TABLE 3.
Population pharmacokinetic parameter estimates of methotrexate in the final model
| Parameter | Final model | Bootstrap (n = 1000) | ||||
|---|---|---|---|---|---|---|
| Estimates | 95% CI | IIV% (shrinkage %) | Median | 95% CI | ||
| CL (L/h) | θ1 | 4.900 | 4.02–5.78 | 23.5 (13) | 4.90 | 4.00–6.75 |
| V1 (L) | θ2 | 9.010 | 5.76–12.26 | — | 9.08 | 4.31–17.03 |
| V2 (L) | θ3 | 5.730 | 3.83–7.63 | 16.1 (20) | 5.59 | 0.77–7.73 |
| Q (L/h) | θ4 | 0.669 | 0.42–0.69 | — | 0.63 | 0.043–0.93 |
| Ccr on CL | θ5 | 0.456 | 0.22–0.69 | — | 0.45 | 0.12–0.93 |
| UV/HV on CL | θ6 | 0.458 | 0.39–0.53 | — | 0.43 | 0.03–0.54 |
| σ (CV) | ||||||
| Proportional (%) | 25.259 | 25.2–25.3 | — (6) | 24.842 | 18.1–34.7 | |
| Additive (μM) | 0.050 | 0.049–0.050 | — (6) | 0.047 | 0.006–0.062 | |
σ values denote intra‐individual variability.
95% CI values were derived from asymptotic SE produced by NONMEM.