What is the recommended dosage of Ertapenem (a carbapenem antibiotic) in a patient with impaired renal function, specifically a glomerular filtration rate (GFR) of 35?

From the FDA Drug Label

The recommended dose of ertapenem in adult patients with CLCR ≤30 mL/min/1.73 m2 is 0. 5 grams every 24 hours. No dosage adjustment is necessary in patients with CLCR ≥31 mL/min/1.73 m2.

The patient's GFR is 35, which is greater than 30 mL/min/1.73 m2.

• No dosage adjustment is necessary for this patient.
• The recommended dose is the standard dose, which is not specified in the provided text for patients with normal renal function or GFR > 30 mL/min/1.73 m2 1.

From the Research

For a patient with a GFR of 35 mL/min, the recommended dosage of ertapenem is 500 mg once daily, as dose adjustment is necessary to prevent potential central nervous system toxicity associated with high plasma levels of the drug in patients with advanced kidney disease 2.

Key Considerations

• Ertapenem is a carbapenem antibiotic with broad-spectrum activity against gram-positive, gram-negative, and anaerobic bacteria, but lacks activity against Pseudomonas and Acinetobacter species.
• The drug is primarily eliminated by the kidneys, which is why dose adjustments become necessary with more severe renal impairment.
• Monitor renal function during therapy, especially if the GFR is borderline, as a decline below 30 mL/min would necessitate reducing the dose to 500 mg once daily.

Administration and Indications

• The standard administration is via intravenous infusion over 30 minutes, or intramuscular injection with lidocaine.
• Treatment duration typically ranges from 3 to 14 days depending on the type and severity of infection being treated.
• Common indications include complicated intra-abdominal infections, complicated skin and skin structure infections, community-acquired pneumonia, complicated urinary tract infections, and acute pelvic infections.

Pharmacokinetics and Dosing

• Approximately 30% of ertapenem is cleared by a session of haemodialysis (HD) 2.
• The recommended dose of 500 mg ertapenem daily is necessary for patients with advanced kidney disease to prevent CNS toxicity 2.
• Other studies have investigated the pharmacokinetics of ertapenem in various patient populations, including critically ill patients with severe sepsis 3 and patients with renal failure treated with continuous hemofiltration 4, but the study by 2 provides the most relevant guidance for dosing in patients with a GFR of 35 mL/min.