Does cannabis interact with cumadin/warfarin? i know that alcohol heightens irn, does marijuana lower it?

Don't know...: We don't know, as far as i can tell it has not been studied. I do know that smoking of any type, increases the risk of vascular events of the type we are generally trying to prevent with anti-coagulation with drugs like coumadin/warfarin. But as for directly affecting inr, we don't really know. Coumadin/warfarin is a dangerous drug with a narrow therapeutic window. I would advise caution.

Possibly: It's possible that some of the 60 different organic compounds contained in cannabis, could interfere with the metabolism of the medications you mentioned, thus either raising or lowering the blood levels of the drugs and subsequently affecting clotting and anti-coagulation. Also, if you have a medical condition requiring coumadin, (warfarin) wouldn't it make sense to try and stay very healthy by not smoking?