title: Oral vitamin K effectively treats international normalised ratio (INR) values in excess of 10. Results of a prospective cohort study.
abstract: Unanticipated elevation of the INR is common in patients receiving warfarin. We performed a prospective cohort study of 107 warfarin-treated patients with INR values of more than 10 who received a single 2.5 mg dose of oral vitamin K. During the first week, one patient experienced major bleeding, and one died. In the first 90 days after enrolment four patients had major bleeding (3.7%, 1.0% to 9.3%), eight patients (7.5%, 3.3% to 14.2%) died and two had objectively confirmed thromboembolism. Based on our low rate of observed major bleeding we conclude that 2.5 mg of oral vitamin K is a reasonable treatment for patients with INR values of more than 10 who are not actively bleeding.
authors.affiliation: Division of Hematology and Thromboembolism, McMaster University Faculty of Health Sciences, St Joseph's Hospital, 50 Charlton Ave. East, Hamilton, Ontario, Canada. crowthrm@mcmaster.ca
authors.forename: Mark A
authors.initials: MA
authors.lastname: Crowther
authors.forename: David
authors.initials: D
authors.lastname: Garcia
authors.forename: Walter
authors.initials: W
authors.lastname: Ageno
authors.forename: Luqi
authors.initials: L
authors.lastname: Wang
authors.forename: Dan M
authors.initials: DM
authors.lastname: Witt
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Clark
authors.forename: Mark D
authors.initials: MD
authors.lastname: Blostein
authors.forename: Susan R
authors.initials: SR
authors.lastname: Kahn
authors.forename: Sam
authors.initials: S
authors.lastname: Schulman
authors.forename: Michael
authors.initials: M
authors.lastname: Kovacs
authors.forename: Marc A
authors.initials: MA
authors.lastname: Rodger
authors.forename: Philip
authors.initials: P
authors.lastname: Wells
authors.forename: David
authors.initials: D
authors.lastname: Anderson
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Ginsberg
authors.forename: Rita
authors.initials: R
authors.lastname: Selby
authors.forename: Sergio
authors.initials: S
authors.lastname: Siragusa
authors.forename: Mauro
authors.initials: M
authors.lastname: Silingardi
authors.forename: MaryBeth B
authors.initials: MB
authors.lastname: Dowd
authors.forename: Clive
authors.initials: C
authors.lastname: Kearon
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020246:Venous Thrombosis / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D014812:Vitamin K / Q000008:administration & dosage* / Q000009:adverse effects; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014812:Vitamin K; D014859:Warfarin