Vancomycin AUC dosing

AUC-guided vancomycin dosing from population estimates or from two levels, with a live drug-level curve.

Previewv0.1.0 · Pending clinical review

Inputs

Method

Patient Shared with every calculator

Actual (total) body weight
Enter, or fill the patient
mL/min

Open the CrCl calculator

Target

Target AUC24mg·h/L, consensus 400 to 600
500
0.7 typical; 0.5 in obesity
L/kg
Loading dose20 to 35 mg/kg, max 3,000 mg
mg/kg

How this dose was built

  1. Kidneys clear vancomycin

    Clearance (CL) is how many liters of blood the body cleans of drug each hour. For vancomycin it rises with kidney function.

  2. The body is a tank

    Volume (V) is how much space the drug spreads into. Bigger patients have bigger tanks, so a loading dose fills the tank fast.

  3. AUC is total exposure

    The shaded area under the curve is the drug exposure over 24 hours. 400 to 600 kills MRSA while protecting the kidneys.

  4. Daily dose = AUC × CL

    Multiply the target exposure by clearance to get the daily dose, then split it into an interval that fits the half-life.

When to use
  • Serious MRSA infections in adults, targeting AUC24 400 to 600 mg·h/L (assuming MIC 1 mg/L).
Pearls and pitfalls
  • Population estimates are a starting point; obtain levels early (often within 24 to 48 h).
  • Draw both levels within the same dosing interval at or near steady state.
  • Obesity: consider Vd 0.5 L/kg and cap loading doses at 3,000 mg.
  • AUC above 600 is linked to more kidney injury.
Method and formulas
AUC24=DailydoseCL
CL=(0.689×CrCl+3.66)×0.06
k=ln(C1C2)Δt
where
AUC24
24-hour exposure, mg·h/L (target 400–600)
CL
Vancomycin clearance, L/h
CrCl
Creatinine clearance, mL/min
k
Elimination rate constant, h⁻¹
C1, C2
Two levels from the same interval, mg/L
Δt
Hours between the two levels

From levels, AUC is the linear-up, log-down trapezoid over one interval, scaled to 24 h.

Evidence
  1. Guideline Rybak MJ, Le J, Lodise TP, et al. Therapeutic monitoring of vancomycin for serious MRSA infections: a revised consensus guideline and review by ASHP, IDSA, PIDS, and SIDP. Am J Health Syst Pharm. 2020;77(11):835-864. PubMed 32191793
  2. Primary Matzke GR, McGory RW, Halstenson CE, Keane WF. Pharmacokinetics of vancomycin in patients with various degrees of renal function. Antimicrob Agents Chemother. 1984;25(4):433-437.
  3. Primary Sawchuk RJ, Zaske DE. Pharmacokinetics of dosing regimens which utilize multiple intravenous infusions: gentamicin in burn patients. J Pharmacokinet Biopharm. 1976;4(2):183-195.
  4. Supporting Pai MP, Neely M, Rodvold KA, Lodise TP. Innovative approaches to optimizing the delivery of vancomycin in individual patients. Adv Drug Deliv Rev. 2014;77:50-57.