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Vol. 32, No. 3, 2002
Issue release date: May–June 2002 (October 2002)
Pathophysiol Haemost Thromb 2002;32:131–133
(DOI:10.1159/000065215)

Prospective Assessment of a Nomogram for the Initiation of Oral Anticoagulation Therapy for Outpatient Treatment of Venous Thromboembolism

Kovacs M.J.a · Anderson D.A.b · Wells P.S.c
aDepartments of Medicine,aLondon Health Sciences Centre, London, Ontario, bQueen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, cOttawa Civic Hospital, Ottawa, Ontario, Canada
email Corresponding Author


 goto top of outline Key Words

  • Warfarin
  • Nomogram
  • Venous thromboembolism

 goto top of outline Abstract

Venous thromboembolism is a common medical problem. Recently, the emphasis has been on a switch to outpatient low molecular weight heparin therapy. Previous warfarin nomograms have been developed only for inpatients. We prospectively assessed a warfarin initiation nomogram in 105 consecutive outpatients; the nomogram requires International Normalized Ratio (INR) testing on only days 3, 5, and 8. Eighty-three percent had a therapeutic INR by day 5 and 98% by day 8. There were no major bleeds and only 6 instances of INR >4.5. This outpatient warfarin nomogram appears to be safe and efficacious in obtaining timely therapeutic levels of warfarin and deserves further study.

Copyright © 2002 S. Karger AG, Basel


 goto top of outline References
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  6. Kovacs MJ, Cruickshank M, Wells PS, Kim H, Chin-Yee I, Morrow B, Boyle E, Kovacs J: Randomized assessment of a warfarin nomogram for initial oral anticoagulation after venous thromboembolic disease. Haemostasis 1998;28:62–69.
  7. Fennerty A, Bolben J, Thomas P, Backhouse G, Bentley DP, Campbell IA, Routledge PA: Flexible induction dose regimen for warfarin and prediction of maintenance dose. Br Med J Clin (Res Ed) 1984;288:1268–1270.
  8. Doecke CJ, Cosh DG, Gallus AS: Standardized initial warfarin treatment: Evaluation of initial treatment response and maintenance dose prediction by randomized trial, and risk factors for an excessive warfarin response. Aust NZ J Med 1991;21:319–324.
  9. Harrison L, Johnston M, Massicotte MP, Crowther M, Moffat K, Hirst J: Comparison of 5-mg and 10-mg loading doses in initiation of warfarin therapy. Ann Intern Med 1997;126:133–136.
  10. Crowther MA, Harrison L, Hirsh J: Warfarin: Less may be better. Ann Intern Med 1997;127:332–333.

 goto top of outline Author Contacts

Dr. Michael J. Kovacs
Room 2760, Phase 1, London Health Sciences Centre
800 Commissioners Road East
London, Ontario N6A 4G5 (Canada)
Tel. +1 519 685 8475, Fax +1 519 685 8477, E-Mail michael.kovacs@lhsc.on.ca


 goto top of outline Article Information

Received: Received: October 10, 2001
Accepted in revised form: June 20, 2002
Number of Print Pages : 3
Number of Figures : 1, Number of Tables : 0, Number of References : 10


 goto top of outline Publication Details

Pathophysiology of Haemostasis and Thrombosis
Official Journal of the ‘Mediterranean League against Thromboembolic Diseases’

Vol. 32, No. 3, Year 2002 (Cover Date: May-June 2002 (Released October 2002))

Journal Editor: H.C. Hemker, Maastricht
ISSN: 1424–8832 (print), 1424–8840 (Online)

For additional information: http://www.karger.com/journals/pht


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