The ultimate goal is to reduce unnecessary antibiotic prescriptions which drive the development of antibiotic resistance in the community. The primary objective of ABACOPD is to demonstrate in a sufficiently sized clinical study that there is no relevant increase in the "failure-rate" for patients with acute moderate exacerbations of COPD (AE-COPD) treated with placebo instead of antibiotic treatment both on top of standard of care. A patient is classified as treatment failure if additional antibiotic therapy is required during treatment period or until the test of cure visit (TOC at day 30, primary endpoint).

Inclusion Criteria:

• Adults, either sex, older or equal than 40 years of age

• For female patients, the following conditions are to be met:

  • has been postmenopausal for at least 1 year, or

  • is surgically incapable of bearing children, or

  • is of childbearing potential, and the following conditions are met:

    • has a negative pregnancy test (urine- or serum-based) immediately before study entry (i.e., before the start of treatment or any other study procedure that could potentially harm the fetus), and one or more of following criteria
    • must agree to abstinence or use an accepted method of contraception. The subject must agree to continue with the same method throughout the study.
    • having only female sexual partners
    • sexual relationship with sterile male partners only

• Patients diagnosed with COPD stages I-IV as defined by the Global initiative for chronic Obstructive Lung disease (GOLD).

and

• Doctor's diagnosis of acute (onset < 7 days) moderate exacerbation of COPD defined by a sustained worsening of the patient's condition (including at least 2 of the following symptoms: increased dyspnea, increased sputum production, sputum purulence and increased cough), from the stable state and beyond normal day-to-day variations, necessitating a change in regular medication in patient with underlying COPD, needing additional medical assistance.
• Absence of community acquired pneumonia or lower respiratory tract infection with a clear indication for antibiotic treatment as determined by Procalcitonin level < 0.25 ng/mL and/or absence of pulmonary infiltrates on routine chest x-ray.
• Smoking history of at least 10 Pack Years or more.
• Patients must be able to complete diaries and quality of life questionnaires.
• Patients must sign and date an informed consent prior to any study procedures.

Exclusion Criteria:

• Severe exacerbation: defined by need for ventilatory support (indicated by severe dyspnea with failure to respond to emergency treatment and/or persistent hypoxemia (PaO2 <50 mm Hg despite O2 administration and / or respiratory acidosis (pH <7.35 and PaCO2> 45mmHg)) or mental confusion or circulatory insufficiency (need of vasopressors)
• Fever (>38.5°C)
• Known impaired hepatic or renal function
• Active or suspected tuberculosis infection of the respiratory tract
• Acute exacerbation of asthma
• Suspected or known hypersensitivity to, or suspected serious adverse reaction to sultamicillin; suspected or known hypersensitivity to penicillins or cephalosporins
• Immunosuppression or Immunosuppressive therapy (cytostatic chemotherapy within last 28 days or neutropenia (neutrophils < 1000/µ)l; systemic corticosteroids (≥20 mg prednisolon equivalent/day > 14 days; HIV-infection; immunosuppression after organ- or bone marrow transplant)- Patients with metastatic or hematological malignancy, splenectomized patients or patients with known hyposplenia or asplenia
• Oral/parenteral antibiotic use within 30 days prior to randomization (a singular administration of antibiotics prior to randomization is allowed)
• In-patient treatment within the last 30 days
• An antibiotic is clearly indicated for treatment of a known infection
• Known MRSA (methicillin-resistant Staphylococcus aureus) colonization or infection
• Patients with known bronchiectasis
• Patients with known bacterial airway colonization (>3 positive sputum cultures in the previous year)
• Progressively fatal disease, or life expectancy ≤6 months
• Mononucleosis
• Lymphatic leukemia
• Severe gastro-intestinal disorders with vomiting and diarrhea
• Women who are breast feeding
• Patients who have received treatment with any other investigational drug within 1 month prior to study entry, or have such treatment planned for the study period during treatment and follow up phase.
• 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 unlikelihood of completing the study.