Antibiotic strategies for eradicating Pseudomonas aeruginosa in people with cystic fibrosis

Background

Lower respiratory tract infection with Pseudomonas aeruginosa (P. aeruginosa) occurs in most people with cystic fibrosis. Once chronic infection is established, P. aeruginosa is virtually impossible to eradicate and is associated with increased mortality and morbidity. Early infection may be easier to eradicate.

Objectives

To determine whether antibiotic treatment of early P. aeruginosa infection in children and adults with cystic fibrosis eradicates the organism and improves clinical and microbiological outcome.

Search strategy

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 abstract books of conference proceedings.

Most recent search: September 2006.

Selection criteria

We included randomised controlled trials of people with cystic fibrosis, in whom P. aeruginosa had recently been isolated from respiratory secretions. We compared combinations of inhaled, oral or intravenous antibiotics with placebo or usual treatment or other combinations of inhaled, oral or intravenous antibiotics. We excluded non-randomised trials, cross-over trials, and those utilising historical controls.

Data collection and analysis

Both authors independently assessed selected trials, assessed methodological quality and extracted data.

Main results

The search identified 19 trials. Three trials (69 participants) were eligible for inclusion, two trials are ongoing. There is evidence from two trials that treatment of early P. aeruginosa infection with inhaled tobramycin results in microbiological eradication of the organism from respiratory secretions more often than placebo, OR 0.15 (95% CI 0.03 to 0.65) and that this effect may persist for up to 12 months. These trials were of low methodological quality.

One randomised controlled trial of oral ciprofloxacin and nebulised colisitin versus usual treatment was identified. This trial was of poor methodological quality. The results suggested treatment of early infection results in microbiological eradication of P. aeruginosa more often than usual treatment, after two years, OR 0.24 (95% CI 0.06 to 0.96). There is insufficient evidence to determine whether antibiotic strategies for the eradication of early P. aeruginosa decrease mortality or morbidity, improve quality of life, or are associated with adverse effects compared to placebo or standard treatment.

Authors' conclusions

We found that nebulised antibiotics, alone or in combination with oral antibiotics, were better than no treatment for early infection with P. aeruginosa. Eradication may be sustained in the short term. Overall, there is insufficient evidence from this review to state which antibiotic strategy should be used for the eradication of early P. aeruginosa infection in CF.