How is initial antibiotic therapy selected for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP)?

Updated: Sep 30, 2020
  • Author: Justina Gamache, MD; Chief Editor: Guy W Soo Hoo, MD, MPH  more...
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Answer

The prevalence and resistance patterns of MDR pathogens vary between institutions and even between ICUs within the same institution. Therefore, appropriate initial antibiotic therapy for HAP and VAP may vary markedly according to hospital site. Antimicrobial prescribing practices should not necessarily be based on national guidelines, but rather on patterns of MDR organisms at individual institutions. [8]

The table below presents first- and second-line antibiotic choices for specific organisms that cause bacterial pneumonia.

Table. Pathogen-Driven Antibiotic Choices [3] (Open Table in a new window)

Organism

First-Line Antimicrobials

Alternative Antimicrobials

Streptococcus pneumoniae

 

Penicillin susceptible

(MIC < 2 mcg/mL)

Penicillin G, amoxicillin

Macrolide, cephalosporin (oral or parenteral), clindamycin, doxycycline, respiratory fluoroquinolone

 

Penicillin resistant

(MIC ≥2 mcg/mL)

Agents chosen on the basis of sensitivity

Vancomycin, linezolid, high-dose amoxicillin (3 g/d with MIC ≤4 mcg/mL

Staphylococcus aureus

 

Methicillin susceptible

Antistaphylococcal penicillin

Cefazolin, clindamycin

 

Methicillin resistant

Vancomycin, linezolid

Trimethoprim- sulfamethoxazole

Haemophilus influenzae

 

Non–beta-lactamase producing

Amoxicillin

Fluoroquinolone, doxycycline, azithromycin, clarithromycin

 

Beta-lactamase producing

Second- or third-generation cephalosporin, amoxicillin/clavulanate

Fluoroquinolone, doxycycline, azithromycin, clarithromycin

Mycoplasma pneumoniae

Macrolide, tetracycline

Fluoroquinolone

Chlamydophila pneumoniae

Macrolide, tetracycline

Fluoroquinolone

Legionella species

Fluoroquinolone, azithromycin

Doxycycline

Chlamydophila psittaci

Tetracycline

Macrolide

Coxiella burnetii

Tetracycline

Macrolide

Francisella tularensis

Doxycycline

Gentamicin, streptomycin

Yersinia pestis

Streptomycin, gentamicin

Doxycycline, fluoroquinolone

Bacillus anthracis (inhalational)

Ciprofloxacin, levofloxacin, doxycycline

Other fluoroquinolones, beta-lactam (if susceptible), rifampin, clindamycin, chloramphenicol

Enterobacteriaceae

Third-generation cephalosporin, carbapenem

Beta-lactam/beta-lactamase inhibitor, fluoroquinolone

Pseudomonas aeruginosa

Antipseudomonal beta-lactam plus ciprofloxacin, levofloxacin, or aminoglycoside

Aminoglycoside plus ciprofloxacin or levofloxacin

Bordetella pertussis

Macrolide

Trimethoprim- sulfamethoxazole

Anaerobe (aspiration)

Beta-lactam/beta-lactamase inhibitor, clindamycin

Carbapenem

MIC = Minimal inhibitory concentration.


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