G
Guest
Warfarin is a very slow acting drug. It works by slowing the body's production of clotting factors. It does nothing to the clotting factors that are already in the blood. So it takes 3 to 5 days to see the full effect of a dose. Therefore, when you test more often you are not seeing the effect of the last dosage change. So if you change the dose more often than once per week you are probably just like a puppy chasing its tail. You may find a level that is in range sheerly by chance, but it will probably not stay in range because of all the dosage changes whose effects are not being seen yet. The quickest way to get into range is to pick a dose that seems to have worked and take it for a week and see what happens. Then you tweak the dose up or down by about the equivalent of one day's dose per week. Example: if you take 35 mg per week and the dose is a little high then take the dose down to 30 mg per week. (5 mg daily except for 2.5 mg on Mon and Fri). If the dose is too low tweak it up the same way (5 mg daily except 7.5 mg on Mon and Fri). Breaking the pills in half works just fine.
In medicine you should never run a test unless you know what you are going to do with the results. In the case of warfarin it is unnecessary to test too often because you almost always need to wait a week from the last dosage change to see what the fnal result will be. The exceptions are INRs below 1.7 and greater than 8 -- or if you are actually bleeding.
In medicine you should never run a test unless you know what you are going to do with the results. In the case of warfarin it is unnecessary to test too often because you almost always need to wait a week from the last dosage change to see what the fnal result will be. The exceptions are INRs below 1.7 and greater than 8 -- or if you are actually bleeding.