Community-Acquired Pneumonia Treatment Guidelines

Outpatient Treatment Options

The American Thoracic Society recommends amoxicillin 1 g three times daily as the first-line treatment for healthy outpatient adults with community-acquired pneumonia (strong recommendation, moderate quality of evidence) 1, 2
The American Thoracic Society suggests doxycycline 100 mg twice daily as a first-line treatment option for healthy adults without comorbidities (conditional recommendation, low quality of evidence) 1, 2
The American Thoracic Society recommends macrolide (azithromycin 500 mg on first day then 250 mg daily or clarithromycin 500 mg twice daily) only in areas with pneumococcal resistance to macrolides <25% (conditional recommendation, moderate quality of evidence) 1, 2
For outpatients with comorbidities, the American Thoracic Society recommends combination therapy with amoxicillin/clavulanate (500 mg/125 mg three times daily, 875 mg/125 mg twice daily, or 2,000 mg/125 mg twice daily) OR a cephalosporin (cefpodoxime 200 mg twice daily or cefuroxime 500 mg twice daily) plus a macrolide (azithromycin 500 mg on first day then 250 mg daily, clarithromycin 500 mg twice daily) or doxycycline 100 mg twice daily 1, 2
The American Thoracic Society suggests respiratory fluoroquinolone (levofloxacin 750 mg daily, moxifloxacin 400 mg daily, or gemifloxacin 320 mg daily) as a monotherapy option for outpatients with comorbidities 1, 2

The American Thoracic Society 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) and a macrolide (azithromycin 500 mg daily or clarithromycin 500 mg twice daily) for patients requiring hospitalization but not intensive care 3
The Infectious Diseases Society of America recommends a β-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a respiratory fluoroquinolone for severe CAP requiring ICU admission 5
For patients with risk factors for Pseudomonas infection, the Infectious Diseases Society of America suggests an antipneumococcal, antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin/levofloxacin or an aminoglycoside plus azithromycin 5

The American Thoracic Society recommends switching from intravenous to oral therapy when patients are hemodynamically stable, improving clinically, able to ingest medications, and have a normally functioning gastrointestinal tract 5
The Infectious Diseases Society of America suggests that for patients admitted through the emergency department, the first antibiotic dose should be administered while still in the ED 5
The American Thoracic Society recommends considering adding vancomycin or linezolid to the treatment regimen for patients with risk factors for methicillin-resistant Staphylococcus aureus (MRSA) 5
The American Thoracic Society recommends that if a patient has had recent exposure to one class of antibiotics, treatment should be with antibiotics from a different class due to increased risk for bacterial resistance 3