What is the recommended dosing for ertapenem (Invanz) in patients with impaired renal function?

Ertapenem Dosing in Renal Impairment

For patients with creatinine clearance >30 mL/min/1.73 m², administer ertapenem 1 gram once daily without dose adjustment; for severe renal impairment (CrCl ≤30 mL/min/1.73 m²) or end-stage renal disease (CrCl ≤10 mL/min/1.73 m²), reduce the dose to 500 mg once daily. 1

Standard Dosing by Renal Function

Normal to Moderate Renal Impairment (CrCl >30 mL/min/1.73 m²)

• Administer 1 gram once daily for all approved indications including complicated intra-abdominal infections, complicated skin/skin structure infections, community-acquired pneumonia, complicated urinary tract infections, and acute pelvic infections 1
• No dose adjustment is necessary for mild to moderate renal insufficiency 2
• Pharmacokinetic studies show only 7% increase in drug exposure with mild RI and 53% increase with moderate RI, which does not warrant dose reduction 2

Severe Renal Impairment (CrCl ≤30 mL/min/1.73 m²)

• Reduce dose to 500 mg once daily 1
• This population experiences a 158% increase in drug exposure compared to normal renal function, necessitating dose reduction 2
• The half-life extends from 4.5 hours to 10.6 hours in advanced renal insufficiency 2

End-Stage Renal Disease (CrCl ≤10 mL/min/1.73 m²)

• Administer 500 mg once daily 1
• Drug exposure increases by 192% and half-life extends to 14.1 hours in ESRD patients 2

Hemodialysis Considerations

If ertapenem is administered within 6 hours prior to hemodialysis, give a supplementary dose of 150 mg following the dialysis session. 1

• Hemodialysis removes approximately 30% of the administered dose 2
• If ertapenem is given at least 6 hours before hemodialysis, no supplementary dose is needed 1
• Always administer the drug after dialysis when possible to avoid premature removal and facilitate directly observed therapy 3
• No data exist for patients on peritoneal dialysis or hemofiltration 1

Route of Administration Options

Intravenous Administration

• Infuse over 30 minutes for all patients 1
• Can be used for up to 14 days of therapy 1
• Reconstitute 1 g vial with 10 mL of Water for Injection, 0.9% Sodium Chloride, or Bacteriostatic Water for Injection, then dilute in 50 mL of 0.9% Sodium Chloride 1

Intramuscular Administration

• Can be used as an alternative for up to 7 days when IM therapy is appropriate 1
• Reconstitute with 3.2 mL of 1.0% lidocaine HCl (without epinephrine) and administer deep IM into large muscle mass 1
• IM ertapenem reconstituted in lidocaine demonstrates comparable tolerability to IM ceftriaxone, with only 1.1% experiencing moderate to severe injection site symptoms 4

Treatment Duration by Indication

• Complicated intra-abdominal infections: 5-14 days 1
• Complicated UTI/pyelonephritis: 10-14 days 3, 1
• Complicated skin/skin structure infections: 7-14 days 1
• Community-acquired pneumonia: 10-14 days (may switch to oral after ≥3 days if clinically improved) 1
• Acute pelvic infections: 3-10 days 1

Critical Pitfalls to Avoid

• Never mix or co-infuse ertapenem with other medications 1
• Do not use diluents containing dextrose (α-D-glucose) 1
• Do not administer reconstituted IM solution intravenously 1
• Avoid administering before hemodialysis sessions when the dose is given within 6 hours of dialysis, as this leads to premature drug removal 1
• No dosage adjustment recommendations can be made for hepatic impairment due to lack of data 1

Special Populations

Pediatric Patients (3 months to 12 years)

• Dose is 15 mg/kg twice daily, not to exceed 1 gram per day 1
• No data exist for pediatric patients with renal impairment or on hemodialysis 1

Elderly and Other Considerations

• No dose adjustment needed based on gender, age, weight, or liver disease in adults with normal renal function 5
• Ertapenem is neither a substrate nor inhibitor of P-glycoprotein or cytochrome P450 enzymes, minimizing drug interaction concerns 5

Clinical Efficacy Context

Ertapenem demonstrates equivalent efficacy to piperacillin-tazobactam and ceftriaxone across approved indications 6, 7, with cure rates of 84.8% for deep tissue infections and 90.5% for complicated UTIs caused by Enterobacteriaceae 7. The once-daily dosing regimen is particularly advantageous for outpatient parenteral antimicrobial therapy and home IV therapy 8.