Hughes et al. 2024
Developing Parametric and Nonparametric Models for Model-Informed Precision Dosing: A Quality Improvement Effort in Vancomycin for Patients With Obesity
Therapeutic Drug Monitoring · 10.1097/FTD.0000000000001214
Structure
A two-compartment model, driven by fat-free mass and creatinine clearance.
Study population
Obese patients — United States and North America. Fitted to 83 patients and 272 concentration observations.
| Covariate | As reported |
|---|---|
| Age | 56.3 (24.3–89.3) yr |
| Weight | 134 (91.6–218) kg |
| BMI | 46.3 (40–70.3) kg/m² |
| CrCl | 174.1 (30.2–579) mL/min |
| SCr | 0.84 (0.4–2.51) 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.
LaTeX source
CL = 5.06 \cdot \left(\frac{CrCl_{FFM}}{100}\right)^{0.851}
V_1 = 64.34 \cdot \frac{FFM}{70}
V_2 = 59.0 \cdot \frac{FFM}{70}
Q = 6.24
Implementation notes
Model specifically developed for class 3 obesity (BMI ≥40 kg/m²). Parameters updated to utilize the NONMEM SAEM estimates rather than nlmixr2. Uses FFM (Janmahasatian) as input to Cockcroft-Gault for CrCl calculation.