What is the recommended dose of ertapenem (carbapenem) for treating urinary tract infections (UTIs)?

Ertapenem Dosing for UTI

For urinary tract infections, ertapenem should be administered as 1 gram intravenously once daily, with treatment duration of 7-14 days for complicated UTIs and acute pyelonephritis. 1, 2, 3

Standard Dosing Regimen

• Dose: 1 gram IV once daily, infused over 30 minutes 1, 4
• Duration:
  • 7-14 days total therapy for complicated UTIs 2, 5
  • Median parenteral duration is 4 days, with option to switch to oral therapy after ≥3 days if clinically improving 2, 3
  • Total treatment course (parenteral + oral) typically 13-14 days 2, 3

Clinical Context for Use

Ertapenem is particularly valuable for:

• ESBL-producing organisms: Ertapenem maintains excellent activity against extended-spectrum β-lactamase-producing Enterobacteriaceae causing UTIs 5, 6
• Carbapenem-resistant Enterobacteriaceae (CRE): For complicated UTIs caused by CRE, newer agents like ceftazidime-avibactam, meropenem-vaborbactam, or plazomicin are preferred over ertapenem 7
• Complicated UTIs: Including acute pyelonephritis, UTIs in males, or infections associated with urological abnormalities 2, 3

Efficacy Data

• Microbiological success rates: 87.9-89.5% for complicated UTIs and acute pyelonephritis, equivalent to ceftriaxone 2, 3
• Urinary concentrations: Achieves very high urine levels (>128 mg/L) maintained for 40% of the dosing interval, sufficient to overcome low-to-intermediate resistance 4
• Most common pathogens covered: Escherichia coli (64.7% of isolates) and Klebsiella pneumoniae (9.8%) 2

Important Caveats

• Not first-line for CRE: While ertapenem has been used for gonorrhea treatment failures with ceftriaxone-resistant strains 7, for CRE-associated UTIs, newer β-lactam/β-lactamase inhibitor combinations are recommended over traditional carbapenems 7
• Switch to oral therapy: After ≥3 days of IV ertapenem with clinical improvement, switch to oral fluoroquinolone (typically ciprofloxacin) based on susceptibilities to complete 13-14 day total course 2, 3
• Pediatric dosing: 15 mg/kg IV every 12 hours (maximum 1 gram/day) for patients 3 months to 12 years; 1 gram once daily for ages 13-17 years 1

Storage After Reconstitution

• Room temperature (25°C): Use within 6 hours 1
• Refrigerated (5°C): Store up to 24 hours, then use within 4 hours after removal 1
• Do not freeze reconstituted solutions 1