Giving aminoglycoside antibiotics intravenously once daily compared to giving them several times per day in people with cystic fibrosis

Review question

We looked for evidence to show the differences between giving intravenous antibiotics once daily compared to giving them several times a day when treating flare ups of disease (pulmonary exacerbations) in people with cystic fibrosis. This is an update of an earlier review.


Most people with cystic fibrosis develop persistent lung infections and they may receive frequent courses of intravenous antibiotics to treat pulmonary exacerbations. Giving the antibiotics just once per day rather than several doses per day reduces the cost of treatment and the time involved.

Search date

The evidence is current to 24 June 2016.

Study characteristics

This review includes four studies with a total of 328 children and adults. All the trials compared once-a-day dosing with three times-a-day dosing.

Key results

The review found that when treating people with cystic fibrosis for pulmonary exacerbations, giving the antibiotics once per day was just as good at as giving them more frequently in terms of lung function and body mass index. The review also found that giving the antibiotics once per day appeared to be less toxic to the kidneys in children. There were no differences between the different treatment schedules for other outcomes that the studies measured.

While once-daily treatment can be just as effective and more convenient than three-times daily treatment, we recommend further studies to look at the long-term safety of this treatment schedule.

Quality of the evidence

We judged that just one of the four studies carried a low risk that any design factors might affect the outcome results. In the remaining three studies, we thought that the fact that it was obvious whether the antibiotics were given once or three times a day could affect some outcome measures (e.g. lung function). Other risk factors were unclear or at low risk of bias. We assessed the evidence for lung function, body mass index and the evidence for side effects (e.g. toxicity) to be moderate to low quality.

Authors' conclusions: 

Once- and three-times daily aminoglycoside antibiotics appear to be equally effective in the treatment of pulmonary exacerbations of cystic fibrosis. There is evidence of less nephrotoxicity in children.

Read the full abstract...

People with cystic fibrosis, who are chronically colonised with the organism Pseudomonas aeruginosa, often require multiple courses of intravenous aminoglycoside antibiotics for the management of pulmonary exacerbations. The properties of aminoglycosides suggest that they could be given in higher doses less often. This is an update of a previously published review.


To assess the effectiveness and safety of once-daily versus multiple-daily dosing of intravenous aminoglycoside antibiotics for the management of pulmonary exacerbations in cystic fibrosis.

Search strategy: 

We searched the Cystic Fibrosis Specialist Register held at the Cochrane Cystic Fibrosis and Genetic Disorders Group's editorial base, comprising references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books of conference proceedings.

Date of the most recent search: 24 June 2016.

Selection criteria: 

All randomised controlled trials, whether published or unpublished, in which once-daily dosing of aminoglycosides has been compared with multiple-daily dosing in terms of efficacy or toxicity or both, in people with cystic fibrosis.

Data collection and analysis: 

The two authors independently selected the studies to be included in the review and assessed the risk of bias of each study; authors also assessed the quality of the evidence using the GRADE criteria. Data were independently extracted by each author. Authors of the included studies were contacted for further information. As yet unpublished data were obtained for one of the included studies.

Main results: 

Fifteen studies were identified for possible inclusion in the review. Four studies reporting results from a total of 328 participants (aged 5 to 50 years) were included in this review. All studies compared once-daily dosing with thrice-daily dosing. One study had a low risk of bias for all criteria assessed; the remaining three included studies had a high risk of bias from blinding, but for other criteria were judged to have either an unclear or a low risk of bias.

There was no significant difference between treatment groups in: forced expiratory volume in one second, mean difference 0.33 (95% confidence interval -2.81 to 3.48, moderate quality evidence); forced vital capacity, mean difference 0.29 (95% confidence interval -6.58 to 7.16, low quality evidence); % weight for height, mean difference -0.82 (95% confidence interval -3.77 to 2.13, low quality evidence); body mass index, mean difference 0.00 (95% confidence interval -0.42 to 0.42, low quality evidence); or in the incidence of ototoxicity, relative risk 0.56 (95% confidence interval 0.04 to 7.96, moderate quality evidence). The percentage change in creatinine significantly favoured once-daily treatment in children, mean difference -8.20 (95% confidence interval -15.32 to -1.08, moderate quality evidence), but showed no difference in adults, mean difference 3.25 (95% confidence interval -1.82 to 8.33, moderate quality evidence). The included trials did not report antibiotic resistance patterns or quality of life.