From the FDA Drug Label
Meropenem has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections Gram-positive bacteria Enterococcus faecalis (vancomycin-susceptible isolates only) Staphylococcus aureus (methicillin-susceptible isolates only) Streptococcus agalactiae Streptococcus pneumoniae (penicillin-susceptible isolates only) Streptococcus pyogenes Viridans group streptococci Gram-negative bacteria Escherichia coli Haemophilus influenzae Klebsiella pneumoniae Neisseria meningitidis Proteus mirabilis Pseudomonas aeruginosa Anaerobic bacteria Bacteroides fragilis Bacteroides thetaiotaomicron Peptostreptococcus species
The Meropenem drug is effective against Gram-positive and Gram-negative bacteria.
- Gram-positive bacteria include:
- Enterococcus faecalis
- Staphylococcus aureus
- Streptococcus agalactiae
- Streptococcus pneumoniae
- Streptococcus pyogenes
- Viridans group streptococci
- Gram-negative bacteria include:
- Escherichia coli
- Haemophilus influenzae
- Klebsiella pneumoniae
- Neisseria meningitidis
- Proteus mirabilis
- Pseudomonas aeruginosa
- Anaerobic bacteria include:
- Bacteroides fragilis
- Bacteroides thetaiotaomicron
- Peptostreptococcus species 1
From the Research
GMXPN Mixed Gram Positive/Gram Negative Flora should be treated with caution, and the combination of vancomycin and piperacillin/tazobactam should be avoided due to the increased risk of acute kidney injury, as shown in the most recent study 2. When treating GMXPN Mixed Gram Positive/Gram Negative Flora, it is essential to consider the clinical context, infection site, and patient factors.
- For mild to moderate infections, empiric antibiotic therapy might include amoxicillin-clavulanate 875/125 mg twice daily for 7-10 days or ciprofloxacin 500 mg twice daily plus clindamycin 300-450 mg four times daily for 7-10 days to cover both gram-positive and gram-negative organisms.
- For severe infections, broader coverage with meropenem 1 g IV every 8 hours may be necessary, as it has been shown to have a lower risk of nephrotoxicity compared to piperacillin-tazobactam when used with vancomycin 3, 4, 2. Key points to consider:
- The presence of mixed flora in normally sterile sites always indicates infection requiring prompt treatment.
- Source control through drainage or debridement is essential for abscesses or infected wounds.
- Mixed flora can represent normal colonization in some body sites like the oral cavity, gastrointestinal tract, or skin, so clinical correlation is necessary to determine if treatment is warranted.
- The most recent study 2 highlights the importance of avoiding the combination of vancomycin and piperacillin/tazobactam due to the increased risk of acute kidney injury, and instead recommends using alternative antibiotics such as cefepime or meropenem.