Table I.
Descriptive statistics of the recombinant human erythropoietin individual maximum a posteriori Bayesian estimates of pharmacokinetic parameters from the population modela
| Parameter | Prior mean (% CV) | Posterior mean (% CV) | Range |
|---|---|---|---|
| Baseline serum erythropoietin (IU/L)b | 13.9 (30) | 11.4 (34) | 6.2–26.6 |
| CLI (Lh) | 0.358 (33) | 0.325 (15) | 0.226–0.468 |
| Vmax (IU/h) | 211 (29) | 239 (44) | 83–634 |
| V2(L) | 3.89 (31) | 4.17 (25) | 1.81–7.10 |
| F0 (%) | 62 (35) | 47 (42) | 15–100 |
| fr (%) | 60 (45) | 78 (46) | 51–93 |
| ka(/h) | 0.034 (36) | 0.039 (47) | 0.016–0.155 |
| D1 (h) | 0.725 (125) | 1.678 (102) | 0.128–12.718 |
| tlag2 (h) | 2.72 (53) | 2.75 (31) | 1.00–5.47 |
Km was fixed at 394 IU/L, Q was fixed at 0.044 L/h, V3 was fixed at 1.64 L, D2 was fixed at 37.8 h, Emax(F) was fixed at 64.9% and ED50(F) was fixed at 63.2 kIU.
Circadian rhythm was fixed to values previously reported by Olsson-Gisleskog et al.[18]
CLI = linear clearance; CV = coefficient of variation; D1 = estimated duration of faster absorption phase; D2 = estimated duration of slower absorption phase; ED50(F) = dose giving 50% of increase in absolute bioavailability; Emax(F) = maximum increase in bioavailability with dose; F0 = minimum absolute bioavailability; fr = bioavailability fraction; ka = first-order absorption rate constant; Km = Michaelis-Menten constant; Q = intercompartmental clearance; tlag2 = lag time for the slower absorption phase; V2 = volume of distribution of the central compartment; V3 = volume of distribution of the peripheral compartment; Vmax = maximum elimination rate of the saturable pathway.