Effectiveness of Antipseudomonal Antibiotics for Pulmonary Exacerbation of Cystic Fibrosis

Nurse injecting medicine into tube of patient
Researchers compared clinical outcomes of single vs double antipseudomonal antibiotics used to treat pulmonary exacerbations in patients with cystic fibrosis.

Patients with cystic fibrosis experiencing pulmonary exacerbations were not found to have greater improvement after therapy with 2 intravenous antipseudomonal antibiotics vs a single antibiotic, according to findings from a retrospective cohort study published in Clinical Infectious Diseases.

Researchers from Seattle, Washington, analyzed medical records from the Cystic Fibrosis Foundation Patient Registry-Pediatric Health Information System dataset collected between 2005 and 2018. Children and adolescents with cystic fibrosis were assessed for clinical outcomes after treatment for pulmonary exacerbations.

Patients were treated with either 2 (n=2123) or 1 (n=455) intravenous antipseudomonal antibiotic. The median age of patients was 16.1 years (interquartile range [IQR], 13.3-18.0) for those receiving 2 intravenous antibiotics and 16.2 years (IQR, 13.3-18.1) for those receiving 1 intravenous antibiotic;  44% and 46% were boys or men, and 75% and 63% were White, respectively. Baseline percent predicted forced expiratory volume in 1 second (ppFEV1) was 78.8% (IQR, 62.8-91.5) and 74.9% (IQR, 60.0-87.8), respectively.  In the previous 12 months, 40% and 54%, respectively, had been given 2 or more intravenous antibiotics.

Change in ppFEV1 was not significantly different between the cohorts (adjusted inverse probability of treatment weighting [aIPTW], -0.84%; 95% CI, -2.25 to 0.56; P =.24) nor was return to 90% or more of baseline (odds ratio [OR], 0.83; 95% CI, 0.61-1.13; P =.24) or time to next pulmonary exacerbation (hazard ratio [HR], 1.04; 95% CI, 0.87-1.24; P =.69).

Compared with patients who received 2 intravenous antibiotics, patients who received 1 intravenous and 1 inhaled antipseudomonal antibiotic had an increased risk for future pulmonary exacerbation (HR, 1.31; 95% CI, 1.06-1.63; P =.014).

Stratified by narrow- and broad-spectrum antibiotics, significant group differences were not observed for change in ppFEV1 (aIPTW, 0.80%; 95% CI, -0.56 to 2.16; P =.90) or return to 90% or more of baseline (OR, 0.99; 95% CI, 0.74-1.32; P =.93). Patients treated with narrow-spectrum antibiotics had a decreased risk for the next pulmonary exacerbation (HR, 0.86; 95% CI, 0.76-0.98; P =.021).

This study was limited by its retrospective design and use of registry data that may include inaccurate or missing data.

The study authors concluded there was little benefit with the use of 2 intravenous antipseudomonal antibiotics vs 1 for patients with pulmonary exacerbation of cystic fibrosis.  Patients living with cystic fibrosis who received narrow-spectrum antibiotics were more effectively protected from future pulmonary exacerbations.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please refer to the original reference for a full list of authors’ disclosures.


Cogen JD, Faino AV, Onchiri F, et al. Association between number of intravenous antipseudomonal antibiotics and clinical outcomes of pediatric cystic fibrosis pulmonary exacerbations. Clin Infect Dis. Published online June 8, 2021. doi:10.1093/cid/ciab525