Antibiotic strategies for eradicating Pseudomonas aeruginosa in people with cystic fibrosis

Background Respiratory tract infections with Pseudomonas aeruginosa occur in most people with cystic fibrosis (CF). Established chronic P aeruginosa infection is virtually impossible to eradicate and is associated with increased mortality and morbidity. Early infection may be easier to eradicate. This is an updated review. Objectives Does giving antibiotics for P aeruginosa infection in people with CF at the time of new isolation improve clinical outcomes (e.g. mortality, quality of life and morbidity), eradicate P aeruginosa infection, and delay the onset of chronic infection, but without adverse effects, compared to usual treatment or an alternative antibiotic regimen? We also assessed cost‐effectiveness. Search methods We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and conference proceedings. Latest search: 24 March 2022. We searched ongoing trials registries. Latest search: 6 April 2022. Selection criteria We included randomised controlled trials (RCTs) of people with CF, in whom P aeruginosa had recently been isolated from respiratory secretions. We compared combinations of inhaled, oral or intravenous (IV) antibiotics with placebo, usual treatment or other antibiotic combinations. We excluded non‐randomised trials and cross‐over trials. Data collection and analysis Two authors independently selected trials, assessed risk of bias and extracted data. We assessed the certainty of the evidence using GRADE. Main results We included 11 trials (1449 participants) lasting between 28 days and 27 months; some had few participants and most had relatively short follow‐up periods. Antibiotics in this review are: oral – ciprofloxacin and azithromycin; inhaled – tobramycin nebuliser solution for inhalation (TNS), aztreonam lysine (AZLI) and colistin; IV – ceftazidime and tobramycin. There was generally a low risk of bias from missing data. In most trials it was difficult to blind participants and clinicians to treatment. Two trials were supported by the manufacturers of the antibiotic used. TNS versus placebo TNS may improve eradication; fewer participants were still positive for P aeruginosa at one month (odds ratio (OR) 0.06, 95% confidence interval (CI) 0.02 to 0.18; 3 trials, 89 participants; low‐certainty evidence) and two months (OR 0.15, 95% CI 0.03 to 0.65; 2 trials, 38 participants). We are uncertain w