Switching from warfarin to DOACs

Dr Mark Crowther is a professor and chair of the Department of Medicine and the Leo Pharma Chair in Thromboembolism Research at McMaster University.

Should we switch patients treated with warfarin to direct oral anticoagulants (DOACs)? Who would benefit, and who would not?

Mark Crowther, MD, MSc: This is an interesting question. Again, it is going to depend on indications. Patients who have a firm indication to stay on warfarin should stay on warfarin. Patients who cannot afford to take a direct oral anticoagulant (DOAC) should probably stay on warfarin. But almost everybody else should be switched.

The reason why almost everybody else should be switched is because the risk of bleeding with warfarin—and particularly intracerebral bleeding—is at least twice as high as with a DOAC. Intracerebral bleeding is associated with a high risk of morbidity and mortality and can occur at any international normalized ratio (INR). So it is unsafe to continue warfarin if DOACs are a real opportunity.

If DOACs are indicated and available, then, in my opinion, warfarin should not be used.