What is the recommended treatment for Community-Acquired Pneumonia (CAP)?

Community-Acquired Pneumonia Treatment

The recommended first-line treatment for community-acquired pneumonia (CAP) is oral amoxicillin at higher doses for patients without penicillin allergy, and a macrolide (erythromycin or clarithromycin) for penicillin-allergic patients. 1

Treatment Algorithm Based on Setting and Severity

Outpatient Treatment (Mild-Moderate CAP)

1. First-line options:

   • Patients without comorbidities:

     • Amoxicillin (preferred) at higher doses 1
     • Alternative: Macrolide (erythromycin or clarithromycin) 1

   • Patients with comorbidities or modifying factors (COPD, recent antibiotics):

     • Amoxicillin-clavulanate or second-generation cephalosporin 2
     • Alternative: Respiratory fluoroquinolone (levofloxacin 750mg daily or moxifloxacin 400mg daily) 1, 3

2. Treatment duration:

   • 5-7 days for uncomplicated pneumonia 1
   • Discontinue when patient is afebrile for 48-72 hours and has no more than 1 CAP-associated sign of clinical instability 1

Hospitalized Patients (Moderate-Severe CAP)

1. Recommended regimen:

   • Combination therapy with beta-lactam (e.g., ceftriaxone) plus a macrolide (e.g., azithromycin) 1, 4
   • Alternative: Respiratory fluoroquinolone monotherapy 1, 3

2. Treatment duration:

   • Minimum 5 days 1
   • 10 days for severe, microbiologically undefined pneumonia 1
   • 14-21 days for Legionella, staphylococcal, or Gram-negative enteric bacilli pneumonia 1

Special Considerations

Suspected Pseudomonas Infection

• Antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, imipenem, meropenem) plus either:
  • Ciprofloxacin or levofloxacin, OR
  • An aminoglycoside and azithromycin, OR
  • An aminoglycoside and an antipneumococcal fluoroquinolone 1

Suspected MRSA

• Add vancomycin or linezolid to the standard regimen 1

Atypical Pathogens

• For coverage of atypical pathogens (Mycoplasma, Chlamydophila, Legionella), include a macrolide or doxycycline in the regimen 1
• Note: A Cochrane review found no significant survival benefit with empirical atypical coverage in hospitalized patients with CAP 5, but current guidelines still recommend this approach due to the difficulty in rapidly identifying these pathogens

Antibiotic Dosing

Amoxicillin

• Higher doses than previously recommended (e.g., 1g three times daily) 1

Azithromycin

• For CAP: 500mg on day 1, followed by 250mg once daily on days 2-5 6
• Alternative: 500mg daily for 3 days 6

Levofloxacin

• For CAP: 750mg daily for 5 days (short course) or 500mg daily for 7-14 days 3

Common Pitfalls to Avoid

1. Delaying antibiotic administration

   • Antibiotics should be administered immediately if the illness is life-threatening 1

2. Inappropriate monotherapy

   • Beta-lactam monotherapy should be avoided in hospitalized patients; combination therapy with a macrolide is preferred 1, 4

3. Overuse of fluoroquinolones

   • Reserve respiratory fluoroquinolones for patients with comorbidities, recent antibiotic use, or penicillin allergy 2, 1

4. Inadequate follow-up

   • Clinical review for all patients at around 6 weeks is recommended 1
   • Follow-up chest radiograph for patients with persistent symptoms or physical signs, or those at higher risk of underlying malignancy 1

5. Neglecting vaccination

   • Recommend influenza and pneumococcal vaccination for high-risk groups 1

Monitoring and Follow-up

• Monitor vital signs at least twice daily, more frequently in severe cases 1
• Assess for clinical stability before discontinuing antibiotics (afebrile for 48-72 hours) 1
• Arrange follow-up at 6 weeks to ensure complete resolution and rule out underlying conditions 1

The treatment of CAP has evolved with increasing antibiotic resistance among common pathogens, particularly S. pneumoniae 7. The current guidelines reflect this changing landscape, emphasizing appropriate empiric coverage while minimizing unnecessary broad-spectrum antibiotic use to reduce resistance development.