I was on Warfarin for about a year after a DVT, leg. I didn't like it because of all the bleeding not to mention the hassle of tests. I lost a lot of blood in a bowel program incident on it, had to be in ICU and get transfusions so they took me off it. This was about 7 years ago. My concern with these things is that if I'm bleeding from a part of my body I can't feel, I could lose a huge amount of blood before noticing. So it seemed dangerous to me, I was always worried I had some internal bleed. But if the DVT had progressed to an actual lung involvement probably they'd still insist on my taking it.