Influence of warfarin on symptoms of fatigue: findings of a randomized trial.
BACKGROUND
Some patients develop fatigue while taking warfarin, but causality is uncertain.


OBJECTIVE
To assess whether warfarin use is associated with fatigue.


METHODS
This investigation was a substudy of a randomized double-blind trial in 13 outpatient thromboembolism clinics. Subjects who had received one month of open-label warfarin therapy for venous thromboembolism due to a transient risk factor were randomly assigned to receive warfarin or placebo for 2 months and followed for another 9 months after stopping the study drug. Fatigue was measured using a Likert scale, and change of fatigue was measured by the patient's global rating.


RESULTS
In 87 subjects, the overall ratings of fatigue were 0.1 unit lower (95% CI 0.6 units lower to 0.4 units higher) while taking warfarin. Global rating for change in fatigue intensity showed no increase of fatigue with warfarin use.


CONCLUSIONS
The short-term use of warfarin was not associated with symptoms of fatigue.
Kovacs
Michael J
MJ
Department of Medicine, University of Western Ontario, London, Ontario, Canada. michael.kovacs@lhsc.on.ca
Kearon
Clive
C
Julian
Jim A
JA
Douketis
James D
JD
Demers
Christine
C
Wells
Philip S
PS
Turpie
Alexander G
AG
Anderson
David R
DR
Kahn
Susan R
SR
Nguyen
Paul V
PV
Green
David
D
Kassis
Jeannine
J
Geerts
William
W
Mackinnon
Betsy
B
Ginsberg
Jeffrey S
JS
D000704:Analysis of Variance; D004311:Double-Blind Method; D005221:Fatigue / Q000139:chemically induced*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020246:Venous Thrombosis / Q000188:drug therapy*; D014859:Warfarin / Q000009:adverse effects* / Q000627:therapeutic use
D014859:Warfarin