In five randomized trials in patients with atrial fibrillation, the annual incidence of major bleeding averaged 1.3% in patients randomly assigned to warfarin therapy (targeted INR generally 2.0 to 3.0), compared with 1.0% in patients randomly assigned to treatment with placebo.
In a case-control study, the risk of intracerebral hemorrhage doubled for each increase of approximately 1 in the INR.
Concomitant use of aspirin has been associated with a higher frequency of bleeding, even in patients treated with warfarin therapy with a mean INR of 1.5. In a large randomized trial comparing the combination of low-dose warfarin therapy and aspirin, 80 mg/d, to aspirin, 160 mg/d, in patients with a history of myocardial infarction, the frequency of spontaneous major hemorrhage during the first year of therapy was increased to 1.4% in patients treated with 3 mg of warfarin (INR < 2.0) and aspirin, 80 mg/d, compared with 0.7% in patients treated with aspirin, 160 mg/d (p = 0.01).
No one is getting put on Coumadin as a first drug after treatment but only occasionally when a patient has clotted they are sometimes put on Coumadin to prevent the clot getting worse. But if we find out the other ones (Clexane, Arixtra, Plavix) then we can see where they rank against Coumadin.
We went through a time period when all the docs seemed to be prescribing Plavix or aspirin only and now we are seeing more of the stronger anticoagulants or combined therapy from some of the docs. Like everything else when looking at anticoagulation, the doctors weighs the risks vs the benefits. If we subtract out the placebo from the Coumadin, the risk would seem to be 0.3%. Small but real.
This is a sensitive topic but I wanted to address it so that we're not fighting fears but looking at real facts, neither inflated nor minimized.