What is the recommended dose of Ertapenem for patients with normal and impaired renal function?

Ertapenem Dosing Recommendations

The standard dose of ertapenem for adult patients with normal renal function is 1 gram IV once daily, while patients with severe renal impairment (creatinine clearance ≤30 mL/min/1.73 m²) should receive a reduced dose of 500 mg daily. 1

Normal Renal Function Dosing

Adults and Adolescents (≥13 years)

• Dose: 1 gram IV or IM once daily 1
• Administration:
  • IV: Infuse over 30 minutes
  • IM: May be used as an alternative to IV administration when appropriate
• Duration: Up to 14 days for IV administration; up to 7 days for IM administration 1

Children (3 months to 12 years)

• Dose: 15 mg/kg twice daily (not to exceed 1 g/day) 1
• Administration: IV or IM as appropriate
• Duration: Varies by indication (typically 5-14 days) 1

Renal Impairment Dosing

Adults with Renal Impairment

• Mild to Moderate Impairment (CrCl >30 mL/min/1.73 m²):

  • No dosage adjustment necessary 1

• Severe Impairment (CrCl ≤30 mL/min/1.73 m²) and End-Stage Renal Disease (CrCl ≤10 mL/min/1.73 m²):

  • 500 mg once daily 1, 2

Hemodialysis Patients

• Base Dose: 500 mg once daily 1
• Supplementary Dose: If ertapenem is administered within 6 hours prior to hemodialysis, give an additional 150 mg dose following the hemodialysis session 1, 2
• Note: Hemodialysis removes approximately 30% of the ertapenem dose 2

Special Considerations

Hepatic Impairment

• No specific dose adjustment recommendations are available for patients with hepatic impairment 1

Stability and Storage

• Ertapenem has moderate stability at room temperature (25°C) for up to 6 hours after reconstitution 3
• When refrigerated (5°C), stability extends to 24 hours 3

Common Pitfalls and Caveats

1. Do not mix or co-infuse ertapenem with other medications 1

2. Do not use diluents containing dextrose (α-D-glucose) for reconstitution or dilution 1

3. Central nervous system toxicity risk in hemodialysis patients:

   • Even the recommended dose of 500 mg daily may accumulate in some hemodialysis patients, especially those with smaller body size
   • Monitor for seizures, hallucinations, and cognitive dysfunction
   • Symptoms typically resolve within 8 days after discontinuation 4

4. Critically ill patients may have altered pharmacokinetics:

   • Higher volume of distribution
   • Lower maximum plasma concentrations
   • Unpredictable intersubject parameters
   • Hypoalbuminemia may affect unbound drug concentrations 5

5. Calculation of creatinine clearance when only serum creatinine is available:

   • Males: (weight in kg) × (140-age in years) ÷ (72 × serum creatinine [mg/100 mL])
   • Females: 0.85 × value calculated for males 1

By following these dosing recommendations and being aware of the potential pitfalls, clinicians can optimize ertapenem therapy while minimizing the risk of adverse effects, particularly in patients with renal impairment.