Shifting patterns of inhaled antibiotic use in cystic fibrosis

Rationale: Antibiotic inhalation has become widely accepted as a standard treatment for cystic fibrosis (CF) airway infection. We assessed the prevalence and context of inhaled antibiotic use in the North American CIF population. Our working hypothesis was that a shift from acute to chronic use of inhaled antibiotics has coincided with increased prevalence of use among CF patients. Methods: Descriptive statistics were collected for 30,833 patients enrolled in the Epidemiologic Study of CF (ESCF) during 1996 through 2005. A multivariate analysis was performed on data from a subgroup of 18,021 patients enrolled in ESCF during 2003 through 2005. Results: The prevalence of inhaled antibiotic use in the North American CF population increased during 1996 through 2005 due to increased chronic use, while acute use to treat pulmonary exacerbations decreased. In 2005, 50% of CF patients used inhaled tobramycin and 9% used inhaled colistin chronically; most of the latter used both agents concurrently Airway obstruction severity and airway infection status were predictors of inhaled antibiotic use. Conclusions: Increased chronic use and decreased acute use of inhaled antibiotics presumably reflect a shift toward more proactive management of airway infections in the North American CIF population. The effects of these usage patterns on long-term clinical outcomes and emergence of antibiotic-resistant Pseudomonas aeruginosa strains warrant further study.