Intervention: Azithromycin
Trial phase: Not Applicable
ATC code: J01FA10 | J01RA07 | J01RA16 | S01AA26
SMILES: CCC1OC(=O)C(C)C(OC2CC(C)(OC)C(O)C(C)O2)C(C)C(OC2OC(C)CC(N(C)C)C2O)C(C)(O)CC(C)CN(C)C(C)C(O)C1(C)O
Sex: All
Age groups: Adult | Older Adult
Healthy volunteers: No
Participants at risk: 242
Group description: 500 mg of Azithromycin (2 capsules of 250 mg) administered orally as a single dose on Day 1, followed by 250 mg capsule of Azithromycin administered orally once daily for 4 days (Day 2 through Day 5).
Eligibility criteria:
Inclusion Criteria:

Clinician suspected Lower Respiratory Tract Infection (LRTI)* based on the presence of at least two qualifying symptoms** OR one qualifying symptom and at least one qualifying vital sign***.

*LRTI will include acute bronchitis, tracheitis, tracheobronchitis, asthma exacerbation, and acute exacerbation of Chronic obstructive pulmonary disease (COPD) but does not include known pneumonia.

**New cough, worsening of chronic cough, new sputum production, increased volume or purulence of chronic sputum production, chest pain, and difficulty breathing.

***Fever (Provider or patient-measured temperature > / = 37.8 degrees Celsius (100.0 degrees Fahrenheit) or patient-reported feverishness), tachycardia of > / = 90 beats/minute, tachypnea of > 20 breaths/minute.

Males and females age > / = 18 years old.
Presentation > / = 24 hours and < / = 28 days after the onset of at least one qualifying symptom related to the acute episode of illness.
Ability to understand study procedures and willing and able to comply with all required procedures and visits for the entire length of study.
Provide written informed consent before initiation of any study procedures.

Exclusion Criteria:

Hospitalized prior to screening and enrollment. Subjects enrolled in clinic or Emergency Department (ED) setting and then hospitalized during the same clinical encounter may be included.

Chronic pulmonary conditions at the investigator's discretion*.

*Such as:

Noninvasive ventilation use for any indication other than obstructive sleep apnea
Long-term invasive mechanical ventilation for any indication
Known diagnosis of cystic fibrosis or chronic bronchiectasis.
Receipt of an investigational product within 30 days prior to Day 1 or plans to potentially start any investigational product within 30 days after the subject's anticipated study completion.
Current enrollment in another clinical trial of an investigational agent.
Known or suspected infection at any other anatomic site requiring antibacterial therapy.

Immunosuppression*

*Includes:

Human Immunodeficiency Virus (HIV) infection with CD4 < 200 based on last known measurement or patient-reported value
History of hematologic malignancies
Receipt of chemotherapy within the previous 6 months or anticipated receipt of chemotherapy during the study period (1 month)
Known to have an absolute neutrophil count of < 500 cells/mL or an expectation of an absolute neutrophil count of < 500 cells/mL during course of the study
Current systemic corticosteroid use (equivalent of 20mg prednisone per day for > / = 2 weeks within the last month)
Systemic non-steroid immunosuppressive or biologic therapy for transplant, rheumatologic conditions, or other conditions within the last month. Biologics used specifically for control of moderate to severe asthma, including anti-IgE monoclonal antibody therapy (Xolair) or IL-5 monoclonal antibodies (Mepolizumab and Reslizumab) are allowed
Contraindication to the use of azithromycin including history of allergy or intolerance to azithromycin or known prolonged QTc interval (> 500 msec).
Any condition that in the judgment of the referring provider or site investigator precludes participation because it could affect subject safety or ability of subject to participate in this trial.
Prior use of azithromycin in the past two weeks.
Use of any systemic antibiotic in the previous 24 hours.
Previous randomization in this trial.