Clinical Health Updates

Azithromycin (Zithromax) effective for cystic fibrosis with chronic pseudomonas

Clinical Question:
Are macrolide antibiotics beneficial for patients with cystic fibrosis and Pseudomonas aeruginosa?

Bottom Line:
Macrolide antibiotics (azithromycin) reduced the frequency of clinical exacerbations and improved the quality of life in patients with cystic fibrosis (CF) chronically infected with Pseudomonas aeruginosa.

Saiman L, Marshall BC, Mayer-Hamblett N, et al. Azithromycin patients with cystic fibrosis chronically infected with Pseudomonas aeruginosa: a randomized controlled trial. JAMA 2003; 290:1749-756.

Study Design:
Randomized controlled trial (double-blinded)

Treatment strategies for cystic fibrosis (CF) lung disease include antibiotics, mucolytics, and anti-inflammatory therapies. Increasing evidence suggests that macrolide antibiotics might be beneficial in patients with CF. The authors determined if an association between azithromycin use and pulmonary function exists in patients with CF. A multicenter, randomized, double-blind, placebo-controlled trial conducted from December 15, 2000, to May 2, 2002, at 23 CF care centers in the United States. Of the 251 screened participants with a diagnosis of CF, 185 (74%) were randomized. Eligibility criteria included age 6 years or older, infection with Pseudomonas aeruginosa for 1 or more years, and a forced expiratory volume in 1 second (FEV1) of 30% or more. Participants were stratified by FEV1 (> or =60% predicted vs <60% n =” 87)”> or =40 kg) of oral azithromycin 3 days a week for 168 days; placebo group (n = 98) received identically packaged tablets. Change in FEV1 from day 0 to completion of therapy at day 168 and determination of safety. Secondary outcomes included pulmonary exacerbations and weight gain. The azithromycin group had a mean 0.097-L (SD, 0.26) increase in FEV1 at day 168 compared with 0.003 L (SD, 0.23) in the placebo group (mean difference, 0.094 L; 95% confidence interval [CI], 0.023-0.165; P =.009). Nausea occurred in 17% more participants in the azithromycin group (P =.01), diarrhea in 15% more (P =.009), and wheezing in 13% more (P =.007). Participants in the azithromycin group had less risk of experiencing an exacerbation than participants in the placebo group (hazard ratio, 0.65; 95% CI, 0.44-0.95; P =.03) and weighed at the end of the study an average 0.7 kg more than participants receiving placebo (95% CI, 0.1-1.4 kg; P =.02).