Table 3.
Summary of pharmacokinetic–pharmacodynamic model parameters and interindividual variability estimates for ropinirole's effect on hyperprolactinaemia
| Parameter | Population Mean | IIV | ||
|---|---|---|---|---|
| Value | %RSE | Value | %RSE | |
| CL (l h –1 ) | 50.7 | 13.7 | 0.0986 | 62.4 |
| V (l) | 444 | 11.8 | 0.0464 | 38.4 |
| Ka (h −1 ) | 0.609 | 40.2 | 0.668 | 48.4 |
| Tlag (h) | 0.595 | 25.2 | 0.32 | 63.1 |
| Kin (ng ml –1 h –1 ) | 154 | 40 | 0.929 | 33.1 |
| L max | 1 | Fixed | NA | NA |
| IC50 (ng ml –1 ) | 1.12 | 8.6 | 0.0326 | 65 |
| Baseline (ng ml –1 ) | 109 | 32.5 | 0.859 | 42 |
| α | 0.226 | 31.7 | 0.355 | 73 |
| γ | 2.1 | 11.4 | NA | NA |
| Residual errors | ||||
|---|---|---|---|---|
| Additive | Proportional | |||
| Observations | value | %RSE | value | %RSE |
| PK | 0.0092 | 25.1 | 0.0209 | 38.5 |
| PD | NA | NA | 0.0125 | 12.2 |
Baseline, initial prolactin concentration in plasma; CL, clearance; IIV, Interindividual variability; Imax, maximal fraction of inhibition; IC50, plasma concentration of ropinirole that results in 50% of Imax; Ka, first order absorption rate constant; Kin, zero order production rate of prolactin; NA, not applicable; Tlag, lag time for absorption; V, volume of central compartment; α, desensitization slope; γ, Hill coefficient