TABLE 2.
Population pharmacokinetic parameters of lamivudine standardized for a median weight of 16.8 kg using an allometric modela
| Model type and parameterb | Mean (RSE %)c value for final model with original data set | Median (95% CI) bootstrap valued |
|---|---|---|
| Structural models | ||
| CL/F (liters/h) | 16.9 (8.7) | 16.7 (13.5-19.8) |
| Vc/F (liters) | 30.8 (9.3) | 31.2 (26-38.3) |
| Vp/F (liters) | 58.6 (23.5) | 57.1 (35-145) |
| Q/F (liters/h) | 4.48 (18.1) | 4.60 (2.87-9.06) |
| Ka (h−1) | 0.71 (NA)e | NA |
| Statistical models | ||
| σ | 0.60 (14.8) | 0.59 (0.51-0.68) |
| ω (CL/F) | 0.30 (30.6) | 0.28 (0.15-0.37) |
Shown are the results from the final model and bootstrap evaluation for 45 HIV-1-infected children enrolled in the BURKINAME-ANRS 12103 study.
The typical parameters represent a patient weighing 16.8 kg according to an allometric model: (typical value) = (typical parameter) × (body weight/16.8)PWR, where PWR = 0.75 for the CL and Q terms and 1 for the Vc and Vp terms. Ka, absorption rate constant (Ka equals the rapid distribution rate constant derived from the estimated pharmacokinetics parameters); CL/F, apparent elimination clearance, Vc/F apparent central volume of distribution; Vp/F, apparent peripheral volume of distribution; Q/F, intercompartmental clearance; σ, residual variability estimates; and ω, interindividual variability estimates.
RSE %, relative standard error (standard error of estimate/estimate × 100).
Statistics from 1,000 bootstrap analyses.
NA, not applicable.