Back to Journals » Clinical Pharmacology: Advances and Applications » Volume 6

Effect of age and sex on warfarin dosing

Authors Khoury G, Sheikh-Taha M

Received 24 April 2014

Accepted for publication 20 May 2014

Published 12 July 2014 Volume 2014:6 Pages 103—106


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Ghada Khoury,1 Marwan Sheikh-Taha2

1School of Pharmacy, 2Department of Pharmacy Practice, Lebanese American University, Byblos, Lebanon

Objective: We examined the potential effect of sex and age on warfarin dosing in ambulatory adult patients.
Methods: We conducted a retrospective chart review of patients attending an anticoagulation clinic. We included patients anticoagulated with warfarin for atrial fibrillation or venous thromboembolism who had a therapeutic international normalized ratio of 2–3 for 2 consecutive months. We excluded patients who had been on any drug that is known to have a major interaction with warfarin, smokers, and heavy alcohol consumers. Out of 340 screened medical records, 96 met the predetermined inclusion criteria. The primary outcome assessed was warfarin total weekly dose (TWD).
Results: There was a statistically significant difference in the TWD among the ages (P<0.01); older patients required lower doses. However there was no statistically significant difference in the TWD between sexes (P=0.281).
Conclusion: Age was found to have a significant effect on warfarin dosing. Even though women did require a lower TWD than men, this observation was not statistically significant.

Keywords: warfarin, INR, anticoagulation, vitamin K antagonists, age

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]