The study was performed to confirm that a single, 2.0 g oral dose of azithromycin sustained release (SR) at least as effective as 7 days of clarithromycin extended release (ER), 1.0 g by mouth once daily, when used to treat adults with mild to moderate community acquired pneumonia (CAP), and that both treatments were safe.

Inclusion Criteria:

Outpatients with a diagnosis of pneumonia, as demonstrated by a productive cough and at least 2 of the following signs and symptoms: rales and/or evidence of pulmonary consolidation; dyspnea or tachypnea; elevated body temperature; or elevated total peripheral white blood cell count (WBC >10,000/mm3) or greater than 15% immature neutrophils were included. Patients were to have a chest radiograph demonstrating evidence of a new infiltrate or consolidation, and a Modified Fine Risk score of ≤ 70 (Fine Class I and II).

Exclusion Criteria:

Patients who were treated with any systemic antibiotic of greater than 1 dose or 1 combination dose (such as cephalosporin and macrolide) within the previous 7 days, or the likelihood of receiving other systemic antibiotics during participation in the study; were hospitalized in the previous 14 days or had an infection acquired in the hospital, and who were residents of a long-term care facility were excluded.