Effects of azithromycin on ozone-induced airway neutrophilia and cytokine release

Exposure of humans to ozone causes increased neutrophils and inflammatory c ytokines in airway lining fluid. Recent research shows that macrolide antib iotics may reduce interleukin (IL)-8 production by bronchial epithelial cel ls and inhibit neutrophil chemotaxis, A double-blind, cross-over study was performed in which 12 healthy subjects underwent two separate 4-h exposures to 0.2 parts per million ozone while exercising intermittently. In the 73.5 h before exposure, subjects were pre treated with either 1,250 mg azithromycin or placebo. Sputum induction cond ucted 74 h pre- and 18 h post-exposure was used to measure total cells, per cent neutrophils, IL-6, and IL-8. There were significant (p<0.05) pre- to post-exposure increases in total ce lls, neutrophils, IL-6 and IL-8 in both the azithromycin and placebo arms. However, no significant differences were found between azithromycin and pla cebo conditions in the post- minus pre-exposure value for these variables. The results suggest that in healthy subjects, in the design used, azithromy cin, in usual clinical doses, does not have anti-inflammatory effects on hu man airways as indicated in the measured variables.