From the Guidelines
For the treatment of community-acquired pneumonia (CAP), the most recent and highest quality study recommends a beta-lactam plus a macrolide or a respiratory fluoroquinolone as the initial empiric therapy for patients with no recent antibiotic use, as stated in the 2019 American Thoracic Society and Infectious Diseases Society of America guidelines 1.
Key Considerations
- The choice of antibiotic therapy depends on the severity of the disease, the presence of comorbidities, and the risk of resistant pathogens.
- For outpatient treatment of mild to moderate CAP in otherwise healthy adults, amoxicillin 1g three times daily for 5 days is recommended as first-line therapy.
- Alternatives include doxycycline 100mg twice daily or azithromycin 500mg on day 1 followed by 250mg daily for 4 more days, particularly if atypical pathogens are suspected.
- For patients with comorbidities or risk factors for resistant pathogens, amoxicillin-clavulanate 875/125mg twice daily plus a macrolide, or a respiratory fluoroquinolone like levofloxacin 750mg daily for 5 days may be appropriate.
Hospitalized Patients
- Severe CAP requiring hospitalization typically needs intravenous antibiotics such as ceftriaxone 1-2g daily plus azithromycin 500mg daily.
- The 2019 guidelines provide a table outlining the initial treatment strategies for inpatients with CAP by level of severity and risk for drug resistance, including the use of beta-lactams, macrolides, and respiratory fluoroquinolones 1.
Supportive Care
- Supportive care includes adequate hydration, fever control, and oxygen supplementation if needed.
- Patients should see improvement within 48-72 hours of starting antibiotics.
Prevention
- Vaccination against pneumococcal disease and influenza is important for prevention, especially in high-risk populations including the elderly and those with chronic conditions. The treatment targets common pathogens like Streptococcus pneumoniae, Haemophilus influenzae, and atypical organisms such as Mycoplasma pneumoniae. Some key points to consider when choosing an antibiotic regimen include the patient's recent antibiotic use, the presence of comorbidities, and the risk of resistant pathogens, as outlined in the 2003 guidelines 1.
From the FDA Drug Label
1.2 Community-Acquired Pneumonia: 7 to 14 Day Treatment Regimen Levofloxacin tablets are indicated for the treatment of community-acquired pneumonia due to methicillin-susceptible Staphylococcus aureus, Streptococcus pneumoniae (including multi-drug-resistant Streptococcus pneumoniae [MDRSP]), Haemophilus influenzae, Haemophilus parainfluenzae, Klebsiella pneumoniae, Moraxella catarrhalis, Chlamydophila pneumoniae, Legionella pneumophila, or Mycoplasma pneumoniae [see Dosage and Administration (2.1) and Clinical Studies (14.2)].
Levofloxacin is indicated for the treatment of community-acquired pneumonia. The drug label provides information on the specific microorganisms that levofloxacin is effective against, including methicillin-susceptible Staphylococcus aureus, Streptococcus pneumoniae, and others.
- Key points:
- Levofloxacin is effective against a range of microorganisms that cause community-acquired pneumonia.
- The drug label provides guidance on the use of levofloxacin for this indication, including dosage and administration information.
- Clinical studies have demonstrated the efficacy of levofloxacin in treating community-acquired pneumonia, with clinical success rates of 93% in one study 2.
From the Research
Community Acquired Pneumonia Overview
- Community-acquired pneumonia (CAP) is a common illness with high rates of morbidity and mortality, with nearly 80% of treatment provided in the outpatient setting 3.
- The predominant pathogen associated with bacterial CAP is Streptococcus pneumoniae, and treatment is often empirical, covering both typical and atypical pathogens 3, 4.
Antibiotic Treatment
- Beta-lactams have historically been considered standard therapy for CAP, but rising resistance rates are a primary concern, and 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 3.
- Fluoroquinolones, such as moxifloxacin, gatifloxacin, and levofloxacin, have shown high clinical success rates (> 90%) in treating CAP due to S pneumoniae, and are effective in treating macrolide-resistant S pneumoniae 3.
- Short-course regimens using azithromycin, telithromycin, and fluoroquinolones have been shown to be efficacious, safe, and tolerable in patients with CAP 3.
Timing of Antibiotic Administration
- Previous studies have indicated that administering antibiotics within 4 hours of admission can improve patient outcomes, such as mortality and time to clinical stability, but results have been heterogeneous and may not be applicable to all healthcare settings 5, 6.
- A prospective cohort study found that administering antibiotics within 4 hours of admission had no significant effect on outcomes, and suggested that patients should be triaged and prioritized according to age, comorbidities, clinical condition, and pneumonia severity 5.
- A systematic review found that antibiotic therapy consisting of beta-lactam plus macrolide combination therapy or fluoroquinolone monotherapy initiated within 4 to 8 hours of hospital arrival was associated with lower adjusted short-term mortality, but the evidence was predominantly from low-quality observational studies 6.
Guidelines and Recommendations
- Guidelines recommend empiric therapy for coverage of both typical and atypical pathogens, and suggest that physicians should keep informed of recent developments in epidemiology, clinical manifestations, and antibiotic resistance 4, 7.
- The use of objective clinical criteria to guide the transition from intravenous to oral antibiotic therapy has been supported by a randomized trial, which reported significantly reduced hospital length of stay and no differences in treatment failure 6.