Table 2.
Estimated population parameters for the canine population undergoing monotherapy with phenobarbital at steady state (final model).
| Population parameters | Value | Stochastic approximation | |
|---|---|---|---|
| S.E. | R.S.E. (%) | ||
| ka_pop (h−1) | 0.6 | Fixed | |
| V_pop (L) | 20 | Fixed | |
| CL_pop (L/h) | 0.015 | 0.001 | 6.26 |
| β_CL_tAGE | −0.15 | 0.057 | 37.5 |
| Kenz_pop h−1 | 0.15 | 0.052 | 34.5 |
| IC50_pop (mg/L) | 1.77 | 0.093 | 5.24 |
| Standard deviation of the random effects | ||||
|---|---|---|---|---|
| Value | CV (%) | |||
| omega_CL | 0.28 | 29.08 | 0.092 | 32.1 |
| gamma_CL | 0.34 | 34.72 | 0.079 | 23.5 |
| Error model parameters | ||||
| a | 1.32 | 0.37 | 27.7 | |
Population pharmacokinetic parameters of the final model, with standard errors (S.E.) and relative standard errors (R.S.E.%) estimated using the stochastic approximation method. ka_pop, population absorption rate constant; V_pop, population apparent volume of distribution; CL_pop, population apparent clearance; β_CL_tAGE, covariate effect of age on CL/F; Kenz_pop, population rate constant for enzyme turnover; IC50_pop, population PB half-maximal inhibition of enzyme degradation.