Aaron P MilstoneDivision of Allergy, Pulmonary and Critical Care, Vanderbilt University Medical Center, Nashville, TN, USAAbstract: Chronic bronchitis is a relatively common entity among patients with underlying chronic obstructive lung disease. Typical treatment includes pulmonary hygiene, bronchodilators, and antimicrobial therapy. In recent years, the duration of antimicrobial therapy in acute exacerbations of COPD has become shorter and shorter. This review summarizes the data on the use of the drug azithromycin for this particular patient population with a focus on 3-day and single-day therapy.Keywords: COPD acute exacerbation, macrolide, azithromycin