Double-blind Placebo Trial to Determine the Efficacy and Safety of Treatment With Azithromycin for 6 Months in Patients With Post-infectious Bronchiolitis Obliterans

Bronchiolitis obliterans (BO) was defined as the presence of signs and symptoms of chronic obstructive lung disease: A) previously documented acute lower respiratory infection (ALRI) with persistence of airway obstruction and respiratory signs and symptoms, such as: dyspnea, tachypnea, retractions, persistent cough, increased antero-posterior diameter of the chest, persistent wheezing, crackles, exercise intolerance; B) findings such as: hyperinflation, atelectasis, and mosaic oligohemia on CT scan; and C) persistent obstructive pattern on pulmonary function test.

Patients were randomly assigned by pharmacy staff in blocks of 4 to receive either capsules of azithromycin 250 mg (Group 1) or placebo (Group 2) 3 days a week for 6 months. Patients whose weight was less than 40 kg received 250 mg 3 days a week (Monday, Wednesday, and Friday) and those weighing more than 40 kg received 500 mg in the same scheme, according to randomization to active drug or placebo. Pulmonary function and number of exacerbations were evaluated. Spirometry and plethysmography were performed at baseline and at 6 months. Variables analyzed were Forced vital capacity (FVC),Flow expiratory volume at the first second (FEV1), Total lung capacity (TLC),Residual volumen(RV),especific conductance (sGaw). Patients had been clinically stable over the previous three weeks.