A friend is an amputee - left leg below knee. He is 60 years old, been on Coumadin several years after developing deep vein thrombosis in good right leg above ankle. He takes no other medications, and has been working with Calc./Mag. and Turmeric for a good amount of time.

How would he transition from Coumadin to one of the aformentioned blood thinners?

I would recommend gradually decreasing the Coumadin while taking a blood thinner like dan shen.  I recommend cutting the Coumadin in half to begin with while using 1/2 teaspoon of dan shen 3 times daily at least 20 minutes.  After a month he should get a prothrombin time test done to see if the dan shen level is good or if it should be increased or other thinners added.  Once adjusted properly the Coumadin can be adjusted again and the same process used until he can get completely off the Coumadin.  He will need to find a doctor to work with on this since he needs to have the PT test done occasionally to make sure there is a proper level of blood thinning.