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ISSUE 6 DECEMBER
Letters to the Editor

Warfarin and antiplatelet drugs

  • Con Aroney, Peter Thompson, Lye Lin Ho, Timothy Brighton

The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

 

Letter to the editor

Editor, – We read with interest the article 'Warfarin, antiplatelet drugs and their interactions' (Aust Prescr 2002;25:81-5) and were disappointed that although the authors emphasise the risks of combining warfarin with aspirin, they fail to acknowledge the proven benefits of this combination in patients with prosthetic heart valves. A recent meta-analysis1 showed that compared with anticoagulation alone, the addition of an antiplatelet drug reduced the risk of not only thromboembolic events (odds ratio 0.41, p < 0.001)but also total mortality (odds ratio 0.49, p < 0.001).

The old view that the combination is dangerous is still held by many doctors and pharmacists. We certainly agree with the authors' recommendation that with the combination, low-dose aspirin should be used and the INR 'kept at the lower end of the desired target', and that patients on the combination should be carefully monitored for possible bleeding complications, including gastrointestinal blood loss. However, the evidence that adding low-dose aspirin to warfarin reduces total mortality by 50% in these patients should not be ignored and needs wide dissemination.

Con Aroney
Associate Professor of Medicine
University of Queensland
Cardiology Department
Prince Charles Hospital
Brisbane

Peter Thompson
Professor of Medicine and Public Health
University of Western Australia
Perth

 

References

  1. Massel D, Little SH. Risks and benefits of adding anti-platelet therapy to warfarin among patients with prosthetic heart valves: a meta-analysis. J Am Coll Cardiol 2001;37:569-78.

Con Aroney

Associate Professor of Medicine, University of Queensland, Cardiology Department, Prince Charles Hospital Brisbane

Peter Thompson

Professor of Medicine and Public Health, University of Western Australia, Perth

Lye Lin Ho

Haematology Registrar, Department of Haematology, South East Area Laboratories Services, St George Hospital, Kogarah, New South Wales

Timothy Brighton

Staff Specialist, Department of Haematology, South East Area Laboratories Services, St George Hospital, Kogarah, New South Wales