Is ertapenem (a carbapenem antibiotic) effective for treating infections caused by Klebsiella pneumoniae?

Ertapenem for Klebsiella Infections

Yes, ertapenem is highly effective for treating Klebsiella pneumoniae infections, particularly those that are carbapenem-susceptible, ESBL-producing, or community-acquired, but it should NOT be used for carbapenem-resistant strains or when Pseudomonas aeruginosa or Enterococcus coverage is needed. 1, 2

FDA-Approved Indications for Klebsiella

• Ertapenem is FDA-approved for treating Klebsiella pneumoniae in complicated urinary tract infections including pyelonephritis (including cases with concurrent bacteremia) and complicated skin and skin structure infections including diabetic foot infections without osteomyelitis 3
• The standard adult dose is 1 gram IV once daily, with treatment duration of 7-14 days depending on infection severity and site 3

Clinical Efficacy Evidence

• In moderate-to-severe community-acquired pneumonia (CAP) caused by Enterobacteriaceae including Klebsiella species, ertapenem 1g once daily demonstrated equivalent efficacy to ceftriaxone 1g once daily and was as efficacious as cefepime 1
• For ESBL-producing K. pneumoniae bacteremia, ertapenem showed comparable therapeutic efficacy to imipenem or meropenem in terms of mortality and microbiological responses 4
• In a case series of ESBL-producing infections (including K. pneumoniae), ertapenem achieved 91% clinical efficacy and 85.7% microbiological cure when used for consolidation therapy 5

When to Use Ertapenem for Klebsiella

Use ertapenem for:

• ESBL-producing K. pneumoniae infections where susceptibility is confirmed 1
• Community-acquired pneumonia with confirmed or suspected Klebsiella 1
• Complicated urinary tract infections and pyelonephritis due to K. pneumoniae 3
• Complicated intra-abdominal infections when Klebsiella is isolated 1, 3
• Pan-sensitive K. pneumoniae bacteremia as an alternative to third-generation cephalosporins 6

Critical Limitations and When NOT to Use Ertapenem

Ertapenem lacks activity against Pseudomonas aeruginosa and Enterococcus species, which are critical gaps in coverage 1, 2:

• Do not use for healthcare-associated pneumonia or nosocomial infections where Pseudomonas coverage is essential 2
• Avoid in ICU patients with severe sepsis or septic shock where broader coverage is needed 2
• Not appropriate for empiric therapy in healthcare-associated infections due to lack of Pseudomonas coverage 2

For carbapenem-resistant K. pneumoniae (CRKP), ertapenem is NOT effective as monotherapy 7:

• First-line agents for CRKP are ceftazidime-avibactam 2.5g IV q8h or meropenem-vaborbactam 4g IV q8h 7
• Ertapenem-containing double-carbapenem therapy showed only 39% clinical success for CRKP infections and should be reserved for situations with extremely limited options 8

Resistance Considerations in Taiwan Context

• In Taiwan, ertapenem is widely used for ESBL-producing and multidrug-resistant Enterobacteriaceae 1
• When new CLSI breakpoints were applied, an additional 12% of ESBL-producing K. pneumoniae isolates became non-susceptible to ertapenem (susceptibility dropped from 90% to 78%) 1
• K. pneumoniae is the predominant cause of CAP with bacteremia in Taiwan, with higher mortality rates than other bacteremic pneumonias 1

Practical Dosing Algorithm

For adults with normal renal function (CrCl >90 mL/min):

• Standard dose: 1 gram IV once daily infused over 30 minutes 3
• Can be given IM for up to 7 days as alternative to IV 3
• Duration: 7-14 days for most infections; up to 28 days for diabetic foot infections 3

For pediatric patients 3 months to 12 years:

• Dose: 15 mg/kg twice daily (not to exceed 1g/day) 3

For patients 13 years and older:

• Dose: 1 gram once daily 3

Common Pitfalls to Avoid

• Never use ertapenem for empiric coverage when Pseudomonas aeruginosa is a consideration - this includes hospital-acquired pneumonia, ventilator-associated pneumonia, and infections in patients with structural lung disease 1, 2
• Do not assume all carbapenems are interchangeable - ertapenem's once-daily dosing and lack of anti-Pseudomonas activity make it fundamentally different from meropenem or imipenem 1, 2
• Avoid using ertapenem for carbapenem-resistant K. pneumoniae - resistance emergence has been documented, and newer agents like ceftazidime-avibactam are far superior 7
• Do not use diluents containing dextrose when preparing ertapenem 3