Table 2.
Population pharmacokinetic estimates of lithium
| Parameter (unit) | Population estimate (between subject variability %) | ||
|---|---|---|---|
| Base modela | Allometric scaling by total body weightb | Allometric scaling by fat-free massc | |
| CL (L/h) | 1.34 (51.6) | 1.50 (44.5) | 1.79 (42.2) |
| V (L)d | 39.7 (8.84) | 63.4 (9.16) | 56.4 (5.51) |
| T1/2abs (min) | 29.3 (39.1) | 27.6 (39.5) | 29.9 (32.2) |
| Tlag (min) | 16.8 (78.7) | 17.5 (76.7) | 17.4 (82.6) |
| T1/2α (h)e | 2.66 (31.7) | 2.96 (10.9) | 2.43 (31.1) |
| T1/2β (h)f | 27.3 (41.0) | 36.2 (25.3) | 27.4 (28.4) |
| CVcp (%) | 38.1 | 39.4 | 38.6 |
| SDcp (mEq/L) | 0.1 (fixed) | 0.1 (fixed) | 0.1 (fixed) |
a
no covariate included
b
CL, V, and T1/2β allometrically scaled based on a standard total body weight of 70 kg to allow comparison to results from adult trials
c
CL, V, and T1/2β allometrically scaled based on a standard fat-free mass of 53 kg
d
V: total volume of distribution (Vc + Vp), average (%CV) calculated from individual parameter estimates of Vc and Vp
e
average (% coefficient of variation) half-life of the α-phase calculated from individual population parameter estimates
f
average (% coefficient of variation) terminal half-life calculated from individual population parameter estimates