Table 1b.
Vancomycin population pharmacokinetic parameter estimates using a variable slope sigmoidal model relating postmenstrual age (PMA) to clearance (CL)
| Parameter | Estimate | BSV | BOV | %SE |
|---|---|---|---|---|
| CLstd ‘mature’ (lh−170kg−1) and RF=1 | 3.79 | 0.209 | 0.122 | 20.2 |
| Vstd (l70kg−1) | 39.4 | 0.197 | – | 2.6 |
| EMATCL50 (weeks) | 33.3 | – | – | 28.3 |
| HillCL | 3.68 | 37.2 | ||
| Fventilation (on CL) | 1.03 | – | – | 3.6 |
| Finotrope (on V) | 1.18 | – | – | 10.8 |
| Kage | 0.00789 | – | – | 64.9 |
| Residual unidentified variability additive | 1.5mgl−1 | – | – | 32.1 |
| proportional | 0.23% | – | – | 11.7 |
BSV and BOV are the between-subject and between-occasion variability expressed as the square root of their variance, SE is the standard error of the structural estimate. V = Vstd×(Wt/70) × Finotrope × Inot l. CL=CLstd × (Wt/70)0.75 × [PMAHillCL/(PMAHillCL + EMATCL50HillCL)]×RF×Fventilation×Vent lh−1where Vstd and CLstd are the population estimates for V and CL, respectively, standardized to a 70-kg person using allometric models; PMA is the postmenstrual age in weeks; EMATCL50 is the PMA at which clearance is 50% that of the mature value; HillCL is the Hill coefficient for clearance; Finotrope and Fventilation are scaling factors applied for the use of inotropes (Inot) or positive pressure artificial ventilation (Vent); Inot and Vent have a value of 1 if present and 0 if absent. The calculation of renal function (RF) is explained in the text.