variations in inr readings

[panda60]

Have been feeling pretty awful the last few days so last night tested my inr which read 2.9. Then remembered I was due to call the clinic today so re-tested and it came out as 3.4! Could this be because I tested after swimming and then eating breakfast (normally check before). I will ask the nurse but am interested to know if anyone has any thoughts.

Thanks

[lucky1]

short answer is yes Your test results will be different morning noon and night.

Why? Warfarin takes 72 hours to build up in you system then decreases by half avery 72 hours ( so it takes a long time to leave the body)

If you look at this curve then superimpose the next curve for each daily dose you will see a ripple along the top and at each part of the day you will be at a different point.

lucky1