my folks would bring back the mexican vanilla when they flew south for the winter. the kind they purchased had variations within the brand. there was the dark and white vanillas, but in the dark there was a "red rooster" and a "black rooster" mark on the bottles. the red rooster was the traditional mexican vanilla flavor--the black rooster was like the vanilla we commonly know in the states. the red rooster has a more "mexican" flavor to it, and is much more concentrated, to my palate. they are all good, though.
the coumadin concern is valid to a certain extent, but most of the manufacturers don't use a coumadin base, any more. there are some good articles on the web about it, so if you take coumadin, just check what brand of vanilla you are using. if the ingredients include "tonka bean", it means that the vanilla isn't real vanilla, but made from tonka beans that contain coumarin; that can affect clotting times and coumadin. (from the description, that's the kind that tastes like regular vanilla!)
an article :
http://www.ptinr.com/data/templates/...aspx?a=850&z=3