Warfarin Institute of America
Dedicated To Your Health
USING A COMBINATION OF WARFARIN, ASPIRIN AND PLAVIX (CLOPIDOGREL) OR TICLID (TICLOPIDINE).
Please note: This page is based on the article Bleeding Complications Associated with Combinations of Aspirin, Thienopyridine Derivatives, and Warfarin in Elderly Patients Following Acute Myocardial Infarction by Buresly et al in Archives of Internal Medicine 2005;165:784-789. This is the most definitive article written to date on this emerging topic.
This study was done from 1996 to 2000 in Canada. In the early part of the study the thienopyridine most used was probably Ticlid (ticlopidine). In 2005, in the US the most used thienopyridine is Plavix (clopidogrel). The study was not designed to differentiate between the two. If anything, I think that the safety data would look even better with clopidogrel being the main thienopyridine.
The study looked at 21,443 patients older than 65 years who survived heart attacks. The patients were divided into five groups. A bleeding event was defined as one that caused a person to be admitted to a hospital. Once a person had a bleeding event, they were considered a bleeder and subsequent bleeds were not counted. Note that since this required hospital admission, minor bleeding such as a bloody nose that lasted 30 minutes or less were not likely to be included. Most of the bleeds in this study were in the gastrointestinal tract.
The aspirin only group covered 20,176 patient-years and had 656 bleeding events for a rate of 0.032 bleeds per patient-year.
The warfarin only group covered 3,314 patient-years and had 195 bleeding events for a rate of 0.059 bleeds per patient-year.
The aspirin and thienopyridine group covered 289 patient-years and had 20 bleeding events for a rate of 0.068 bleeds per patient-year.
The aspirin and warfarin group covered 407 patient-years and had 34 bleeding events for a rate of 0.083 bleeds per patient year.
The aspirin, warfarin and thienopyridine group covered 12 patient years and had 1 bleeding event for a rate of 0.085 bleeds per patient-year.
The authors noted several limitations of the study. No data was collected on the INR values of patients who were taking warfarin. There was no assignment to randomized groups, so people who were at the highest risk of bleeding may simply not have been given any of the medications. On the other hand, this is the way that patients are assigned to therapy in real-life practice, so the study may present data that are closer to everyday practice than if it had been controlled more tightly.
Other factors associated with increased risk of bleeding were older age, prior strokes, kidney failure, stomach ulcers, diabetes and bleeding before the heart attack occurred.
The data suggest that the rate of bleeding is low, but significant. Giving the three-drug therapy probably doubles the risk of bleeding but that actual percentage is still low. People who have the other risk factors should be aware of the higher risk of bleeding and understand the need to seek medical attention should a bleed occur.
SEE A CATALOG OF PUBLICATIONS AVAILABLE FROM LODWICK CREATIONS, LLC.
LEARN HOW YOU CAN BECOME LISTED ON THE HONOR ROLL OF SUPPORTERS AND TAKE ADVANTAGE OF THE BENEFITS
REQUEST A MEDICATION CONSULTATION
© 2005 Lodwick Creations, LLC
Home Back to interactions list
Contact Mr. Lodwick at allodwick@earthlink.net
Last updated April 25, 2005
