Table 4. Population pharmacokinetic and pharmacodynamic parameters of higenamine hydrochloride.
| Parameter | Estimate (%CV) | Inter-individual variability (%CV) | Boostrap |
|
|---|---|---|---|---|
| Median (%CV) | Median (2.5th, 97.5th percentiles) | |||
| Vc (L) | 18.7 (6.6) | 8.7 (4.1) | 19.1 (17.5) | 14.0–27.0 |
| Vp (L) | 43.0 (3.3) | 45.9 (25.5) | 25.1–71.4 | |
| Km (μg/L) | 3.1 (3.7) | 4.1 (0.3) | 3.6 (89.1) | 0.635–12.3 |
| Vmax (L/min) | 48.3 (1.4) | 1.7 (0.4) | 49.7 (37.5) | 28.0–100.0 |
| CLd (L/min) | 3.8 (5.2) | 1.0 (0.05) | 3.7 (10.3) | 2.66–4.18 |
| Plasma residual error | 0.260 (6.1) | 0.256 (9.2) | 0.206–0.295 | |
| E0 (bpm) | 68 (2.0) | 0.7 (0.1) | 68 (3.4) | 64–73 |
| Emax (bpm) | 73 (3.8) | 0.1 (0.01) | 74 (8.6) | 63–88 |
| EC50 (μg/L) | 8.1 (9.1) | 8.5 (31.0) | 4.4–14.6 | |
| Heart rate residual error | 0.089 (8.1) | 0.089 (12.0) | 0.066–0.106 | |
Vc=apparent volume of distribution of the central compartment; Vp=apparent volume of distribution of the peripheral compartment; Km=Michaelis-Menten constant; Vmax=maximal rate of metabolism; CLd=inter-compartmental clearance; CV=coefficient of variance; E0=baseline heart rate; EC50=concentration of drug producing 50% of maximum increase in heart rate; Emax=maximum increase in heart rate; bpm=beats per minute.