Low Molecular Weight Heparin Administered once versus twice Daily in Patients with Venous Thromboembolism A Meta-analysis
Francis Couturaud, Jim A. Julian, Clive Kearon
Hamilton Civic Hospitals Research Centre and McMaster University, Hamilton, Ontario, Canada
Background. Low molecular weight heparin is as effective and safe
as unfractionated heparin for treatment of acute venous thromboembolism.
It is uncertain whether low molecular weight heparin should be
administered once-daily or twice-daily in this setting. Method. A metaanalysis
of randomized studies which directly compared once- and
twice-daily administration of low molecular weight heparin for the
treatment of acute venous thromboembolism was performed. A literature
search was performed using Advanced Pub Med and the Cochrane
library database, and abstracts from recent meetings were reviewed.
Two investigators extracted data independently. Results. Five studies,
involving 1522 patients, were eligible. There were no statistically
significant differences in the frequencies of symptomatic (odds ratio,
0.85 in favor of once-daily therapy at three months, p = 0.6), and
asymptomatic, recurrent venous thromboembolism; total and major
bleeds (odds ratio, 1.16 in favor of twice-daily therapy at 10 days,
p = 0.8); and death, at 10 days, as well as at three months of follow-up.
Conclusion. Once- daily low molecular weight heparin appears to be as
effective and safe as twice-daily administration for the acute treatment
of venous thromboembolism. However, there is inadequate data from
studies that directly compared once-daily and twice-daily administration
to be able to exclude the possibility of a higher frequency of fatal
bleeding with once-daily therapy.