Ertapenem for Urinary Tract Infections
Ertapenem is effective for treating complicated urinary tract infections (cUTIs), particularly those caused by extended-spectrum β-lactamase (ESBL)-producing organisms, and is FDA-approved for this indication. 1
FDA Approval and Indications
Ertapenem is specifically FDA-approved for the treatment of complicated urinary tract infections including pyelonephritis due to:
- Escherichia coli (including cases with concurrent bacteremia)
- Klebsiella pneumoniae 1
Efficacy for Different Types of UTIs
Complicated UTIs
- Ertapenem demonstrates excellent efficacy against complicated UTIs, with clinical cure rates of 92% reported in outpatient settings 2
- Particularly effective for pyelonephritis, which represented 39% of successfully treated cases in outpatient parenteral antimicrobial therapy (OPAT) studies 2
ESBL-Producing Organisms
- Ertapenem maintains potent activity against ESBL-producing Enterobacteriaceae, with 100% susceptibility reported in studies of resistant urinary pathogens 3
- Clinical studies show successful treatment of UTIs caused by ESBL-producing bacteria, with negative urine cultures achieved within 2-5 days of starting treatment 4
Prostatitis
- Effective for prostatitis cases, which represented 15% of successfully treated infections in OPAT studies 2
- Particularly useful for outpatient management of prostatitis caused by resistant organisms 5
Pharmacokinetic Advantages for UTIs
- High urinary concentrations (>128 mg/L) maintained for approximately 40% of the dosing interval 6
- Mean elimination half-life of 6.1 hours supports once-daily dosing 6
- Achieves sufficient concentrations in urine to overcome low to intermediate resistance 6
Limitations and Considerations
- Lower microbiological cure rates observed with Klebsiella pneumoniae infections (OR = 0.21 [95%CI: 0.05 to 0.85]) compared to other pathogens 2
- For bloodstream infections without septic shock, ertapenem may be preferred to imipenem or meropenem due to its narrower spectrum (conditional recommendation, moderate certainty of evidence) 7
- For ESBL-producing Enterobacterales, ESCMID guidelines conditionally recommend trimethoprim-sulfamethoxazole for non-severe cUTIs or as stepdown targeted therapy 7
Administration Options
- Standard dosing: 1g IV once daily 1
- Can be administered subcutaneously in outpatient settings with good efficacy 5
- Pediatric dosing: 15 mg/kg IV every 12 hours for children 3 months to 12 years; 1g IV once daily for ages 13-17 years 1
Place in Therapy
- Particularly valuable for outpatient parenteral antimicrobial therapy (OPAT) due to once-daily dosing convenience 5, 2
- Excellent option for treating resistant organisms in the community setting, with studies showing 100% clinical cure at the end of therapy 5
- Should be reserved for complicated UTIs or those caused by resistant organisms to prevent further development of resistance 7
Monitoring and Follow-up
- Urine cultures should be obtained before initiating treatment to guide therapy
- Follow-up cultures during treatment show sterility can be achieved within 2-5 days of starting therapy 4
- Monitor for relapse, which can occur in approximately 20% of patients within three months of treatment completion 5
Ertapenem represents an effective option for treating complicated UTIs, particularly those caused by resistant organisms, with the convenience of once-daily dosing that facilitates outpatient management.