What is the recommended treatment for an inpatient with community-acquired pneumonia (CAP) at a hospital?

Treatment of Inpatient Community-Acquired Pneumonia

For hospitalized patients with community-acquired pneumonia not requiring ICU admission, use either ceftriaxone 1-2 g IV daily plus azithromycin 500 mg daily OR respiratory fluoroquinolone monotherapy (levofloxacin 750 mg IV daily or moxifloxacin 400 mg IV daily), both with strong evidence and equivalent efficacy. 1

Non-ICU Hospitalized Patients

First-Line Regimens (Equal Efficacy)

Option 1: β-lactam plus macrolide combination 2, 1

• Ceftriaxone 1-2 g IV daily PLUS azithromycin 500 mg daily
• Alternative β-lactams: cefotaxime 1-2 g IV every 8 hours OR ampicillin-sulbactam 3 g IV every 6 hours 1
• This combination provides coverage for typical bacterial pathogens (S. pneumoniae, H. influenzae, M. catarrhalis) and atypical organisms (Mycoplasma, Chlamydophila, Legionella) 1

Option 2: Respiratory fluoroquinolone monotherapy 2, 1

• Levofloxacin 750 mg IV daily OR moxifloxacin 400 mg IV daily
• Systematic reviews demonstrate fewer clinical failures and treatment discontinuations compared to β-lactam/macrolide combinations 1
• Preferred for penicillin-allergic patients 2, 1

Critical Timing Considerations

• Administer the first antibiotic dose in the emergency department immediately upon diagnosis 1, 3
• Delayed administration beyond 8 hours increases 30-day mortality by 20-30% 1

Transition to Oral Therapy

Switch from IV to oral antibiotics when the patient meets ALL of the following criteria: 1

• Hemodynamically stable
• Clinically improving
• Able to ingest medications
• Normal gastrointestinal function
• Typically occurs by day 2-3 of hospitalization 1

Recommended oral step-down regimens: 1

• Amoxicillin 1 g orally three times daily PLUS azithromycin 500 mg orally daily
• Alternative: Continue respiratory fluoroquinolone orally (levofloxacin 750 mg daily or moxifloxacin 400 mg daily)

ICU-Level Severe Pneumonia

Combination therapy is mandatory for all ICU patients—monotherapy is inadequate for severe disease. 1

Standard ICU Regimen

β-lactam PLUS either azithromycin OR respiratory fluoroquinolone 2, 1, 3

• Ceftriaxone 2 g IV daily (or cefotaxime 1-2 g IV every 8 hours or ampicillin-sulbactam 3 g IV every 6 hours)
• PLUS azithromycin 500 mg IV daily OR levofloxacin 750 mg IV daily OR moxifloxacin 400 mg IV daily
• Systemic corticosteroids within 24 hours may reduce 28-day mortality in severe CAP 3

Duration of Therapy

Treat for a minimum of 5 days AND until the patient is afebrile for 48-72 hours with no more than one sign of clinical instability. 1, 3

• Typical duration for uncomplicated CAP: 5-7 days total (including IV days) 1, 4
• Evidence shows short-course treatment (≤6 days) has equivalent clinical cure rates with fewer adverse events compared to ≥7 days 1
• Extended duration (14-21 days) required for: 1
  • Legionella pneumophila
  • Staphylococcus aureus
  • Gram-negative enteric bacilli

Special Populations Requiring Broader Coverage

Pseudomonas aeruginosa Risk Factors

Add antipseudomonal coverage if ANY of the following are present: 1

• Structural lung disease (bronchiectasis, COPD with frequent exacerbations)
• Recent hospitalization with IV antibiotics within 90 days
• Prior respiratory isolation of P. aeruginosa

Antipseudomonal regimen: 1

• Antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem)
• PLUS ciprofloxacin 400 mg IV every 8 hours OR levofloxacin 750 mg IV daily
• PLUS aminoglycoside (gentamicin 5-7 mg/kg IV daily or tobramycin 5-7 mg/kg IV daily) PLUS azithromycin

MRSA Risk Factors

Add MRSA coverage if ANY of the following are present: 1

• Prior MRSA infection or colonization
• Recent hospitalization with IV antibiotics
• Post-influenza pneumonia
• Cavitary infiltrates on imaging

MRSA regimen: 1

• Add vancomycin 15 mg/kg IV every 8-12 hours (target trough 15-20 mg/mL) OR linezolid 600 mg IV every 12 hours
• Continue base regimen for typical/atypical coverage

Penicillin-Allergic Patients

Use respiratory fluoroquinolone monotherapy (levofloxacin 750 mg IV daily or moxifloxacin 400 mg IV daily) for non-ICU patients. 2, 1

For ICU patients with penicillin allergy: 1

• Respiratory fluoroquinolone PLUS aztreonam 2 g IV every 8 hours

Diagnostic Testing

Obtain BEFORE initiating antibiotics in all hospitalized patients: 1

• Blood cultures (two sets)
• Sputum Gram stain and culture (if productive cough)
• Urinary antigen testing for Legionella pneumophila serogroup 1 (consider in severe CAP or ICU patients)
• COVID-19 and influenza testing when these viruses are circulating in the community 3

Critical Pitfalls to Avoid

• Never use macrolide monotherapy for hospitalized patients—provides inadequate coverage for typical bacterial pathogens like S. pneumoniae 1
• Avoid extending therapy beyond 7 days in responding patients without specific indications—increases antimicrobial resistance risk without improving outcomes 1, 4
• Do not use cefuroxime, cefepime, piperacillin-tazobactam, or carbapenems as first-line empiric therapy unless specific risk factors for Pseudomonas or MRSA are present 1
• Avoid indiscriminate fluoroquinolone use due to FDA warnings about serious adverse events (tendon rupture, peripheral neuropathy, aortic dissection) and resistance concerns 2
• Never delay antibiotic administration beyond 8 hours in hospitalized patients 1, 3

Follow-Up

• Clinical review at 48 hours or sooner if clinically indicated 1
• Chest radiograph NOT required before hospital discharge in patients with satisfactory clinical recovery 1
• Schedule clinical review at 6 weeks for all hospitalized patients 1
• Chest radiograph at 6 weeks reserved for those with persistent symptoms, physical signs, or high risk for underlying malignancy (smokers, age >50 years) 1