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Alcohol misuse, genetics, and major bleeding among warfarin therapy patients in a community setting
Author(s) -
Roth Joshua A.,
Bradley Katharine,
Thummel Kenneth E.,
Veenstra David L.,
Boudreau Denise
Publication year - 2015
Publication title -
pharmacoepidemiology and drug safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.023
H-Index - 96
eISSN - 1099-1557
pISSN - 1053-8569
DOI - 10.1002/pds.3769
Subject(s) - medicine , warfarin , odds ratio , alcohol use disorders identification test , vkorc1 , logistic regression , adverse effect , emergency medicine , cyp2c9 , poison control , injury prevention , cytochrome p450 , metabolism , atrial fibrillation
Purpose Little is known about the impact of alcohol consumption on warfarin safety, or whether demographic, clinical, or genetic factors modify risk of adverse events. We conducted a case–control study to assess the association between screening positive for moderate/severe alcohol misuse and the risk of major bleeding in a community sample of patients using warfarin. Methods The study sample consisted of 570 adult patients continuously enrolled in Group Heath for at least 2 years and receiving warfarin. The main outcome was major bleeding validated through medical record review. Cases experienced major bleeding, and controls did not experience major bleeding. Exposures were Alcohol Use Disorders Identification Test Consumption Questionnaire (AUDIT‐C) scores and report of heavy episodic drinking (≥5 drinks on an occasion). The odds of major bleeding were estimated with multivariate logistic regression models. The overall sample was 55% male, 94% Caucasian, and had a mean age of 70 years. Results Among 265 cases and 305 controls, AUDIT‐C scores indicative of moderate/severe alcohol misuse and heavy episodic drinking were associated with increased risk of major bleeding (OR = 2.10, 95% CI = 1.08–4.07; and OR = 2.36, 95% CI = 1.24–4.50, respectively). Stratified analyses demonstrated increased alcohol‐related major bleeding risk in patients on warfarin for ≥1 year and in those with a low‐dose genotype ( CYP2C9 * 2 /* 3 , VKORC1 ( 1173G > A ), CYP4F2 * 1 ), but not in other sub‐groups evaluated. Conclusions Alcohol screening questionnaires, potentially coupled with genetic testing, could have clinical utility in selecting patients for warfarin therapy, as well as refining dosing and monitoring practices. Copyright © 2015 John Wiley & Sons, Ltd.