What is the recommended dose of cefazolin for a patient with complicated bacteremia due to Methicillin-Sensitive Staphylococcus Aureus (MSSA) and End-Stage Renal Disease (ESRD)?

From the Guidelines

For patients with complicated MSSA bacteremia and ESRD, the recommended dose of cefazolin is 20 mg/kg (actual body weight), rounded to the nearest 500-mg increment, after dialysis. This dosage recommendation is based on the guidelines for the diagnosis and management of intravascular catheter-related infection, which suggest that patients who receive empirical vancomycin and are found to have CRBSI due to methicillin-susceptible S. aureus should be switched to cefazolin 1. The guidelines specify that for cefazolin, a dosage of 20 mg/kg (actual body weight), rounded to the nearest 500-mg increment, after dialysis is recommended 1.

The duration of therapy for complicated MSSA bacteremia should be at least 4-6 weeks, with the exact duration determined by clinical response, source control, and clearance of positive blood cultures 1. Cefazolin is the preferred beta-lactam for MSSA infections due to its narrow spectrum, excellent activity against MSSA, and favorable safety profile. In ESRD patients, cefazolin has prolonged elimination, requiring less frequent dosing compared to patients with normal renal function.

Key considerations in the treatment of complicated MSSA bacteremia in ESRD patients include:

• Source control through removal of infected devices or drainage of abscesses is essential for successful treatment of complicated bacteremia 1.
• Blood levels should be monitored if available, especially in critically ill patients, to ensure therapeutic concentrations.
• The infected catheter should always be removed for patients with hemodialysis CRBSI due to S. aureus, and a temporary (nontunneled catheter) should be inserted into another anatomical site 1.
• Empirical antibiotic therapy should include vancomycin and coverage for gram-negative bacilli, based on the local antibiogram 1.

Overall, the treatment of complicated MSSA bacteremia in ESRD patients requires careful consideration of antibiotic dosing, duration of therapy, and source control, as well as monitoring of blood levels and clinical response 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION ... Severe, life-threatening infections (e.g., endocarditis, septicemia)* 1 gram to 1. 5 grams every 6 hours ... Dosage Adjustment for Patients With Reduced Renal Function Cefazolin may be used in patients with reduced renal function with the following dosage adjustments: Patients with creatinine clearance rates of 10 mL/min. or less or serum creatinine of 4. 6 mg % or greater should be given 1/2 the usual dose every 18 to 24 hours.

For a patient with complicated bacteremia due to MSSA and ESRD, the recommended dose of cefazolin is 1/2 the usual dose for severe infections.

• The usual dose for severe infections is 1 gram to 1.5 grams every 6 hours.
• For patients with ESRD (creatinine clearance rates of 10 mL/min. or less), the dose should be 1/2 of 1 gram to 1.5 grams, given every 18 to 24 hours. So, the dose is 0.5 to 0.75 grams every 18 to 24 hours 2.

From the Research

Cefazolin Dosing for Complicated Bacteremia with MSSA in Patients with ESRD

• The recommended dose of cefazolin for patients with complicated bacteremia due to Methicillin-Sensitive Staphylococcus Aureus (MSSA) and End-Stage Renal Disease (ESRD) is not explicitly stated in the provided studies, but several studies provide guidance on cefazolin dosing in patients with ESRD.
• A study published in 1998 3 suggests that a 1 g intravenous dose of cefazolin post-dialysis (750 mg in patients weighing <50 kg) is safe and effective for infections with documented sensitivity to cefazolin in anuric hemodialysis patients.
• Another study published in 2011 4 found that dosing cefazolin 2-3 g on each hemodialysis session in anuric patients with Staphylococcal bacteremia leads to earlier discharge and less cost, with a 30-day mortality of 7% compared to 15% with cloxacillin.
• A more recent study published in 2024 5 describes the population pharmacokinetics of unbound cefazolin in infected hospitalized patients requiring intermittent high-flux haemodialysis and suggests that a 2 g three-times-weekly post-dialysis dosing regimen can provide optimal treatment for MSSA infections.
• Additionally, a study published in 1998 6 evaluated the clinical efficacy and serum concentrations of cefazolin as empiric therapy in hemodialysis-related infections and found that cefazolin at doses of approximately 20 mg/kg administered post-HD appears to be a safe and effective empiric therapy.

Considerations for Cefazolin Dosing in ESRD Patients

• It is essential to consider the patient's renal function and dialysis schedule when determining the cefazolin dose, as supratherapeutic dosing can lead to significant neurotoxic effects, as reported in a case study published in 2025 7.
• The studies suggest that cefazolin can be an effective and safe alternative to vancomycin for the treatment of MSSA infections in patients with ESRD, but the dosing regimen should be carefully considered to avoid toxicity and ensure optimal treatment outcomes.