TABLE 2

Urinary excretion of BUP and its metabolites over a dose interval. Paired analysis: mid-pregnancy versus late pregnancy, and late pregnancy versus postpartum

Data presented as mean ± S.D. Mid-pregnancy, 22–26 weeks of gestation; late pregnancy, 34–38 weeks of gestation.

Parameter		Mid-pregnancy (n = 4)	Late Pregnancy (n = 4)	Late Pregnancy (n = 11)	Postpartum (n = 11)
Creatinine clearance^{^a}	(mL/min)	185 ± 45^*	166 ± 33	175 ± 38^*	128 ± 23
Renal clearance	CL_R BUP (mL/min)	23.1 ± 12.5	9.06 ± 5.80	17.2 ± 19.0	38.9 ± 77.7
	CL_R OHBUP (mL/min)	3.77 ± 3.19	1.34 ± 0.22	2.98 ± 3.58	3.08 ± 3.44
	CL_R TB (mL/min)	72.1 ± 48.3	34.6 ± 12 6	56.8 ± 50.0	49.1 ± 32.1
	CL_R EB (mL/min)	50.9 ± 40.3	20.4 ± 7.13	32.5 ± 32.4	27.8 ± 18.3
% of dose recovered as	BUP	0.59 ± 0.24	0.25 ± 0.24	0.51 ± 0.59	0.87 ± 1.01
	OHBUP-free	1.20 ± 1.03	0.53 ± 0.17	1.27 ± 1.63	1.47 ± 1.98
	OHBUP-glucuronide	7.97 ± 4.47	11.69 ± 8.10	13.8 ± 15.7^*	6.25 ± 5.47
	TB-free	15.9 ± 11.1	6.37 ± 6.71	10.0 ± 9.52	8.30 ± 6.30
	TB-glucuronide	1.07 ± 0.73	0.82 ± 0.83	3.10 ± 2.20^*	1.00 ± 1.15
	EB-free	1.71 ± 1.54	0.47 ± 0.48	0.76 ± 0.68	1.00 ± 0.76
	EB-glucuronide	2.55 ± 1.93	4.00 ± 3.88	0.56 ± 0.40	0.42 ± 0.37

↵^a The number of subjects in paired analysis of estimated renal creatinine clearance was the same as in Table 1.
↵* P < .05.