Community-Acquired Pneumonia Treatment Guidelines

Initial Assessment and Management

The American Thoracic Society recommends that severity assessment should guide the decision between outpatient versus inpatient treatment, with tools like CURB-65 helping identify patients who can be safely treated as outpatients 1
The American College of Emergency Physicians suggests that for patients admitted through the emergency department, the first antibiotic dose should be administered while still in the ED to minimize time to treatment 1
Empiric antibiotic therapy should be initiated in adults with clinically suspected and radiographically confirmed community-acquired pneumonia regardless of initial serum procalcitonin level, as recommended by the Infectious Diseases Society of America 1

For previously healthy outpatients with no recent antibiotic therapy, the Infectious Diseases Society of America recommends a macrolide or doxycycline 2
For outpatients with comorbidities or recent antibiotic therapy, the American Thoracic Society suggests an advanced macrolide or a respiratory fluoroquinolone 2
For suspected aspiration with infection, the Infectious Diseases Society of America recommends amoxicillin-clavulanate or clindamycin 2

The British Thoracic Society recommends combined oral therapy with amoxicillin and a macrolide for patients requiring hospital admission for clinical reasons 3
Most non-severe inpatients can be adequately treated with oral antibiotics, as suggested by the American Thoracic Society 3
When oral treatment is contraindicated, the British Thoracic Society recommends parenteral choices including intravenous ampicillin or benzylpenicillin, together with erythromycin or clarithromycin 3

The American Thoracic Society recommends that patients with severe pneumonia should be treated immediately after diagnosis with parenteral antibiotics 3
An intravenous combination of a broad-spectrum β-lactamase stable antibiotic together with a macrolide is preferred, as recommended by the Infectious Diseases Society of America 3
For patients intolerant of β-lactams or macrolides, the American Thoracic Society suggests a fluoroquinolone with enhanced activity against S. pneumoniae together with intravenous benzylpenicillin 3

For patients with non-severe, microbiologically undefined pneumonia, the British Thoracic Society proposes 10 days of treatment 3
For severe pneumonia where legionella, staphylococcal, or Gram-negative enteric bacilli are suspected or confirmed, treatment should be extended to 14-21 days, as recommended by the American Thoracic Society 3
Newer evidence suggests patients with community-acquired pneumonia can be treated for a minimum of 5 days if they are clinically stable, as suggested by the Infectious Diseases Society of America 1

Patients should be switched from intravenous to oral therapy when they are hemodynamically stable and improving clinically, as recommended by the American College of Physicians 1
Criteria for switch include improvement in cough and dyspnea, afebrile, decreasing white blood cell count, and functioning gastrointestinal tract with adequate oral intake, as suggested by the American Thoracic Society 4

For patients who fail to improve as expected, there should be a careful review of the clinical history, examination, prescription chart, and results of all available investigations, as recommended by the British Thoracic Society 3
Further investigations, including a repeat chest radiograph, CRP, white cell count, and additional microbiological testing should be considered, as suggested by the American Thoracic Society 3

Clinical review should be arranged for all patients at around 6 weeks, either with their general practitioner or in a hospital clinic, as recommended by the American College of Physicians 1
A chest radiograph should be arranged at follow-up for patients with persistent symptoms or physical signs, or who are at higher risk of underlying malignancy, as suggested by the American Thoracic Society 1