Table 3.

Steady-State Pharmacokinetics and Paroxetine Levels

Analyte	Trial A (n = 43)		Trial B (n=60)
	Tramadol	Desmetramadol	Tramadol	Desmetramadol
(+)-M1
Cssmin, ng/mL, M (SD)	28(7)	26 (6)	11 (6)	38 (9)
90% CI*		.85–1.08		3.4–4.3
P value				<.001
Cssmax, ng/mL, M (SD)	37 (10)	36(10)	14 (8)	51 (11)
90% CI		.88–1.13		3.4–4.3
P value				<.001
t1/2, h, M (SD)			18 (39)	8 (6)
P value				.065
(−)-M1
Cssmin, ng/mL, M (SD)	30(6)	21 (5)	25 (7)	25 (8)
90% CI		.69-.76		.95–1.09
P value				.64
Cssmax, ng/mL, M (SD)	42 (9)	30 (9)	35(10)	35(10)
90% CI		.67-.76		.93–1.07
P value				.79
t1/2, h, M (SD)			12(8)	7(5)
P value				<.001
(+)-tramadol
Cssmin, ng/mL, M (SD)	85(33)	ND	183 (49)	ND
Cssmax, ng/mL, M (SD)	143 (36)	ND	295 (62)	ND
t1/2, h, M (SD)			8.6 (2.5)	ND
(−)-tramadol
Cssmin, ng/mL, M (SD)	68 (27)	ND	140 (41)	ND
Cssmax, ng/mL, M (SD)	122(32)	ND	242 (56)	ND
t1/2, h, M (SD)			7.2 (2.3)	ND
Paroxetine, ng/mL, M (SD)	NA	NA	11 (8)	12(9)

Abbreviations: M, mean; NA, not applicable; ND, not detected.

^*The pharmacokinetic parameter is statistically bioequivalent if the 90% CI is within the range of .80 to 1.25.