Intravenous antibiotics for pulmonary exacerbations in people with cystic fibrosis

Cystic fibrosis is a multisystem disease characterised by the production of thick secretions causing recurrent pulmonary infection, often with unusual bacteria. Intravenous (IV) antibiotics are commonly used in the treatment of acute deteriorations in symptoms (pulmonary exacerbations); however, recently the assumption that exacerbations are due to increases in bacterial burden has been questioned. This is an update of a previously published review. To establish whether IV antibiotics for the treatment of pulmonary exacerbations in people with cystic fibrosis improve short-term and long-term clinical outcomes. We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews and ongoing trials registers. Date of last search of Cochrane Trials Register: 19 June 2024. Randomised controlled trials and the first treatment cycle of cross-over studies comparing IV antibiotics (given alone or in an antibiotic combination) with placebo, or inhaled or oral antibiotics for people with cystic fibrosis experiencing a pulmonary exacerbation. Studies comparing different IV antibiotic regimens were also eligible. We assessed studies for eligibility and risk of bias, and extracted data. Using GRADE, we assessed the certainty of the evidence for the outcomes lung function % predicted (forced expiratory volume in one second (FEV ) and forced vital capacity (FVC)), time to next exacerbation and quality of life. We included 45 studies involving 2810 participants. The included studies were mostly small, and inadequately reported, many of which were quite old. The certainty of the evidence was mostly low. Combined intravenous antibiotics versus placebo Data reported for absolute change in % predicted FEV and FVC suggested a possible improvement in favour of IV antibiotics, but the evidence is very uncertain (1 study, 12 participants; very low-certainty evidence). The study did not measure time to next exacerbation or quality of life. Intravenous versus nebulised antibiotics Five studies (122 participants) reported FEV , with analysable data only from one study (16 participants). We found no difference between groups (moderate-certainty evidence). Three studies (91 participants) reported on FVC, with analysable data from only one study (54 participants). We are very uncertain on the effect of nebulised antibiotics (