Clinical & Hospital Pharmacy

Renal Dosing Adjuster

Pairs Cockcroft-Gault creatinine clearance and CKD-EPI 2021 eGFR with evidence-based dose tiers for 20 renally cleared medicines.

Clinical decision support — verify before prescribing

Confirm every recommendation against the official FDA package insert and your institution's guidelines. This tool does not know the indication, the severity of infection, or the patient's other medicines.

Cockcroft-Gault CrCl

44.6mL/min

Ideal Body Weight (71.4 kg) · CKD-EPI eGFR 46.6 (G3a)

Vancomycin — CrCl 30–49 mL/min

Dose: 15 mg/kg · Interval: Every 24 hoursAUC-guided dosing or trough level monitoring (15–20 mcg/mL for severe MRSA) required.

Critical clinical warning

High risk of nephrotoxicity with AUC > 650 mg·h/L or concurrent loop diuretics/aminoglycosides.

Patient biometrics

Cockcroft-Gault needs a stable serum creatinine.

Age

years

Biological sex

Total body weight

Height

Serum creatinine

Must be at steady state.

IBW (Devine)71.4kg

AdjBW (40%)76.4kg

BMI27.1kg/m²

CrCl weight basis

Normal Weight: Ideal Body Weight (IBW) standard for Cockcroft-Gault estimation.

Cockcroft-Gault CrCl44.6mL/min

dosing standard

CKD-EPI (2021, race-free) eGFR46.6mL/min/1.73 m²

Stage G3a

KDIGO categoryMild to Moderate (45–59 mL/min/1.73m²)

Patient scenario

Renal pharmacopeia

20 of 20 medications shown.

Medication

Vancomycin (Vancocin)

Antibiotics

Indication: Severe Gram-positive infections, MRSA bacteremia, endocarditis

Usual dose: 15–20 mg/kg IV q8–12h (Max 2 g/dose). Target AUC/MIC: 400–600 mg·h/L

ASHP/IDSA Guidelines

Active recommendation (patient CrCl 44.6 mL/min)

The tier the patient's clearance falls into.

CrCl rangeCrCl 30–49 mL/min

caution

Adjusted dose15 mg/kg

Dosing intervalEvery 24 hours

Clinical notesAUC-guided dosing or trough level monitoring (15–20 mcg/mL for severe MRSA) required.

All dose tiers

Every band published for Vancomycin.

CrCl range	Dose	Interval	Status
CrCl ≥ 50 mL/min	15–20 mg/kg (actual body weight)	Every 8 to 12 hours	safe
CrCl 30–49 mL/min← patient	15 mg/kg	Every 24 hours	caution
CrCl 15–29 mL/min	15 mg/kg	Every 24 to 48 hours	caution
CrCl < 15 mL/min	15–20 mg/kg loading dose, then level-guided	Redose when level < 15–20 mcg/mL	monitored

Haemodialysis15–25 mg/kg loading dose; redose 5–10 mg/kg after HD when serum level < 15–20 mcg/mL (High-flux dialyzers remove 30–50%).

CRRT20–25 mg/kg loading dose, then 10–15 mg/kg IV q24–48h or continuous infusion with AUC monitoring.

Peritoneal dialysis1–2 g IP loading dose, then 30 mg/kg IP every 3–5 days or 15–30 mg/L in each dialysate bag.

Clinical pearls

Calculate actual body weight for loading dose, but monitor trough/AUC closely in morbidly obese patients.
Co-administration with Piperacillin-Tazobactam increases acute kidney injury (AKI) incidence significantly.

Source: ASHP/IDSA Guidelines (Rybak MJ, et al. ASHP/IDSA/PIDS/SIDP Consensus Guidelines. Am J Health-Syst Pharm. 2020;77(11):835-864.) · last reviewed 2024 Q4.

Creatinine clearance for dosing uses Cockcroft-Gault:

CrCl = ((140 − age) × weight kg) / (72 × SCr mg/dL) × 0.85 if female

The weight is chosen by a heuristic: actual body weight if the patient is below IBW, adjusted body weight (IBW + 0.4 × excess) above 120% of IBW, otherwise Devine IBW (50 kg male / 45.5 kg female, + 2.3 kg per inch over 5 feet).

Kidney function for staging uses CKD-EPI 2021, which no longer includes a race term:

eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.209 × 0.9938^age × 1.012 if female

κ is 0.7 for women and 0.9 for men; α is −0.241 and −0.302 respectively. KDIGO stages are G1 ≥ 90, G2 60–89, G3a 45–59, G3b 30–44, G4 15–29 and G5 below 15 mL/min/1.73 m².

The dose tier is then matched on CrCl, not eGFR, because that is what FDA labelling uses.

Common questions

Because they answer different questions. Almost all renal dosing bands in FDA labelling were derived with Cockcroft-Gault, which uses actual body weight and is not normalised to body surface area. CKD-EPI eGFR is normalised to 1.73 m² and is the standard for staging chronic kidney disease, so it is shown alongside for context.

IBW in normal-weight patients, actual weight if the patient is below their IBW, and adjusted body weight once actual weight exceeds 120% of IBW. Using actual weight in obesity substantially overestimates clearance and can lead to overdosing. The Auto setting applies this and states its reasoning.

No. Both equations assume creatinine is at steady state. In rapidly changing renal function the serum creatinine lags behind the true clearance, so the calculated value will be too high while the patient is deteriorating and too low while they recover.

They use different inputs. Cockcroft-Gault is weight-driven, so a heavy patient gets a higher CrCl and a light or sarcopenic one a lower one; CKD-EPI ignores weight entirely and normalises to body surface area. Large divergence is expected at the extremes of body size — which is exactly where prescribing needs most care.

Prepared by the PharmaWallah student team. Verify results with your textbook or instructor. Report an error · Editorial policy