Efficacy of concomitant administration of clarithromycin and acetylcysteine in bronchiolitis obliterans in seventeen sulfur mustard-exposed patients: An open-label study

Background: Victims of sulfur mustard (SM) gas exposure experience different types of chronic pulmonary disease, manifested as cough, sputum production, and dyspnea. Conventional therapies (eg, immunosuppressive drugs, corticosteroids) have not been effective in these patients.

Objective: This study was carried out to determine the efficacy of concomitant administration of the macrolide clarithromycin and the mucolytic agent acetylcysteine in the treatment of bronchiolitis obliterans in SM-exposed patients.

Methods: This open-label clinical study was conducted at the Research Center of Chemical Injuries, Baqiyatallah Medical Sciences University, Tehran, Iran. Clarithromycin and acetylcysteine were administered concomitantly for 6 months to male SM-exposed patients with chronic bronchitis and bronchiolitis obliterans who were nonresponsive to conventional treatments. Efficacy analysis included symptom assessment and pulmonary function tests (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], and FEV1/FVC ratio) using spirometry, performed at baseline and after 2 and 6 months of treatment.

Results: Seventeen male patients (mean [SD] age, 38.3 [5.3] years [range, 31-50 years]; mean [SD] body weight, 77.9 [15.7] kg) were included in the study. Cough and sputum production were each found in 10 of 17 patients (58.8%) at baseline and were improved in all 10 patients after the administration of clarithromycin and acetylcysteine. FEV1 and FVC also were improved, by mean (SD) 10.6% (9.7%) (P < 0.001 vs baseline) and 12.9% (13.6%) (P = 0.001 vs baseline). No significant change in FEV1/FVC ratio was found.

Conclusions: In this study of concomitant administration of clarithromycin and acetylcysteine for the treatment of bronchiolitis obliterans in SM-exposed patients, symptoms and pulmonary function were improved. These results may have been related to the therapeutic effects of a macrolide antibiotic on chronic bronchitis and bronchiolitis obliterans in these patients. Based on the results of this study, we recommend this treatment for chemical warfare victims with recurrent exacerbation of bronchitis who do not respond to conventional treatment.