I'm quite confused... my Dr. set my target at 2-3. He started me out on 5mg, which proved to be too much based on the test, so then switched me to 2.5mg. So far, so good. But 2.5mg proved to be not enough... so he then switched me back to 5mg. ??? He's done this several times now, hence my confusion. I know Coumadin is available in all kinds of dosage levels; why isn't he trying something between 2.5 and 5mg, say 3, or 4, or something other than yo-yo-ing back and forth between too much and too little? All he'll say is that it's going to be confusing until things get ironed out. I'd like a little more detail on why he's doing this, when it seems perfectly straightforward to me that more than 2.5 but less than 5 is clearly called for. Thanks!