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Cockcroft-Gault Equation:
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The Cockcroft-Gault equation is a widely used formula for estimating creatinine clearance (CrCl), which serves as a surrogate for glomerular filtration rate (GFR). It's particularly useful for drug dosing adjustments in patients with renal impairment.
The calculator uses the Cockcroft-Gault equation:
Where:
Explanation: The equation estimates creatinine clearance based on age, weight, serum creatinine, and gender, providing a practical tool for renal function assessment.
Details: Creatinine clearance estimation is essential for appropriate drug dosing, particularly for medications with narrow therapeutic windows that are primarily eliminated by the kidneys.
Tips: Enter age in years, weight in kilograms, serum creatinine in mg/dL, and select gender. All values must be valid (age between 1-120, weight > 0, creatinine > 0).
Q1: Why use Cockcroft-Gault equation?
A: It's one of the most widely validated equations for drug dosing adjustments and is referenced in many medication guidelines and prescribing information.
Q2: What are normal CrCl values?
A: Normal CrCl is approximately 90-120 mL/min for young adults, decreasing with age. Values below 60 mL/min indicate renal impairment.
Q3: When should ideal body weight be used?
A: For obese patients (BMI > 30), ideal body weight should be used instead of actual body weight for more accurate estimation.
Q4: Are there limitations to this equation?
A: Less accurate in elderly patients, those with extreme body weights, muscle wasting diseases, and rapidly changing renal function.
Q5: How does this differ from eGFR?
A: CrCl estimates creatinine clearance while eGFR estimates glomerular filtration rate. Many drug dosing guidelines specifically reference CrCl.