Table 2.
Population parameter estimates for the placebo effect and for the PK/PD model and their estimated 95% confidence intervals (square breackets). The extent of interindividual variability (random effect parameter) is also reported as coefficient of variation (CV%).
| Parameter | Fixed effect | Random effect | Residualerror | |
|---|---|---|---|---|
| Placebo | Cs* | 5.29 | 0.113 (CV% = 34) | 0.157 |
| [4.77, 5.81] | [0.005, 0.22] | [0.07, 0.24] | ||
| Amplitude | 0.101 | 2.29 (CV% = 151) | ||
| [0.007, 0.19] | [0, 10.56] | |||
| tmax (h) | 7.43 | (*) | ||
| [6.34, 8.51] | ||||
| kout (h−1) | 0.0498 | 3.51 (CV% = 187) | ||
| [0.03, 0.07] | [0, 7.93] | |||
| Saliva | Imax | 0.722 | (*) | 0.053 |
| [0.51,0.94] | [0.03, 0.07] | |||
| IC50 (ng ml−1) | 269 | 2.95 (CV% = 171) | ||
| [25.96 512.] | [0,6.46] | |||
| Plasma | Imax | 1.0 | (*) | 0.04 |
| [0.99, 1.01] | [0.02. 0.06] | |||
| IC50 (ng ml−1) | 24.3 | 1.22 (CV% = 110) | ||
| [23.27, 25.33] | [.18,2.26] |
*
For these parameters the random effects were not included in the model on the basis of objective function change criteria.