TABLE 3.
Final model parameter estimates for tenofovir pharmacokinetics
| Parametere | Model estimate (95% CI) | % RSEf (% shrinkage) | Bootstrap estimateg (95% CI) |
|---|---|---|---|
| ka (h−1) | 2.87 (1.83, 3.91) | 18.5 | 2.87 (2.27, 4.16) |
| CL/F (liters/h) | 37.2 (34.10, 40.29) | 4.2 | 37.40 (33.57, 40.26) |
| Vc/F (liters) | 127 (83.10, 170.90) | 17.6 | 128.73 (86.26, 188.48) |
| Vp/F (liters) | 646 (555.45, 736.55) | 7.2 | 649.55 (547.62, 737.81 |
| Q/F (liters/h) | 107 (70.94, 143.06) | 17.2 | 108.60 (73.26, 144.98) |
| IIV in ka | 0.714 (0.389, 1.039) | 23 (57)d | 0.817 (0.350, 1.497) |
| IIV in CL | 0.0312 (0.025, 0.037) | 10 (17) | 0.0309 (0.025, 0.038) |
| CLCRa,b | 0.442 (0.375, 0.509) | 8 | 0.445 (0.372, 0.511) |
| Treatment arma,c | 8 (6.47, 9.53) | 10 | 7.93 (6.51, 9.55) |
| Black non-Hispanica,c | 3.17 (1.54, 4.80) | 26 | 3.29 (1.65, 4.90) |
| “Other” race/ethnicitya,c | 4.09 (2.40, 5.78) | 21 | 4.11 (2.53, 5.84) |
| CCV RV | 0.0645 (0.0576, 0.0714) | 5 (16) | 0.0641 (0.0575, 0.0712) |
a
On CL/F.
b
Power model.
c
Additive shift.
d
Significant ETABAR.
e
ka, absorption rate constant; CL/F, apparent plasma clearance; Vc/F, apparent volume of distribution in the central compartment. Vp/F, apparent volume of distribution in the peripheral compartment; Q/F, apparent intercompartmental clearance; IIV, interindividual variability; CLCR, creatinine clearance; CCV RV, constant coefficient of variation, residual variability.
f
RSE, relative standard error.
g
960/1,000 = 96% runs contributed; 36 runs with minimization terminated were skipped when calculating the bootstrap results, and 4 runs with estimates near a boundary were skipped when calculating the bootstrap results.