Community-Acquired Pneumonia Treatment Guidelines

Outpatient Treatment

The American Thoracic Society recommends amoxicillin 1 g three times daily for healthy outpatients with community-acquired pneumonia (strong recommendation, moderate quality evidence) 1, 2
For adults with comorbidities, the American College of Chest Physicians suggests combination therapy with amoxicillin/clavulanate plus a macrolide (strong recommendation, moderate quality evidence) 1, 3
The Infectious Diseases Society of America recommends respiratory fluoroquinolone monotherapy as an alternative for patients with comorbidities (strong recommendation, moderate quality evidence) 1, 4

The American Thoracic Society recommends combined therapy with a β-lactam plus a macrolide for non-severe community-acquired pneumonia (strong recommendation, moderate quality evidence) 5, 3
For severe community-acquired pneumonia, the British Thoracic Society suggests intravenous combination of a broad-spectrum β-lactamase stable antibiotic together with a macrolide (strong recommendation, moderate quality evidence) 3, 4

The American College of Chest Physicians recommends a treatment duration of 10 days for severe community-acquired pneumonia without identified pathogens (strong recommendation, moderate quality evidence) 3
For specific pathogens like Legionella, staphylococcal, or Gram-negative enteric bacilli, the Infectious Diseases Society of America suggests a treatment duration of 14-21 days (strong recommendation, moderate quality evidence) 4

The American Thoracic Society recommends that patients with recent exposure to one class of antibiotics should receive treatment from a different class due to increased risk of bacterial resistance (strong recommendation, moderate quality evidence) 5, 3
For patients not improving on initial therapy, the British Thoracic Society suggests adding or substituting a macrolide if on amoxicillin monotherapy (strong recommendation, moderate quality evidence) 4

The American College of Chest Physicians warns against underestimating the severity of pneumonia, which can lead to inappropriate treatment intensity (strong recommendation, moderate quality evidence) 5, 3
The Infectious Diseases Society of America advises against using macrolide monotherapy in areas with high pneumococcal resistance (≥25%) (strong recommendation, moderate quality evidence) 5, 1

The American Thoracic Society recommends clarithromycin 500 mg twice daily or clarithromycin extended-release 1,000 mg daily for healthy outpatients with suspected atypical pneumonia 6, 7
For outpatient adults with comorbidities, clarithromycin may be used as part of combination therapy, with a recommended dosage of 500 mg twice daily or extended-release 1,000 mg once daily, combined with a beta-lactam such as amoxicillin/clavulanate 6, 7

The American College of Chest Physicians recommends avoiding macrolide monotherapy, including clarithromycin, in areas with high pneumococcal resistance to macrolides (≥25%) 6