Table 2.
Final Model Parameter Estimates and 95% CI From the Original Dataset and Bootstrap Analyses
| NONMEM Analysis | Bootstrap Analysis | |||
|---|---|---|---|---|
| Parameter | Estimate (% SE) | 95% CI | Median | 95% CI |
| CLun (L/h) | 11.2 (5.5) | 10–2.4 | 11.2 | 10.3–2.3 |
| V1 (L/70 kg) | 142 (4.8) | 128.6–55.4 | 143 | 127–179 |
| Q (L/h) | 444 (15.8) | 306.4–581.6 | 429 | 189–611 |
| V2 (L/70 kg) | 175 (4.2) | 160.5–189.5 | 175 | 131–191 |
| Fu | 0.25 (2.1) | 0.24–0.26 | 0.25 | 0.24–0.26 |
| θRACE | 1.30 (8.3) | 1.08–1.51 | 1.30 | 1.14–1.47 |
| Interindividual variance (% SE) | ||||
| IIV of CLun | 0.104 (28.5) CV% = 32.2 | 0.046, 0.162 | 0.101 | 0.065, 0.139 |
| IIV of V1 | 0.046 (29.8) CV% = 21.5 | 0.019, 0.073 | 0.052 | 0.018, 0.127 |
| IIV of Q | 1.78 (21.7) CV% = 133 | 1.02, 2.54 | 1.72 | 0.146, 2.52 |
| IIV of V2 | 0.055 (33.5) CV% = 23.5 | 0.019, 0.092 | 0.051 | 0.029, 0.149 |
| IIV of Fu | 0.036 (13.4) CV% = 18.9 | 0.026, 0.045 | 0.043 | 0.027, 0.045 |
| Residual variance (% SE) | ||||
| RUVun, Prop | 0.032 (16.4) CV% = 17.8 | 0.022, 0.042 | 0.031 | 0.022, 0.042 |
| RUVTot, Prop | 0.024 (14.4) CV% = 15.5 | 0.017, 0.031 | 0.021 | 0.018, 0.031 |
| RUVTot, additive SD (mg/L) = 0.05 | 0.002 (19.9) | 0.001, 0.003 | 0.002 | 0.001, 0.003 |
CI, confidence interval; CLun, unbound carbamazepine clearance estimated for an African American individual (considered to be the reference group); V1, central volume of distribution; Q, intercompartmental clearance; V2, peripheral volume of distribution; Fu, fraction unbound; θRACE, race effect, has a power of 1 if the patient is Caucasian, and a power of zero if the patient is African American; IIV, interindividual variability; %CV, percentage coefficient of variation; RUVun and RUVTot are residual unexplained variability in the unbound concentration and total concentration, respectively, expressed as a proportional error variance.