TABLE 3.
Final model parameter estimates and variability for tenofovir pharmacokineticsa
| Parameter | Final model |
Bootstrap analysis, final model |
|||
|---|---|---|---|---|---|
| Population median | %RSE | Median | 2.5% | 97.5% | |
| Structural (base) model | |||||
| CL/F (liter/h/kg0.75) | 2.07 | 0.09 | 2.00 | 1.85 | 2.16 |
| V1/F (liter/kg) | 6.37 | 1.07 | 6.34 | 4.87 | 8.70 |
| V2/F (liter/kg) | 9.55 | 1.20 | 9.60 | 8.12 | 12.30 |
| Ka (h−1) | 6.93 | NA | NA | NA | NA |
| Q (liter/h/kg0.75) | 3.14 | 0.95 | 3.15 | 0.05 | 4.69 |
| SCr factor | −0.65 | 0.13 | −0.66 | −0.90 | −0.36 |
| Statistical model | |||||
| BSV (%) | |||||
| Vss/F | 25 | 21 | 24 | 5 | 40 |
| CL/F | 24 | 12 | 23 | 17 | 29 |
| IOV-CL/F | 26 | 15 | |||
| Residual variability | |||||
| Proportional (% CV) | 3.0 | 2.6 | 3.0 | 1.1 | 6.0 |
| Power exponent | 1.43 | 0.08 | 1.38 | 1.25 | 1.54 |
a
Vss/F, volume of distribution at steady state; IOV, interoccasion (within-subject) variability; CL/F, apparent clearance; Ka, absorption rate constant; V1/F, apparent volume of distribution of the central compartment; V2/F, apparent volume of distribution of the peripheral compartment; Q, intercompartmental clearance; SCr, serum creatinine; NA, not applicable; %RSE, relative standard error of parameter estimate. Between-subject variability and residual (proportion) variability estimates are shown as percent coefficient of variation (% CV).