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Published on: January 2, 2017

In vitro activity of ertapenem against common clinical isolates in relation to human pharmacokinetics

I Friedland1, L A Mixson, A Majumdar

  • 1Merck Research Laboratories, West Point, PA, USA.

Journal of Chemotherapy (Florence, Italy)
|December 5, 2002
PubMed

Insights

Ertapenem demonstrated potent in vitro activity against common bacterial pathogens, including Enterobacteriaceae and anaerobes, exceeding ceftriaxone and piperacillin-tazobactam in many cases. Its efficacy supports its use in treating various severe infections.

Area of Science:

  • Microbiology
  • Pharmacology
  • Infectious Diseases

Background:

  • Antibiotic resistance is a growing concern in treating complicated infections.
  • Ertapenem, ceftriaxone, and piperacillin-tazobactam are key antibiotics for various bacterial infections.
  • Understanding comparative in vitro activity is crucial for effective antimicrobial stewardship.

Purpose of the Study:

  • To compare the in vitro activity of ertapenem against key bacterial pathogens.
  • To relate antimicrobial activity to achievable plasma concentrations.
  • To evaluate ertapenem's potential in treating complicated intra-abdominal, skin, urinary tract infections, and pneumonia.

Main Methods:

  • In vitro susceptibility testing of ertapenem, ceftriaxone, and piperacillin-tazobactam against clinical isolates.
  • Determination of Minimum Inhibitory Concentration (MIC) values, including MIC90.
  • Correlation of MIC values with known pharmacokinetic data (plasma concentrations).

Main Results:

  • Ertapenem showed greater potency against methicillin-susceptible Staphylococcus aureus (MSSA), Enterobacteriaceae, and anaerobes compared to the other agents.
  • Piperacillin-tazobactam was most active against enterococci and Pseudomonas aeruginosa.
  • High susceptibility rates to ertapenem were observed across Enterobacteriaceae, streptococci, MSSA, Haemophilus influenzae, Moraxella catarrhalis, and anaerobes.

Conclusions:

  • Ertapenem exhibits broad in vitro activity, particularly against Enterobacteriaceae and anaerobes, with MIC90 values below therapeutic targets.
  • Achieved plasma concentrations of ertapenem support its efficacy for the entire dosing interval.
  • Ertapenem is a potent option for treating infections caused by susceptible pathogens, though piperacillin-tazobactam retains advantages against specific organisms like P. aeruginosa.

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