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. Author manuscript; available in PMC: 2009 Oct 5.
Published in final edited form as: Pharmacotherapy. 2008 Sep;28(9):1084–1097. doi: 10.1592/phco.28.9.1084

Table 5.

Selected studies evaluating the influence of CYP2C9 and / orVKORC1 on risk of hemorrhage

Study Design Polymorphisms
Assessed		 Risk of Hemorrhage
Minor Major
Case Control
(36 cases, 52 controls)82 		CYP2C9 *2, *3 2.7 [0.9, 8.1] 3.7 [1.4, 9.5]
Retrospective cohort
(n=180)38 		CYP2C9 *2, *3 Minor and Major Combined
2.6 [1.2, 5.7]
Retrospective Cohort
(n=186)40 		CYP2C9 *2, *3 NE 2.4 [1.2, 4.9]
Prospective cohort
(n=446, 227 AA)36 		CYP2C9 *2, *3
VKORC1-1173 		CYP2C9
1.3 [0.8, 1.9]
VKORC1
0.8 [0.5, 1.3]		 CYP2C9
3.0 [1.2, 7.5]
VKORC1
1.7 [0.7, 4.4]

Study participants were on warfarin 36,38,40,82

All comparisons are presented for variant versus wild-type genotypes at a non-directional statistical significance of 0.05.

NE – not evaluated or not reported.

AA: African American.

Minor hemorrhage included mild nosebleeds, microscopic hematuria, mild bruising, and mild hemorrhoidal bleeding.

Major hemorrhage combined serious, life-threatening and fatal bleeding episodes as defined by Fihn et al.83