The following is a summary of how patients were transitioned from warfarin to each medication in the clinical trials.
Apixaban: stop warfarin and start when INR < 2.0
Dabigatran: stop warfarin and start when INR < 2.0
Rivaroxaban: stop warfarin and start when INR < 3.0 (but see Additional Information below)
In RELY and ARISTOTLE, the noac was started when INR < 2, in ENGAGE-AF when INR < 2.5, and ROCKET when INR < 3. In the ROCKET trial, rivaroxaban had 6 times higher bleeding rates in the first 7 days. Therefore, we recommend starting the novel agent when the INR is decreasing down toward 2.0 however documentation of INR <2.0 may be unnecessary. For example, if the patient has labs checked and the INR is 2.4, it would be reasonable to ask the patient to not take any medication for one day then start the new agent the following morning without having the patient recheck labs.