You should not stop taking warfarin or change the dose unless advised to do so by your doctor. Your doctor will tell you how long you need to take warfarin for, and when you should stop taking it.
Some people will take warfarin long term, for as long as their blood-clotting risk continues. Other uses (such as after surgery) are usually short term.
Sometimes your risk of bleeding may increase, so your doctor may reduce your dose, or stop your warfarin indefinitely or for a short period.
When to stop taking warfarin
Your doctor may advise you to stop taking warfarin because of:
- factors that increase your risk of severe bleeding, including some illnesses
- a high International Normalised Ratio (INR) blood test result
- certain pre-planned surgical procedures or major dental work. Make sure you tell your surgeon or dentist you are taking warfarin before any planned procedure.
If your warfarin was stopped for a short period only, your doctor will tell you when you need to start your treatment again, including the dose you need to take and whether you need any INR blood tests.
Because warfarin can take a few days to start working, your doctor may also briefly put you on another medicine — such as heparin or a related medicine like enoxaparin (Clexane) or dalteparin (Fragmin) — to stop your blood from being able to clot as quickly as possible. Make sure you know when to stop and start these extra medicines.
If your warfarin has been stopped indefinitely, your doctor will continue to monitor you to see if you need to start taking it again.
In the following video, Dr John Worthington explains the medical procedures that don’t require you to stop taking warfarin beforehand.