Table 2.
Population pharmacodynamic parameter estimates of morphine EEG effect obtained with the sigmoidal Emax model after hysteresis minimisation with the extended catenary biophase distribution model
| Parameter | Estimate | CV% | LLCI–ULCI |
|---|---|---|---|
| Structural model | |||
| E0 (μV) | 44.6 | 2.3 | 42.6–46.6 |
| Emax (μV) | 44.5 | 8.0 | 37.5–51.5 |
| EC50 (ng ml−1) | 451 | 17.3 | 298–604 |
| nH | 2.32 | 10.4 | 1.85–2.79 |
| Interindividual variability | |||
| ω2 kE0 | 0.034 | 17.8 | 0.022–0.045 |
| ω2 kEmax | 0.121 | 24.1 | 0.064–0.178 |
| Residual variability | |||
| Proportional error | 0.027 | 7.6 | 0.023–0.031 |
Abbreviations: CV%, coefficient of variation; E0, no-drug response; Emax, intrinsic activity; EC50, measure of potency; nH, slope factor; LLCI, lower limit of confidence interval; ULCI, upper limit of confidence interval.