This is a nice review on azithromycin to prevent chronic obstructive pulmonary disease exacerbations (COPD exacerbations).
A recent Cochrane analysis and a retrospective VA study were both found that continuous azithromycin use decreased the incidence of COPD exacerbations in patients with mild-moderate COPD (OR 0.55). However, azithromycin use did not improve quality of life and was associated with a slightly increased cardiovascular risk (by increasing the QT interval) and increased the risk of hearing loss. See the link below for details:
Do you think patients with COPD should be placed on continuous azithromycin?