Treatment of coumarin-associated coagulopathy: a systematic review and proposed treatment algorithms.
BACKGROUND
An excessive anticoagulant effect because of coumarins is frequently encountered.


OBJECTIVE
To review available literature on the management of warfarin-associated coagulopathy and to propose evidence-based treatment algorithms.


METHODS
Data sources were Medline and Embase. Papers published between 1966 and December 2005 describing randomized trials or prospective cohort studies evaluating treatments for coumarin-associated coagulopathy were abstracted.


RESULTS
Low dose oral vitamin K rapidly and reliably returns the international normalized ratio (INR) to the usual therapeutic range in non-bleeding patients. Simple withholding of acenocumarol results in rapid correction of its anticoagulant effect. The impact of oral vitamin K on phenprocumon-associated coagulopathy cannot be determined from available literature. Intravenous vitamin K and coagulation factors should be given to patients with major or life-threatening hemorrhage. The optimal dose and type of coagulation factor is not known.


CONCLUSIONS
Vitamin K therapy is an effective treatment for INR prolongation in patients with coumarin-associated coagulopathy; coagulation factor replacement is required, in addition, in patients with major bleeding or with indication for immediate correction of their INR. Clinical trials powered to detect differences in rates of bleeding and thrombosis are now required to determine if vitamin K reduces the risk of bleeding without causing thrombosis in non-bleeding patients with prolonged INR.
Dentali
F
F
Department of Clinical Medicine, University of Insubria, Varese, Italy.
Ageno
W
W
Crowther
M
M
D000465:Algorithms; D001685:Biological Factors / Q000627:therapeutic use; D001778:Blood Coagulation Disorders / Q000139:chemically induced* / Q000188:drug therapy*; D003374:Coumarins / Q000009:adverse effects*; D006470:Hemorrhage / Q000139:chemically induced / Q000188:drug therapy; D006801:Humans; D014812:Vitamin K / Q000627:therapeutic use
D001685:Biological Factors; D003374:Coumarins; D014812:Vitamin K