Ertapenem Dosing for UTI in Patients with Renal Impairment
For patients with urinary tract infections and renal impairment, ertapenem should be dosed at 500 mg once daily when creatinine clearance is ≤30 mL/min/1.73 m², and 1 g once daily when creatinine clearance is >30 mL/min/1.73 m². 1
Dosing Guidelines Based on Renal Function
- For patients with normal renal function (CrCl >90 mL/min/1.73 m²), the standard dose for complicated UTI is 1 g once daily for 10-14 days 1
- For patients with mild to moderate renal impairment (CrCl >30 mL/min/1.73 m²), no dosage adjustment is necessary - continue with 1 g once daily 1
- For patients with severe renal impairment (CrCl ≤30 mL/min/1.73 m²), reduce dose to 500 mg once daily 1, 2
- For patients with end-stage renal disease on hemodialysis (CrCl ≤10 mL/min/1.73 m²), administer 500 mg once daily 1, 2
Hemodialysis Considerations
- If ertapenem is administered within 6 hours prior to hemodialysis, a supplementary dose of 150 mg is recommended following the hemodialysis session 1, 2
- If ertapenem is given at least 6 hours prior to hemodialysis, no supplementary dose is needed 1
- Administer the drug after dialysis to avoid premature removal of the drug and to facilitate directly observed therapy 3
Administration Method
- Ertapenem should be infused intravenously over a period of 30 minutes 1
- Do not mix or co-infuse ertapenem with other medications 1
- Do not use diluents containing dextrose 1
- Ertapenem can be administered intravenously for up to 14 days 1
Efficacy and Safety Considerations
- Ertapenem is highly effective for complicated urinary tract infections when dosed appropriately according to renal function 4, 5
- In patients with renal impairment, the elimination half-life is prolonged (from 4.5 hours in normal renal function to 14.1 hours in ESRD), necessitating dose adjustment 2
- High ertapenem concentrations (>128 mg/L) can be maintained in the urine for approximately 40% of the dosing interval, which helps overcome low to intermediate resistance 4
Important Monitoring and Precautions
- Monitor for signs of neurotoxicity, particularly in patients with CKD, as acute reversible peripheral neuropathy has been reported even with renally adjusted doses 6
- Urinary pH may affect drug efficacy - patients with renal insufficiency and alkaline urine may have delayed bacterial clearance (>3 days) compared to those with acidic urine (<3 days) 5
- Regular assessment of renal function is recommended during therapy 2
- When only serum creatinine is available, use the Cockcroft-Gault equation to estimate creatinine clearance:
- Males: (weight in kg) × (140-age in years) ÷ (72 × serum creatinine [mg/dL])
- Females: 0.85 × (value calculated for males) 1
Clinical Pearls
- Ertapenem is a once-daily carbapenem, making it convenient for outpatient parenteral antimicrobial therapy 7
- No dosage adjustments are needed based on gender, age, weight, or liver disease 7
- For complicated UTIs, the recommended duration of treatment is 10-14 days 1, 3
- Ertapenem at 1 g once daily is listed as an appropriate option for mixed infections including those affecting the urinary tract 3