So, the good news is that your Coaguchek is closely aligned with the lab results.
If it were me, I would test myself after the two days of holding your warfarin. Since you have your own Coaguchek and it seems accurate, I see no downside in testing. I know that many are in the testing weekly mindset, apparently even some clinics, but when your INR is going wild, in my view you want to test more frequently, so as to not overcorrect.
During my wild, amiodarone fueled, week, my INR went from 3.1 to 9.7, to 1.6 then to 5.6. The Coumadin Clinic had me down at the lab testing daily. They even had me test twice one day, as we wanted to see which direction things were headed within 4 hours after taking vitamin k.
Holding warfarin for two full days, then dropping to half a dose for several days seems like a very big reaction. It may very well be warranted, but it could result in undershooting your INR. For example, it is entirely possible, even if unlikely, that you could be under 2.0 INR after holding for two days. That would be very good information to know before going on half a daily dose for several more days before retesting.
Ideally, you want a gentle landing into range, rather than a yo yo week of undershooting then possible overshooting again.
I'm not saying not to follow their guidance, that is, of course, what you should do. But, having a bit more spot checking on how quickly your INR is moving won't hurt, in my view.
For what it's worth, during my wild week, when I was at 5.6, they had me hold for one day, then test again the next morning before deciding on whether to hold again or dose. It dropped significantly from the one day hold and they decided to dose me the next day, rather than have me hold for another day. I was soon in range, and you will be too.
It seems like you have had a bit of a wild week, almost certainly caused by the grapefruit. But, 5.6-5.8 is really not that alarming. When I hit 9.7 INR I was very concerned. I asked the clinic if I should check into the ER and get intravenous vitamin K. They said that they don't have patients generally do that until they hit 12 or 13 INR. They gave me a prescription for vitamin K and told me to just be very careful not to fall or hit my head for the next few days. Boxing was clearly off the menu.
So, your INR is a little out of range. But, the good news is that you and the clinic are aware of it and are taking action. You are relatively new to warfarin and it sounds like early fluctuations are normal, especially when adding something, like grapefruit, which interferes with how warfarin acts. Just be sensible and don't do anything likely to cause a bleed in the next few days and you should be back in range soon. Until then, put a hold on the machete juggling and sky diving
