. Author manuscript; available in PMC: 2021 Mar 1.

Published in final edited form as: Anesthesiology. 2020 Mar;132(3):491–503. doi: 10.1097/ALN.0000000000003065

Table 2.

Pharmacodynamic parameter estimates for fentanyl derived from effect site modeling of pupil diameter during and after a fixed-dose IV infusion pre- and post-treatment in the placebo and St. John’s wort group (n = 8 in each). Results are mean± SD.

Parameter	Placebo		St. John’s wort
Parameter	Pre	Post	Pre	Post
E_max (mm)	7.64 ± 0.86	7.49 ± 0.88	7.53 ± 1.63	7.50 ± 1.29
EC₅₀ (ng/mL)	1.22 ± 0.83	1.16 ± 1.56	1.13 ± 0.74	1.38 ± 0.89
k_e0 (min⁻¹)	0.080 ± 0.044	0.070 ± 0.059	0.062± 0.023	0.090 ± 0.060
T_½,ke0 (min)	12.9 ± 5.5	10.9 ± 6.3	11.9 ± 5.8	13.0 ± 9.3

Generalized estimating equation analysis did not reveal a statistically significant treatment-by-day interaction for any of the parameter estimates.