Ertapenem Dosing in Renal Impairment
For patients with severe renal impairment (creatinine clearance ≤30 mL/min/1.73 m²) or end-stage renal disease, reduce the ertapenem dose to 500 mg once daily. 1
Standard Dosing for Reference
- Patients with normal renal function (creatinine clearance >90 mL/min/1.73 m²) receive 1 gram once daily intravenously or intramuscularly 1
- No dosage adjustment is necessary for patients with creatinine clearance >30 mL/min/1.73 m² 2, 1
Dose Adjustments Based on Renal Function
Mild to Moderate Renal Impairment
- Creatinine clearance 31-90 mL/min/1.73 m²: Continue standard 1 gram once daily dosing without adjustment 1, 3
- Patients with mild renal impairment (CLCR 60-90 mL/min/1.73 m²) show only a 1.5-fold increase in unbound drug exposure, which does not warrant dose reduction 1
- Moderate renal impairment (CLCR 31-59 mL/min/1.73 m²) results in a 2.3-fold increase in unbound AUC but remains within acceptable therapeutic range 1
Severe Renal Impairment and ESRD
- Creatinine clearance ≤30 mL/min/1.73 m²: Reduce dose to 500 mg once daily 2, 1
- End-stage renal disease (CLCR <10 mL/min/1.73 m²): Use 500 mg once daily 1, 3
- The rationale for dose reduction is that unbound drug exposure increases 4.4-fold in advanced renal impairment and 7.6-fold in ESRD compared to healthy subjects 1
Hemodialysis Considerations
If ertapenem is administered within 6 hours prior to hemodialysis, give a supplementary dose of 150 mg following the dialysis session. 2, 1
- Hemodialysis removes approximately 30% of the administered ertapenem dose during a 4-hour session 1, 3
- If ertapenem is given at least 6 hours before hemodialysis, no supplementary dose is needed 1
- The 150 mg supplementary dose represents 30% of the reduced daily dose (500 mg) for patients with severe renal impairment 3
Important Clinical Considerations
Calculating Creatinine Clearance
- When only serum creatinine is available, use the Cockcroft-Gault equation to estimate creatinine clearance 1:
- Males: (weight in kg) × (140 - age in years) / [(72) × serum creatinine (mg/100 mL)]
- Females: 0.85 × (value calculated for males)
- Serum creatinine must represent steady-state renal function for accurate estimation 1
Pediatric Patients
- There are no data available for dose adjustments in pediatric patients with renal impairment 1
- Standard pediatric dosing (15 mg/kg twice daily, not to exceed 1 g/day) applies only to those with normal renal function 1
Common Pitfalls to Avoid
- Do not use dextrose-containing diluents for reconstitution or dilution of ertapenem 1
- Failing to provide the supplementary post-hemodialysis dose when ertapenem is given within 6 hours of dialysis 1
- Assuming that less frequent dosing maintains adequate time above MIC in critically ill patients, who may have altered pharmacokinetics beyond renal impairment alone 4
- In critically ill patients with severe sepsis and normal renal function, standard dosing may still result in suboptimal drug concentrations due to increased volume of distribution and altered protein binding 5