What is the treatment for community-acquired pneumonia (CAP)?

Treatment of Community-Acquired Pneumonia (CAP)

The treatment of community-acquired pneumonia should be stratified based on patient setting and risk factors, with a beta-lactam plus macrolide combination or respiratory fluoroquinolone monotherapy as primary options for hospitalized patients, while outpatients can be treated with either a macrolide, doxycycline, or a respiratory fluoroquinolone depending on risk factors. 1

Outpatient Treatment

Previously Healthy Patients (No Comorbidities)

• No recent antibiotic therapy:

  • First-line: Macrolide (e.g., azithromycin) or doxycycline 2, 1
  • Azithromycin: 500mg on day 1, followed by 250mg daily for days 2-5 3
  • Doxycycline: 100mg twice daily 1

• Recent antibiotic therapy (within past 3 months):

  • Respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin 750mg) 2
  • OR advanced macrolide plus high-dose amoxicillin 2
  • OR advanced macrolide plus high-dose amoxicillin-clavulanate 2

Patients with Comorbidities (COPD, diabetes, heart failure, malignancy)

• No recent antibiotic therapy:

  • Respiratory fluoroquinolone 2
  • OR advanced macrolide 2

• Recent antibiotic therapy:

  • Respiratory fluoroquinolone alone 2
  • OR beta-lactam plus macrolide 2

Inpatient Treatment (Non-ICU)

• First-line options:

  • Respiratory fluoroquinolone monotherapy (strong recommendation; level I evidence) 2
  • OR beta-lactam (cefotaxime, ceftriaxone, or ampicillin) plus macrolide (strong recommendation; level I evidence) 2, 1

• For penicillin-allergic patients:

  • Respiratory fluoroquinolone 2

Inpatient Treatment (ICU)

• Standard therapy:

  • Beta-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a respiratory fluoroquinolone (strong recommendation) 2

• For Pseudomonas risk:

  • Antipseudomonal beta-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin/levofloxacin OR aminoglycoside plus azithromycin/fluoroquinolone 2, 1

• For CA-MRSA risk:

  • Add vancomycin or linezolid to standard regimen 2, 1

• For penicillin-allergic patients:

  • Respiratory fluoroquinolone and aztreonam 2

Special Considerations

Antibiotic Administration

• First dose should be administered while still in the emergency department for hospitalized patients 2
• Ensure coverage for both typical and atypical pathogens in empiric therapy 1

Treatment Duration

• Minimum duration: 5 days 1
• Patient should be afebrile for 48-72 hours and have no more than one sign of clinical instability before discontinuation 1
• Most patients respond within 3-5 days; extended courses are rarely necessary 1

Switching from IV to Oral Therapy

• Switch when patient is:
  • Hemodynamically stable
  • Clinically improving
  • Able to take oral medications
  • Has normally functioning gastrointestinal tract 2, 1

Common Pitfalls and Caveats

1. Macrolide resistance: In regions with high rates (>25%) of macrolide-resistant S. pneumoniae, avoid macrolide monotherapy 2

2. Recent antibiotic exposure: If a patient has had recent exposure to one class of antibiotics, use a different class for empiric therapy due to increased risk of resistance 1

3. QT prolongation risk with macrolides: Consider the risk of QT prolongation with azithromycin, especially in elderly patients or those with cardiac conditions 3

4. Fluoroquinolone adverse events: Be aware of increasing reports of adverse events related to fluoroquinolone use (tendinopathy, peripheral neuropathy) 1

5. Clostridium difficile risk: All antibiotics can cause C. difficile-associated diarrhea, which can range from mild to fatal colitis 3

6. Inadequate coverage: Never use macrolide monotherapy in HIV-infected patients due to increased risk of drug-resistant S. pneumoniae 1

7. Delayed treatment: Do not delay antibiotic administration while waiting for diagnostic test results in moderate to severe CAP 1

By following these evidence-based recommendations and considering patient-specific factors, clinicians can optimize the management of community-acquired pneumonia and improve patient outcomes.