• Stop warfarin therapy 4 to 5 days before surgery and use postoperative prophylaxis with a combination of low-dose heparin therapy, 5000 U SC, and warfarin therapy.
• Stop warfarin therapy 4 to 5 days before surgery, and replace it with low-dose heparin therapy, 5000 U SC preoperatively, or a prophylaxis dose of low molecular weight heparin, then commence low-dose heparin or low molecular weight heparin and warfarin therapy postoperatively.
• Stop warfarin therapy 4 to 5 days before surgery and replace it with full-dose heparin or full-dose low molecular weight heparin (LMWH) therapy. Therapy can be administered by SC injection to an outpatient, or it can be given as a continuous IV infusion when the patient is admitted to the hospital in preparation for surgery and discontinued 5 hours before surgery with the expectation that the anticoagulant effect will have worn off at the time of surgery. It is also possible to continue SC heparin or LMWH and stop it 24 hours before surgery.
• Continue warfarin at a lower dose, and operate at INR of 1.3 to 1.5. The dose can be lowered 4 to 5 days prior to surgery. Warfarin can be restarted postoperatively and supplemented with low-dose heparin, if necessary.
• For dental procedures, tranexamic acid or epsilon aminocaproic acid mouthwash has been used successfully without interrupting anticoagulant therapy.

Source: Hirsh J, Dalen JE, Anderson DR, et al. Oral anticoagulants: mechanism of action, clinical effectiveness and optimal therapeutic range. Chest. 1998;114:445S-469S.