TABLE 3.

Perturbed writhing PK/PD model parameters obtained from single‐agent administration

Single model
Trazodone					Gabapentin
Parameter	Units	Estimate	%CV	%SE	Parameter	Units	Estimate	%CV	%SE
k 2	L/μmoles/min	10.9		22.9	k 2	L/μmoles/min	0.0459		32.2
Interindividual variability					Interindividual variability
${\overline{\omega }}_{k_2}^2$		1.42	119.2	27.8	${\overline{\omega }}_{k_2}^2$		1.97	140.4	27.8
Intra‐individual variability					Intra‐individual variability
${\sigma }_{\mathrm{add}}^2$		3.20		19.8	${\sigma }_{\mathrm{add}}^2$		2.17		17.1

Note: Model parameters results of trazodone using PD data from 0.075, 0.15, 0.5, 1.5, 2.5, and 4.5 mg/kg and gabapentin using PD data from 1.5, 5 and 15 mg/kg.

Abbreviations: %CV, percent coefficient of variation; %SE, percent standard error; k ₂, potency parameter; PK/PD, pharmacokinetic/pharmacodynamic; ω, interindividual variability; σ, intra‐individual variability.