Inclusion Criteria:

- Diagnosis of chronic bronchitis (chronic cough and sputum production on most days for three consecutive months for more than two consecutive years) and clinical evidence of AECB as demonstrated by both the following symptoms:

1. Production of purulent sputum as defined by Gram stained sputum specimen
2. Presence of all of the following:

i. Increased sputum production

ii. Increased dyspnea

iii. Increased cough

• At least two exacerbations of AECB in the past 12 months

Exclusion Criteria:

• A chest radiograph consistent with pneumonia
• Treatment with any systemic antibiotic within the twenty-one days prior to study entry or those with a chance of receiving other systemic antibiotics during study participation