Warfarin Factsheet

What is Warfarin?

Warfarin is a medication prescribed for you by your doctor to prevent blood clots. Some medical conditions are known to predispose patients to blood clots including AF (atrial fibrillation), and mechanical valve replacements. If you are predisposed to blood clots your doctor might prescribe Warfarin.

Warfarin medication works by slowing the time it takes for your blood to clot. It is important to monitor the clotting times of your blood while you are taking Warfarin. Your doctor will order regular blood tests to monitor your INR level. The INR (International Normalised Ratio) test measures the partial thromboplastin time of the extrinsic pathway of the clotting cascade – meaning it is a test related to a very specific part of the blood-clotting pathway in your blood.

How Do Cannabinoid Medications Interact With Warfarin?

Warfarin is metabolised (or broken down) in the liver by enzymes. These are the same enzymes that break down the cannabinoid medicines, so it’s important to monitor your INR more closely when you start cannabinoid medicines and when your cannabinoid dose is increased.

When To See Your Doctor

If the cannabinoids affect your INR levels your doctor may need to adjust your Warfarin dose.

Signs your Warfarin dose is too high might be bruising easily or bleeding of the gums. If this happens see your doctor immediately to get your INR level checked.

INR levels should be monitored weekly during initiation and up-titration of cannabinoids. Be sure to tell your GP that you have started taking cannabinoids, and get your INR blood test weekly until your cannabinoid dose has stabilised.

You should also tell your GP if your cannabinoid dose is increased after a review appointment.

To begin your journey with eCS Clinic, you can book you free consultation online or book your free consultation via phone on (03) 9117 9000. 

If you have any questions about the information in this factsheet or about anything else.