Table 3.
Pharmacokinetics Parameters
| Single dose after 4 weeks of LT3 therapy (two-compartment model with lag time for absorption) | ||||||
|---|---|---|---|---|---|---|
| N = 14 | Tlag (hours) | ka (h−1) | V (dL) | ke (h−1) | k12 (h−1) | k21 (h−1) |
| Total T3 | 0.62 | 1.94 | 86.7 | 0.12 | 0.13 | 0.08 |
| SD | 0.28 | 0.79 | 19 | 0.013 | 0.01 | 0.02 |
| fT3 | 0.66 | 2.40 | 42.4 | 0.10 | 0.10 | 0.05 |
| SD | 0.29 | 0.91 | 9.2 | 0.018 | 0.02 | 0.01 |
| Single dose of LT3 while hypothyroid (transit absorption compartment into a one-compartment model) | |||||
|---|---|---|---|---|---|
| N = 5 | Ktr (h−1) | Mtt (hours) | ka (h−1) | V (dL) | ke (h−1) |
| Total T3 | 11.7 | 2.0 | 3.5 | 149 | 0.24 |
| SD | 10.4 | 1.1 | 1.6 | 42 | 0.14 |
| fT3 | 11.7 | 1.4 | 1.7 | 63,100 | 0.13 |
| SD | 3.8 | 0.9 | 1.2 | 16,300 | 0.003 |
k12, distribution rate constant (from 1 - > 2); k21, distribution rate constant lag time for absorption; ka, absorption rate constant; ke, elimination rate constant; ktr, transit compartment rate constant; Mtt, mean transit time; SD, standard deviation; Tlag, lag time for absorption; V, volume of distribution.