Nebulized Azithromycin Versus Oral Azithromycin as Anti-Inflammatory Therapy in Children with Cystic Fibrosis: A Prospective Randomized Open-Label Trial

Background: Oral azithromycin is recommended as anti-inflammatory therapy for patients with cystic fibrosis (CF) 6 years of age and older to improve lung function and reduce exacerbations. Objectives: We evaluated the short-term efficacy and safety of nebulized azithromycin as anti-inflammatory therapy in children with CF chronically infected with Pseudomonas aeruginosa. Methods: In a randomized prospective study, children aged 8 - 18 years with clinically stable CF and FEV1 25% - 75% predicted with no recent use of oral, intravenous or inhaled antipseudomonal antibiotics and azithromycin were randomized to receive either nebulized azithromycin (70 mg daily) or oral azithromycin 3 times per week for 28 days. Primary endpoint was changes in pulmonary function (FEV1). Secondary outcomes included changes in Pseudomonas aeruginosa (PA) colonization characteristics (count, phenotype), quality of life and weight. Results: A total of 280 patients were screened, of whom 60 were found eligible. Forty five patients (25 in the nebulized group) and 20 in the oral group) completed the study. After 28 days of treatment, nebulized azithromycin was significantly associated with improvements in FEV1 % predicted, quality of life measure and weight. Also PA count was significantly decreased. Importantly, improvements of FEV1 % predicted, quality of life, weight and the decline in PA count were statistically significantly greater with nebulized azithromycin compared with oral azithromycin. No significant difference was observed in PA phenotype in either treatment arms. Conclusions: Nebulized azithromycin is associated with a significant improvement in lung function, PA count, quality of life and weight in clinically stable CF children with chronic PA infection. The improvements observed were greater compared with oral azithromycin. Nebulized azithromycin could be suggested as a new therapeutic strategy for this life-limiting disease. Further clinical trials with novel nebulizer formulation of azithromycin and large number of participants are needed to further assess the efficacy, safety and sustained effect of this new therapeutic approach in children with CF.