Given long-term at low dosages, erythromycin, a macrolide antibiotic, significantly reduced the frequency and severity of exacerbations in patients with moderate to severe chronic obstructive pulmonary disease (COPD). In a recent study, researchers randomly assigned 109 patients with COPD to take either a placebo or 250 mg of erythromycin twice a day for 1 year. Patients recorded exacerbations and hospitalizations on a daily diary card. Researchers monitored their conditions using spirometry, sputum testing, and blood testing for bacterial infection and markers of inflammation. Here are some key findings:

* Patients in the placebo group experienced 60% of COPD exacerbations.

* Patients in the placebo group had more than twice as many hospitalizations (14 versus 6).

* The median duration of symptoms from exacerbations from onset to resolution was 13 for the placebo group, versus 9 days for those taking erythromycin.

Researchers note that not all patients in the study received recommended treatments known to reduce exacerbations, such as inhaled corticosteroid therapy. They call for more research to assess the benefits of long-term antibiotic therapy over currently recommended standard therapies.

Source: Seemungal TA, Wilkinson TM, Hurst JR, Perera WR, Sapsford RJ, Wedzicha JA. Long-term erythromycin therapy is associated with decreased chronic obstructive pulmonary disease exacerbations. Am J Respir Crit Care Med. 2008;178(11):1139-1147.