Generally, an INR of 3.5 isn't going to cause the nose bleed. He does seem to be a unique case. Does he run high blood pressure? The more I read through this thread, I'm starting to wonder if he's not a borderline Hemophiliac. You might want to ask the Doctor to check his clotting factors.
If I start getting too high, I'll eat a can of spinach or brussel sprouts which generally seem to knock the level down rather quickly. I don't have an exact amount of time, but I'm guessing within 24 hours. I'm not a Doctor, so you can take this idea but don't consider it gospel. What works for me, may not work for him or may cause him to fall too low and we don't want that to happen.
Home testing would be recommended though it's sometimes tough to get the insurance companies to pay for the machine and testing supplies. The wonderful people at QAS offer the protime unit from right here at VR. See the link below:
http://www.hometestmed.com/frames.php?f=http://www.hometestmed.com/p_protime.htm
They also have representitives that frequent this forum and answer questions about the unit, testing and so forth.
Given his cir***stances, I think it might be a good idea to check into either Coagucheck or Protime and see if it's possible to get a unit for him. I know the people here from QAS will go above and beyond in trying to get an insurance claim approved for you.
Check into it, it can't hurt to try!
P.S. You can reach Michele at QAS from email or Private Messaging from
http://www.valvereplacement.com/forums/member.php?s=&action=getinfo&userid=547