Warfarin (Vitamin K Antagonist; VKA) doesn’t have to be confusing. In this lecture from This is Why, Dr. Busti will explain warfarin's (Coumadin) pharmacology in a simple, clinically relevant way. It is perfect for anyone reviewing anticoagulation.

‍

You’ll learn how to:
- Mechanism of action: how warfarin works as a vitamin K antagonist (VKA) (VKOR inhibition)
- What PT/INR measures and why INR monitoring matters
- How to start warfarin dosing (and what affects dose response)
- Bridging with heparin/LMWH (warfarin bridge / heparin bridge) and when it’s needed
- High-yield warfarin interactions (CYP2C9 inhibitors/inducers) + vitamin K foods
- Warfarin reversal basics (including vitamin K reversal)

‍

The goal = make medical education easy and clinically relevant.

‍

Chapter Table of Contents
00:00 Warfarin Explained: Vitamin K Antagonist Overview
01:43 Warfarin vs DOACs: Where It Still Fits in Therapy
04:17 Warfarin Indications: AFib Stroke Prevention and VTE
05:03 When Warfarin Is Preferred: Mechanical Valves and APS
07:04 Warfarin Mechanism of Action: Vitamin K Recycling and VKORC1
08:06 Vitamin K Dependent Factors: II VII IX X and Protein C S
10:00 Warfarin Metabolism: S vs R Enantiomers Explained
11:17 Major Drug Interactions: CYP2C9 and CYP3A4 Inhibitors
12:15 Delayed Onset Explained: Why Warfarin Takes Days to Work
15:56 Warfarin and Coagulation Cascade: PT INR vs aPTT
19:26 Before Starting Warfarin: Baseline Labs and Risk Assessment
22:06 Pharmacogenetics: VKORC1 and CYP2C9 Dosing Impact
23:19 INR Monitoring and Diet: Vitamin K Consistency Matters
26:14 INR Targets: 2 to 3 Standard, 2.5 to 3.5 Mechanical Valves
28:43 Supratherapeutic INR and Reversal: Vitamin K PCC and FFP

‍

If this helped you, please like, subscribe to our YouTube Channel, and share it with a classmate or colleague. That will help this new channel continue producing free, high-yield medical education content.

‍

Don’t forget to turn on notifications on YouTube so you don’t miss upcoming lectures in pharmacology, medical rounds, and more!

‍

#WarfarinPharmacology #VitaminKAntagonist #WarfarinDosing #WarfarinInteractions #drbusti

‍

Disclaimer:
This content is for educational purposes only and is not medical advice. It does not replace individualized evaluation, diagnosis, or treatment. Always seek the advice of a qualified health provider with questions about a medical condition and never delay care because of educational content.