I spontaneously developed several DVTs (blood clots) in my leg within the past two years. My hematologist placed me on Coumadin to reduce the chance of DVTs. He informed me that I would have to take it for the rest of my life. He said I could develop arterial blood clots as well. I was treated with Pradaxa during the time I had the blood clots. He said I could use Pradaxa in place of the Coumadin. It is very expensive, and (of course) my insurance will not cover it. So, I am taking Coumadin and getting my protime taken frequently.