Table 4.
Population estimates of PD parameters and variabilities for S(−)-atenolol with (ISO) and without (non-ISO) isoprenaline-induced tachycardia
| Parameter | Value (CV) ISO | Value (CV) non-ISO |
|---|---|---|
| Structural parameters | ||
| E0 (b.p.m.) | 517 (2.6%) | 362 (5.5%) |
| Emax (b.p.m.) | −168 (8.8%) | −43.0 (41.2%) |
| EC50 (ng ml−1) | 49.0 (28.8%) | 27.9 (97.1%) |
| Ke0 (min−1) | 0.042 (28.1%) | NE |
| n | 0.950 (36.3%) | NE (fixed at n=1) |
| Interindividual variability (IIV) | ||
| ωE02 | 297 (50.1%) | 1380 (55.4%) |
| omega2Emax | 1860 (49.5%) | 913 (55.9%) |
| Residual error | ||
| σPD2 | 747 (21.6%) | 250 (23.2%) |
Abbreviations: CV, coefficient of variation; E0, baseline heart rate, EC50, potency of the drug, Emax, maximal effect of isoprenaline, keo, equilibrium rate constant for the effect compartment; PD, pharmacodynamics; n, Hill coefficient; NE, not estimated.