Cockcroft-Gault

Estimates creatinine clearance for drug dosing.

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Creatinine Clearance (Cockcroft-Gault Equation)

Cockcroft-Gault

Estimates creatinine clearance for drug dosing.

Gender

MaleFemale

Age

Patient's age

years

Weight

Patient's weight (Normal range: 50-100 kg)

Height

Patient's height (Normal range: 150-190 cm)

Serum Creatinine

Serum creatinine level (Normal range: 0.6-1.2 mg/dL)

Creatinine Clearance (Cockcroft-Gault): — —

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Instructions

The Cockcroft-Gault equation estimates creatinine clearance (CrCl), serving as a practical marker for kidney function. It is particularly useful in adjusting drug dosing for patients with renal impairment. The formula incorporates age, body weight, sex, and serum creatinine to approximate clearance in milliliters per minute. Clinicians should collect the patient’s most recent serum creatinine level, body weight, and demographic data before calculation. Although widely used, it may overestimate renal function in obese or edematous patients and underestimate it in those with reduced muscle mass.

Overview

When to use

Why use

Evidences

Interpretation

Cockcroft-Gault CrCl in mL/min = [(140 – age) × (weight in kg) / (72 × serum creatinine in mg/dL)] × (0.85 if female)

The Cockcroft–Gault (C–G) equation was derived in 1976 to estimate creatinine clearance (CrCl) from serum creatinine in adults, using age and weight, with a sex adjustment (multiply by 0.85 for women); it was developed from predominantly male inpatients with measured 24‑h CrCl and became widely used for drug dosing

https://www.ncbi.nlm.nih.gov/books/NBK544228/

A historical deconstruction notes methodological issues in the original derivation (e.g., circularity introducing weight), yet acknowledges the equation’s entrenched clinical role for bedside dosing decisions

https://nzmj.org.nz/media/pages/journal/vol-125-no-1350/the-cockroft-and-gault-formula-for-estimation-of-creatinine-clearance-a-friendly-deconstruction/945379baeb-1696472177/the-cockroft-and-gault-formula-for-estimation-of-creatinine-clearance-a-friendly-deconstruction.pdf

Compared with measured clearance, C–G shows only moderate correlation in hospitalized older adults and may misestimate kidney function, particularly in elderly women and at extremes of body size; careful weight selection and awareness of bias are needed

https://pmc.ncbi.nlm.nih.gov/articles/PMC8554604/

For general CKD assessment, CKD‑EPI equations often outperform C–G and MDRD; in drug dosing contexts, some studies show CKD‑EPI better correlates with actual drug clearance (e.g., ganciclovir), though clinical differences can be small and regulators/labels may still specify C–G

https://pmc.ncbi.nlm.nih.gov/articles/PMC6089827/

Overview

When to use

Why use

Evidences

The Cockcroft-Gault equation, first introduced in 1976, is a widely applied method for estimating renal function through creatinine clearance (CrCl). This equation provides clinicians with an easily obtainable bedside estimate of kidney performance without requiring timed urine collections, which were traditionally used to measure clearance directly. By incorporating patient age, weight, sex, and serum creatinine concentration, it offers a practical means to tailor drug dosing and evaluate renal function.

One of its primary clinical applications is in guiding dosage adjustments for renally cleared medications such as antibiotics, anticoagulants, and chemotherapeutics. This ensures efficacy while minimizing the risk of drug accumulation and toxicity in patients with impaired renal function. The Cockcroft-Gault equation is also commonly referenced in drug labeling, making it integral to pharmacotherapy decision-making.