Skip to main content

Table 1 Drug levels and metabolite/parent ratios before and after rifampin administration

From: Profound reduction in tamoxifen active metabolite endoxifen in a breast cancer patient treated with rifampin prior to initiation of an anti-TNFα biologic for ulcerative colitis: a case report

 

Blood sample

Baseline

2-weeks post rifampin

10-weeks post rifampin

Analyte, nM (%)a

   

 Tamoxifen

225.25

171.18 (24.0)

259.12 (0.0)

 NDM-tam

386.32

177.38 (54.1)

365.66 (5.4)

 4-OH-tam

6.41

2.67 (58.3)

4.29 (33.0)

 Endoxifen

46.03

15.75 (65.8)

29.45 (36.0)

Metabolite/Parent ratio (%)a

 NDM-tam/tamoxifen

1.715

1.036 (39.6)

1.411 (17.8)

 4-OH-tam/tamoxifen

0.028

0.016 (45.1)

0.017 (41.8)

 endoxifen/tamoxifen

0.204

0.092 (55.0)

0.114 (44.4)

 endoxifen/NDM-tam

0.119

0.089 (25.5)

0.081 (32.4)

 endoxifen/4-OH-tam

7.185

5.892 (18.0)

6.862 (4.5)

  1. a% reduction from baseline measurement
Back to article page

BMC Cancer

ISSN: 1471-2407

Contact us