Does Merrem (meropenem) cover anaerobes?

From the Guidelines

Merrem (meropenem) is effective against anaerobes, as evidenced by its inclusion in guidelines for treating infections where anaerobic coverage is necessary. The most recent and highest quality study, 1, supports the use of meropenem as part of the antibiotic regimen for anorectal emergencies, which often involve anaerobic bacteria. According to this study, meropenem 1 g 8-hourly is recommended as one of the options for initial empiric antimicrobial therapy in unstable patients.

Key Points About Merrem and Anaerobic Coverage

• Meropenem has a broad spectrum of activity that includes anaerobic bacteria, making it suitable for infections where anaerobes are suspected or confirmed.
• The drug's mechanism of action, inhibiting bacterial cell wall synthesis, is effective against anaerobes, including those that produce beta-lactamases.
• In clinical practice, meropenem can be used as monotherapy for mixed aerobic-anaerobic infections, eliminating the need for additional anaerobic coverage.
• The dosage of meropenem can be adjusted based on the severity of the infection and the patient's renal function, but typical dosing is 1 gram intravenously every 8 hours for serious infections in adults with normal renal function.

Clinical Considerations

• When treating infections that may involve anaerobes, such as intra-abdominal infections, complicated skin and soft tissue infections, or aspiration pneumonia, meropenem is a viable option due to its broad-spectrum activity.
• The choice of antibiotic should always consider local epidemiology and resistance patterns, as well as the specific clinical context of the patient.
• As with any antibiotic, monitoring for efficacy and potential side effects is crucial, and adjustments to the treatment regimen may be necessary based on clinical response and microbiological results.

From the FDA Drug Label

The clinical efficacy rates by pathogen are provided in Table 8

MICROORGANISMS1Meropenem for Injection n 2/N 3(%) 4Imipenem-cilastatin n 2/N 3(%) 4

Anaerobes Bacteroides fragilis10/11 (91)9/10 (90) Peptostreptococcus Species 10/13 (77)14/16 (88)

Merrem (meropenem) covers certain anaerobes, including Bacteroides fragilis and Peptostreptococcus Species, as shown in the clinical efficacy rates by pathogen in Table 8 2.

From the Research

Merrem and Anaerobes

• Merrem, also known as meropenem, is a broad-spectrum antibacterial agent that has been shown to be effective against a wide range of bacteria, including anaerobes 3, 4, 5, 6, 7.
• The drug has a broad spectrum of in vitro activity against Gram-positive and Gram-negative pathogens, including extended-spectrum beta-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae, as well as anaerobes 4, 6.
• Studies have demonstrated that meropenem is highly active against anaerobic bacteria, with MICs that are comparable to or lower than those of other antibiotics, such as imipenem and metronidazole 5.
• Meropenem has been shown to be effective in the treatment of infections caused by anaerobes, including intra-abdominal infections, skin and skin structure infections, and respiratory tract infections 3, 6, 7.
• The drug's efficacy against anaerobes is due in part to its stability against beta-lactamases and its ability to penetrate into tissues and fluids, including those where anaerobes are commonly found 4, 6.