Community-Acquired Pneumonia Treatment Guidelines

Outpatient Treatment

The American College of Chest Physicians recommends amoxicillin 1 g every 8 hours for outpatients with community-acquired pneumonia (CAP) without comorbidities 1
The American College of Chest Physicians recommends doxycycline 100 mg twice daily as an alternative for outpatients with CAP without comorbidities 1
For patients with comorbidities, the American College of Chest Physicians recommends respiratory fluoroquinolone monotherapy (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) 2
The American College of Chest Physicians also recommends combination therapy with a β-lactam plus a macrolide (azithromycin 500 mg daily or clarithromycin 500 mg twice daily) for patients with comorbidities 2

The American College of Chest Physicians strongly recommends combination therapy with a β-lactam (ampicillin + sulbactam 1.5–3 g every 6 h, cefotaxime 1–2 g every 8 h, ceftriaxone 1–2 g daily, or ceftaroline 600 mg every 12 h) plus a macrolide (azithromycin 500 mg daily or clarithromycin 500 mg twice daily) for inpatients with CAP (strong recommendation, high quality evidence) 3
The American College of Chest Physicians strongly recommends respiratory fluoroquinolone monotherapy (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) as an alternative for inpatients with CAP (strong recommendation, high quality evidence) 3
For patients with contraindications to both macrolides and fluoroquinolones, the American College of Chest Physicians conditionally recommends β-lactam plus doxycycline 100 mg twice daily (conditional recommendation, low quality evidence) 3

The American College of Chest Physicians recommends selecting an antibiotic from a different class if a patient has received antibiotics within the previous 3 months due to increased risk of bacterial resistance 2
For regions with high rates (>25%) of macrolide-resistant S. pneumoniae, the American College of Chest Physicians recommends considering alternative regimens even for patients without comorbidities 4
The American College of Chest Physicians notes that fluoroquinolones provide coverage for both typical and atypical pathogens with high lung penetration and low resistance rates, but carry risk of adverse events 2
For patients with risk factors for MRSA or P. aeruginosa, the American College of Chest Physicians recommends specific coverage for these pathogens 3

Common bacterial pathogens in CAP include Streptococcus pneumoniae, Haemophilus influenzae, Chlamydia pneumoniae, and Staphylococcus aureus, according to the American College of Physicians 5
Atypical pathogens include Mycoplasma pneumoniae, Legionella pneumophila, and Chlamydophila pneumoniae, according to the American College of Physicians 5

The American College of Chest Physicians recommends that treatment duration should generally not exceed 8 days in responding patients 4

Newer antibiotics including lefamulin and omadacycline show promise for CAP treatment, especially against resistant pathogens, but require further validation in outpatient settings, according to the American College of Chest Physicians 3

The European Respiratory Society recommends treatment should generally not exceed 8 days in a responding patient, with biomarkers like procalcitonin guiding shorter treatment duration 6
The Infectious Diseases Society of America suggests antibiotic treatment should be initiated immediately after CAP diagnosis, as delays worsen outcomes in patients with CAP and sepsis 6

For severe CAP requiring ICU, the American Thoracic Society recommends non-antipseudomonal cephalosporin III plus macrolide, or moxifloxacin/levofloxacin ± non-antipseudomonal cephalosporin III, with antipseudomonal coverage if risk factors for P. aeruginosa exist 6