Creatinine Clearance (Cockcroft-Gault)
Estimates creatinine clearance for weight-based drug dosing (not for CKD staging).
How to use & interpret
The Cockcroft–Gault equation estimates creatinine clearance (an absolute value in mL/min) from age, weight, sex and serum creatinine. Unlike eGFR, it is not normalised to body surface area, which matters for certain drugs.
It remains the reference for dosing several narrow-therapeutic-index and renally-cleared drugs (notably the DOACs, aminoglycosides and some chemotherapy), and at extremes of body weight. Choose the appropriate body weight (ideal or adjusted in obesity) and remember it is unreliable in unstable renal function.
Score interpretation
CrCl ≥60 ml/min: Full-dose renal dosing for most drugs. Normal drug clearance.
→ Standard drug dosing. Verify individual drug SPCs for dose adjustments.
CrCl 30–59 ml/min: Dose reduction required for many renally cleared drugs.
→ Halve dose or extend interval for renally cleared drugs (e.g. dabigatran, metformin, LMWH, antibiotics). Check individual drug SPC.
CrCl 15–29 ml/min: Significant dose reductions. Many drugs contraindicated.
→ Avoid: metformin, NSAIDs, direct oral anticoagulants (most). Check dose: LMWH, antibiotic regimens. Nephrology review.
CrCl < 15 ml/min: Near-dialysis range. Most renally cleared drugs contraindicated.
→ Nephrology review. Most renally excreted drugs contraindicated or need major dose reduction.
Interpretation bands for the CrCl (C-G). Apply clinical judgement and local guidance.
Frequently asked questions
Cockcroft–Gault or eGFR for drug dosing?
Follow the drug's labelling: many DOACs and nephrotoxic drugs are dosed by absolute Cockcroft–Gault creatinine clearance, whereas most general dosing now uses CKD-EPI eGFR. When they disagree at extremes of size, the drug-specific method wins.
References
- Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976.
Related
Curated clinical cross-links plus same-class fallbacks.
- Vancomycin (Renal Dosing) · Antibiotic Dosing in CKD
- Gentamicin (Renal Dosing/TDM) · Antibiotic Dosing in CKD
- Phenylephrine · Alpha-1 Adrenergic Agonist (Pure Vasoconstrictor)
- Hydrocortisone (ICU — Stress Dosing) · Corticosteroid (ICU/Septic Shock)
- Carbimazole · Antithyroid Drug
- Zoledronic Acid · Bisphosphonate (IV)
- Sepsis Screening and Sepsis Six · UK Sepsis Trust; NICE NG51; Surviving Sepsis Campaign 2021
- Unintentional Weight Loss Workup · NICE NG12; BSG
- Chronic Fatigue Workup · NICE NG206; BMJ Best Practice
- Lymphadenopathy Workup · NICE NG12; BMJ Best Practice
- Pre-op Medical Clearance · NICE NG45; ESC 2022
- Secondary Hypertension Workup · NICE NG136; ESH 2023
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.