Parameter estimates from PK/PD modeling
Parameter estimate ± S.E. from nonlinear regression analysis of pooled mdr1a(+/+) mouse data.
Parameter | Alfentanil | Fentanyl | Loperamide | Meperidine | Methadone | Morphine | Sufentanil |
|---|---|---|---|---|---|---|---|
| Ka (min-1) | 0.35 ± 0.03 | 0.07 ± 0.07 | 0.063 ± 0.015 | 0.39 ± 0.18 | 0.55 ± 0.13 | 0.27 ± 0.04 | 0.32 ± 0.12 |
| Cl (ml · min-1 · kg-1) | 82 ± 3 | 90 ± 40 | 58 ± 7 | 190 ± 40 | 127 ± 12 | 95 ± 5 | 19 ± 3 |
| Vc (ml · kg-1) | 1000 ± 60 | 3000 ± 3000 | 32,000 ± 3000 | 6100 ± 1200 | 8800 ± 600 | 2900 ± 180 | 400 ± 80 |
| Cld (ml · min-1 · kg-1) | 40 ± 30 | ||||||
| Vp (ml · kg-1) | 5000 ± 13,000 | ||||||
| Clup (ml · min-1 · kg-1) | 4 ± 3 | 8 ± 3 | 0.04 ± 0.06 | 100 ± 40 | 27 ± 4 | 9.5 ± 0.5 | 37 ± 14 |
| Clefflux (ml · min-1 · kg-1) | 22 ± 17 | 3.4 ± 1.4 | 0.3 ± 0.5 | 8 ± 4 | 5.1 ± 0.9 | 1.9 ± 1.4 | 12 ± 5 |
| EC50 (ng/g) | 9.2 ± 1.7 | 6.4 ± 1.1 | 100 ± 6 | 2200 ± 110 | 510 ± 60 | 38 ± 4 | 1.0 ± 0.2 |
| γ | 1.8 ± 0.4 | 1.4 ± 0.3 | 2.7 ± 0.5 | 7.8 ± 4.2 | 3.7 ± 1.1 | 2.3 ± 0.5 | 2.5 ± 1.3 |
| K p,brain | 0.195 ± 0.0087 | 2.3 ± 0.2 | 0.115 ± 0.014 | 6.8 ± 0.5 | 3.3 ± 0.2 | 1.1 ± 0.6 | 2.1 ± 0.3 |
| keq (min-1) | 0.64 ± 0.09 | 0.14 ± 0.04 | 0.025 ± 0.010 | 0.13 ± 0.03 | 0.073 ± 0.014 | 0.009 ± 0.006 | 0.16 ± 0.06 |
| t1/2eq,brain (min)a | 1.08 ± 0.16 | 4.9 ± 1.3 | 27 ± 11 | 5.4 ± 1.1 | 9.6 ± 1.8 | 74 ± 45 | 4.3 ± 1.6 |
↵ a t1/2eq,brain were calculated from 0.693/keq,brain.