How to Convert Between Anticoagulants
One of the most common questions from prescribers that I have answered in the past year concerns how to convert from 1 anticoagulant to anothe
One of the most common questions from prescribers that I have answered in the past year concerns how to convert from 1 anticoagulant to another, especially following the release of the newer rivaroxaban, apixaban, and dabigatran.
Perhaps the physician wants the patient to avoid multiple labs with warfarin monitoring, or maybe the patient cannot keep his or her vitamin K-rich food intake consistent with warfarin. Whatever the reason, factor Xa inhibitors (apixaban, fondaparinux, and rivaroxaban) and a direct thrombin inhibitor (dabigatran) are chipping into the warfarin market for different indications.
The biggest thing to keep in mind is how long 1 dose of the anticoagulant lasts. It is also wise to know the patient's renal function in the anticoagulants that are renally adjusted, as well as which anticoagulants affect INR or can affect INR.
CONVERTING APIXABAN (ELIQUIS)
Warfarin to apixaban
Stop warfarin and start apixaban when INR <2.
Apixaban to warfarin
Start warfarin and stop apixaban 3 days later, or stop apixaban, begin a parenteral anticoagulant (UFH or LMWH) and warfarin at the time apixaban would have been due, and then stop LMWH or UFH when INR therapeutic.
LMWH/fonda to apixaban
Stop LMWH/fonda and start apixaban 0-2 hours before next LMWH/fonda dose is due.
Heparin to apixaban
Stop heparin and start apixaban at the same time.
Apixaban to LMWH/UFH
Stop apixaban and start LMWH/UFH at the time when apixaban would have been due.
Apixaban to oral anticoagulant other than warfarin
Stop apixaban and begin the other agent at the time when the next scheduled dose of apixaban would have been due.
CONVERTING DABIGATRAN (PRADAXA)
Warfarin to dabigatran
Stop warfarin and start dabigatran when INR <2.
Dabigatran to warfarin
CrCl >50 mL/min: Start warfarin and stop dabigatran 3 days later
CrCl 31-50 mL/min: Start warfarin and stop dabigatran 2 days later
CrCl 15-30 mL/min: Start warfarin and stop dabigatran 1 day later
LMWH/fonda to dabigatran
Stop parenteral anticoagulant and administer dabigatran 0-2 hrs before the next parenteral dose would have been administered.
IV heparin to dabigatran
Administer first dose of dabigatran at the time of discontinuation of IV heparin infusion.
Dabigatran to LMWH/UFH
CrCl >30 mL/min: Start 12 hours after the last dose of dabigatran
CrCl <30 mL/min: Start 24 hours after the last dose of dabigatran
Dabigatran to oral anticoagulant other than warfarin
Stop dabigatran and begin the other anticoagulant at the time when the next dose of dabigatran would have been due.
*Dabigatran may alter INR results
CONVERTING RIVAROXABAN (XARELTO)
Warfarin to rivaroxaban
Stop warfarin and start when INR <2. However, the manufacturer advises when INR <3.
Rivaroxaban to warfarin
Start warfarin and stop rivaroxaban 3 days later, or stop rivaroxaban, begin LMWH/UFH and warfarin at same time when the next dose of rivaroxaban would have been given, and then stop LMWH/UFH when INR is acceptable.
LMWH/fonda to rivaroxaban
Stop LMWH/fonda and start rivaroxaban 0-2 hours before the next dose of LMWH/fonda would have been given.
IV heparin to rivaroxaban
Administer first dose of rivaroxaban at the same time as d/c heparin.
Rivaroxaban to LMWH/fonda
Stop rivaroxaban and administer at the time when the next dose of rivaroxaban would have been given.
Rivaroxaban to oral anticoag other than warfarin
Stop rivaroxaban and begin the other anticoagulant at the time when the next scheduled dose of rivaroxaban would have been adminsitered.
References:
Alberts MJ, Eikelboom JW, Hankey GJ. Antithrombotic therapy for stroke prevention in non-valvular atrial fibrillation. Lancet Neurology. 2012;11:1066—81.
Schulman S, Crowther MA. How I treat with anticoagulants in 2012: new and old anticoagulants, and when and how to switch. Blood. 2012;119:3016—23.
