From the FDA Drug Label
Adults Infection *Recommended Dose/Duration of Therapy *DUE TO THE INDICATED ORGANISMS (See INDICATIONS AND USAGE.) Community-acquired pneumonia (mild severity) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5
The recommended dose and duration of azithromycin for the treatment of community-acquired pneumonia (mild severity) in adults is 500 mg on Day 1, followed by 250 mg once daily on Days 2 through 5 1.
- Dose: 500 mg on Day 1,250 mg on Days 2-5
- Duration: 5 days This dosing regimen is for mild severity community-acquired pneumonia.
From the Research
For inpatient treatment of pneumonia with azithromycin, the recommended dosage is 500 mg intravenously (IV) once daily for the first 1-2 days, followed by 500 mg orally once daily to complete a total 5-7 day course, as supported by the most recent study 2. This regimen is typically used as part of combination therapy, most commonly with a beta-lactam antibiotic such as ceftriaxone (1-2 g IV daily) or ampicillin-sulbactam (1.5-3 g IV every 6 hours), as azithromycin alone is not recommended for empiric inpatient pneumonia treatment. The combination therapy provides coverage against typical bacterial pathogens (via the beta-lactam) and atypical organisms like Mycoplasma, Legionella, and Chlamydophila (via azithromycin). Azithromycin's long half-life allows for once-daily dosing, and its excellent tissue penetration achieves high concentrations in the lungs. Some key points to consider when using azithromycin for pneumonia treatment include:
- Transitioning patients from IV to oral therapy when clinically improving with stable vital signs, ability to take oral medications, and normal gastrointestinal function.
- Monitoring for potential side effects including QT prolongation, hepatotoxicity, and gastrointestinal symptoms.
- Adjusting dosing in patients with severe hepatic impairment, though no adjustment is needed for renal impairment. The most recent study 2 compared azithromycin plus β-lactam with levofloxacin plus β-lactam for severe community-acquired pneumonia and found no significant differences in 28-day mortality and in-hospital mortality, supporting the use of azithromycin in combination therapy. Other studies, such as 3, 4, 5, and 6, also support the efficacy of azithromycin in treating pneumonia, but are less relevant due to their older publication dates and less direct comparison to current treatment regimens.