What Causes Intermittent Nausea After Warfarin Intake Post Heart Valve Transplant?

Hello,So let s get to the point.I am after a heart valve transplant (Aortic), it s a mechanical valve.Thus, of course, I have to take Warfarin, which I do (8 mg daily), and of course I also check my INR from time to time (Once per 1-3 weeks depending on different circumstances).The actual question is:I get a random high kind of symptoms from time to time, I feel a little light headed, and moving around (especially my head) is weirdly enjoyable. Kind of like being drunk, yet without a clouded mind that the alcohol gives you.It happens very rarely (so far only 3-4 times while my operation was around 1.5 yrs ago), but I have no idea if I should be worried or not, or what are the reasons.Can anyone clear this up for me?