When should a carbapenem (antibiotic) be considered for empiric use?

From the Guidelines

Carbapenems should be considered for empiric use in patients with severe infections who are at high risk for multidrug-resistant organisms or in situations where other antibiotics have failed, as recommended by the most recent guidelines 1.

Key Considerations

• Patients with severe infections, such as healthcare-associated pneumonia, complicated intra-abdominal infections, severe urinary tract infections with risk factors for resistance, neutropenic fever unresponsive to initial therapy, and severe sepsis in patients recently hospitalized or treated with broad-spectrum antibiotics, may benefit from empiric carbapenem use.
• The choice of empiric antibiotic therapy should be based on the clinical condition of the patient, individual risk for infection by resistant pathogens, and local resistance epidemiology, as outlined in the guidelines 1.
• Carbapenems, such as meropenem, imipenem-cilastatin, ertapenem, or doripenem, are effective against a wide range of pathogens, including extended-spectrum beta-lactamase (ESBL) producing organisms and AmpC beta-lactamase producers.
• Typical dosing for meropenem is 1g IV every 8 hours (adjusted for renal function), while imipenem-cilastatin is typically given as 500mg IV every 6 hours.
• It is essential to use carbapenems judiciously due to their broad spectrum of activity and potential to promote further resistance, and to de-escalate therapy to more targeted antibiotics whenever possible, as recommended by the guidelines 1.

Important Points to Consider

• The guidelines emphasize the importance of antibiotic stewardship, with antibiotic coverage narrowed as soon as culture results are available and given for as short a time as possible 1.
• Initial use of carbapenems may lead to higher resolution of severe infections and lower mortality in patients with nosocomial or critically ill patients 1.
• The emerging threat of multidrug-resistant organisms highlights the importance of considering local resistance epidemiology when selecting empiric antibiotic therapy 1.

From the FDA Drug Label

1.4 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of meropenem for injection and other antibacterial drugs, meropenem for injection should only be used to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

A carbapenem, such as meropenem, should be considered for empiric use when:

• The infection is proven or strongly suspected to be caused by susceptible bacteria.
• Local epidemiology and susceptibility patterns suggest the presence of susceptible bacteria.
• Culture and susceptibility information are not available, but the infection is severe or life-threatening.

It is essential to use carbapenems judiciously and only when necessary to minimize the development of drug-resistant bacteria 2.

Similarly, for imipenem,

1.10 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of Imipenem and Cilastatin for Injection, USP (I.V.) and other antibacterial drugs, Imipenem and Cilastatin for Injection, USP (I.V.) should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

A carbapenem, such as imipenem, should be considered for empiric use when:

• The infection is proven or strongly suspected to be caused by susceptible bacteria.
• Local epidemiology and susceptibility patterns suggest the presence of susceptible bacteria.
• Culture and susceptibility information are not available, but the infection is severe or life-threatening.

It is essential to use carbapenems judiciously and only when necessary to minimize the development of drug-resistant bacteria 3.

From the Research

Considerations for Empiric Use of Carbapenems

• Carbapenems, such as imipenem and meropenem, are broad-spectrum antibiotics that should be considered for empiric use in certain situations 4, 5, 6, 7, 8.
• These antibiotics are effective against a wide range of bacteria, including streptococci, methicillin-sensitive staphylococci, Neisseria, Haemophilus, anaerobes, and common aerobic gram-negative nosocomial pathogens, including Pseudomonas 4.
• The decision to use carbapenems empirically should be based on the severity of the infection, the likelihood of resistant organisms, and local resistance patterns 5, 6, 8.
• Carbapenems should be considered for treatment of mixed bacterial infections and aerobic gram-negative bacteria that are not susceptible to other beta-lactam agents 4.
• In critically ill patients, such as those with severe pneumonia or septicemia, carbapenems may be considered as part of empiric therapy, especially if there is a risk of resistant organisms 5, 6, 8.
• The use of carbapenems should be judicious and based on clinical judgment, as indiscriminate use can promote resistance to these antibiotics 4, 6, 7.

Specific Situations for Empiric Use

• Nosocomial intra-abdominal infections: carbapenems, such as meropenem and imipenem/cilastatin, may be considered for empiric treatment due to their broad-spectrum activity against common pathogens, including difficult-to-treat organisms like Pseudomonas aeruginosa and Bacteroides spp. 8.
• Severe pneumonia: carbapenems, such as imipenem and meropenem, may be considered as part of empiric therapy, especially if there is a risk of resistant organisms 5, 6.
• Septicemia: carbapenems may be considered for empiric treatment, especially if there is a risk of resistant organisms 5, 6.