Study on Effectiveness of Low Dose Theophylline as Add-on to Inhaled Corticosteroid for Patients with Sulfur Mustard Induced Bronchiolitis

Abstract

Background: Theophylline may reverse steroid resistance and decrease inflammation in patients with chronic pulmonary disease and sulfur mustard (SM) induced bronchiolitis. This study was designed to assess the effects of low-dose theophylline on improvement of pulmonary function tests (PFTs) of SM exposed patients. Methods: In this comparative observational study, a group of SM-exposed victims during the Iraq-Iran war who were treated with oral slow releasing (SR) theophylline, salmetrol, fluxitide, omeprazole and NAC (study group) were compared to a group of age and gender matched SM-exposed patients who received same medications except oral SR theophylline (historical control group). PFTs were measured at the beginning of the study and after 8 weeks of the treatment. Results: In total, 33 subjects in the study group and 27 subjects in the control group were studied. Mean (SD) age of all subjects was 51 (14.1) years. In the study group, on the 8th week post-treatment, PFTs decreased, though the differences of tests between before and after treatment were not significant. In the control group, all the tests decreased in the same period and these reductions were not also significant. However, the changes in PFTs were significantly different between the two groups. The results of most PFTs in the controls decreased in greater extents compared to theophylline treated patients. This shows that despite theophylline was unable to improve the patients; it was partially able to decelerate the reductions in PFTs. Conclusion: Theophylline may not improve PFTs of SM exposed patients but it may decelerate the progress of the underlying respiratory disease. Further studies in this setting with higher doses of theophylline and longer term of evaluation are needed to better understand the pathophysiological mechanism of SM induced bronchiolitis and the effectiveness of the treatment with theophylline.