Table 3.

Predicted pharmacodynamic parameters (with coefficient of variation for) for escitalopram, paroxetine and sertraline at steady-state conditions for SERT occupancy and 5-HTP-potentiated behavioral syndrome score

Drug	Response	EC50 (ng mL−1)	EC80 (ng mL−1)	Emax	γ	ke0 (h−1)	SERT occupancy at 5-HTP EC50 (%)	5-HTP score at 80% SERT occupancy (%)
Escitalopram	SERT occ	11 (13)	18	100	2.8 (23)	0.4	94
	5-HTP score	28 (81)	—	100	0.8 (37)	5.0		42
Paroxetine	SERT occ	5.3 (139)	18	100	1.1 (95)	0.4	93
	5-HTP score	52 (13)	—	100	1.4 (15)	0.8/0.8/3.0a		17
Sertraline	SERT occ	7.1 (20)	24	100	1.2 (14)	1.0	94
	5-HTP score	80 (40)	—	100	NA	1.0/0.0/5.0a		23

Abbreviations: 5-HTP, 5-hydroxytryptophan; NA, not applicable; SERT, serotonin transporter.

Acute non-steady-steady data were collapsed with an effect-compartment model. A sigmoidal E_max model was fitted to the pooled data from the three doses. E_max was locked at 100% for all fits.

^aLow/medium/high dose, respectively.