Treatment of Community-Acquired Pneumonia (CAP)
For community-acquired pneumonia, the recommended first-line treatment is a β-lactam (such as amoxicillin, cefotaxime, or ceftriaxone) plus a macrolide (preferably azithromycin), or alternatively, a respiratory fluoroquinolone (such as levofloxacin 750 mg daily) as monotherapy. 1
Treatment Selection Based on Patient Setting and Risk Factors
Outpatient Treatment
Previously healthy patients with no risk factors for drug-resistant Streptococcus pneumoniae (DRSP):
Patients with comorbidities:
- Respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin 750 mg) OR
- β-lactam (high-dose amoxicillin or amoxicillin-clavulanate) plus a macrolide 1
Inpatient Treatment (Non-ICU)
Standard therapy:
Penicillin-allergic patients:
- Respiratory fluoroquinolone OR
- Aztreonam plus a macrolide 1
ICU Treatment
Standard therapy:
- β-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a respiratory fluoroquinolone 1
For suspected Pseudomonas infection:
- Antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin/levofloxacin or an aminoglycoside plus azithromycin 1
For suspected CA-MRSA:
- Add vancomycin or linezolid to standard therapy 1
Pathogen-Specific Treatment
| Pathogen | Treatment Options |
|---|---|
| Streptococcus pneumoniae | Beta-lactams (amoxicillin, cefotaxime, ceftriaxone) [1] |
| Mycoplasma pneumoniae | Macrolide (azithromycin preferred) [1] |
| Legionella spp. | Levofloxacin (preferred), moxifloxacin, or macrolide ± rifampicin [1] |
| Chlamydophila pneumoniae | Doxycycline, macrolide, levofloxacin, or moxifloxacin [1] |
| Coxiella burnetii | Doxycycline, levofloxacin, or moxifloxacin [1] |
Treatment Duration
- Uncomplicated cases: 7-10 days of treatment 1
- Minimum duration: 5 days, with patient being afebrile for 48-72 hours before discontinuation 1
- Treatment discontinuation criteria:
- Temperature ≤37.8°C for at least 48 hours
- Resolution of respiratory symptoms
- Hemodynamic stability
- Normal oral intake capability
- Normal mental status 1
Switching from IV to Oral Therapy
Patients can be switched from IV to oral therapy when they:
- Are hemodynamically stable
- Show clinical improvement
- Can ingest medications
- Have a normally functioning gastrointestinal tract 1
Supportive Care
- Oxygen therapy to maintain SaO₂ >92%
- Intravenous fluids if dehydrated
- Regular monitoring of vital signs, mental status, and oxygen saturation
- Nutritional support in prolonged illness
- Positioning to optimize respiratory function
- Antipyretics for fever and discomfort
- Cough management if distressing 1
Prevention Strategies
- Pneumococcal vaccination for all adults 65 years or older
- Annual influenza vaccination for all adults
- Smoking cessation for hospitalized smokers
- Pneumococcal vaccination for smokers who will not quit 1
Common Pitfalls to Avoid
- Inadequate initial coverage: Ensure empiric therapy covers both typical and atypical pathogens 1, 4
- Delayed switch from IV to oral: Transition as soon as clinically improved 1
- Inappropriate duration: Avoid unnecessarily prolonged courses 1
- Failure to recognize treatment failure: Monitor for clinical improvement within 48-72 hours 1
- Overuse of antibiotics: Use narrow-spectrum antibiotics when a pathogen is identified 1, 5
- Overlooking atypical pathogens: Only 37% of patients with Legionella, Mycoplasma, or Chlamydophila pneumonia receive appropriate coverage 5
By following these evidence-based recommendations, clinicians can optimize treatment outcomes for patients with community-acquired pneumonia while minimizing antibiotic resistance.