TABLE 2.
Population PK model parameter estimates and covariate effects associated with the final model for gentamicina
| Parameter | Value | RSE (%)c | BSV CV (%) | RSE (%)c | BOV CV (%) | RSE (%)c |
|---|---|---|---|---|---|---|
| CL (liters/h/62.8 kg NFM)b | 4.58 | 1.55 | 16.5 | 17.1 | 20.7 | 5.62 |
| V1 in oncology patients (liters/57.5 kg NFM)b | 18.1 | 2.43 | 23.8 | 22.9 | ||
| V1 in nononcology patients (liters/57.5 kg NFM)b | 21.4 | 4.78 | 26.0 | 31.9 | ||
| Q in oncology patients (liters/h/56.1 kg NFM) | 0.57 | 4.88 | 29.4 | 40.0 | ||
| Q in nononcology patients (liters/h/56.1 kg NFM) | 0.84 | 12.2 | 59.8 | 38.4 | ||
| V2 (liters/56.1 kg NFM) | 18.2 | 13.6 | 67.6 | 35.6 | ||
| Covariate model | ||||||
| θserum creatinine | 0.58 | 4.26 | ||||
| Ffat on CL | 0.48 | 27.2 | ||||
| Ffat on V1 | 0.10 | 31.7 | ||||
| Ffat on Q | 0 fix | |||||
| Ffat on V2 | 0 fix | |||||
| Residual-error model | ||||||
| Proportional (%) | 29.3 | 2.21 | ||||
| Additive (mg/liter) | 0.05 | 16.9 | ||||
BOV, between-occasion variability; BSV, between-subject variability; CV, coefficient of variation; Ffat, fat factor; FFM, fat-free mass; NFM, normal fat mass; OFV, objective function value; Q, intercompartmental clearance; V1, volume of distribution of the central compartment; V2, volume of distribution of the peripheral compartment.
For clearance (CL), standard NFM (NFMstd) is calculated as NFMstd = 56.1 + 0.48 × (70 − 56.1) = 62.8 kg; for V1, standard NFM is calculated as NFMstd = 56.1 + 0.10 × (70 − 56.1) = 57.5 kg.
Relative standard errors (RSE) for both fixed- and random-effect values were obtained using the sampling importance resampling (SIR) method.