title: Practical application of the 10-mg warfarin initiation nomogram.
abstract: Initiation of warfarin therapy is a clinical challenge. A 10-mg warfarin initiation nomogram was recently validated in a randomized controlled trial. We sought to determine the efficacy and safety of this 10-mg warfarin initiation nomogram in 'real-life' daily practice. A retrospective cohort including all outpatients beginning concurrent treatment with warfarin and low-molecular-weight heparin over a 24-month period in our Thrombosis Unit was reviewed. Eight hundred and forty-one patients were included; of them, 640 (76.1%) were started on the nomogram. The nomogram was entirely followed in 324 patients (38.5%). The efficacy and safety profile was similar to that observed in the original clinical trial; 86% of patients managed according to the nomogram reached the international normalized ratio target of 2.0-3.0 within 5 days. Mean duration of low-molecular-weight heparin treatment was 6.0 +/- 1.9 days, and 3.7% of patients had an international normalized ratio of at least 5.0 in the first 4 weeks of treatment. The 10-mg nomogram effectively results in an early therapeutic international normalized ratio with a good safety profile in 'real-life' daily practice.
authors.affiliation: Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa, Ontario, Canada. pwells@ohri.ca
authors.forename: Philip S
authors.initials: PS
authors.lastname: Wells
authors.forename: Grégoire
authors.initials: G
authors.lastname: Le Gal
authors.forename: Sarah
authors.initials: S
authors.lastname: Tierney
authors.forename: Marc
authors.initials: M
authors.lastname: Carrier
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications; D015331:Cohort Studies; D004198:Disease Susceptibility; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D010045:Outpatients; D012189:Retrospective Studies; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*; D014812:Vitamin K / Q000008:administration & dosage; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D014812:Vitamin K; D014859:Warfarin