Azithromycin in bronchiolitis obliterans complicating bone marrow transplantation: a preliminary study.

Bronchiolitis obliterans (BO) is a serious noninfectious pulmonary complication following allogeneic bone marrow transplantation (BMT). Azithromycin, a macrolide antibiotic, may have a beneficial effect in BO through its anti-inflammatory effect. The aim of the current study was to investigate the potential effect of azithromycin on pulmonary function tests (PFTs) in BO complicating BMT. PFTs of 153 post-BMT patients were followed; eight patients out of 153 (12%) developed obstructive airway disease on their PFTs, along with characteristic findings of BO on high-resolution computed tomography of the chest. These patients were given azithromycin 500 mg q.d. for 3 days, followed by 250 mg three times a week for 12 weeks. Clinically significant improvements were achieved both in forced vital capacity, where the mean (95% confidence interval) increase reported was 410 mL (0.16-0.65), which was an average improvement of 21.57%, and in the forced expiratory volume in one second, where the mean increase noticed was 280 mL (0.10-0.44), which was an average improvement of 20.58%. In conclusion, the potential role of azithromycin in the treatment of bronchiolitis obliterans is intriguing and it warrants further testing.