A Coumadin Clinic just opened at the hospital across the street from my pharmacy. I am a new pharmacy tech, and I'm now entering a lot of (what seems like) funky weird warfarin prescriptions. For example, I recently filled an rx for warfarin 3.5mg every other day alternating with 4mg QOD. This means that I have to fill an rx for 2.5mg tablets and 1mg tablets to fill only one part of the rx. The other part is the 4mg tablets.
From what I understand, these patients of the Coumadin Clinic are monitored with a test/lab work called a PT/INR. What is this test and how does it relate to their warfarin dosing? And how does warfarin work in the body?