All of them were undergoing IC treatment for their PA colonised bronchiectasis for at least 6 months from January 2011 to January 2013 in our hospital. None of them was diagnosed with CF. Besides demographics, the frequency and duration of hospitalisation for respiratory exacerbations and emergency episodes were counted in each patient before and after colistin intensive treatment. These two values were considered as efficacy parameters. Data were compared using a student’s t test for paired samples. Regarding the cost analysis, only hospitalisation-related expenditure and inhaled colistin treatment costs were included. Neither concomitant antibiotic treatment, nor expenditure related to medical consultations were measured.

Results 13 patients were female and mean age was 74.8. Mean treatment duration was 16.56 months and mean colistin expenditure was 7,504.44 € per patient. Average number of hospital admissions before treatment was 1.52 per patient with a mean duration of 8.37 days. These were reduced after treatment, with 0.79 hospitalisations per patient with a mean duration of 5.45 days. This generated savings of 1402.9 € per patient overall. The emergency episodes also decreased from 1.87 to 1.45. Although these differences showed clinical relevance, they did not reach statistical significance.

Conclusions Though the limited sample size does not enable us to demonstrate the real difference, inhaled colistin may be considered a cost-effective option to treat patients with pseudomonas-infected bronchiectasis but no CF.

No conflict of interest.