From the FDA Drug Label
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 a creatinine clearance of 55 mL/min. or greater or a serum creatinine of 1. 5 mg % or less can be given full doses. Patients with creatinine clearance rates of 35 to 54 mL/min. or serum creatinine of 1.6 to 3 mg % can also be given full doses but dosage should be restricted to at least 8 hour intervals. Patients with creatinine clearance rates of 11 to 34 mL/min. or serum creatinine of 3.1 to 4. 5 mg % should be given 1/2 the usual dose every 12 hours. 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.
The dosing of cefazolin in patients with impaired renal function is as follows:
- Full dose for patients with creatinine clearance ≥ 55 mL/min or serum creatinine ≤ 1.5 mg%
- Full dose every 8 hours for patients with creatinine clearance 35-54 mL/min or serum creatinine 1.6-3 mg%
- Half dose every 12 hours for patients with creatinine clearance 11-34 mL/min or serum creatinine 3.1-4.5 mg%
- Half dose every 18-24 hours for patients with creatinine clearance ≤ 10 mL/min or serum creatinine ≥ 4.6 mg% 1
From the Research
Cefazolin dosing should be adjusted in patients with impaired renal function based on creatinine clearance (CrCl). For patients with CrCl 35-54 mL/min, the recommended dose is 1-2 g every 8 hours. When CrCl is 11-34 mL/min, reduce to 1-2 g every 12 hours. For severe impairment with CrCl ≤10 mL/min, administer 0.5-1 g every 18-24 hours. Hemodialysis patients should receive a loading dose of 1-2 g, followed by 0.5-1 g after each dialysis session, as cefazolin is significantly removed by hemodialysis 2. For continuous renal replacement therapy, doses typically range from 1-2 g every 12-24 hours depending on the method used.
Key Considerations
- Cefazolin is primarily eliminated by the kidneys, and reduced renal function leads to drug accumulation, potentially causing neurotoxicity including seizures if doses aren't reduced 3.
- Therapeutic drug monitoring may be beneficial in critically ill patients with fluctuating renal function to ensure optimal dosing.
- A linear correlation was established between the overall elimination rate-constants and the creatinine clearances in the subjects under investigation, allowing for dosage regimes adapted to each individual case according to the degree of renal function 4.
Dosing Adjustments
- For CrCl 35-54 mL/min: 1-2 g every 8 hours
- For CrCl 11-34 mL/min: 1-2 g every 12 hours
- For CrCl ≤10 mL/min: 0.5-1 g every 18-24 hours
- For hemodialysis patients: loading dose of 1-2 g, followed by 0.5-1 g after each dialysis session
- For continuous renal replacement therapy: 1-2 g every 12-24 hours, depending on the method used 2.