From the FDA Drug Label
Patients with creatinine clearance rates 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. Dosage Adjustment for Patients With Reduced Renal Function Cefazolin may be used in patients with reduced renal function with the following dosage adjustments
The dose of 1 gram IV every day is not explicitly stated as a renal dose adjustment in the provided drug label. However, according to the label, patients with normal renal function (creatinine clearance of 55 mL/min or greater) can receive full doses. The usual adult dose for moderate to severe infections is 500 mg to 1 gram every 6 to 8 hours, and for acute, uncomplicated urinary tract infections, it is 1 gram every 12 hours. Given the information, 1 gram IV every day would be less than the recommended dose for patients with normal renal function, suggesting it could be a renal dose adjustment for patients with reduced renal function, but the exact adjustment is based on the patient's creatinine clearance rate. For patients with creatinine clearance rates of 11 to 34 mL/min, the recommended dose is 1/2 the usual dose every 12 hours. Since the usual dose for some infections is 1 gram, 1 gram IV every day could be considered a dose for patients with creatinine clearance rates of 35 to 54 mL/min, where the dosage should be restricted to at least 8-hour intervals, but this is not explicitly stated for a daily dose. Therefore, 1 gram IV every day may be considered a renal dose adjustment, but the provided label does not directly support this answer for all patients with reduced renal function. 1
From the Research
Cefazolin 1 gram IV daily is considered a reduced dose, typically used for patients with severe renal impairment, and is a renal dose adjustment. The standard dosing for cefazolin in patients with normal renal function is usually 1-2 grams IV every 8 hours (3 times daily), which equals 3-6 grams total daily dose. The 1 gram IV daily dose represents a significant reduction and would be appropriate for patients with severe renal impairment, typically with a creatinine clearance less than 10-15 mL/min or for patients on hemodialysis, as supported by a study from 2. This reduced dosing is necessary because cefazolin is primarily eliminated by the kidneys, and impaired renal function leads to drug accumulation and potential toxicity if standard doses are used, as shown in studies such as 3, 4, and 5. Before administering this dose, it's essential to confirm the patient's renal function through laboratory tests such as serum creatinine and calculated creatinine clearance. For patients on dialysis, the timing of the dose relative to dialysis sessions is also crucial, as cefazolin can be removed during hemodialysis, and a study from 2 suggests a postdialysis dose of 1 gram IV for patients weighing over 50 kg. Key points to consider include:
- Renal function significantly impacts cefazolin pharmacokinetics and pharmacodynamics, as demonstrated in 6.
- The dose should be adjusted according to the patient's creatinine clearance, with more frequent dosing needed for patients with better renal function, as indicated in 6.
- Cefazolin can be an effective and safe alternative to vancomycin in chronic hemodialysis patients, as shown in 2.