Part One: Warfarin Dosing Guidelines

Special Considerations in the Elderly - Bleeding

• Increased age associated with increased sensitivity at usual doses

• Comorbidity

• Increased drug interactions

• ? Increased bleeding risk independent of the above

Notes:

The elderly are at special risk for bleeding because:

• Increased age is associated with an increased sensitivity to warfarin, therefore the elderly often require lower doses of warfarin to maintain their INR in the therapeutic range

• They often have concomitant disorders that either influence their response to warfarin or expose them to the risk of bleeding

• These disorders may require therapy with drugs that either interfere with the pharmacodynamics of warfarin or increase the risk of bleeding

• Increased age itself (due to increased vascular fragility) might be an independent risk factor for warfarin-associated bleeding.

Because of an increased sensitivity to warfarin, comorbidity and increased drug interactions, the elderly require even more careful management of dose adjustment.In the case of intracranial hemorrhage, there may be a slight, but real increased risk in the very elderly regardless of the quality of management.

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About this presentation:

The content of these pages is from a presentation called  "Management of Oral Anticoagulant Therapy: Principles & Practice," prepared by the American Heart Association's Post-Graduate Education Committee of the Council on Clinical Cardiology.  Supported by an educational grant from DuPont Pharmaceuticals.

Authors: Jack Ansell, M.D., Jack Hirsch, M.D., Nanette K. Wenger, M.D.

Data current as of October 1999.

Endorsed by the Anticoagulation Forum and the American Heart Association Council on Atherosclerosis, Thrombosis, and Vascular Biology.

The entire PowerPoint presentation is available from the American Heart Association.