Brooks et al. 2026 (low SCr)

Leveraging real-world data to create vancomycin population pharmacokinetic models in younger adults and patients with low serum creatinine

Journal of the American Pharmacists Association Pharmacotherapy · 10.1016/j.japhar.2025.100026

Structure

A two-compartment model, driven by weight, age, sex and serum creatinine.

Study population

General patients — United States and North America. Fitted to 2,354 patients and 6,729 concentration observations.

Covariate As reported
Age 60 (21–91) yr
Weight 68 (35–155) kg
BMI 24.4 (14–57) kg/m²
CrCl 161 (56–539) mL/min
SCr 0.5 (0.2–0.8) mg/dL

Reported as the source publication gives them — mean ± SD, or median with range or interquartile range.

Equations

The model's structural parameters as Chorus implements them.

CL=7.055(FFM55)0.78(max(SCr,0.3382)0.4)0.2209AgeeffectSexeffect,CLCL = 7.055 \cdot \left(\frac{FFM}{55}\right)^{0.78} \cdot \left(\frac{\max(SCr, 0.3382)}{0.4}\right)^{-0.2209} \cdot Age_{effect} \cdot Sex_{effect,CL}Ageeffect=Age2.285Age2.285+78.422.285/35.82.28535.82.285+78.422.285Age_{effect} = \frac{Age^{-2.285}}{Age^{-2.285} + 78.42^{-2.285}} \Big/ \frac{35.8^{-2.285}}{35.8^{-2.285} + 78.42^{-2.285}}Sexeffect,CL=0.904 if Male, else 1.0Sex_{effect,CL} = 0.904 \text{ if Male, else } 1.0V1=66.15FFM55Sexeffect,V1V_1 = 66.15 \cdot \frac{FFM}{55} \cdot Sex_{effect,V1}Sexeffect,V1=0.863 if Male, else 1.0Sex_{effect,V1} = 0.863 \text{ if Male, else } 1.0V2=56.76FFM55V_2 = 56.76 \cdot \frac{FFM}{55}Q=2.900Q = 2.900
LaTeX source
CL = 7.055 \cdot \left(\frac{FFM}{55}\right)^{0.78} \cdot \left(\frac{\max(SCr, 0.3382)}{0.4}\right)^{-0.2209} \cdot Age_{effect} \cdot Sex_{effect,CL}
Age_{effect} = \frac{Age^{-2.285}}{Age^{-2.285} + 78.42^{-2.285}} \Big/ \frac{35.8^{-2.285}}{35.8^{-2.285} + 78.42^{-2.285}}
Sex_{effect,CL} = 0.904 \text{ if Male, else } 1.0
V_1 = 66.15 \cdot \frac{FFM}{55} \cdot Sex_{effect,V1}
Sex_{effect,V1} = 0.863 \text{ if Male, else } 1.0
V_2 = 56.76 \cdot \frac{FFM}{55}
Q = 2.900

Implementation notes

Model explicitly developed for patients with low serum creatinine (<0.8 mg/dL). Uses measured SCr directly, bounded to a data-derived minimum of 0.3382 mg/dL.

Simulation settings

Models

selected

Dose candidates (mg)

Interval candidates (h)

Demographics

Physical characteristics.

kg
cm
yr