What is Community-Acquired Pneumonia (CAP)?

From the Guidelines

Community-acquired pneumonia (CAP) should be treated with empiric antibiotics based on severity and risk factors, with a minimum treatment duration of 5 days, as recommended by the most recent guidelines 1. The choice of antibiotics should target common pathogens like Streptococcus pneumoniae, Haemophilus influenzae, and atypical organisms.

• For outpatient treatment of healthy individuals, amoxicillin 1g three times daily for 5 days is recommended.
• For patients with comorbidities or recent antibiotic use, consider amoxicillin-clavulanate 875/125mg twice daily or a respiratory fluoroquinolone like levofloxacin 750mg daily for 5 days.
• Hospitalized non-ICU patients typically receive a combination of a beta-lactam (ceftriaxone 1-2g daily) plus a macrolide (azithromycin 500mg daily), while ICU patients may need broader coverage with piperacillin-tazobactam plus azithromycin or a respiratory fluoroquinolone. Key considerations in the management of CAP include:
• Severity of illness, with more severe cases requiring broader antibiotic coverage and closer monitoring.
• Risk factors for drug-resistant pathogens, such as recent hospitalization or antibiotic use.
• Clinical stability, with extension of therapy after 5 days guided by validated measures of clinical stability, as recommended by the American College of Physicians 1. Supportive care with adequate hydration, oxygen if needed, and follow-up within 48-72 hours for outpatients is essential, as emphasized in the guidelines from the American Thoracic Society and Infectious Diseases Society of America 1.

From the FDA Drug Label

14 CLINICAL STUDIES

Adult patients with clinically and radiologically documented nosocomial pneumonia were enrolled in a multicenter, randomized, open-label study comparing intravenous levofloxacin (750 mg once daily) followed by oral levofloxacin (750 mg once daily) for a total of 7 to 15 days to intravenous imipenem/cilastatin (500 to 1000 mg every 6 to 8 hours daily) followed by oral ciprofloxacin (750 mg every 12 hours daily) for a total of 7 to 15 days.

The FDA drug label does not answer the question about CAP.

From the Research

Community-Acquired Pneumonia (CAP) Overview

• CAP is a common illness with high rates of morbidity and mortality, with nearly 80% of treatment provided in the outpatient setting 2.
• The predominant pathogen associated with bacterial CAP is Streptococcus pneumoniae 2.

Treatment of CAP

• Treatment of CAP is often empirical, covering both typical and atypical pathogens 2.
• Beta-lactams have been considered standard therapy, but rising resistance rates are a primary concern 2.
• Current guidelines recommend combination therapy with a beta-lactam and a macrolide or an antipneumococcal fluoroquinolone alone for patients with comorbidities or recent antibiotic therapy 2.
• Fluoroquinolones, such as moxifloxacin, gatifloxacin, and levofloxacin, have shown high clinical success rates (> 90%) in treating CAP due to S pneumoniae 2.

Antibiotic Management and Duration

• The use of azithromycin, telithromycin, and fluoroquinolones in short-course regimens has been shown to be efficacious, safe, and tolerable in patients with CAP 2.
• High-dose, short-course therapies may represent a significant advance in the management of CAP 2.
• Recent studies suggest that short treatment durations (5-7 days or less) may be sufficient for CAP, and clinical criteria can be used to discontinue antibiotic treatment 3.
• The choice of antibiotic therapy for severe CAP should consider the severity of disease, likely offending pathogens, and the potential for resistance 4, 5.

Diagnostic Considerations

• Diagnosis of acute community-acquired pneumonia is based on history, physical examination, and chest x-ray 6.
• Appropriate diagnostic studies for patients with moderately-severe to severe pneumonia include sputum Gram's stain and culture, blood cultures, and acute serum sample 6.