What is the management for moderate risk pneumonia?

Management of Moderate Risk Community-Acquired Pneumonia

For hospitalized patients with moderate risk community-acquired pneumonia, treat with a beta-lactam (ceftriaxone 2g IV daily, cefotaxime 2g IV q8h, or ampicillin-sulbactam 3g IV q6h) combined with a macrolide (azithromycin 500mg IV/PO daily preferred over erythromycin), OR monotherapy with a respiratory fluoroquinolone (levofloxacin 750mg IV/PO daily or moxifloxacin 400mg IV/PO daily) for 5-8 days. 1, 2, 3

Initial Antibiotic Selection

First-Line Regimens (Choose One):

Beta-lactam + Macrolide Combination:

• Ceftriaxone 2g IV q24h PLUS azithromycin 500mg IV/PO daily 1, 2, 3
• Cefotaxime 2g IV q8h PLUS azithromycin 500mg IV/PO daily 1, 2
• Ampicillin-sulbactam 3g IV q6h PLUS azithromycin 500mg IV/PO daily 1, 2
• Piperacillin-tazobactam 4.5g IV q6h PLUS macrolide 1

Fluoroquinolone Monotherapy:

• Levofloxacin 750mg IV/PO once daily 1, 2, 4
• Moxifloxacin 400mg IV/PO once daily 1, 2

The combination therapy provides coverage for both typical bacteria (S. pneumoniae, H. influenzae) and atypical pathogens (Mycoplasma, Chlamydophila, Legionella), while fluoroquinolone monotherapy covers the same spectrum with a single agent. 1, 2, 3

Alternative for Penicillin Allergy:

• Respiratory fluoroquinolone (levofloxacin 750mg or moxifloxacin 400mg) as monotherapy 1, 2
• Aztreonam 2g IV q8h PLUS a macrolide (if severe beta-lactam allergy) 1

Duration of Therapy

Treat for 5-8 days total in responding patients. 1, 2, 5

Specific criteria for discontinuation:

• Minimum 5 days of treatment completed 2, 5
• Afebrile for 48-72 hours 2
• No more than 1 sign of clinical instability (heart rate >100, respiratory rate >24, systolic BP <90mmHg, oxygen saturation <90%, inability to take oral intake, altered mental status) 2

Exception: Treat for 14 days if Legionella, S. aureus, or gram-negative enteric bacilli are identified. 1, 6

Transition from IV to Oral Therapy

Switch to oral antibiotics when ALL of the following are met: 2

• Hemodynamically stable
• Clinical improvement evident (decreased fever, improved respiratory symptoms)
• Able to ingest medications
• Functioning gastrointestinal tract

Use the same antibiotic class when switching (e.g., IV levofloxacin → PO levofloxacin 750mg daily; IV ceftriaxone + IV azithromycin → PO amoxicillin 1g TID + PO azithromycin 500mg daily). 1, 2

Special Circumstances Requiring Modified Regimens

Risk Factors for Pseudomonas (any of the following):

• Structural lung disease (bronchiectasis, COPD with frequent exacerbations)
• Recent hospitalization with IV antibiotics in past 90 days
• Chronic corticosteroid use

Use antipseudomonal coverage: 2

• Piperacillin-tazobactam 4.5g IV q6h OR cefepime 2g IV q8h OR imipenem 500mg IV q6h OR meropenem 1g IV q8h
• PLUS ciprofloxacin 400mg IV q8h OR levofloxacin 750mg IV daily

Risk Factors for MRSA (any of the following):

• Prior MRSA infection/colonization
• IV drug use
• Recent hospitalization with IV antibiotics in past 90 days
• Severe influenza with secondary bacterial pneumonia

Add MRSA coverage: 2

• Vancomycin 15mg/kg IV q8-12h (target trough 15-20 mcg/mL) OR
• Linezolid 600mg IV/PO q12h

Aspiration Risk:

Standard regimens provide adequate coverage; do NOT routinely add anaerobic coverage (clindamycin, metronidazole) unless lung abscess or empyema present. 1, 3

Timing of First Dose

Administer the first antibiotic dose while still in the emergency department, ideally within 4-8 hours of presentation. 1, 2 Delays beyond 8 hours are associated with increased 30-day mortality in hospitalized patients. 1

Diagnostic Testing to Guide Therapy

Obtain before antibiotics when feasible (but do NOT delay treatment): 1, 2

• Blood cultures (2 sets from separate sites)
• Sputum Gram stain and culture (if productive cough and can be obtained within 4 hours)
• Urine pneumococcal antigen
• Urine Legionella antigen (serogroup 1)
• Influenza and COVID-19 testing during relevant seasons

These tests identify pathogens in only 38% of cases but allow de-escalation when specific organisms are identified. 1, 3

Monitoring Response

Assess daily for: 1, 6

• Temperature normalization
• Respiratory rate improvement
• Oxygen saturation stability
• Hemodynamic stability

If no improvement by 72 hours, consider: 1, 6

• Repeat chest imaging
• Additional microbiologic testing (CT chest, bronchoscopy if indicated)
• Complications (empyema, abscess)
• Alternative diagnoses
• Resistant organisms or inadequate spectrum

Common Pitfalls to Avoid

• Do NOT use fluoroquinolones if patient received them in past 3 months (increased resistance risk). 2
• Do NOT use macrolide monotherapy for hospitalized moderate-risk patients (inadequate for resistant S. pneumoniae). 1, 2
• Do NOT extend treatment beyond 8 days in responding patients without specific indications (increases C. difficile risk and resistance). 1, 5
• Do NOT add anaerobic coverage routinely for suspected aspiration without abscess/empyema. 3
• Do NOT delay antibiotics for diagnostic testing completion. 1, 2