Meropenem Coverage Spectrum
Meropenem is a broad-spectrum carbapenem antibiotic that covers Gram-positive, Gram-negative, and anaerobic bacteria, including Pseudomonas aeruginosa, Enterobacteriaceae, Streptococcus pneumoniae, methicillin-susceptible Staphylococcus aureus, and most anaerobes, but not methicillin-resistant staphylococci or Enterococcus faecium. 1, 2
Gram-Positive Coverage
- Streptococcus pneumoniae (including penicillin-susceptible isolates) 1, 3
- Streptococcus pyogenes and Streptococcus agalactiae 1
- Viridans group streptococci 1
- Beta-hemolytic streptococci 3
- Enterococcus faecalis (vancomycin-susceptible isolates only) 1
- Methicillin-susceptible Staphylococcus aureus 1, 3
Gram-Negative Coverage
- Pseudomonas aeruginosa (with better activity than imipenem) 3, 4
- Escherichia coli 1
- Klebsiella pneumoniae 1
- Proteus mirabilis 1
- Haemophilus influenzae 1, 3
- Neisseria meningitidis 1
- Acinetobacter species (variable susceptibility) 2, 5
- Enterobacteriaceae, including ESBL-producing strains 2, 3
- Aeromonas species 5
- Branhamella catarrhalis (Moraxella catarrhalis) 5
- Neisseria gonorrhoeae 5
- Campylobacter species 5
Anaerobic Coverage
- Bacteroides fragilis 1
- Bacteroides thetaiotaomicron 1
- Peptostreptococcus species 1
- Most anaerobes other than Clostridium difficile 5
Notable Resistant Organisms
- Methicillin-resistant Staphylococcus aureus (MRSA) 3, 5
- Enterococcus faecium 3, 5
- Stenotrophomonas maltophilia (Pseudomonas/Xanthomonas maltophilia) 5
- Some highly penicillin- and cephalosporin-resistant pneumococci may have reduced susceptibility 6
Clinical Applications
- Meropenem is indicated for complicated skin and skin structure infections, complicated intra-abdominal infections, and bacterial meningitis in pediatric patients ≥3 months 1
- It's used for nosocomial pneumonia, septicemia, febrile neutropenia, and complicated urinary tract infections in many countries 2
- Preferred over imipenem in patients with risk factors for Pseudomonas aeruginosa due to better activity and the option to increase dosing up to 6g daily 6
- Recommended for meningitis caused by gram-negative bacilli that produce extended-spectrum β-lactamases 6
- Used in carbapenem-resistant Acinetobacter baumannii infections in combination with colistin 6
Advantages Over Other Carbapenems
- Better activity against Pseudomonas aeruginosa compared to imipenem 3, 4
- Lower seizure potential than imipenem, making it suitable for meningitis treatment 2, 7
- Better CNS tolerability allowing for higher dosing 7, 4
- Can be administered as an intravenous bolus or infusion 7
Limitations
- Not effective against methicillin-resistant staphylococci 3
- Not effective against Enterococcus faecium 3, 5
- Poor activity against Stenotrophomonas maltophilia 5
- May not be effective against highly penicillin- and cephalosporin-resistant pneumococci 6
Meropenem's broad spectrum of activity makes it an important option for empiric therapy of serious infections, particularly when Pseudomonas aeruginosa is a concern or when treating infections in critically ill patients 2, 4.