Inclusion Criteria:

Patients meeting all of the following criteria will be considered for enrollment into the study:

• Outpatients, male or female, aged 35 years or older
• Patients with a documented history of chronic bronchitis, characterized by cough and excessive sputum production for most days of at least three months for 2 consecutive years
• Patients with a clinical diagnosis of acute exacerbation of chronic bronchitis (AECB), presumed due to bacterial infection based on increased sputum purulence with either increased dyspnea or sputum volume
• Patients producing spontaneous sputum
• Patients with three or less AECB in the previous 12 months

Exclusion Criteria:

Patients presenting with any of the following will not be included in the study:

• Patients with a known diagnosis of bronchiectasis; cystic fibrosis; lung cancer or lung metastases; active pulmonary tuberculosis; or with suspected pneumonia.
• Patients with present acute respiratory failure or patients requiring aggressive airway management
• Hospitalized patients and patients from institutional care facilities
• Patients treated with antibiotics within 14 days prior to enrollment
• Patients who are receiving other medications, including systemic antimicrobial agents; or who have other disease conditions or infections that could interfere with the evaluation of drug efficacy or safety.
• Patients with a concomitant condition (including clinically relevant cardiovascular, hepatic, neurologic, endocrine, or other major systemic disease) making either implementation of the protocol or interpretation of the study results difficult
• Patients with a progressively fatal disease, or life expectancy ≤ three months
• Patients who have received any other investigational drug within 1 month prior to study entry, or have such treatment planned for the study period
• Patients with a recent (within the previous three months) history of alcohol or drug abuse
• Immunocompromised patients including, but not limited to: patients with known HIV infection (CD4 + <200/mm3); known neutropenia (<1500 neutrophils/mm3); chronic corticosteroid therapy (≥ 10mg/day prednisolone equivalent during at least three months); immunodepressant treatment within the previous six months; splenectomized patients or patients with known hyposplenia or asplenia.
• Patients with mental conditions rendering them unable to understand the nature, scope, and possible consequences of the study
• Patients unlikely to comply with the protocol, e.g., uncooperative attitude, inability to return for follow-up visits, and are unlikely to complete the study
• Patients having received anti-pneumococcal immunization in the previous six months before study entry
• Patients with suspected or known hypersensitivity to, or suspected serious adverse reactions to the study medication, or to ß-lactams or macrolide classes of antibiotics
• Patients diagnosed with myasthenia gravis
• Women who are breast-feeding or who are pregnant
• Women who are of childbearing potential who do not agree to use an approved contraceptive method during the study
• Patients with galactose intolerance, lactase deficiency or glucose-galactose malabsorption
• Patients with a known history of long QTc syndrome (e.g., personal or family history of syncope or arrhythmia)
• Patients treated within 2 weeks prior to study entry, or requiring treatment during study medication, with CYP3A4 inducers such as rifampicin, phenytoin, carbamazepine, phenobarbital, and St John's wort
• Patients requiring treatment during the study period with drugs not permitted by the clinical study protocol
• Patients known to have impaired hepatic function
• Patients known to have impaired renal function
• Patients already enrolled in this study