Does ertapenem (a carbapenem antibiotic) cover pneumonia?

Ertapenem Coverage for Pneumonia

Ertapenem is indicated for the treatment of community-acquired pneumonia (CAP) due to Streptococcus pneumoniae (penicillin-susceptible isolates only), Haemophilus influenzae (beta-lactamase negative isolates only), or Moraxella catarrhalis. 1

Indications and Antimicrobial Spectrum

Ertapenem is a Group 1 carbapenem with FDA approval for community-acquired pneumonia. Its spectrum of activity includes:

• Covered pathogens in pneumonia:

  • Streptococcus pneumoniae (penicillin-susceptible isolates only)
  • Haemophilus influenzae (beta-lactamase negative isolates only)
  • Moraxella catarrhalis 1

• General antimicrobial spectrum:

  • Broad activity against many Gram-positive and Gram-negative bacteria
  • Effective against Enterobacteriaceae, including ESBL and AmpC-producing strains
  • Active against most anaerobic bacteria 2

Clinical Use in Pneumonia

Ertapenem is specifically mentioned in guidelines for CAP in certain clinical scenarios:

• Hospitalized patients with CAP (non-ICU):

  • May be used in patients at risk of gram-negative enteric bacteria, particularly ESBL-producing strains
  • Appropriate when there is no risk (or after exclusion) of Pseudomonas aeruginosa 3

• Limitations in pneumonia coverage:

  • Not active against Pseudomonas aeruginosa
  • Not active against Acinetobacter species
  • Limited activity against enterococci
  • Not appropriate for hospital-acquired pneumonia where these pathogens are common 4

Clinical Evidence

A matched cohort study showed that ertapenem demonstrated superior clinical response in frail elderly patients with complicated community-acquired pneumonia. In patients aged 65 or older, first-line treatment with ertapenem was an independent protective factor against mortality (0.1,95%CI 0.1-0.7) 5.

Important Considerations and Caveats

• Dosing: Standard dose is 1g once daily IV 4

  • Recent pharmacokinetic studies suggest that in critically ill patients with ventilator-associated pneumonia or obese patients, the standard dose may not provide adequate free drug concentrations 4

• Key limitations:

  • Not suitable for late-onset nosocomial pneumonia
  • Not active against MRSA, Pseudomonas, or Acinetobacter 2
  • Should not be used as empiric therapy when these pathogens are suspected

• Carbapenem stewardship:

  • Guidelines recommend limiting carbapenem use to preserve activity and prevent emergence of resistance
  • Consider carbapenem-sparing regimens when appropriate 3

Algorithm for Appropriate Use of Ertapenem in Pneumonia

1. Appropriate for:

   • Community-acquired pneumonia requiring hospitalization (non-ICU)
   • Patients at risk for ESBL-producing Enterobacteriaceae
   • Patients with no risk factors for Pseudomonas aeruginosa

2. Not appropriate for:

   • Hospital-acquired or ventilator-associated pneumonia
   • Patients at risk for Pseudomonas aeruginosa infection
   • Patients with suspected MRSA pneumonia

3. Alternative regimens when ertapenem is not appropriate:

   • For Pseudomonas risk: Antipseudomonal cephalosporin, acylureidopenicillin/β-lactamase inhibitor, or Group 2 carbapenem (meropenem) plus either ciprofloxacin or a macrolide plus aminoglycoside 3
   • For standard CAP without ESBL risk: Non-antipseudomonal cephalosporin plus macrolide, or respiratory fluoroquinolone 3

Ertapenem offers the advantage of once-daily dosing and is particularly valuable in treating patients with risk factors for resistant Enterobacteriaceae while avoiding unnecessary Pseudomonas coverage in community settings where this pathogen is uncommon.