Creatinine Clearance (Cockcroft-Gault)
Creatinine clearance for drug dose adjustment. Not equivalent to eGFR.
About this calculator
The Cockcroft-Gault formula estimates creatinine clearance (CrCl) for renal function assessment. Proposed by Cockcroft and Gault (Nephron, 1976) in a cohort of 249 men. Formula: CrCl = (140 – age) × weight (kg) / (72 × creatinine in mg/dL); multiply by 0.85 for women. Clinical use. Drug dosing in renal impairment. Reference for most FDA labels (metformin, dabigatran, apixaban, aminoglycosides, vancomycin, cefepime). Despite the introduction of CKD-EPI 2021 as the eGFR standard, the FDA retains Cockcroft-Gault as the dosing reference due to extensive historical pharmacokinetic data. Interpretation. >90 mL/min – normal function. 60-89 – mild decrease. 30-59 – moderate decrease (CKD stage 3), many drugs require dose adjustment. 15-29 – severe decrease (stage 4), most nephrotoxic and renally cleared drugs are contraindicated or need major adjustment. <15 – end-stage renal disease (stage 5), renal replacement indicated. When to use CrCl vs eGFR. CrCl Cockcroft-Gault – for drug dosing (historical standard). eGFR CKD-EPI 2021 – for CKD classification and prognosis. In obesity Cockcroft-Gault overestimates CrCl when using actual body weight – use ideal body weight or adjusted IBW + 0.4 × (actual – IBW). Limitations. Overestimates CrCl in young muscular men, overestimates in sarcopenic older patients. Not validated in pregnancy – use 24-hour urine collection. In rapidly changing creatinine (AKI) it does not reflect current function – the formula assumes steady state.
Source
Formula version: 1976-v1
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