Effect of Azithromycin on Lung Function in 6-18 Year-olds With Cystic Fibrosis (CF) Not Infected With P. Aeruginosa

Inclusion Criteria

• Male or female, 6-18 years of age at enrollment
• Confirmed diagnosis of CF
• Written informed consent (and assent when applicable)
• Clinically stable at enrollment as assessed by the site investigator
• FEV1 % predicted > 50%
• Ability to comply with medication use, study visits, and study procedures
• Ability to swallow a 250 mg tablet

Exclusion Criteria

• Weight less than 18.0 kg
• Respiratory culture positive for P. aeruginosa, NTM, or B. cepacia complex within 1 year or at screening, or AFB positive at screening
• Allergy to macrolide antibiotics
• Use of macrolide antibiotics (e.g., azithromycin, clarithromycin) within 60 days of screening
• Use of systemic corticosteroids or intravenous or oral antibiotics within 14 days of screening
• Initiation of high dose ibuprofen, Pulmozyme®, hypertonic saline or aerosolized antibiotics within 30 days of screening
• Chronic therapy with drugs known to have rare but serious interactions with azithromycin: amiodarone, digoxin, disopyramide, lovastatin, pimozide, rifabutin, and nelfinavir
• Investigational drug use within 30 days of screening
• Laboratory abnormalities (creatinine, liver function or neutropenia) at screening and confirmed at follow-up testing prior to randomization
• History of biliary cirrhosis, portal hypertension, or splenomegaly, or splenomegaly on physical exam
• History of ventricular arrhythmia
• Other major organ dysfunction, excluding pancreatic dysfunction
• History of lung transplantation or currently on lung transplant list
• Relative decrease in FEV1 % predicted ≥ 20% between the screening and enrollment visit
• Positive serum pregnancy test at screening
• Pregnant, breastfeeding, or if post-menarche female, unwilling to practice birth control during participation in the study
• History of alcohol, illicit drug or medication abuse within 1 year of screening in the judgment of the site investigator
• Presence of a condition or abnormality that in the opinion of the site investigator would compromise the safety of the subject or the quality of the data