82 young people with CF (6-21 years, mean age 11.0 years, SD 3.3 years), 40 in azithromycin group, 42 in placebo group. FEV1 >40% predicted. 19 patients were infected with Pseudomonas aeruginosa.
Interventions
Azithromycin 250 mg tablet 3 times per week (>40 kg, 500 mg) versus placebo.
Outcome measures
Relative change in FEV1 and FVC % predicted, number of pulmonary exacerbations, additional antibiotic treatment (oral and IV), lung microbiology and adverse events.
Main results
The relative change in FEV1 at month 12 did not differ significantly between the two groups. The number of pulmonary exacerbations (count ratio 0.50 (95% CI 0.32 to 0.79), p < 0.005), the time elapsed before the first pulmonary exacerbation (hazard ratio 0.37 (95% CI 0.22 to 0.63), p < 0.0001), and the number of additional courses of oral antibiotics were significantly reduced in the azithromycin group regardless of the infectious status (count ratio 0.55 (95% CI 0.36 to 0.85), p < 0.01). No severe adverse events were reported.
Authors' conclusions
Long term use of low dose azithromycin in young patients with cystic fibrosis has a beneficial effect on lung disease expression, even before infection with Pseudomonas aeruginosa.