What is the recommended treatment for community-acquired pneumonia?

Community-Acquired Pneumonia Treatment

For community-acquired pneumonia (CAP), the recommended first-line treatment is a β-lactam (ampicillin-sulbactam, cefotaxime, ceftriaxone, or ceftaroline) plus a macrolide (azithromycin or clarithromycin), or monotherapy with a respiratory fluoroquinolone (levofloxacin 750 mg or moxifloxacin 400 mg). 1

Treatment Selection Based on Setting and Severity

Outpatient Treatment

• Mild CAP:
  • First choice: β-lactam plus macrolide
    • Azithromycin 500 mg on day 1, then 250 mg daily for days 2-5 2
  • Alternative: Respiratory fluoroquinolone monotherapy
    • Levofloxacin 750 mg daily for 5 days 3

Hospitalized (Non-ICU) Patients

• Moderate CAP:
  • First choice: Intravenous β-lactam (ceftriaxone or ampicillin-sulbactam) plus macrolide
  • Alternative: Respiratory fluoroquinolone monotherapy

ICU Patients

• Severe CAP:
  • β-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either macrolide or respiratory fluoroquinolone
  • Fluoroquinolone monotherapy is not recommended for ICU patients 1

Special Considerations

MRSA Risk Factors

• Prior MRSA infection/colonization
• Recent hospitalization
• Recent antibiotic use

Management: Add MRSA coverage (vancomycin or linezolid) and obtain cultures/nasal PCR to allow de-escalation 1

Pseudomonas Risk Factors

• Structural lung disease
• Recent hospitalization
• Frequent/recent antibiotic use
• Prior Pseudomonas isolation

Management: Add antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, ceftazidime, imipenem, meropenem, or aztreonam) and obtain cultures 1

Pathogen-Specific Treatment

• Streptococcus pneumoniae: β-lactams (amoxicillin, cefotaxime, ceftriaxone)
• Mycoplasma pneumoniae: Macrolide (azithromycin preferred)
• Legionella spp.: Levofloxacin (preferred), moxifloxacin, or macrolide ± rifampicin
• Chlamydophila pneumoniae: Doxycycline, macrolide, levofloxacin, or moxifloxacin
• Coxiella burnetii: Doxycycline, levofloxacin, or moxifloxacin 1

Treatment Duration

• Standard duration: 7-10 days
• Extended duration (14 days): Atypical pathogens like Legionella
• Extended duration (14-21 days): Pseudomonas infections, slow clinical response, severe immunosuppression, or complicated pneumonia 1

Monitoring Response

• Monitor body temperature, respiratory parameters, and hemodynamic stability
• Consider treatment failure if no improvement after 72 hours 1
• For hospitalized patients, consider switching from IV to oral therapy when clinically stable and able to tolerate oral medications 4

Pediatric Considerations

For children with CAP:

• Ages 2 months to 5 years: High-dose amoxicillin for 7-10 days
• Older children: Macrolide therapy
• Hospitalized children: Macrolide plus β-lactam inhibitor 5

Common Pitfalls to Avoid

1. Inadequate initial coverage: Ensure coverage for both typical and atypical pathogens
2. Delayed switch from IV to oral: Transition when clinically appropriate to reduce hospital stay
3. Inappropriate duration: Avoid excessive treatment duration beyond recommended guidelines
4. Failure to recognize treatment failure: Reassess if no improvement after 72 hours
5. Overuse of broad-spectrum antibiotics: De-escalate therapy when culture results become available 1

Evidence Quality and Considerations

Recent evidence from JAMA (2024) confirms that up to 40% of identified CAP cases may have viral etiology, with Streptococcus pneumoniae identified in approximately 15% of patients with an identified cause 4. Despite some debate about the necessity of atypical coverage 6, 7, current guidelines from the American Thoracic Society strongly recommend combination therapy with a β-lactam plus macrolide or fluoroquinolone monotherapy to ensure adequate coverage of all potential pathogens 1.