RESUMO
BACKGROUND: The effects of inhaled corticosteroids (ICS) on markers of oxidative stress in patients with stable COPD are unclear. OBJECTIVES: The aim was to investigate the effect of ICS on exhaled H(2)O(2) in stable COPD patients and to compare ICS with different lung deposition. METHODS: Forty-one stable patients with moderate COPD (FEV(1) approximately 60% predicted) were randomized to sequence 1; first HFA-134a beclomethasone dipropionate (HFA-BDP, an ICS with more peripheral deposition) 400 microg b.i.d., then fluticasone propionate (FP, an ICS with more central deposition) 375 microg b.i.d. (n = 20) or sequence 2; first FP, then HFA-BDP (n = 21). Both 4-week treatment periods were preceded by a 4-week washout period. After each period, the concentration of H(2)O(2) in exhaled breath condensate was measured. RESULTS: The H(2)O(2) concentration decreased significantly after the first treatment period in both sequence 1 and 2 (p < 0.05, p = 0.01, respectively). In neither sequence was there a return to baseline values after the second washout, indicating a carry-over effect. The concentrations remained low in both sequences during the second treatment period. CONCLUSIONS: Both ICS appeared to reduce exhaled H(2)O(2) in stable COPD patients. However, this study showed no difference between ICS with different deposition patterns, which in part may be due to the carry-over effect.