What are the recommended IV antibiotics for inpatient pneumonia?

IV Antibiotics for Inpatient Pneumonia

For inpatient pneumonia, the recommended initial empiric IV antibiotic therapy should be based on the type of pneumonia, risk factors for multidrug-resistant (MDR) pathogens, and severity of illness, with piperacillin-tazobactam plus a macrolide or a respiratory fluoroquinolone being the cornerstone of therapy for most hospitalized patients. 1

Initial Empiric Therapy Based on Pneumonia Type

Hospital-Acquired Pneumonia (HAP) or Healthcare-Associated Pneumonia (HCAP)

Patients NOT at high risk of mortality and NO risk factors for MRSA:

• Piperacillin-tazobactam 4.5 g IV q6h
• OR Cefepime 2 g IV q8h
• OR Levofloxacin 750 mg IV daily
• OR Imipenem 500 mg IV q6h
• OR Meropenem 1 g IV q8h 1

Patients NOT at high risk of mortality but WITH risk factors for MRSA:

• One of the above antibiotics PLUS
• Vancomycin 15 mg/kg IV q8-12h (target trough 15-20 mg/mL)
• OR Linezolid 600 mg IV q12h 1

Patients at high risk of mortality or who received IV antibiotics in the prior 90 days:

• Two of the following (avoid using two β-lactams):
  • Piperacillin-tazobactam 4.5 g IV q6h
  • OR Cefepime/ceftazidime 2 g IV q8h
  • OR Levofloxacin 750 mg IV daily/Ciprofloxacin 400 mg IV q8h
  • OR Imipenem 500 mg IV q6h/Meropenem 1 g IV q8h
  • OR Amikacin 15-20 mg/kg IV daily/Gentamicin 5-7 mg/kg IV daily/Tobramycin 5-7 mg/kg IV daily
  • OR Aztreonam 2 g IV q8h
• PLUS MRSA coverage:
  • Vancomycin 15 mg/kg IV q8-12h
  • OR Linezolid 600 mg IV q12h 1

Nosocomial Pneumonia

• Piperacillin-tazobactam 4.5 g IV q6h plus an aminoglycoside
• Treatment duration: 7-14 days 2
• For P. aeruginosa infections, continue aminoglycoside therapy 2

Community-Acquired Pneumonia (CAP) - Hospitalized Patients

Non-ICU patients:

• β-lactam (ceftriaxone, cefotaxime, ampicillin-sulbactam) PLUS a macrolide
• OR Respiratory fluoroquinolone monotherapy (levofloxacin 750 mg or moxifloxacin) 3

ICU patients:

• β-lactam (ceftriaxone, cefotaxime) PLUS either a macrolide or a respiratory fluoroquinolone 3

Dosing Considerations

Standard Dosing

• Piperacillin-tazobactam: 4.5 g IV q6h (standard for most indications) 2
• Cefepime: 1-2 g IV q8-12h 1
• Ceftazidime: 2 g IV q8h 1
• Imipenem: 500 mg IV q6h or 1 g IV q8h 1
• Meropenem: 1 g IV q8h 1
• Levofloxacin: 750 mg IV daily 1
• Ciprofloxacin: 400 mg IV q8h 1
• Vancomycin: 15 mg/kg IV q12h (target trough 15-20 μg/mL) 1
• Linezolid: 600 mg IV q12h 1

Renal Adjustment

For patients with renal impairment (CrCl ≤40 mL/min), dose adjustments are necessary:

• For piperacillin-tazobactam:
  • CrCl 20-40 mL/min: 2.25 g IV q6h (non-nosocomial); 3.375 g IV q6h (nosocomial)
  • CrCl <20 mL/min: 2.25 g IV q8h (non-nosocomial); 2.25 g IV q6h (nosocomial)
  • Hemodialysis: 2.25 g IV q12h (non-nosocomial); 2.25 g IV q8h (nosocomial) 2

Duration of Therapy

• HAP/VAP/HCAP: 7-14 days 1
• CAP: 5-7 days for most patients; longer duration may be needed for complicated cases 3

Special Considerations

Pseudomonas aeruginosa Coverage

When P. aeruginosa is suspected or confirmed:

• Use an antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, ceftazidime, imipenem, or meropenem)
• PLUS either a fluoroquinolone (ciprofloxacin or levofloxacin) or an aminoglycoside 1

MRSA Coverage

When MRSA is suspected (prior IV antibiotics within 90 days, hospitalization in unit with >20% MRSA prevalence, or high mortality risk):

• Add vancomycin or linezolid to the regimen 1

Atypical Pathogen Coverage

• For suspected Legionella pneumophila: Include a macrolide (azithromycin) or fluoroquinolone (ciprofloxacin or levofloxacin) rather than an aminoglycoside 1

Pitfalls and Caveats

1. Delayed appropriate therapy increases mortality: Inappropriate initial antibiotic therapy has been associated with increased mortality. Start appropriate empiric therapy promptly based on local resistance patterns 1

2. De-escalation: Once culture results are available, narrow the antibiotic spectrum based on susceptibility results to reduce the risk of resistance development 1

3. Aminoglycoside monitoring: When using aminoglycosides, monitor drug levels (trough levels for gentamicin and tobramycin should be <1 μg/mL, for amikacin <4-5 μg/mL) 1

4. Vancomycin monitoring: For vancomycin, maintain trough levels at 15-20 μg/mL for optimal efficacy against MRSA 1

5. Fluoroquinolone resistance: Be aware of increasing fluoroquinolone resistance, especially in areas with high usage. The prevalence of S. pneumoniae resistance to levofloxacin in the US has been reported as <1% overall 4

6. Combination therapy for severe pneumonia: For patients with severe pneumonia or at high risk of mortality, combination therapy is recommended to ensure adequate coverage of all potential pathogens 1

7. Drug interactions and compatibility: Piperacillin-tazobactam and aminoglycosides should be reconstituted, diluted, and administered separately to avoid incompatibility 2