Antibiotics for Eradicating Pseudomonas Aeruginosa in People with Cystic Fibrosis

A Cochrane review [Abstract] 1 included 60 trials; seven trials (744 participants) with a duration between 28 days and 27 months were eligible for inclusion. Two RCTs suggest that treatment of early P. aeruginosa infection with inhaled tobramycin results in microbiological eradication of the organism from respiratory secretions more often than placebo at two months (OR 0.15, 95% CI 0.03 to 0.65; 2 studies, n=43) and that this effect may persist for up to 12 months.

In one RCT (n=26), the odds of being chronically infected with P. aeruginosa was reduced in the oral ciprofloxacin and nebulised colisitin group compared to the placebo group after 24 months (OR 0.12, 95% CI 0.02 to 0.79).

One trial comparing 28 days to 56 days treatment with nebulised tobramycin solution for inhalation in 88 participants showed that both treatments were effective and well-tolerated, with no notable additional improvement with longer over shorter duration of therapy. However, this trial was not powered to detect non-inferiority or equivalence.

A trial of oral ciprofloxacin with inhaled colistin versus nebulised tobramycin solution for inhalation alone (223 participants) failed to show a difference between the two strategies, although it was underpowered to show this. A further trial of inhaled colistin with oral ciprofloxacin versus nebulised tobramycin solution for inhalation with oral ciprofloxacin also showed no superiority of the former, with increased isolation of Stenotrophomonas maltophilia in both groups.

A recent trial (306 children) comparing cycled nebulised tobramycin solution for inhalation to culture-based therapy and also ciprofloxacin to placebo showed fewer participants in the cycled therapy group with one or more isolates of Pseudomonas aeruginosa, odds ratio 0.51 (95% CI 0.31 to 0.28).There is insufficient evidence to determine whether antibiotic strategies decrease mortality or morbidity, improve quality of life, or are associated with adverse effects compared to placebo or standard treatment.

Comment: The quality of evidence is downgraded by limitations in study quality (unclear allocation concealment) and by imprecise results (limited study size for each comparison).

References

• Langton Hewer SC, Smyth AR. Antibiotic strategies for eradicating Pseudomonas aeruginosa in people with cystic fibrosis. Cochrane Database Syst Rev 2017;(4):CD004197. [PubMed]
• Remmington T, Jahnke N, Harkensee C. Oral anti-pseudomonal antibiotics for cystic fibrosis. Cochrane Database Syst Rev 2016;7():CD005405. [PubMed]