Never use a loading dose of warfarin
Alas, I saw a patient get a 10 mg dose of warfarin followed by 5 mg daily after which their INR blasted off at the speed of light. I asked my preceptor about this and apparently the ACCP guidelines now have a recommendation to consider a mini loading dose in non-high risk patients. Supposedly this has been shown to achieve therapeutic INR faster. I still don’t like this whole mini loading dose idea though. Based on what was emphasized from my classes, it seemed like the next big thing was going to be CYP2C9 genetic testing for all as soon as it got cheap enough so we wouldn’t have to play the racial guessing game (African Americans get more warfarin, white people less, not sure about Asians).
Part of me is starting to like Xarelto (rivaroxaban). Maybe it’s because it’s an easier drug to manage or maybe it’s because the drug rep brought some amazing hispanic food. Maybe warfarin is on the same path as other narrow therapeutic drugs that have fell by the wayside.