TABLE 4.
SMX PopPK parameter estimates from the final modela
| Parameter | Final model |
Bootstrap analysis (n = 1,000)b |
|||
|---|---|---|---|---|---|
| Estimate | RSE (%) | 2.5th percentile | Median | 97.5th percentile | |
| Ka (h−1) | 0.58 | 43.9 | 0.1 | 0.6 | 1.3 |
| CL/F70 kg (liters/h) | 1.46 | 5.1 | 1.30 | 1.45 | 1.76 |
| V/F70 kg (liters) | 24 | 10.0 | 6 | 23 | 29 |
| TM50 (years) | 0.12 | 16.4 | 0.05 | 0.13 | 0.17 |
| Hill | 2.13 | 59.6 | 0.3 | 2.3 | 11.4 |
| Exponent for ALB effect on CL/F | −0.77 | 34 | −1.5 | −0.76 | −0.20 |
| IIV(CL/F) (%) | 35.9 | 46.2 | 9.2 | 33.2 | 51.3 |
| IIV(V/F) (%) | 40.6 | 41.1 | 18.3 | 39.6 | 114.1 |
| ρ (CL/F − V/F) | 0.1 | 56.7 | −0.1 | 0.1 | 0.3 |
| Proportional error (%) | 46.9 | 16.7 | 34.7 | 45.8 | 53.4 |
| Additive error (mg/liters) | 5.1 | 38.0 | 1.8 | 5.5 | 322 |
SMX, sulfamethoxazole; PK, pharmacokinetic; RSE, relative standard error; Ka, population absorption rate constant; CL/F70 kg, apparent population clearance estimate scaled to a 70-kg adult; V/F70 kg, apparent population volume of distribution estimate scaled to a 70-kg adult; TM50, maturation half-life calculated as a function of postnatal age (in years); Hill, Hill coefficient in the Emax maturation function; ALB, albumin concentration; SCR, serum creatinine concentration; IIV(CL/F), interindividual variability in drug clearance; IIV(V/F), interindividual variability in the volume of distribution; ρ (CL/F − V/F), correlation between random-effect parameters for CL/F and V/F.
One hundred twenty-six runs were skipped when the bootstrap results were calculated due to minimization termination. One hundred six runs with estimates near a boundary were skipped when the bootstrap results were calculated.