Erdosteine (ER), a multimechanism, mucoactive agent with anti-oxidant and anti-inflammatory properties, has been shown to improve lung function, decrease plasma reactive oxygen species (ROS), and 8-isoprostane levels in patients with chronic obstructive pulmonary disease (COPD).

To assess vs. placebo the effect of ER on the exercise-induced oxidative stress by measuring and comparing the release of pro-inflammatory mediators in severe COPD patients.

The double blind, placebo controlled study was carried out in 24 severe (GOLD Class III) COPD patients, aged >40 yr, randomized to receive either oral ER (600 mg/day, 8 males, mean age 70.5 yr) or placebo (9 males, mean age 70.8 yr) for 10 days. All patients performed a 6-min walking test (6MWT) before and after both treatments.

Mean ROS plasma levels increased significantly, but equally, in each group following the baseline 6MWT (p = ns). At the end of both treatments, a significant difference in mean plasma ROS increase from baseline became clear between the ER (+14.6% ± 2.7) and the placebo group (+24.4% ± 3.8) after the second 6MWT (p < 0.025). A similar significant trend was proved for the mean 8-isoprostane increase, which changed from baseline by +14.1% ± 2.6 in the ER, and by +26.3 ± 2.9 in the placebo group, respectively, after the second 6MWT (p < 0.006).

Data from the present study are suggesting that ER is effective in reducing the release of inflammatory mediators due to the exercise-induced oxidative stress in severe COPD patients.