Immunomodulatory effects of macrolides: implications for practicing clinicians.

Macrolides are regarded as the drugs of choice for the treatment of diffuse panbronchiolitis (DPB) due to their favorable effects on patient outcomes. These drugs decrease sputum production, thereby improving pulmonary function. Moreover, these effects are independent of dosing with respect to clarithromycin, erythromycin, and roxithromycin. The marked success of macrolides in this disease is a direct effect of impeding the inflammatory cascade. With their abilities to reduce the secretion of proinflammatory cytokines, ameliorate the infiltration of inflammatory cells into the airways, and reduce mucus secretion, macrolides are able to improve pulmonary function and quality of life in patients with chronic inflammatory diseases of the airways. Although prolonged use of macrolides raises concerns of increased adverse effects, data do not support such occurrences. With respect to concerns of resistance, it should be noted that in Japan, where macrolides are part of the treatment for DPB, these agents continue to be used effectively as antimicrobial agents. Therefore, the potential benefits of the immunomodulatory effects of macrolides in other conditions such as cystic fibrosis, chronic sinusitis, asthma, and chronic bronchitis are under investigation.