1. What is the Cockcroft-Gault Equation?

The Cockcroft-Gault equation estimates creatinine clearance (CrCl) which approximates glomerular filtration rate (GFR). It was developed in 1973 and remains widely used for drug dosing adjustments.

2. How Does the Calculator Work?

The calculator uses the Cockcroft-Gault equation:

Where:

• \( Age \) — Age in years
• \( Weight \) — Body weight in kg
• \( SCr \) — Serum creatinine (mg/dL)
• \( Adjustment \) — 0.85 for females, 1.0 for males

Explanation: The equation accounts for age-related decline in kidney function and differences in muscle mass between genders.

3. Importance of GFR Calculation

Details: While not as accurate as modern equations for estimating true GFR, Cockcroft-Gault remains important for medication dosing, particularly for drugs with narrow therapeutic windows.

4. Using the Calculator

Tips: Enter age in years, weight in kg, serum creatinine in mg/dL, and select gender. All values must be valid (age 1-120, weight >0, SCr >0).

5. Frequently Asked Questions (FAQ)

Q1: Why use Cockcroft-Gault instead of CKD-EPI?
A: Cockcroft-Gault is still preferred for drug dosing calculations as many medication guidelines were developed using this equation.

Q2: What are normal CrCl values?
A: Normal is approximately 90-120 mL/min for young adults, decreasing with age.

Q3: Should ideal or actual body weight be used?
A: Use actual body weight unless patient is obese (BMI >30), then use adjusted body weight.

Q4: Are there limitations to this equation?
A: Less accurate in elderly, malnourished, obese, amputees, and those with rapidly changing kidney function.

Q5: Is this suitable for all medications?
A: Some drugs require more precise GFR estimation methods. Always consult specific drug guidelines.