- Macrolide are antibiotics active against Gram-positive bacteria, but these agents exhibit also an antiinflammatory activity with several mechanisms suggested. The benefit of macrolides in the treatment of pulmonary disease is well known, although in some cases there is a lack of understanding of the exact pathway in which they contribute to the therapy. Several studies have examined the benefits of macrolide treatment on patients with chronic asthma. Possible modes of action include direct anti-bacterial activity, specifically against Chlamydia pneumonia, decreased metabolism of steroid drugs, and a modulation of the immune response. Some of the studies show overall asthma symptoms improvement, reducing corticosteroid requirements and an increase in FEV1. Cystic Fibrosis patients using macrolide therapy had fewer pulmonary exacerbations, delayed onset of the first pulmonary exacerbation, and a reduced need for additional antibiotic therapy. Low dose erythromycin treatment (less than a therapeutic dose for bacterial infection) in patients with diffuse panbronchiolitis showed significantly survival increase, suggesting that the anti-inflammatory properties of the antibiotic are responsible for the improvement. This article will review the use of macrolide therapy in various lung diseases.